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Biology subjects

Burke, N.

Publications and source records attributed to Burke, N..

3 recordsLinked to original sources

Decoding human sperm signalling: Phosphoproteomic discovery of kinases governing fertilization competency

Capacitation, the process whereby sperm gain the functional competence to fertilize an egg in the absence of de novo transcription and translation, is orchestrated by a hierarchy of kinases driving the phosphorylation of sperm proteins. While increased phosphorylation, in particular tyrosine phosphorylation, is a revered hallmark of fertilization competency in our species, only a limited repository of phosphorylated substrates and kinases have ever been reported from human sperm. To broaden therapeutic targets for sperm targeted contraceptives and infertility therapies, we adapted a contemporary phosphoproteomic technique termed EasyPhos to generate bespoke methodology for the investigation of human sperm signalling. This approach yielded high depth phosphoproteomes of non-capacitated and capacitated human spermatozoa with in silico investigation of the phosphosites revealing 52 kinases with previously uncharacterized roles in sperm capacitation. Investigating the function of the putative sperm capacitation kinases identified yielded several kinases with novel roles in the regulation of sperm function. Of particular interest, polo like kinase 1 (PLK1) inhibition significantly reduced progressive sperm motility, attenuated capacitation-associated tyrosine phosphorylation and reduced the sperm acrosome reaction, an essential step to achieve fertilization. These findings reveal extensive phosphoproteome remodelling during human sperm capacitation, expanding the landscape of molecular targets for fertility control.

Cell Biology↗

Characterisation of Geometric Variance in the Epithelial Nerve Net of the Ctenophore Pleurobrachia pileus

Neuroscience currently lacks a diverse repertoire of model organisms, resulting in an incomplete understanding of what principles of neural function generalise and what are species-specific. Ctenophores display many neurobiological and experimental features which make them a promising candidate to fill this gap. They possess a nerve net distributed across their outer body surface, just beneath the epithelial layer. There is a long-held assumption that nerve nets are simple and random while lacking distinct organisational principles. We want to challenge this assumption and determine how stereotyped the structure of this network really is. We validated an approach to estimate body surface area in Pleurobrachia pileus using custom Optical Projection Tomography and Light Sheet Morphometry imaging systems. We used an antibody against tyrosylated -tubulin to visualise the nerve net in situ. We used an automated segmentation approach to extract the morphological features of the nerve net. We characterised organisational rules of the epithelial nerve net in P. pileus in animals of different sizes and at different regions of the body. We found that specific morphological features within the nerve net are largely un-changed during growth. These properties must be essential to the functionality of the nervous system and therefore are maintained during a change in body size. We have also established the principles of organisation of the network and showed that some of the geometric properties are variable across different parts of the body. This suggests that there may be different functions occurring in regions with different structural characteristics. This is the most comprehensive structural description of a nerve net to date. This study also demonstrates the amenability of the ctenophore P. pileus for whole organism network analysis and shows their promise as a model organism for neuroscience, which may provide insights into the foundational principles of nervous systems.

neuroscience↗

The Incubot: A 3D Printer-Based Microscope for Long-Term Live Cell Imaging within a Tissue Culture Incubator

Commercial live cell imaging systems represent a large financial burden to research groups, while current open source incubator microscopy systems lack adaptability and are sometimes inadequate for complex imaging experimentation. We present here a low-cost microscope designed for inclusion within a conventional tissue culture incubator. The build is constructed using an entry level 3D printer as the basis for the motion control system, with Raspberry Pi imaging and software integration, allowing for reflected, oblique, and fluorescence imaging of live cell monolayers. The open source nature of the design is aimed to facilitate adaptation by both the community at large and by individual researchers/groups. The development of an adaptable and easy-to-use graphic user interface (GUI) allows for the scientist to be at the core of experimental design. Simple modifications of the base GUI code, or generation of an entirely purpose-built script, will allow microscopists to place their experimental design as the priority, as opposed to designing experiments to fit their current equipment. The build can be constructed for a cost of roughly C1000 and thus serves as a low-cost and adaptable addition to the open source microscopy community. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=176 SRC="FIGDIR/small/121608v2_ufig1.gif" ALT="Figure 1"> View larger version (68K): org.highwire.dtl.DTLVardef@1aa58ceorg.highwire.dtl.DTLVardef@ac4678org.highwire.dtl.DTLVardef@467ae2org.highwire.dtl.DTLVardef@12da951_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