title: Transgenic RNAi-mediated reduction of MSY2 in mouse oocytes results in reduced fertility.
abstract: MSY2 is implicated in regulating the stability and translation of maternal mRNAs during mouse oogenesis. We report here that by driving the expression of a transgene encoding an Msy2 hairpin dsRNA in growing oocytes using the oocyte-specific Zp3 promoter, the amount of MSY2 protein was reduced by at least 60% in fully grown oocytes. The decrease appeared specific because no decrease was observed in either non-targeted mRNAs or proteins. Fertility of transgenic females was severely reduced. Although transgenic eggs could be inseminated, the eggs did not exhibit the normal series of oscillations in intracellular Ca2+, resume meiosis, undergo cortical granule exocytosis, or ZP2 cleavage to ZP2f. Transgenic oocytes also displayed a higher incidence of both the non-surrounded nucleolus chromatin morphology, and abnormal meiotic spindle formation was observed following oocyte maturation. Transgenic oocytes contained less total mRNA (approximately 75-80% that of non-transgenic oocytes) and displayed a reduced level of protein synthesis. Moreover, several of the maturation-associated changes in protein synthesis failed to occur in the transgenic oocytes. These results support a role for MSY2 in stabilizing maternal mRNAs in growing oocytes, a process essential to generate meiotically and developmentally competent oocytes.
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, PA 19104-6018, USA.
authors.forename: Junying
authors.initials: J
authors.lastname: Yu
authors.forename: Manqi
authors.initials: M
authors.lastname: Deng
authors.forename: Sergey
authors.initials: S
authors.lastname: Medvedev
authors.forename: Juxiang
authors.initials: J
authors.lastname: Yang
authors.forename: Norman B
authors.initials: NB
authors.lastname: Hecht
authors.forename: Richard M
authors.initials: RM
authors.lastname: Schultz
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D005260:Female; D005298:Fertility / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009865:Oocytes / Q000378:metabolism*; D016372:RNA, Antisense / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D017931:DNA Primers; D016372:RNA, Antisense; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; C116047:Ybx2 protein, mouse