Analysis of sperm molecules needed for ferilization in C. elegans

Fertilization is the biological process through which life is propagated and genetic variation is generated. Its importance to sexually reproducing species is unrivaled, but we are far from obtaining a complete understanding of how this process occurs. This thesis is a study of sperm molecules involved in Caenorhabditis elegans fertilization with the ultimate goal of elucidating and understanding the function of fertilization molecules across species. The first chapter provides an introduction to the field of fertilization, a brief overview of what is currently known, and it concludes with the use and advantages of using C. elegans as a model system to study fertilization. The second chapter describes a method that utilizes single nucleotide polymorphisms (SNPs) to streamline the initial genetic mapping of newly isolated mutants. An example of this method for linkage mapping is provided, and I compare and contrast this method to traditional and other SNP approaches. The third chapter describes the phenotypic characterization and initial mapping of the as28 mutation resulting in a temperature sensitive sterility in C. elegans. The mutation causes a sperm activation defect causing abnormal spermatid morphology. Mapping of this mutant strain revealed that the observed phenotype is the result of two mutations, which has complicated characterization of this mutant phenotype. The fourth chapter describes the cloning of spe-13. Mutations in spe-13 result in worms that produce morphologically and physiologically normal spermatids that mature into spermatozoa that are unable to fertilize oocytes. The identification of spe-13 has proved to be difficult with traditional mapping techniques due to its chromosomal position. Using whole genome sequencing, we identified spe-13 candidate genes in an effort to clone this elusive gene. In the final chapter, I summarize and discuss future directions for each project that has been described in this thesis work.M.S.Includes bibliographical references (p. 58-65)by Julie S. Han