title: Sperm postacrosomal WW domain-binding protein is not required for mouse egg activation.
abstract: To begin embryonic development, the zygote must resume the cell cycle correctly after stimulation by sperm-borne oocyte-activating factors (SOAFs). The postacrosomal WW domain-binding protein (PAWP) is one of the strongest SOAF candidates and is widely conserved among eutherian mammals. It has been reported that the microinjection of recombinant PAWP protein can trigger not only Ca(2+) oscillations in mammalian eggs but also intracellular Ca(2+) release in amphibian eggs. It was also suggested that PAWP is involved in the formation of high-quality spermatozoa. On the other hand, negligible SOAF activity for PAWP cRNA has also been reported. In this study, we generated PAWP null mice and examined the fertilizing ability of male mice. Electron microscopy showed no aberrant morphology in spermatogenesis. Intracytoplasmic injection of a single spermatozoon from the null mouse line showed that depletion of PAWP elicited no quantitative differences in Ca(2+) oscillations or in subsequent development of the embryos. We conclude that PAWP does not play an essential role in mouse fertilization.
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Yuhkoh
authors.initials: Y
authors.lastname: Satouh
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka, Japan Graduate School of Medicine, Osaka University, Osaka, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Nozawa
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka, Japan Graduate School of Medicine, Osaka University, Osaka, Japan School of Pharmaceutical Sciences, Osaka University, Osaka, Japan ikawa@biken.osaka-u.ac.jp.
authors.forename: Masahito
authors.initials: M
authors.lastname: Ikawa
mesh_terms: D000177:Acrosome / Q000378:metabolism*; D000818:Animals; D020013:Calcium Signaling / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics* / Q000502:physiology*; D005260:Female; D005306:Fertilization; D008297:Male; D008540:Meiosis / Q000187:drug effects; D051379:Mice; D018345:Mice, Knockout; D009865:Oocytes / Q000378:metabolism; D010063:Ovum / Q000502:physiology*; D011247:Pregnancy; D029589:Seminal Plasma Proteins / Q000235:genetics* / Q000502:physiology*; D020554:Sperm Injections, Intracytoplasmic; D013091:Spermatogenesis; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; C519841:PAWP protein, mouse; D029589:Seminal Plasma Proteins
keywords: Ca2+; acrosome; fertilization; meiotic arrest; spermatogenesis