Go to the About Us section
Go to the Courses section
Go to the Research section
Go to the Specialist Services & Consultancy section
Go to the Outreach section
Go to the New Students section
You can find details about all the staff in the department below.
return to full list
Department of Biological and Medical Sciences
Faculty of Health and Life Sciences
Gipsy Lane Campus, Sinclair SNC1.01
I am an independent Research Fellow in Cell and Developmental Biology. My research group is mainly studying the development of the nervous system and synaptic connections. Our model is C. elegans but we also collaborate with groups using comb jelly fish to understand the evolution of nervous systems in animals.
My lab also collaborates internally with Alistair McGregor to understand eye size specification during development. Vision is an important sensory system and we use Drosophila for our genetic, morphological and behavioural analysis.
"Nervous system and brain development"
My lab is interested in the development of the nervous system, how connections are formed in the correct time and space and which components are crucial to assemble the synaptic vesicle fusion machinery. We take advantage of the well characterised and fairly stereotypic connectome to identify and analyse defects in mutants that lack multiple core proteins that are throught to be involved in synapse assembly to better understand the regulation of synaptic vesicle fusion and thus neurotransmission. We use a variety of imaging techniques including Confocal microscopy as well as high resolution 3D Serial Block Face SEM and TEM tomogaphy for ultrastructural analysis.
During animal development it is crucial that organ size is correctly specified. More crucially so in important sensory organs as eyes. Insect compound eyes show a huge variety or sizes and shapes, but even within Drosophila species we can find large variation in eye size. We are utilising the large genetic and molecular tool kit available in Drosophila to identify the genetic basis of natural eye size variation and combine it with advanced 3D imaging techniques like synchrotron radiation tomography to identify morphological differences between Drosophila species. Predictions on the effects of eye size on Drosophila vision can then be tested in behavioural assays.
Lewis Cockram (PhD student)
Dr. Franziska Franke (Post doc)
Dr. Alexandra Buffry (Post doc)
BBSRC (2019) – The eyes have it: genetic, morphological and functional analysis of differences in compound eyes between Drosophila species
Research Excellence Award 2021-22 “How is eye size regulated?”
1) Understanding the formation of the presynaptic active zone ultrastructure through analysis of known and new components
2) Genetic, morphological and functional analysis of differences in compound eyes between Drosophila species
Currently open application for a PhD project:
The compound eyes of insects exhibit striking variation in size, reflecting adaptation to different lifestyles and habitats. However, the genetic and developmental bases of variation in insect eye size is poorly understood, which limits our understanding of how these important morphological differences evolve. To address this, we further explored natural variation in eye size within and between four species of the Drosophila melanogaster species subgroup. We found extensive variation in eye size among these species, and flies with larger eyes generally had a shorter inter-ocular distance and vice versa. We then carried out quantitative trait loci (QTL) mapping of intra-specific variation in eye size and inter-ocular distance in both D. melanogaster and D. simulans. This revealed that different genomic regions underlie variation in eye size and inter-ocular distance in both species, which we corroborated by introgression mapping in D. simulans. This suggests that although there is a trade-off between eye size and inter-ocular distance, variation in these two traits is likely to be caused by different genes and so can be genetically decoupled. Finally, although we detected QTL for intra-specific variation in eye size at similar positions in D. melanogaster and D. simulans, we observed differences in eye fate commitment between strains of these two species. This indicates that different developmental mechanisms and therefore, most likely, different genes contribute to eye size variation in these species. Taken together with the results of previous studies, our findings suggest that the gene regulatory network that specifies eye size has evolved at multiple genetic nodes to give rise to natural variation in this trait within and among species.
