Staff Profiles

My teaching strongly reflects both my multidisciplinary research interests as well as my commitment to shaping and influencing curriculum development within the department. Furthermore, I have an excellent overview of the curriculum, teaching at all levels, including on almost all of the modules that are compulsory for Biology (BG) for which I am the subject coordinator, as well as supervision of undergraduate research projects. 

 

 

Modules taught

Undergraduate Teaching

Level 4: U14501 (Biodiversity; lectures), U14502 (Biology of Cells; practicals), and U15503 (Science in Practice; PASS tutorials)

Level 5: U15529 (Research Methods for Biological and Environmental Sciences; seminars), U15531 (Molecular Biology; lectures), U15532 (Genetics; lectures and practicals), U15534 (Developmental Biology; lectures and seminars), and U15552 (Animal Behaviour; lectures)

Level 6: U15571 (Evolution and Animal Development; module leader; lectures, practicals and all marking), U15584 (Environmental Change; lectures, mentoring NERC grant application proposals, and student seminars), U15570 (Science and Humanity; ran discussion sessions), U14699 (Projects; statistics training session and supervision of project students), U14588 (Independent Study in Life Sciences; supervision of students), and U15591 (Advanced Topics in Wildlife Conservation).

 

 

Supervision

Postgraduate Teaching and Supervision

P10201 (Taxonomy and Identification; lectures), P10202 (Ecology for Conservation; lectures), P10299 (Research Project 60 credits; supervision of research projects); P10401 (Research Methods; Module leader; lectures, practicals and seminars),P10403 (Molecular Ecology and Population Genetics; lectures), P10405 (Research Project 120 credits; supervision of students), and P10501 (Research Project on the MBiol Biology 80 credits;Module leader).

 

PhD student supervision (as first supervisor):

Current

• Luca Livraghi (PhD)
• Nora Braak (PhD)
• April Duncan (Masters)

Alumni

• Dr Jean-Michel Carter (currently postdoc at the University of Bath; https://www.researchgate.net/profile/Jean-Michel_Carter)
• Luke Evans (Masters; currently doing a PhD at the University of Reading)

 

Much of life history theory has been developed without regard to the actual developmental genetic basis of the variation in the traits being investigated. My research aims, however, to achieve a synthesis of life history models with developmental genetic models of evolution. In particular, the main research strand in my lab is to investigate: how do mothers produce eggs and regulate the development of their offspring under different environmental conditions, and what is the significance of transgenerational effects. Aspects of offspring development investigated include embryonic body axes formation, extra-embryonic tissue specification, formation and functionality, growth, reproduction and wing morphology. The approach taken in my lab is highly multidisciplinary, integrating ecology, evolution and developmental biology.

I use butterflies as my main model system, in particular the Speckled Wood butterfly (Pararge aegeria).  

 

Research group membership

Butterfly Ecological Evolutionary Developmental Biology

Within larger research groupings of:

• Molecular Cell and Development Biology - Developmental Biology

• Evolution Ecology Environment and Conservation - Biodiversity and Evolution

• Evolution Ecology Environment and Conservation - Evolutionary Genetics

Research Group Lab Members

Current

• Luca Livraghi (PhD)
• Nora Braak (PhD)
• Dr Sebastian Kittelmann (Postdoc)

Alumnus

• Dr Jean-Michel Carter (currently postdoc at the University of Bath)

Research grants and awards

Research Excellence Award

Research projects

• The evolution of Shx genes
• The formation and functioning of the butterfly serosa
• The effects of drought on butterfly development
• The effects of viral infections on butterfly wing development
• Dorsal-ventral patterning in butterflies

Collaborations

Nationally

• University of Oxford: Prof Peter Holland, and various members of his research group on individual projects relating to butterfly genomics and evolution of Shx genes (co-supervisor for Luca Livraghi)
• University of Cambridge: Prof Paul Brakefield and Dr Oskar Brattstrom
• CEH, Wallingford: Dr Melanie Gibbs (Pararge aegeria development and maternal effects)(co-supervisor for Luca Livraghi and Nora Braak)
• Oxford Brookes University: Dr Andy Jones (effects of pesticides on butterflies)
• University of Reading: Drs Tom Oliver and Richard Walters, and their PhD-student Luke Evans (butterfly responses to climate change)
• University of Exeter: Dr Ben Longdon (butterfly RNA viruses)

 

Internationally

• Institut de Biologia Evolutiva, CSIC-UPF, Barcelona: Drs Leonardo Dapporto and Roger Vila, and their group members (biogeography of Pararge aegeria)
• University of New Orleans: Dr Simon Lailvaux (butterfly flight performance under drought conditions)
• Université catholique de Louvain: Prof Hans van Dyck (Pararge aegeria evolutionary ecology)
• George Washington University: Dr Arnaud Martin (the role of WntA in butterfly wing patterning)
• University of Cologne: Prof Siegfried Roth (embryonic axis formation in butterflies)

Further information

Research and academic profiles: Researchgate and LinkedIn

ResearcherID is N-6582-2013 (linked to Orcid)

