Characterizing the role of sperm-supplied proteins SPE-11 and F07A5.2 during spermatogenesis and early development in Caenorhabditis elegans

Abstract

Haploid genomes from sperm and oocytes are required to form a diploid zygote during fertilization. In addition to haploid genomes other components from these specialized cells are essential for the success of both molecular and physiological events from fertilization to embryogenesis. So far spe-11 is the only known sperm-specific gene required for the early events of embryonic development in C. elegans. Embryos fertilized by spe-11 mutant sperm show abnormal meiosis, form a weak eggshell and do not orient the first mitotic spindle correctly. SPE-11 localizes as a fenestrated ring around the DNA in nuclei undergoing spermatogenesis. We have recently identified another sperm protein, F07A5.2, that interacts with SPE-11. I have found that a deletion allele of F07A5.2 reduces embryonic viability in hermaphrodites and that this reduction is rescued when fertilized by wildtype sperm. However, F07A5.2 deletion sperm mated to wild-type females does not result in reduction in embryonic lethality, indicating that F07A5.2 is not behaving as a strict paternal-effect gene. Through the creation of the GFP::F07A5.2 line, we found that F07A5.2 has a similar localization pattern to SPE-11 where proteins appear as a fenestrated ring around the DNA of nuclei during spermatogenesis. It also localizes to non-germline cells. These experiments have helped determine the potential roles of the newly discovered F07A5.2 gene in C. elegans.