Biology subjects

Williams, S. B.

Publications and source records attributed to Williams, S. B..

4 recordsLinked to original sources

bioRxiv2024

Natural variation in starvation sensitivity maps to a point mutation in phospholipase IPLA2-VIA in Drosophila melanogaster

Resistance to starvation is a classic complex trait where genetic and environmental variables can greatly modify an animals ability to survive without nutrients. Genetic analyses in Drosophila have shown that starvation resistance is highly polygenic with different genetic architectures in different mapping populations. In this study we sought to dissect the genetic basis of starvation resistance among a set of mitonuclear genotypes carrying different mtDNAs paired with specific nuclear genomes from the Drosophila Genetic Reference Panel (DGRP). We focused on differences between one of the most sensitive strains (DGRP-765) and a strain with more moderate resistance (DGRP-315) whose starvation phenotypes appeared to be modified by alternative mtDNAs. Using complementary pooled-sequencing and forward genetic mapping approaches, we identified regions of chromosomes 2L, 3L and 3R contributing to starvation sensitivity and localize a major effect locus modifying starvation resistance to the coding region of phospholipase iPLA2-VIA. These analyses further confirm that the alternative mtDNAs had little influence on variation in starvation resistance between the genotypes studied. The sensitive line shows a starvation-dependent depletion of glucose and glycogen that is modified by hemi- and heterozygosity in the iPLA2-VIA region. These findings contribute to our understanding of the complex genetic relationship between resistance to starvation stress and nutrient metabolism.

genetics↗

bioRxiv2023

Koalas, cameras and a primary school: Obtaining ecological insights for land management through a mini-citizen science project with young students.

Koalas are an endangered species in Eastern Australia and the management of habitat revegetation sites is essential for the marsupials survival. This report summarises the results of a partnership between revegetation managers and a local primary school that connected children to real world scientific practice. Ten infrared motion sensor cameras were installed on a five-year-old revegetation offset site in south-east Queensland, Australia to capture movements of koalas and other fauna. Primary school students screened images from these cameras for animal presence in a mini-citizen science project through an easy-to-use website created specifically for this project. Aspects of these results were used to modify the lands management by site supervisors. This report outlines processes involved in having Queensland primary school students participate in a mini web-based citizen science project, presents some of the ecological results obtained through the investigation and makes recommendations for future projects of this type.

scientific communication and education↗

bioRxiv2019

Cornichon Homolog-3 (CNIH3) Modulates Spatial Memory in Female Mice

Cornichon homolog-3 (CNIH3) is an AMPA receptor (AMPAR) auxiliary protein that traffics AMPARs to the postsynaptic membrane and potentiates AMPAR signaling. AMPARs are key components of hippocampal synaptic plasticity and memory formation, however the role of CNIH3 in memory has yet to be elucidated. To study the role of CNIH3 on mouse behavior, we bred and characterized a line of Cnih3-/- mice from C57BL/6 Cnih3tm1a(KOMP)Wtsi mice obtained from the Knockout Mouse Project (KOMP). In agreement with previous studies of CNIH3 in the brain, we observed concentrated expression of Cnih3 in the dorsal hippocampus, a region associated with spatial learning and memory. Therefore, we tested Cnih3+/+, Cnih3+/-, and Cnih3-/- mice in the Barnes maze paradigm to measure spatial memory. We observed no change in spatial memory in male Cnih3+/- and Cnih3-/- mice compared to male Cnih3+/+ controls, however, Cnih3-/- female mice made significantly more primary errors, had a higher primary latency, and took less efficient routes to the target in the maze compared to Cnih3+/+ female mice. Next, to investigate an enhancement of spatial memory by Cnih3 overexpression, specifically in the dorsal hippocampus, we developed an AAV5 viral construct to express wild-type Cnih3 in excitatory neurons. Female mice overexpressing Cnih3 made significantly fewer errors, had a lower primary latency to the target, and took more efficient routes to the maze target compared to YFP expressing control females. No change in spatial memory was observed in male Cnih3 overexpression mice. This study, the first to identify sex-specific effects of the AMPAR auxiliary protein CNIH3 on spatial memory, provides the groundwork for future studies investigating the role of CNIH3 on sexually dimorphic AMPAR-dependent behavior and hippocampal synaptic plasticity.

neuroscience↗

bioRxiv2019

Hippocampal Activity Dynamics During Contextual Reward Association in Virtual Reality Place Conditioning

Exposure to environmental contexts associated with drug use can induce cravings that promote continued use and/or relapse. Opioid abuse is marked by high relapse rates, suggesting that contextual memories formed during opioid use may be particularly strong. While it is known that reward-seeking behavior is controlled by the mesolimbic reward circuit, little is understood about how contextual memories are altered by drug use. The dorsal hippocampus (dHPC) is necessary for multiple types of contextual learning and the place-specific activity of CA1 place cells map out space in a given environment. Here we examined the neuronal representation of context as animals developed morphine-paired environmental associations using a conditioned place preference (CPP) paradigm. To investigate changes in the hippocampal encoding before, during, and after drug-pairing, we developed a virtual reality (VR) morphine CPP (Mor-CPP) paradigm and used in vivo two-photon calcium imaging to record the activity of CA1 pyramidal neurons. We found increased activity in rewarded contexts following real-time operant conditioning with water rewards, but not after Mor-CPP training, suggesting different neural encoding mechanisms for natural reinforcers and morphine.

neuroscience↗