For our molting work on NHR-23, we generated an endogenous GFP::AID::3xFLAG knock-in strain using genome editing. Much to our surprise, we observed NHR-23 expression in L4 germ cell nuclei which had never been reported before. Using the auxin-inducible degron system, we were able to deplete NHR-23 in the germ line and bypass molting defects and lethality caused by nhr-23 mutation or RNAi. This approach revealed that NHR-23 was necessary for spermatogenesis. NHR-23 depletion caused an arrest in prometaphase I and failure to load Major Sperm Protein into sperm-specific membranous organelles (Ragle et al., 2020). We work closely with Diane Shakes' lab at the College of William and Mary on this project. We are now pursuing what genes NHR-23 regulates to promote spermatogenesis. Factors of interest include kinases and phosphatases, as well as a poorly understood group of proteins that regulate the polymerization of Major Sperm protein.
This work is supported by an NSF CAREER award designed to support junior transfer students at UC Santa Cruz through the Developing Researchers, Educators, And Mentors (DREAM) program. I have developed a peer-led program designed to annually recruit four junior transfer students into my lab (the DREAM team) to conduct a year-long research program. These students will serve as mentors and tutors to incoming junior transfer students the following academic year. The goal is to help transfer student acclimatize and build community and STEM identity.