Journal articles

• Braak N, Neve R, Jones AK, Gibbs M, Breuker CJ, 'The effects of insecticides on butterflies – a review'
  Environmental Pollution 242 (A) (2018) pp.507-518
  ISSN: 0269-7491 eISSN: 1873-6424
  Abstract Pesticides, in particular insecticides, can be very beneficial but have also been found to have harmful side effects on non-target insects. Butterflies play an important role in ecosystems, are well monitored and are recognised as good indicators of environmental health. The amount of information already known about butterfly ecology and the increased availability of genomes make them a very valuable model for the study of non-target effects of pesticide usage. The effects of pesticides are not simply linear, but complex through their interactions with a large variety of biotic and abiotic factors. Furthermore, these effects manifest themselves at a variety of levels, from the molecular to metapopulation level. Research should therefore aim to dissect these complex effects at a number of levels, but as we discuss in this review, this is seldom if ever done in butterflies. We suggest that in order dissect the complex effects of pesticides on butterflies we need to integrate detailed molecular studies, including characterising sequence variability of relevant target genes, with more classical evolutionary ecology; from direct toxicity tests on individual larvae in the laboratory to field studies that consider the potentiation of pesticides by ecologically relevant environmental biotic and abiotic stressors. Such integration would better inform population-level responses across broad geographical scales and provide more in-depth information about the non-target impacts of pesticides.Website 
• Livraghi L, Vodă R, Evans LC, Gibbs M, Dincă V, Holland PWH, Shreeve TG, Vila R, Dapporto L, Breuker CJ, 'Historical and current patterns of gene flow in the butterfly Pararge aegeria'
  Journal of Biogeography 45 (7) (2018) pp.1628-1639
  ISSN: 0305-0270 eISSN: 1365-2699
  Abstract Aim. We have investigated the phylogeography and genetic structure of the Speckled Wood butterfly (Pararge aegeria) across its entire distribution range and studied its dispersal both on mainland and across sea straits. The apparent lack of gene flow between Sardinia and Corsica was further investigated by means of mating experiments. Location. Europe and North Africa. Methods. We sampled 345 individuals and sequenced one mitochondrial gene (Cytochrome c Oxidase subunit I, COI) for all samples and two nuclear genes (wingless and zerknullt) for a subset of the specimens. A total of 22 females from Corsica and Sardinia were used to establish a series of crosses to investigate reproductive compatibility and were screened for the presence of Wolbachia. Bayesian inference (BI) and haplotype networks were employed to infer phylogenetic relationships and a Principal Coordinate Analysis (PCoA) was used to represent 4 geographical patterns of genetic diversity. Mating and courtship data were analysed using linear mixed effect models. Results. We detected two main COI lineages separated by the Mediterranean Sea and maintained over relatively short sea straits. While nuclear gene variation was generally in agreement with that of COI, this was not the case in all areas (e.g. Iberian Peninsula and Corsica/Sardinia). Mating experiments revealed no evidence of reproductive isolation between the lineages, nor clear relation to Wolbachia infection status. Main conclusions. We propose that following the post-glacial recolonisation of Europe, the ancestral COI lineage of P. aegeria was maintained in North Africa and Mediterranean islands, while a new lineage colonised from Eastern Europe, replacing and apparently outcompeting the ancestral variant. Several hypotheses are discussed that may explain the local discordance between the nuclear genes and COI, including sex-specific dispersal, selection and differential rates of gene evolution.Website 
• Gibbs M, Van Dyck H, Breuker, CJ, 'Flight-induced transgenerational maternal effects influence butterfly offspring performance during times of drought'
  Oecologia 186 (2) (2018) pp.383-391
  ISSN: 0029-8549 eISSN: 1432-1939
  Abstract Maternal condition can generate resource-related maternal effects through differential egg provisioning that can negatively affect offspring performance especially when offspring growth occurs in stressful or sub-optimal environments. Using the Speckled Wood butterfly, Pararge aegeria (L.) we tested the hypothesis that repeated periods of  intensive flight during female oviposition affects egg provisioning and reduces offspring performance when larval development occurs under stressful conditions on drought stressed host plants. We investigated whether (after controlling for egg size) maternal age and flight treatment resulted in changes in egg provisioning and whether this contributed to variation in offspring traits across life stages. Age-related changes in maternal condition were found to generate resource-related maternal effects that influenced offspring traits across all life stages. Flight-induced changes in maternal egg provisioning were found to have direct consequences for offspring development in the egg and larval stages.. There were significant interactive effects between maternal age and flight on larval development and growth. Compared to offspring from forced flight mothers, offspring from control (no forced flight) mothers that hatched from eggs laid early in the oviposition period (i.e. by younger mothers) had shorter larval development times and heavier pupal masses, suggesting that offspring from mothers in relatively good condition may be able to buffer some of the costs associated with growth on drought stressed host plants. Our multi-factor study demonstrates the importance of considering the various, and often interacting, mechanisms by which maternal effects may influence offspring performance in stressful environments.Website 
• Mazo-Vargas A, Concha C, Livraghi L, Massardo D, Wallbank RWR, Zhang L, Papador JD, Martinez-Najera D, Jiggins CD, Kronforst MR, Breuker CJ, Reed RD, Patel NH, McMillan WO, and Martin A, 'Macroevolutionary shifts of WntA function potentiate butterfly wing-pattern diversity'
  Proceedings of the National Academy of Sciences 114 (40) (2017) pp.10701-10706
  ISSN: 0027-8424 eISSN: 1091-6490
  Abstract Butterfly wing patterns provide a rich comparative framework to study how morphological complexity develops and evolves. Here we used CRISPR/Cas9 somatic mutagenesis to test a patterning role for WntA, a signaling ligand gene previously identified as a hotspot of shape-tuning alleles involved in wing mimicry. We show that WntA loss-of-function causes multiple modifications of pattern elements in seven nymphalid butterfly species. In three butterflies with a conserved wing-pattern arrangement, WntA is necessary for the induction of stripe-like patterns known as symmetry systems and acquired a novel eyespot activator role specific to Vanessa forewings. In two Heliconius species, WntA specifies the boundaries between melanic fields and the light-color patterns that they contour. In the passionvine butterfly Agraulis, WntA removal shows opposite effects on adjacent pattern elements, revealing a dual role across the wing field. Finally, WntA acquired a divergent role in the patterning of interveinous patterns in the monarch, a basal nymphalid butterfly that lacks stripe-like symmetry systems. These results identify WntA as an instructive signal for the prepatterning of a biological system of exuberant diversity and illustrate how shifts in the deployment and effects of a single developmental gene underlie morphological change.Website 
• Longdon B, Day J, Schulz N, Leftwich PT, de Jong MA, Breuker CJ, Gibbs M, Obbard DJ, Wilfert L, Smith SCL, McGonigle JE, Houslay TM, Wright LI, Livraghi L, Evans LC, Friend LA, Chapman T, Vontas J, Kambouraki N, Jiggins FM, 'Vertically transmitted rhabdoviruses are found across three insect families and have dynamic interactions with their hosts'
  Proceedings of the Royal Society of London. Series B 284 (1847) (2017) pp.1-9
  ISSN: 0080-4649
  Abstract A small number of free-living viruses have been found to be obligately vertically transmitted, but it remains uncertain how widespread vertically transmitted viruses are and how quickly they can spread through host populations. Recent metagenomic studies have found several insects to be infected with sigma viruses (Rhabdoviridae). Here, we report that sigma viruses that infect Mediterranean fruit flies (Ceratitis capitata), Drosophila immigrans, and speckled wood butterflies (Pararge aegeria) are all vertically transmitted. We find patterns of vertical transmission that are consistent with those seen in Drosophila sigma viruses, with high rates of maternal transmission, and lower rates of paternal transmission. This mode of transmission allows them to spread rapidly in populations, and using viral sequence data we found the viruses in D. immigrans and C. capitata had both recently swept through host populations. The viruses were common in nature, with mean prevalences of 12% in C. capitata, 38% in D. immigrans and 74% in P. aegeria. We conclude that vertically transmitted rhabdoviruses may be widespread in a broad range of insect taxa, and that these viruses can have dynamic interactions with their hosts.Website 
• Lailvaux SP, Breuker CJ, Van Damme R, 'Water Stress Affects Development Time but Not Takeoff Performance in the Butterfly Pararge aegeria'
  Physiological and Biochemical Zoology 90 (1) (2017) pp.63-74
  ISSN: 1522-2152
  Abstract Most organisms are limited in the amount and type of resources they are able to extract from the environment. The juvenile environment is particularly important in this regard, as conditions over ontogeny can influence the adult phenotype. Whole-organism performance traits, such as locomotion, are susceptible to such environmental effects, yet the specific biotic and abiotic factors driving performance plasticity have received little attention. We tested whether speckled wood Pararge aegeria L. butterflies reared under conditions of water stress exhibited poorer flight morphology and performance than control individuals. Despite large differences in mortality between treatments, we found no effects of water stress treatment on takeoff performance and only minor treatment effects on flight morphology. However, butterflies reared on water-stressed diets exhibited both significantly greater mortality and longer development times than did control individuals. Pararge aegeria larvae may compensate for this stress by prolonging development, resulting in similar realized performance capacities at least in takeoff performance in surviving adult butterflies; other measures of flight performance remain to be considered. Alternatively, the adult phenotype may be insulated from environmental effects at the larval stage in these insects.Website 
• De Keyser R, Breuker CJ, Hails RS, Dennis RLH, Shreeve TG, 'Why small is beautiful: wing colour is free from thermoregulatory constraint in the small lycaenid butterfly, Polyommatus icarus'
  PLoS ONE 10 (4) (2015)
  ISSN: 1932-6203
  Abstract

  We examined the roles of wing melanisation, weight, and basking posture in thermoregulation in Polyommatus Icarus, a phenotypically variable and protandrous member of the diverse Polyommatinae (Lycaenidae). Under controlled experimental conditions, approximating to marginal environmental conditions for activity in the field (= infrequent flight, long duration basking periods), warming rates are maximised with fully open wings and maximum body temperatures are dependent on weight. Variation in wing melanisation within and between sexes has no effect on warming rates; males and females which differ in melanisation had similar warming rates. Posture also affected cooling rates, consistent with cooling being dependent on convective heat loss. We hypothesise that for this small sized butterfly, melanisation has little or no effect on thermoregulation. This may be a factor contributing to the diversity of wing colours in the Polyommatinae. Because of the importance of size for thermoregulation in this small butterfly, requirements for attaining a suitable size to confer thermal stability in adults may also be a factor influencing larval feeding rates, development time and patterns of voltinism. Our findings indicate that commonly accepted views of the importance of melanisation, posture and size to thermoregulation, developed using medium and large sized butterflies, are not necessarily applicable to small sized butterflies.