Male genital structures are among the most rapidly evolving morphological traits and are often the only features that can distinguish closely related species. This process is thought to be driven by sexual selection and may reinforce species separation. However, while the genetic bases of many phenotypic differences have been identified, we still lack knowledge about the genes underlying evolutionary differences in male genital organs and organ size more generally. The claspers (surstyli) are periphallic structures that play an important role in copulation in insects. Here, we show that divergence in clasper size and bristle number between Drosophila mauritiana and Drosophila simulans is caused by evolutionary changes in tartan (trn), which encodes a transmembrane leucine-rich repeat domain protein that mediates cell–cell interactions and affinity. There are no fixed amino acid differences in trn between D. mauritiana and D. simulans, but differences in the expression of this gene in developing genitalia suggest that cis-regulatory changes in trn underlie the evolution of clasper morphology in these species. Finally, analyses of reciprocal hemizygotes that are genetically identical, except for the species from which the functional allele of trn originates, determined that the trn allele of D. mauritiana specifies larger claspers with more bristles than the allele of D. simulans. Therefore, we have identified a gene underlying evolutionary change in the size of a male genital organ, which will help to better understand not only the rapid diversification of these structures, but also the regulation and evolution of organ size more broadly.
The endoplasmic reticulum (ER) is a highly dynamic polygonal membrane network composed of interconnected tubules and sheets (cisternae) that forms the first compartment in the secretory pathway involved in protein translocation, folding, glycosylation, quality control, lipid synthesis, calcium signalling, and metabolon formation. Despite its central role in this plethora of biosynthetic, metabolic and physiological processes, there is little quantitative information on ER structure, morphology or dynamics. Here we describe a software package (AnalyzER) to automatically extract ER tubules and cisternae from multi-dimensional fluorescence images of plant ER. The structure, topology, protein-localisation patterns, and dynamics are automatically quantified using spatial, intensity and graph-theoretic metrics. We validate the method against manually-traced ground-truth networks, and calibrate the sub-resolution width estimates against ER profiles identified in serial block-face SEM images. We apply the approach to quantify the effects on ER morphology of drug treatments, abiotic stress and over-expression of ER tubule-shaping and cisternal-modifying proteins.
The cytoskeleton is an early attribute of cellular life and its main components are composed of conserved proteins (Fletcher and Mullins, 2010). The actin cytoskeleton has a direct impact on cell size control in animal cells (Fletcher and Mullins, 2010; Faix et al., 1996), but its mechanistic contribution to cellular growth in plants remains largely elusive. Here, we reveal a role of actin in cell size regulation in plants. The actin cytoskeleton shows proximity to vacuoles, and the phytohormone auxin not only controls the organisation of actin filaments, but also impacts on vacuolar morphogenesis in an actin-dependent manner.
Pharmacological and genetic interference with the actin-myosin system abolishes the auxin effect on vacuoles and thus disrupts its negative influence on cellular growth. SEM-based 3D nanometre resolution imaging of the vacuoles revealed that auxin controls the constriction and luminal size of the vacuole. We show that this actin-dependent mechanism controls the relative cellular occupancy of the vacuole, thus proposing an unanticipated mechanism for cytosol homeostasis during cellular growth.
My expertise is electron microscopy, including various preparation methods (chemical fixation, High Pressure Freezing and Freeze Substitution, microwave fixation), EM tomography, serial sectioning, Serial Block Face SEM, Correlative microscopy and 3D reconstructions (using Imaris, Amira, iMod or Reconstruct). I have prepared and imaged a variety of organisms (Trichoplax, C. elegans, Drosophila, Zebrafish, ctenophores, plants) during my scientific career.
Recently I started using synchrotron radiation microtomography for 3D morphological studies in Drosophila eyes.
I have also experience in Confocal microscopy and standard molecular biology techniques as Western Blot, PCR, cloning, in-situ-hybridisation, Yeast-2-Hybrid etc.
Royal microscopy Society and European Microscopy SocietyBritish Society for Developmental BiologyThe Genetics SocietyBritish Neuroscience Association
I studied Biology in the University of Goettingen, Germany where I obtained my Diploma. My thesis investigated the evolution of the nervous system and neurons using SNARE proteins as potential markers for neuronal anchestors in the early metazoan Trichoplax adhaerens.
During my PhD at the European Neuroscience Institute in Goettingen I used the model organism C. elegans to understand how synaptic transmission is regulated through the presynaptic density which is thought to be involved in vesicle tethering and recruitment to the presynaptic fusion site.
As post-doc I worked with Prof. Martin Goepfert to understand how mechanical stimuli lead to the opening of mechanosensory ion channels to generate an electric signal in the sensory neurons in Drosophila and identified ankyrin repeats of the mechanosensory ionchannel NOMPC as connection between the ion channel in the cell membrane and the microtubules.