Mice homozygous for an insertional mutation in the Zp3 gene lack a zona pellucida and are infertile

• DOI: 10.1242/dev.122.9.2903
• Publication Date: 2021-04-23T19:04:09Z
• Authors: Tracy Rankin; Mary Familari; Eric Lee; Ann Ginsberg; Nancy Dwyer; Joan Blanchette-M...; John Drago; Heiner Westphal; Jurrien Dean
• Keywords: Zona pellucida glycoprotein; Germinal vesicle

Mammalian oocytes synthesize and secrete a zona pellucida that surrounds the growing oocytes, ovulated eggs preimplantation embryos. The extracellular matrix is composed of three glycoproteins (ZP1, ZP2, ZP3) are involved in folliculogenesis, species-specific fertilization, passage early embryo down oviduct. We have established mouse line which Zp3 has been inactivated by homologous recombination with an insertional mutation. Neither transcripts nor ZP3 protein was detected female mice homozygous for mutation (Zp3-/-), whereas both ZP1 ZP2 were present mutant oocytes. Homozygous Zp3-/- had follicles germinal-vesicle-intact but lacked disorganized corona radiata. Although underwent germinal vesicle breakdown (GVBD) prior to ovulation, cumulus-oocyte complex markedly disrupted often separate from cumulus cells. After hormone-induced masses oviducts mice, zona-free observed only half females and, these, less than 10% normal number [correction mumber] detected. No 2-cell embryos recovered after mating males proven be fertile, none became visibly pregnant or produced offspring. These results demonstrate genetic defect gene causes infertility given conserved nature pellucida, similar phenotype expected other mammals.