Discipline: Biological Sciences
Subcategory: Cell and Molecular Biology
Tre Landry - University of Georgia
Co-Author(s): Diana Chu, Vanessa Cota, and Luis Quintinilla, San Francisco State University
Meiosis is a type of cell division that produces four genetically dissimilar haploid cells, either sperm or oocytes. Errors in meiosis can result in aneuploidy, which is when a cell has an abnormal number of chromosomes causing birth defects. It is important to acquire an understanding of factors that have roles in regulating meiosis to develop diagnostic and treatment options. My project focuses on factors that control sperm meiosis. In sperm, microtubules aid in chromosome congression and segregation with the help of many proteins. These proteins’ roles and localization patterns are expected to be regulated by the sperm-specific PP1 phosphatases GSP-3 and GSP-4. Immunostaining revealed that these phosphatases localize to chromosomes during segregation. In their absence, defects in division were observed. Segregation defects led us to investigate two motor proteins that move chromosomes: KLP-19 and dynein. KLP-19 localizes at the mid-region of chromosomes and provides a force that pushes them towards the opposite poles. Dynein localizes at the outer face of chromosomes and provides a force that moves chromosomes along microtubules. The localization and roles described previously have been found in oocyte meiosis but not confirmed in sperm. To determine their localization in sperm, immunostaining of both motor proteins using the model organism C. elegans will be done in wildtype and gsp-3/4 mutant strains. We suspect that KLP-19 and dynein are regulated by GSP-3/4 and knockdown of gsp-3/4 will result in mislocalization of these target motor proteins and loss of their function. Through my experiment, I found that dynein localizes similarly in gsp-3/4 mutants as they do in wildtype, possibly suggesting they are not regulated by GSP-3/4. Future experiments utilizing live-imaging or co-immunoprecipitation would provide more information on whether these proteins interact or not.
Funder Acknowledgement(s): NSF RUI (1244517); NSF CAREER (0747515)
Faculty Advisor: Diana Chu, firstname.lastname@example.org
Role: My role in this experiment was to observe the effects of gsp-3/4 mutants on dynein. I maintained the wildtype and mutant strain for my experiments, carried out the immunostaining, and obtained images using confocal microscopy.