Degree Type
Honors Capstone Project
Date of Submission
Spring 5-1-2018
Capstone Advisor
Sarah Hall
Honors Reader
Eleanor Maine
Capstone Major
Biology
Capstone College
Arts and Science
Audio/Visual Component
no
Capstone Prize Winner
no
Won Capstone Funding
no
Honors Categories
Sciences and Engineering
Subject Categories
Biology | Chemistry | Life Sciences | Other Chemistry
Abstract
Environmental stress experienced in utero or in early life has profound effects on the behavior and physiology of an adult animal. Interestingly, genome-wide association studies in humans have shown that early-life stress not only affects the exposed individual, but also their future generations. However, the molecular mechanisms of how early-life stress can impact physiology transgenerationally in the absence of the original stress are not well understood. To study the mechanisms and consequences of environmental stress on adult phenotypes, we utilize the life cycle of the model organism Caenorhabditis elegans. In favorable conditions, the life cycle of C. elegans includes 5 stages – larval stages L1, L2, L3, and L4, and the adult stage. However, when worms experience starvation, heat, or crowding (high pheromone levels) in early life, they enter a stress-resistant ‘dauer’ stage. Our lab has previously shown the postdauer adults that transiently passed through the dauer stage due to starvation (postdauers, PDStv) had a significantly smaller brood-size (fewer progeny) than the worms that bypassed the dauer stage (controls, CONStv). In contrast, the postdauer adults that had entered the dauer stage due to crowding (PDPhe) had significantly larger brood-sizes than adults that bypassed the dauer stage (CONPhe). Here, we show that the decreased brood-size phenotype of PDStv worms is inherited for at least four generations, even though the progeny of PDstv animals have not experienced starvation or passed through dauer stage. In contrast, the increased brood-size phenotype of PDPhe is not transgenerational. We also show that the hrde-1 mutants that transiently passed through the dauer stage due to starvation lose the ability to inherit the brood-size phenotype transgenerationally -- only the animals that had experienced starvation directly show the brood-size phenotype similar to that of the wild-type animals. This indicates that HRDE-1, a nuclear Argonaute protein, is required for inheritance of brood-size phenotype transgenerationally.
Recommended Citation
Rafi, Ibnul, "Decreased Brood-Size of Starvation-Induced Postdauer Adults is Inherited Transgenerationally via HRDE-1" (2018). Renée Crown University Honors Thesis Projects - All. 1171.
https://surface.syr.edu/honors_capstone/1171
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This work is licensed under a Creative Commons Attribution 4.0 International License.
