Phillips, Patrickde Verteuil Yeboah, Precious2020-09-242020-09-242020-09-24https://hdl.handle.net/1794/25607Environmental fluctuations are ubiquitous in nature and can serve to drive phenotypic differences among individuals in an environment-specific manner, a phenomenon known as phenotypic plasticity. Phenotypic plasticity can have implications for an organism’s fitness. Here, I address how two distinct environmental perturbations (acute nutrient deprivation and treatment with a compound known to extend lifespan) impact individual life-history traits within and across generations using the Caenorhabditis elegans nematode model system. To quantitively assess the impacts of acute maternal starvation, I engineered a novel microfluidic device to starve adults and simultaneously collect progeny with fine-scale temporal resolution. I found no evidence for changes in maternal provisioning of embryos (egg size) laid under acute maternal starvation, highlighting that, even in the face of limited nutrient availability, equal investment is provided to embryos in-utero. This consistency in provisioning is further evidenced by the fact that I also found no significant changes to life history traits such as lifespan and reproductive output in offspring produced by starved parents. To quantitively assess the role that timing of application of a compound previously identified lifespan extension (Thioflavin T) might play in shifting longevity responses, I contrasted early intervention responses from treatment early in development to those observed after treatment as adults. Here, I identify a novel, recoverable, developmental delay state induced by Thioflavin T treatment in a dose-dependent manner after larval treatment. These effects include disruption of normal development and increased early life mortality while on the compound, as well as decreased reproductive output and, importantly, increased longevity, after recovery following removal from the compound. Using mutants in known stress response pathways to assess specificity of response, it appears that developmental exposure results in a general hormetic stress response acting across multiple stress response systems. Overall my dissertation explores the way environmental perturbations affect life history trajectories within and across generations. Using a combination of novel experimental approaches and high throughput techniques, I find that the major drivers of phenotypic plasticity in my experiments to be the type of environmental stressor and the age of treatment onset. This work includes unpublished coauthored material.en-USAll Rights Reserved.Biological Fitness Trade OffsDevelopmental DelayEnvironmental PerturbationsLifespanMaternal StarvationThioflavin TElectronic Thesis or Dissertation