  Website 
• Carter JM, Gibbs M, Breuker CJ, 'Divergent RNA Localisation Patterns of Maternal Genes Regulating Embryonic Patterning in the Butterfly Pararge aegeria'
  PLoS One 10 (12) (2015) pp.1-21
  ISSN: 1932-6203
  Abstract

  The maternal effect genes responsible for patterning the embryo along the antero-posterior (AP) axis are broadly conserved in insects. The precise function of these maternal effect genes is the result of the localisation of their mRNA in the oocyte. The main developmental mechanisms involved have been elucidated in Drosophila melanogaster, but recent studies have shown that other insect orders often diverge in RNA localisation patterns. A recent study has shown that in the butterfly Pararge aegeria the distinction between blastodermal embryonic (i.e. germ band) and extra-embryonic tissue (i.e. serosa) is already specified in the oocyte during oogenesis in the ovariole, long before blastoderm cellularisation. To examine the extent by which a female butterfly specifies and patterns the AP axis within the region fated to be the germ band, and whether she specifies a germ plasm, we performed in situ hybridisation experiments on oocytes in P. aegeria ovarioles and on early embryos. RNA localisation of the following key maternal effect genes were investigated: caudal (cad), orthodenticle (otd), hunchback (hb) and four nanos (nos) paralogs, as well as TDRD7 a gene containing a key functional domain (OST-HTH/LOTUS) shared with oskar. TDRD7 was mainly confined to the follicle cells, whilst hb was exclusively zygotically transcribed. RNA of some of the nos paralogs, otd and cad revealed complex localisation patterns within the cortical region prefiguring the germ band (i.e. germ cortex). Rather interestingly, otd was localised within and outside the anterior of the germ cortex. Transcripts of nos-O formed a distinct granular ring in the middle of the germ cortex possibly prefiguring the region where germline stem cells form. These butterfly RNA localisation patterns are highly divergent with respect to other insects, highlighting the diverse ways in which different insect orders maternally regulate early embryogenesis of their offspring.

  Website 
• Quah S, Breuker CJ, Holland PWH, 'A diversity of conserved and novel ovarian microRNAs in the speckled wood (Pararge aegeria)'
  PLoS One 10 (11) (2015) pp.1-15
  ISSN: 1932-6203
  Abstract

  microRNAs (miRNAs) are important regulators of animal development and other processes, and impart robustness to living systems through post-transcriptional regulation of specific mRNA transcripts. It is postulated that newly emergent miRNAs are generally expressed at low levels and with spatiotemporally restricted expression domains, thus minimising effects of spurious targeting on animal transcriptomes. Here we present ovarian miRNA transcriptome data for two geographically distinct populations of the Speckled Wood butterfly (Pararge aegeria). A total of 74 miRNAs were identified, including 11 newly discovered and evolutionarily-young miRNAs, bringing the total of miRNA genes known from P. aegeria up to 150. We find a positive correlation between miRNA age and expression level. A common set of 55 miRNAs are expressed in both populations. From this set, we identify seven that are consistently either ovary-specific or highly upregulated in ovaries relative to other tissues. This ‘ovary set’ includes miRNAs with known contributions to ovarian function in other insect species with similar ovaries and mode of oogenesis, including miR-989 and miR-2763, plus new candidates for ovarian function. We also note that conserved miRNAs are overrepresented in the ovary relative to the whole body.

  Website 
• Ferguson L, Marletaz F, Carter JM, Taylor WR, Gibbs M, Breuker CJ, Holland PWH, 'Ancient expansion of the Hox cluster in Lepidoptera generated four homeobox genes implicated in extra-embryonic tissue formation'
  PLoS Genetics 10 (10) (2014) pp.1-12
  ISSN: 1553-7390
  Abstract

  Gene duplications within the conserved Hox cluster are rare in animal evolution, but in Lepidoptera an array of divergent Hox-related genes (Shx genes) has been reported between pb and zen. Here, we use genome sequencing of five lepidopteran species (Polygonia c-album, Pararge aegeria, Callimorpha dominula, Cameraria ohridella, Hepialus sylvina) plus a caddisfly outgroup (Glyphotaelius pellucidus) to trace the evolution of the lepidopteran Shx genes. We demonstrate that Shx genes originated by tandem duplication of zen early in the evolution of large clade Ditrysia; Shx are not found in a caddisfly and a member of the basally diverging Hepialidae (swift moths). Four distinct Shx genes were generated early in ditrysian evolution, and were stably retained in all descendent Lepidoptera except the silkmoth which has additional duplications. Despite extensive sequence divergence, molecular modelling indicates that all four Shx genes have the potential to encode stable homeodomains. The four Shx genes have distinct spatiotemporal expression patterns in early development of the Speckled Wood butterfly (Pararge aegeria), with ShxC demarcating the future sites of extraembryonic tissue formation via strikingly localised maternal RNA in the oocyte. All four genes are also expressed in presumptive serosal cells, prior to the onset of zen expression. Lepidopteran Shx genes represent an unusual example of Hox cluster expansion and integration of novel genes into ancient developmental regulatory networks.

  Website 
• Grinsted L, Breuker CJ, Bilde T, 'Cooperative breeding favors maternal investment in size over number of eggs in spiders'
  Evolution 68 (7) (2014) pp.1961-1973
  ISSN: 0014-3820
  Abstract

  The transition to cooperative breeding may alter maternal investment strategies depending on density of breeders, extent of reproductive skew, and allo-maternal care. Change in optimal investment from solitary to cooperative breeding can be investigated by comparing social species with nonsocial congeners. We tested two hypotheses in a mainly semelparous system: that social, cooperative breeders, compared to subsocial, solitarily breeding congeners, (1) lay fewer and larger eggs because larger offspring compete better for limited resources and become reproducers; (2) induce egg size variation within clutches as a bet-hedging strategy to ensure that some offspring become reproducers. Within two spider genera, Anelosimus and Stegodyphus, we compared species from similar habitats and augmented the results with a mini-meta-analysis of egg numbers depicted in phylogenies. We found that social species indeed laid fewer, larger eggs than subsocials, while egg size variation was low overall, giving no support for bet-hedging. We propose that the transition to cooperative breeding selects for producing few, large offspring because reproductive skew and high density of breeders and young create competition for resources and reproduction. Convergent evolution has shaped maternal strategies similarly in phylogenetically distant species and directed cooperatively breeding spiders to invest in quality rather than quantity of offspring.

