Date of Award

Summer 2020

Document Type


Degree Name

Master of Science (MS)


Biological Sciences

First Advisor

Petrella, Lisa1 N

Second Advisor

Abbott, Allison

Third Advisor

Manogaran, Anita


Organisms are subjected to environments that can fluctuate and cause them stress. Therefore, organisms must have the ability to adapt to the stress to survive and propagate. Temperature stress is becoming an increasingly relevant type of stress due to climate change and is known to affect fertility in many types of organisms including the model organism Caenorhabditis elegans. Here we examine the role of LIN-35, the single C. elegans homolog of the tumor suppressor Retinoblastoma (pRB), in fertility under moderate temperature stress. We found that lin-35 mutants lose fertility more drastically under moderate temperature stress than wildtype worms, and that this loss of fertility is dependent on both somatic and germline expression of LIN-35. A common cellular response to stress is programmed cell death via apoptosis. In C. elegans, the only adult tissue that exhibits apoptosis is the germline and while germline apoptosis eliminates ~50% of all oogenic germ cell nuclei during normal oogenesis, the induction of higher levels of germline apoptosis appears to be a general response to stressful conditions. LIN-35 was previously shown to be important for germline apoptosis but because it cannot bind to DNA by itself it must work with other partners to regulate genes. A group of proteins LIN-35 works with in some contexts is the DREAM complex, a conserved multi-subunit transcriptional repressor complex. We found that there is an induction of germline apoptosis under moderate temperature stress and that LIN-35 and the DREAM complex are important for this induction. The DREAM complex and LIN-35 are also important for DNA damage induced apoptosis. Together this indicates a general role for LIN-35 and the DREAM complex in the induction of germline apoptosis in response to stress. This role in germline apoptosis may be the role in the germline that LIN-35 has that helps it to preserve fertility.

Included in

Biology Commons