Analysis of GLD-1 Protein Turnover in the Germline of Caenorhabditis  elegans

Natalie Stabenow, Biology

Faculty Mentor: Dr. Sudhir Nayak

              The purpose of this summer’s research is to study germline development in the nematode Caenorhabditis elegans (C. elegans).  The two sexes of C. elegans are hermaphrodites and males.  Hermaphrodites produce both sperm and oocytes and can thus self-fertilize, while males produce only sperm and must mate with a hermaphrodite.  We are interested in an RNA binding protein called GLD-1, which stands for defective in Germ Line Development.  This protein is expressed in the germline and is part of a multi-protein complex that controls various aspects of reproduction and cell proliferation in hermaphrodites.  A transgene of green fluorescent protein (GFP) coupled to the GLD-1 coding region allows us to study altered levels of GLD-1 expression under UV light. 

              The focus of my project is to determine how GLD-1 protein levels are regulated in the germline.  A particular area of interest is the mechanism of degradation, which may possibly be by the addition of ubiquitin to GLD-1.  The 26S proteasome, a complex that degrades tagged proteins, would then recognize the ubiquitin and degrade the protein.  In normal worms, degradation of GLD-1 occurs prior to the onset of oocyte development, and the expression of GLD-1 drops after this stage.  However, in worms that have mutations in proteins in the same complex as GLD-1, expression continues past this stage and results in decreased or  no production of offspring.  I have focused on optimizing techniques necessary to study these interactions and modifications this summer, and am preparing to conduct experiments to explore these possibilities. My research will be continued throughout the year as an independent study, and I look forward to collecting data.

Personal Statement

              Summer research with Dr. Nayak in the Summer Undergraduate Research Program has been one of the most valuable experiences I have had.  Guidance from my mentor allowed me to explore my project independently, and strengthened my laboratory skills and knowledge.  The overall atmosphere in the program was very conducive to learning, and professor-student interaction reached a level that is rarely achieved in the classroom.  Several SURP luncheons allowed students from different departments present their research and to interact outside of the labs. Within the biology department, activities such as ultimate frisbee games, berry picking, dinners at professors’ houses, miniature golfing, and trips to the movies all contributed to a friendly environment.  Although we worked very hard on our projects, we also had a great deal of fun.  This experience allowed me to explore research as a career possibility.  I regret not participating in this program earlier in my college career, and given the chance, would apply again in a heartbeat.  It has further renewed my interest in the field of biology, and I look forward to continuing my research in the fall.