  Website 
• Carter JM, Baker SC, Pink R, Carter DRF, Collins A,Tomlin J, Gibbs M, Breuker CJ, 'Unscrambling butterfly oogenesis'
  BMC Genomics 14 (-) (2013) pp.283-
  ISSN: 1471-2164
  Abstract

  Background
  Butterflies are popular model organisms to study physiological mechanisms underlying variability in oogenesis and egg provisioning in response to environmental conditions. Nothing is known, however, about; the developmental mechanisms governing butterfly oogenesis, how polarity in the oocyte is established, or which particular maternal effect genes regulate early embryogenesis. To gain insights into these developmental mechanisms and to identify the conserved and divergent aspects of butterfly oogenesis, we analysed a de novo ovarian transcriptome of the Speckled Wood butterfly Pararge aegeria (L.), and compared the results with known model organisms such as Drosophila melanogaster and Bombyx mori.
   Results A total of 17306 contigs were annotated, with 30% possibly novel or highly divergent sequences observed. Pararge aegeria females expressed 74.5% of the genes that are known to be essential for D. melanogaster oogenesis. We discuss the genes involved in all aspects of oogenesis, including vitellogenesis and choriogenesis, plus those implicated in hormonal control of oogenesis and transgenerational hormonal effects in great detail. Compared to other insects, a number of significant differences were observed in; the genes involved in stem cell maintenance and differentiation in the germarium, establishment of oocyte polarity, and in several aspects of maternal regulation of zygotic development.
  Conclusions This study provides valuable resources to investigate a number of divergent aspects of butterfly oogenesis requiring further research. In order to fully unscramble butterfly oogenesis, we also now also have the resources to investigate expression patterns of oogenesis genes under a range of environmental conditions, and to establish their function

  Website 
• De Keyser R, Shreeve TG, Breuker CJ, Hails RS, Schmitt, T, 'Polyommatus icarus butterflies in the British Isles: evidence for a bottleneck'
  Biological Journal of the Linnean Society 107 (1) (2012) pp.123-136
  ISSN: 0024-4066
  Abstract

  Phylogeographical research has revealed several paradigm patterns of postglacial range expansion from the Mediterranean peninsulas to more northern parts of Europe. These range expansions have consequences for the genetic constitution of populations. Although many studies have been performed in mainland Europe, the colonization history of the British Isles is relatively poorly studied; the genetic consequences of the last glacial readvances and the climate optimum conditions, as well as the implications of the recent climatic conditions on the population genetic structures, are little understood. Therefore, we selected the common blue butterfly Polyommatus icarus as a model species for understanding more generally the colonization patterns of the British Isles and the genetic dynamics on these islands. Allozyme analyses of this butterfly show a rather high genetic diversity over continental Europe without major genetic differentiation. The situation on the British Isles is completely different. Here, populations show a much lower genetic diversity compared to mainland Europe. The genetic constitution is well differentiated from that observed on the European mainland, and the genetic differentiation among populations in Britain is stronger than at the European scale. These results support the hypothesis that a relatively cold-tolerant species such as the common blue could have colonized the British Isles early during the late glacial period and survived the last glacial readvances in small refugia in the South. The retraction of this species in small isolated populations could have caused the genetic impoverishment found. The subsequent forest climax during the climate optimum possibly restricted further expansion of this early succession species to small pockets all over the British Isles, resulting in the genetic patchwork that is still observed. Additionally, the relatively cool and rainy conditions one these islands might have caused bottlenecks, possibly enforcing these genetic patterns.

  Website 
• Gibbs M, Van Dyck H, Breuker C, 'Development on drought-stressed host plants affects life history, flight morphology and reproductive output relative to landscape structure'
  Evolutionary Applications 5 (1) (2012) pp.66-75
  ISSN: 1752-4563
  Abstract

  With global climate change, rainfall is becoming more variable. Predicting the responses of species to changing rainfall levels is difficult because, for example in herbivorous species, these effects may be mediated indirectly through changes in host plant quality. Furthermore, species responses may result from a simultaneous interaction between rainfall levels and other environmental variables such as anthropogenic land use or habitat quality. In this eco-evolutionary study, we examined how male and female Pararge aegeria (L.) from woodland and agricultural landscape populations were affected by the development on drought-stressed host plants. Compared with individuals from woodland landscapes, when reared on drought-stressed plants agricultural individuals had longer development times, reduced survival rates and lower adult body masses. Across both landscape types, growth on drought-stressed plants resulted in males and females with low forewing aspect ratios and in females with lower wing loading and reduced fecundity. Development on drought-stressed plants also had a landscape-specific effect on reproductive output; agricultural females laid eggs that had a significantly lower hatching success. Overall, our results highlight several potential mechanisms by which low water availability, via changes in host plant quality, may differentially influence P. aegeria populations relative to landscape structure.

  Website 
• Hesketh H, Gibbs M, Breuker C, Van Dyck H, Turner E, Hails R, 'Exploring sub-lethal effects of exposure to a nucleopolyhedrovirus in the speckled wood (Pararge aegeria) butterfly'
  Journal of Invertebrate Pathology 109 (1) (2012) pp.165-168
  ISSN: 0022-2011
  Abstract

  This study investigated the sub-lethal effects of larval exposure to baculovirus on host life history and wing morphological traits using a model system, the speckled wood butterfly Pararge aegeria (L.) and the virus Autographa californica nucleopolyhedrovirus. Males and females showed similar responses to the viral infection. Infection significantly reduced larval growth rate, whilst an increase in development time allowed the critical mass for pupation to be attained. There was no direct effect of viral infection on the wing morphological traits examined. There was, however, an indirect effect of resisting infection; larvae that took longer to develop had reduced resource investment in adult flight muscle mass.

  Website 
• Bots J, Breuker CJ, Kaunisto KM, Koskimaki J, Van Gossum H, Suhonen J, 'Wing Shape and Its Influence on the Outcome of Territorial Contests in the Damselfly Calopteryx Virgo'
  Journal of Insect Science 12 (2012)
  ISSN: 1536-2442
  Abstract Male mating success is often determined by territory ownership and traits associated with successful territory defense. Empirical studies have shown that the territory owner wins the majority of fights with challenging males. Several physical and physiological traits have been found to correlate with resource holding potential. In addition, in aerial insects, wing design may also have a strong influence on resource holding potential, since it determines efficiency and precision during flight. However, this possibility has not yet been thoroughly evaluated using the modern technique of geometric morphometrics to analyze shape. Therefore, this study examined whether wing shape affects the outcome of male-male contests in the territorial damselfly, Calopteryx virgo (L.) (Odonata: Calopterygidae). Wing shape and also traditional flight-related morphological measures were compared between 27 pairs of winners and losers from experimental territorial contests. Contrary to expectations, there were no differences between winners and losers in all studied wing traits (shape, length, width, total surface, aspect ratio, and wing loading). However, highly significant differences in wing shape and size were detected between the fore- and hindwing. It is currently not known how these differences relate to flight performance, since previous biomechanical studies in damselflies assumed fore- and hindwings to have an identical planform.Website 
• Posnien N, Hopfen C, Hilbrant M, Ramos-Womack M, Murat S, Schonauer A, Herbert S, Nunes M, Arif S, Breuker C J, Schlotterer C, Mitteroecker P, McGregor AP, 'Evolution of eye morphology and rhodopsin expression in the Drosophila melanogaster species subgroup.'
  PLoS ONE 7 (5) (2012) pp.e37346-
  ISSN: 1932-6203
  Abstract

  A striking diversity of compound eye size and shape has evolved among insects. The number of ommatidia and their size are major determinants of the visual sensitivity and acuity of the compound eye. Each ommatidium is composed of eight photoreceptor cells that facilitate the discrimination of different colours via the expression of various light sensitive Rhodopsin proteins. It follows that variation in eye size, shape, and opsin composition is likely to directly influence vision. We analyzed variation in these three traits in D. melanogaster, D. simulans and D. mauritiana. We show that D. mauritiana generally has larger eyes than its sibling species, which is due to a combination of larger ommatidia and more ommatidia. In addition, intra- and inter-specific differences in eye size among D. simulans and D. melanogaster strains are mainly caused by variation in ommatidia number. By applying a geometric morphometrics approach to assess whether the formation of larger eyes influences other parts of the head capsule, we found that an increase in eye size is associated with a reduction in the adjacent face cuticle. Our shape analysis also demonstrates that D. mauritiana eyes are specifically enlarged in the dorsal region. Intriguingly, this dorsal enlargement is associated with enhanced expression of rhodopsin 3 in D. mauritiana. In summary, our data suggests that the morphology and functional properties of the compound eyes vary considerably within and among these closely related Drosophila species and may be part of coordinated morphological changes affecting the head capsule.

