Biology subjects

Gilmore, I. S.

Publications and source records attributed to Gilmore, I. S..

3 recordsLinked to original sources

bioRxiv2025

An intercellular metabolic relay for brain sparingin Drosophila

Brain sparing protects growth of the central nervous system (CNS) at the expense of other developing organs during nutrient restriction. This survival strategy is conserved from Drosophila to mammals but little is known about its underlying metabolic mechanisms. Here, we show that CNS uptake and catabolism of circulating glutamine is essential for neural stem cell proliferation during brain sparing but not normal brain development. Glutamine is imported into perineurial glia of the blood-brain-barrier, which upregulate glutaminase (Gls) and vesicular glutamate transporter 1 (VGlut1) to promote glutaminolysis and glutamate secretion. Neural stem cells then import released glutamate via excitatory amino acid transporter 1 (Eaat1) and maintain it at homeostatic levels via glutamine synthetase 1 (Gs1). Glutamine nitrogen contributes surprisingly little to newly synthesized DNA or protein in neural stem cells but its carbon fuels the oxidative tricarboxylic acid cycle. These findings identify an intercellular metabolic relay specifically required to sustain the proliferation of neural stem cells during brain sparing.

developmental biology↗

bioRxiv2024

Identification of a specialized lipid barrier for Drosophila metamorphosis

In many terrestrial insects, the onset of metamorphosis marks a transition from humid to dry environments. Yet how metamorphosing insect pupae protect themselves against the threat of dehydration remains unclear. Here, we identify the chemical composition and biosynthetic origins of a lipid desiccation barrier specific to the pupal and sexually-immature adult stages of Drosophila melanogaster. This barrier comprises unisex hyper-long hydrocarbons, 29-37 carbons in length, which are synthesized by larval oenocytes and stored in the larval fat body before being deployed on the pupal and young adult cuticles. We show that the fatty acid elongase EloHL is required for the biosynthesis of hyper-long hydrocarbons that are essential for the barrier to water loss during metamorphosis. Across the Drosophila genus, many species express unisex profiles of hyper-long hydrocarbons and, as young adults, transition to sex-specific shorter hydrocarbons with known pheromonal functions. The desert species D. mojavensis, however, retains hyper-long hydrocarbons during adulthood likely as an adaptation to an arid environment. Our study reveals how the cuticular lipid barrier is tuned to meet changing environmental pressures during insect development and evolution.

developmental biology↗

bioRxiv2019

Cryo-OrbiSIMS for 3D molecular imaging of a bacterial biofilm in its native state

We describe a method for label-free molecular imaging of biological materials, preserved in a native state, by using an OrbiSIMS instrument equipped with cryogenic sample handling and developing a high-pressure freezing protocol compatible with mass spectrometry. We studied the 3D distribution of quorum sensing signalling molecules, nucleobases and bacterial membrane molecules, in a mature Pseudomonas aeruginosa biofilm, with high spatial-resolution and high mass-resolution.

microbiology↗