  Website 
• Gibbs M, Breuker C, Van Dyck H, 'Flight during oviposition reduces maternal egg provisioning and influences offspring development in Pararge aegeria (L.)'
  Physiological Entomology 35 (1) (2010) pp.29-39
  ISSN: 0307-6962
  Abstract

  As a result of increased habitat fragmentation in anthropogenic landscapes, flying insects may be required to travel over larger distances in search of resources such as suitable host plants for oviposition. The oogenesis-flight syndrome hypothesis predicts that physiological constraints caused by an overlap in the resources used by thoracic muscles during flight and during oogenesis (e.g. carbohydrates, lipids and water) result in a resource trade-off, with any resources used during flight no longer available for reproduction. Increased flight costs could therefore potentially result in a decrease in maternal provisioning of eggs. In the present study, the speckled wood butterfly Pararge aegeria (L.) is used to investigate whether increased flight during oviposition results in changes in maternal investment in eggs and whether this contributes to variation in the development of offspring in subsequent life stages. Forcing females to fly during oviposition directly influences egg size and embryonic development time, and indirectly influences (through changes in egg size) egg hatching success and larval development time. These effects are mediated through 'selfish maternal effects', with mothers forced to fly maximizing their fecundity at the expense of investment to individual egg size. The present study demonstrates that a change in maternal provisioning as a result of increased flight during oviposition has the potential to exert nongenetic cross-generational fitness effects in P. aegeria. This could have important consequences for population dynamics, particularly in fragmented anthropogenic landscapes.

  Website 
• Gibbs M, Breuker C, Hesketh H, Hails R, Van Dyck H, 'Maternal effects, flight versus fecundity trade-offs, and offspring immune defence in the Speckled Wood butterfly, Pararge aegeria'
  BMC Evolutionary Biology 10 (2010)
  ISSN: 1471-2148
  Abstract

  Background Maternal condition can generate resource-related maternal effects through differential egg provisioning, and can greatly affect offspring performance. In the present study, the speckled wood butterfly Pararge aegeria (L.) was used to investigate whether (after controlling for egg size) maternal age, and increased flight during the oviposition period, resulted in changes in egg provisioning and whether this contributed to variation in offspring performance, i) early in development (egg stage and early post-hatching development), and ii) later in larval development after being exposed to the model viral pathogen system; the baculovirus Autographa californica multinucleocapsid nucleopolyhedrovirus (AcMNPV). Results Age-related changes in maternal egg provisioning were observed to influence egg stage development only. Flight-induced changes in maternal egg provisioning had direct consequences for offspring growth and survival across each life stage from egg to adulthood; offspring from forced flight mothers had lower larval masses and longer development times. Offspring with lower larval masses also had reduced survival after exposure to the viral pathogen. Conclusion The present study demonstrates that a change in maternal provisioning as a result of increased flight during the oviposition period has the potential to exert non-genetic cross-generational fitness effects in P. aegeria. This could have important consequences for population dynamics, particularly in fragmented anthropogenic landscapes.

  Website 
• Bots J, Breuker C, Van Kerkhove A, Van Dongen S, De Bruyn L, Van Gossum H, 'Variation in flight morphology in a female polymorphic damselfly: intraspecific, intrasexual, and seasonal differences'
  Canadian Journal of Zoology 87 (1) (2009) pp.86-94
  ISSN: 0008-4301
  Abstract

  In aerial animals, flight morphology needs to be designed to allow daily behavioural activities. Within species differences in behaviour can therefore be expected to relate to differences in flight morphology, not only between males and females but also between same-sex members when they use different behavioural strategies. In female polymorphic damselflies, one female morph is considered a male mimic that resembles the male's body colour and behaviour (andromorph), whereas the other is dissimilar (gynomorph). Here, we questioned whether males, andromorphs, and gynomorphs of the damselfly Enallagma cyathigerum (Charpentier, 1840) differ in flight morphology, with andromorphs being more similar to males than gynomorphs. In addition, we evaluated whether differences in flight morphology are consistent or whether some morphs are more plastic in response to seasonal environmental fluctuations. Most morphometrics showed similar seasonal plasticity for males and both female morphs, which could only partly be explained from allometry. Consistent with high manoeuvrability in flight, males had broader wings and lower wing loading than females. Variation between female morphs was less pronounced, with no consistent differences in length, aspect ratio, total surface, and wing loading. However, we detected morph-specific differences in shape and width, with andromorphs having broader wings than gynomorphs similarly to males.

  Website 
• Hunt J, Breuker C, Sadowski J, Moore A, 'Male-male competition, female mate choice and their interaction: determining total sexual selection'
  Journal of Evolutionary Biology 22 (1) (2009) pp.13-26
  ISSN: 1010-061X
  Abstract

  Empirical studies of sexual selection typically focus on one of the two mechanisms of sexual selection without integrating these into a description of total sexual selection, or study total sexual selection without quantifying the contributions of all of the mechanisms of sexual selection. However, this can provide an incomplete or misleading view of how sexually selected traits evolve if the mechanisms of sexual selection are opposing or differ in form. Here, we take a two-fold approach to advocate a direction for future studies of sexual selection. We first show how a quantitative partitioning and examination of sexual selection mechanisms can inform by identifying illustrative studies that describe both male-male competition and female mate choice acting on the same trait. In our sample, the most common trait where this occurred was body size, and selection was typically linear. We found that male-male competition and female mate choice can be reinforcing or opposing, although the former is most common in the literature. The mechanisms of sexual selection can occur simultaneously or sequentially, and we found they were more likely to be opposing when the mechanisms operated sequentially. The degree and timing that these mechanisms interact have important implications for the operation of sexual selection and needs to be considered in designing studies. Our examples highlight where empirical data are needed. We especially lack standardized measures of the form and strength of selection imposed by each mechanism of sexual selection and how they combine to determine total sexual selection. Secondly, using quantitative genetic principles, we outline how the selection imposed by individual mechanisms can be measured and combined to estimate the total strength and form of sexual selection. We discuss the evolutionary consequences of combining the mechanisms of sexual selection and interpreting total sexual selection. We suggest how this approach may result in empirical progress in the field of sexual selection.

  Website 
• de Jong PW, Breuker CJ, de Vos H, Vermeer KMCA, Oku K, Verbaarschot P, Nielsen JK, Brakefield PM, 'Genetic differentiation between resistance phenotypes in the phytophagous flea beetle, Phyllotreta nemorum'
  Journal of Insect Science 9 (2009)
  ISSN: 1536-2442
  Abstract

  The flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae) is genetically polymorphic for resistance against the defences of one of its host plants, Barbarea vulgaris R.Br. (Brassicales: Brassicaceae). Whereas resistant flea beetles are able to use B. vulgaris as well as other cruciferous plants as food, non-resistant beetles cannot survive on B. vulgaris. This limitation to host plant use of non-resistant beetles could potentially lead to asymmetric gene flow and some degree of genetic isolation between the different resistance-genotypes. Therefore, we studied the extent of genetic differentiation at neutral allozyme loci between samples of flea beetles that were collected at different locations and first tested for resistance phenotype. Since earlier work has shown a weak, but significant, effect of geographical distance between the samples on their genetic differentiation, in the present study variation at the neutral allozyme loci in P. nemorum was partitioned between geographical distance and resistance-phenotype. Both sources independently contributed statistically significantly to population differentiation. Thus, there appears to be a limitation to genetic exchange between the resistant and non-resistant flea beetles when corrections are made for their geographic differentiation. This is consistent with the presence of some degree of host race formation in this flea beetle.

  Website 
• Gibbs M, Breuker C, Smiseth P, Moore A, 'Does sibling competition have a sex-specific effect on offspring growth and development in the burying beetle Nicrophorus vespilloides?'
  Entomologia Experimentalis et Applicata 126 (2) (2008) pp.158-164
  ISSN: 0013-8703
  Abstract

  During offspring growth, reduction in resource availability through competitive interactions will restrict how large individuals can become. Given that selection to mature at a large size will be greater for the sex in which large size provides the highest fitness return, sex-specific differences in response to a decrease in resource availability may be expected. Using Nicrophorus vespilloides Herbst (Coleoptera: Silphidae) we examined the sex-specific response of offspring to resource availability through sibling competition. We found that males and females were affected similarly by an increase in the level of sibling competition as brood size increased. Interestingly, although male N. vespilloides were consistently heavier than females, over a range of brood sizes, they were only significantly heavier than females at intermediate brood sizes. At present, the causes behind this finding remain unclear.

  Website 
• Breuker CJ, Brakefield PM, Gibbs M, 'The association between wing morphology and dispersal is sex-specific in the glanville fritillary butterfly Melitaea cinxia (Lepidoptera; nymphalidae)'
  European Journal of Entomology 104 (2007) pp.445-452
  ISSN: 1210-5759 eISSN: 1802-8829
  Abstract

  We examined whether dispersal was associated with body and wing morphology and individual quality, and whether such an association was sex-specific, in the Glanville fritillary butterfly Melitaea cinxia (L.) in Paldiski on the north coast of Estonia. Body weight, size and shape of both fore- and hindwing, wing aspect ratio and wing loading were used as measures of body and wing morphology. Fluctuating asymmetry (FA) of wing shape was used as a measure of individual quality. Males and females did not differ in dispersal rates, despite large differences in overall morphology and FA. Females had a significantly higher wing loading and aspect ratio, but a lower FA than males. Females, but not males, that dispersed differed in forewing shape from those that did not disperse. The sex-specifity of the covariation between dispersal and forewing shape is most probably due to wing shape being associated with different life-history traits in both sexes, resulting in different selection pressures on wing shape in each of the sexes.

• Breuker CJ, De Jong PW, Victoir K, Vrieling K,Brakefield PM, 'Pleiotropic effects associated with an allele enabling the flea beetle Phyllotreta nemorum to use Barbarea vulgaris as a host plant'
  Evolutionary Ecology 21 (2007) pp.13-26
  ISSN: 0269-7653
  Abstract

  In the Danish region of Kværkeby, a mutation in an, as yet, unknown single autosomal gene has resulted in a dominant resistance (R-) allele in the flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae). It enables the beetle to overcome the defences of Barbarea vulgaris ssp. arcuata (Opiz.) Simkovics G-type (Brassicaceae) and use it as a host plant. In this study, we investigated the pleiotropic effects associated with the presence of this particular R-allele in female P. nemorum. These females had the R-allele backcrossed into the genetic background of non-resistant beetles. The effects were investigated under both favourable and stressful conditions (cold shock). The presence of the R-allele in a non-resistant genetic background caused a very high mortality in resistant individuals during the early stages of development under both conditions, but it did not affect the adult life-history traits longevity, body size and fecundity, under both conditions. Regardless of temperature treatment, resistant females in general were found to lay significantly more eggs. Developmental stability, as measured by tibia length fluctuating asymmetry, was not correlated with overall developmental stress in this study.

  Website 
• Breuker CJ, Gibbs M, Van Dyck H, Brakefield PM, Klingenberg CP, Van Dongen S, 'Integration of wings and their eyespots in the speckled wood butterfly Pararge aegeria'
  Journal of Experimental Zoology Part B-Molecular and Developmental Evolution 308B (4) (2007)
  Website 
• Gibbs M, Breuker CJ, 'Effect of larval rearing density on adult life history traits and developmental stability of the dorsal eyespot pattern in speckled wood butterfly, Pararge aegeria'
  Entomologia Experimentalis et Applicata 118 (2006) pp.41-47
  ISSN: 0013-8703
  Abstract

  Behavioural stresses such as crowding are thought to incur a metabolic cost to insect larvae, and fluctuating asymmetry (FA) has been shown to be a possible indicator of this stress. A study of a Madeiran population of the butterfly Pararge aegeria L. (Lepidoptera: Satyrinae) shows that larval crowding affects larval development and growth, with female larvae being more adversely affected than males. It was predicted that if larval crowding increases FA, male and female P. aegeria adults may show different responses to this stress. The FA of five different wing pattern elements on the dorsal hindwings of adult male and female P. aegeria that had been reared at different larval densities was measured. Crowding in P. aegeria resulted in a trait-specific and sex-specific increase in FA. Although a significant correlation between FA and longevity was not observed, there was a significant correlation with egg-laying rate. Stressed females increased their egg-laying rate. An increased egg-laying rate may carry a further fitness cost through the offspring of stressed females, because high egg-laying rates are associated with a decline in oviposition site quality.

   

   

  Website 
• Breuker CJ, Patterson JS, Klingenberg CP, 'A single basis for developmental buffering of Drosophila wing shape.'
  PLoS ONE 1 (1) (2006)
  ISSN: 1932-6203
  Abstract

  The nature of developmental buffering processes has been debated extensively, based on both theoretical reasoning and empirical studies. In particular, controversy has focused on the question of whether distinct processes are responsible for canalization, the buffering against environmental or genetic variation, and for developmental stability, the buffering against random variation intrinsic in developmental processes. Here, we address this question for the size and shape of Drosophila melanogaster wings in an experimental design with extensively replicated and fully controlled genotypes. The amounts of variation among individuals and of fluctuating asymmetry differ markedly among genotypes, demonstrating a clear genetic basis for size and shape variability. For wing shape, there is a high correlation between the amounts of variation among individuals and fluctuating asymmetry, which indicates a correspondence between the two types of buffering. Likewise, the multivariate patterns of shape variation among individuals and of fluctuating asymmetry show a close association. For wing size, however, the amounts of individual variation and fluctuating asymmetry are not correlated. There was a significant link between the amounts of variation between wing size and shape, more so for fluctuating asymmetry than for variation among individuals. Overall, these experiments indicate a considerable degree of shared control of individual variation and fluctuating asymmetry, although it appears to differ between traits.

  Website 
• Breuker CJ, Victoir K, De Jong PW, Van der Meijden E, Brakefield PM, Vrieling K, 'AFLP markers for the R-gene in the flea beetle, Phyllotreta nemorum, conferring resistance to defences in Barbarea vulgaris.'
  Journal of Insect Science 5 (38) (2005)
  ISSN: 1536-2442
  Abstract

  A so-called R-gene renders the yellow-striped flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) resistant to the defenses of the yellow rocket Barbarea vulgaris R.Br. (Brassicacea) and enables it to use it as a host plant in Denmark. In this study, genetic markers for an autosomal R-gene, inherited as a single, dominant locus in flea beetles from the Danish locality “Kværkeby” are described, and a genetic linkage map around this particular R-gene is constructed, using the technique of AFLP (Amplified Fragment Length Polymorphism).

   

• Breuker CJ, Brakefield PM, 'Lack of response to selection for lower fluctuating asymmetry of mutant eyespots in the butterfly Bicyclus anynana'
  Heredity 91 (2003) pp.17-27
  ISSN: 0018-067X
  Abstract

  Fluctuating asymmetry (FA) is claimed both to provide a means of evaluating developmental stability, and to reflect an individual's quality or the stress experienced during development. FA refers to the nondirectional variation between left and right sides, whereas directional asymmetry (DA) refers to a significant directional variation between the sides. We studied four eyespots on the dorsal forewing of the tropical butterfly, Bicyclus anynana. Two of the eyespots were specified by a mutant allele, Spotty, that was fixed in the stock. These eyespots showed higher FA than the two flanking, wild-type eyespots, although they are all formed by the same developmental pathway. We applied artificial selection for lower FA of the novel eyespots in an attempt to increase their developmental stability. There was significant variation present in individual FA in our study. However, this did not change as a result of the artificial selection. Most of the variation in FA can be accounted for by individual differences in developmental stability rather than by the applied selection or by environmental variation. Thus, it was not possible to produce any increased developmental stability of the novel eyespots by selecting for low FA. The estimates of realized heritability for both FA and DA of each eyespot were not significantly different from zero. The results suggest that FA provides little, if any, potential for exploring the mechanistic basis of developmental stability.

  Website 
• Breuker CJ, Brakefield PM, 'Heat stress in the developmentally sensitive period of butterfly eye spots fails to increase fluctuating asymmetry.'
  Evolution and Development 5 (2003) pp.231-239
  ISSN: 1520-541X eISSN: 1525-142X
  Abstract

   Fluctuating asymmetry (FA) is considered to provide a means of evaluating developmental stability and to reflect an individual's quality or the stress experienced during development. Stress is predicted to increase the phenotypic variation of both FA and trait size. In this study we examined the effect of a particular heat shock on both FA and size of eyespots in the butterfly, Bicyclus anynana. We also examined whether those eyespots thought to be involved in partner choice and sexual selection were particularly sensitive to stress. We applied a heat shock of 39.5°C for 3 h before, during, and after a sensitive period in eyespot development. We examined the FA, variation in FA, size, and variation in size of five eyespots, two on the dorsal forewing (sexually selected traits), two on the ventral forewing, and one on the ventral hindwing (nonsexually selected traits). For each sex and treatment, the heat shock did not result in significant changes in mean trait size and FA nor in the variation of size and FA. There were no differences in the response to the heat shock between sexually and nonsexually selected traits. We discuss how the increased production of heat shock proteins, including HSP60, may have stabilized development and how this might explain the results.

• Hanski I, Breuker CJ, Schöps K, Setchfield R, Nieminen M, 'Population history and life history influence the migration rate of female Glanville fritillary butterflies.'
  Oikos 98 (2002) pp.87-97
  ISSN: 0030-1299 eISSN: 1600-0706
  Abstract

  This study examines the causes of emigration from small fragments of suitable habitat in a species that has a distinct metapopulation structure, frequent turnover of local populations, and substantial migration among local populations and currently unoccupied habitat fragments. We conducted a field experiment in which 727 individuals of the Glanville fritillary butterfly (Melitaea cinxia) originating from four regions were marked and released simultaneously in a natural environment. In three of the four source regions, larvae for the experiment were collected from dozens of small local populations, some of which had been established in the previous summer (new populations), whereas the remaining populations were older. In two of the source regions, female butterflies prefer a host plant (Veronica spicata) that is not present in the release area, where there is only Plantago lanceolata, the preferred host plant of females from the other two source regions. We found that migration rate of males was unrelated to any of the factors studied in this experiment. In contrast, two factors influenced the migration rate of females. First, Veronica-preferring females had higher emigration rate than Plantago-preferring females from the Plantago-containing release patches, demonstrating that the individual perception of habitat quality significantly influences the migration rate of females. Second, females from newly-established populations were more dispersive than females from older populations, supporting the notion that metapopulation processes (recurrent colonizations) select for increased migration. The observed migration rate was not correlated with any body size measurements, and thus the observed differences in migration rate were apparently caused by differences in the behaviour of female butterflies rather than in their flight capacity.

  Website 
• Breuker CJ, Brakefield PM, 'Female choice depends on size but not symmetry of dorsal eyespots in the butterfly Bicyclus anynana'
  Proceedings of the Royal Society of London. Series B, Containing papers of a Biological character. Royal Society (Great Britain) 269 (2002) pp.1233-1239
  ISSN: 0962-8452
  Abstract

  The eyespots on the ventral wings of Bicyclus anynana butterflies are exposed when at rest and interact with predators. Those on the dorsal surface are not exposed in this way, and may be involved in courtship and mate choice. In this study, we examined whether the size and fluctuating asymmetry (FA) of dorsal eyespots are reliable signals of male quality. High developmental stability is considered to result in low FA, and to be associated with high quality. Individuals of high quality are predicted to produce sexually selected traits that are large and symmetrical, at a relatively low cost. In this study, we manipulated eyespot development to uncouple eyespot size and FA in order to examine their independent roles in signalling to the female. Individual females in cages were given the choice between two or three males differing in eyespot traits. The results indicate that although size per se of the eyespots is used as a signal, FA and wing size are not. We discuss the use of FA in studies of sexual selection and aspects of sexual selection on dorsal eyespot size.

   

   

   

  Website 
• Verhoog MD, Breuker CJ, Brakefield PM, 'The influence of genes for melanism on the activity of the flour moth, Ephestia kuehniella.'
  Animal Behaviour 14 (2001) pp.148-156
  ISSN: 0003-3472
  Abstract

  We investigated the effects of genes controlling melanism on levels and patterns of activity, potential nonvisual components of fitness, of adult Mediterranean flour moths,Ephestia kuehniellaZeller (1879). Six genotypes of two melanic strains (Ala nigra and black) were used. We monitored continuously the walking or flight activity of 45 mated females per genotype during the third night of their lives, using automatic electrostatic techniques to carry out the measurements. Although there was high individual variation within genotypes, bb (melanic) females were more active than the two nonmelanic genotypes of the black strain (b+, ++) because they tended to show more bouts of activity. There were no differences in the average length of these bouts, or in the timing of initial and final activity. Overall, the females of the black strain were significantly more active than the females of the Ala nigra strain. The results are discussed in the context of the evolution of melanism in moths.

  Website 
• Brakefield PM, El Filali E, Van Der Laan R, Breuker CJ, Saccheri IJ, Zwaan B, 'Effective population size, reproductive success and sperm precedence in the butterfly, Bicyclus anynana, in captivity'
  Journal of Evolutionary Biology 14 (2001) pp.148-156
  ISSN: 1010-061X
  Abstract

  A pedigree approach is used to estimate the effective population size yn two population cages of the butterfly, Bicyclus anynana. Each cage was founded with 54 individually marked adults of each sex. Matings were recorded over a 3-day period. Eggs were then collected from each female over a similar period before the numbers of hatching larvae were counted to assess progeny number. The males showed a higher variance in reproductive success than the females. Since about one-quarter of all females mated more than once, we also examined the pattern of sperm precedence using molecular markers or, in separate crossing experiments, wing pattern mutants. Both instances of complete first and last male sperm precedence, as well as of sperm mixing, were found. In some crosses a ‘leakiness’ was found in which some of the early eggs laid by a female were fertilized by a male partner which was subsequently completely unsuccessful. However, the estimates of effective population size were largely unaffected by the pattern of sperm precedence. Estimates for Ne : N in each cage were close to 0.60. The possibility of obtaining comparable estimates in selected natural populations of butterflies is discussed.

  Website 
• Brakefield PM, Breuker CJ, 'The genetical basis of fluctuating asymmetry for developmentally integrated traits in a butterfly eyespot pattern'
  Proceedings of the Royal Society of London series B Biological Sciences 263 (1996) pp.1557-1563
  ISSN: 0962-8452
  Abstract

  We measured fluctuating asymmetry (FA) for a series of eyespots on left and right wings of the butterfly Bicyclus anynana. F1 offspring were reared in favourable conditions from two groups of selected parents with comparatively low and high FA, respectively. The data suggest that eyespots under strong visual selection from predators may show reduced FA. The results showed no indication of heritable variation for FA and no correlation in FA across eyespots within individuals. An additional experiment showed that a mutant allele specified a novel eyespot which tended to be more asymmetric. Our results indicate that caution is necessary in using FA of specific traits as some genome-level index of developmental stability.

  Website 

Book chapters

• Livraghi L, Martin A, Gibbs M, Braak N, Arif S, and Breuker CJ, 'CRISPR/Cas9 as the key to unlocking the secrets of butterfly wing pattern development and its evolution' in Richard ffrench-Constant (ed.), Butterfly wing patterns and mimicry, Elsevier (2018)
  ISBN: 9780128137703
  Abstract With the exception of a few moth and butterfly species, gene-editing tools in Lepidoptera have been lagging behind other well-studied insects. In order to elucidate gene function across the order, it is necessary to establish tools that enable such gene manipulation. CRISPR/Cas9 is a promising technique and here we review the recent progress made in implementing the technique in butterflies; from broad patterning of the wing, to the development of specific colours in particular wing sections, to eyespot formation. The often species-specific responses to the CRISPR/Cas9-induced mutations in candidate genes, underscore the significance of these genes in the wide evolutionary diversification of butterfly wing patterns. We further discuss potential caveats in the interpretation of the resulting mutant phenotypes obtained through CRISPR/Cas9 gene editing. Finally, we discuss the possibilities CRISPR/Cas9 offers beyond mere knockout of candidate genes, including the potential for the generation of transgenics that will further elucidate the developmental genetic basis for wing pattern evolution.Website 
• Carter J, Gibbs M, Breuker CJ, 'Studying oogenesis in a non-model organism using transcriptomics; assembling, annotating and analysing your data' in Nezis I (ed.), Oogenesis Protocols, Springer (2016)
  ISBN: 978-1-4939-3793-6 eISBN: 978-1-4939-3795-0
  Abstract

  This chapter provides a guide to processing and analysing RNA-Seq data in a non-model organism. This approach was implemented for studying oogenesis in the Speckled Wood Butterfly Pararge aegeria. We focus in particular on how to perform a more informative primary annotation of your non-model organism by implementing our multi-BLAST annotation strategy. We also provide a general guide to other essential steps in the next generation sequencing analysis workflow. Before undertaking these methods we recommend you familiarise yourself with command line usage and fundamental concepts of database handling. Most of the operations in the primary annotation pipeline can be performed in Galaxy (or equivalent standalone versions of the tools) and through the use of common database operations (e.g. to remove duplicates) but other equivalent programs and/or custom scripts can be implemented for further automation.

  Website 
• Breuker CJ, Gibbs M, Merckx T, Van Dongen S, Van Dyck H, 'The use of geometric morphometrics in studying butterfly wings in an evolutionary ecological context' in Morphometrics for Non-morphometricians, Springer Verlag (2010)
  ISBN: 978-3-642-26370-5
  Abstract

  Morphometrics is concerned with the study of variations and change in the form (size and shape) of organisms or objects adding a quantitative element to descriptions and thereby facilitating the comparison of different objects and organisms. This volume provides an introduction to morphometrics in a clear and simple way without recourse to complex mathematics and statistics. This introduction is followed by a series of case studies describing the variety of applications of morphometrics from paleontology and evolutionary ecology to archaeological artifacts analysis. This is followed by a presentation of future applications of morphometrics and state of the art software for analyzing and comparing shape.

  Website 

Other publications

• Breuker CJ, Debat V, Klingenberg CP, 'Functional evo-devo'
  Trends in Ecology and Evolution 21 (2006) pp.488-492ISSN: 0169-5347 eISSN: 1872-8383
  Abstract
  Functional factors such as optimal design and adaptive value have been the central concern of evolutionary biology since the advent of the New Synthesis. By contrast, evolutionary developmental biology (evo-devo) has concentrated primarily on structural factors such as the ways in which body parts can be built. These different emphases have stood in the way of an integrated understanding of the role of development in evolution. Here, we try to bridge this gap by outlining the relevance of functional factors in evo-devo. We use modularity and the view of development as a flexible evolutionary system to outline a unified perspective that includes both structural and functional aspects.
   
  Website 

Areas of expertise

Expertise in evolutionary developmental biology, in particular where it pertains Lepidoptera.

• Reviewer for the following journals: Trends in Ecology and Evolution, Evolution, Genetics, Genetica, PLOS ONE, BMC Genomics, BMC Evolutionary Biology, Proceedings of the Royal Society of London Series B, Belgian Journal of Zoology, Animal Behaviour, Mechanisms of Ageing and Development, Open Biology, Zootaxa, Experimental Gerontology, Oikos, American Naturalist, Heredity, Journal of Evolutionary Biology, Journal of Experimental Biology, Journal of Negative Results in Ecology and Evolutionary Biology
• Reviewer for textbooks published by Oxford University Press

Membership of professional bodies

• Academic Editor for PLOS ONE
• Current Membership: Butterfly Conservation, British Society for Developmental Biology (BSDB), and Genetics Society.
• Past Membership: European Society for Evolutionary Biology (ESEB), and Euro Evo Devo (EED)

Further information

• Research Knowledge and Exchange Committee (RKEC) member since 2011
• Faculty Mitigating Circumstances Panel member since 2014

Other publicity

Public Awareness and Outreach Activities

• Science Bazaar – yearly event where I run the “Become an Egghead” activity.
• The ABC of Amazing Butterfly Colours (Oxfordshire Science Festival during National Science week)
• Talks at local schools and presentations at nurseries
• Oxford Festival of Nature 2016
• Social media such as Twitter, Facebook and blogs
• Invited Presentations at Upper Thames Branch annual members day of Butterfly Conservation as well as a national Butterfly Conservation meeting in 2016

Further information

Butterfly Tennis Balls!

https://www.ceh.ac.uk/news-and-media/blogs/butterfly-tennis-balls