Oocyte-specific deletion of complex and hybrid N-glycans leads to defects in preovulatory follicle and cumulus mass development
- 1 February 2009
- journal article
- research article
- Published by Bioscientifica in Reproduction
- Vol. 137 (2), 321-331
- https://doi.org/10.1530/rep-07-0469
Abstract
Complex and hybridN-glycans generated byN-acetylglucosaminyltransferase I (GlcNAcT-I), encoded byMgat1, affect the functions of glycoproteins. We have previously shown that females with oocyte-specific deletion of a floxedMgat1gene using a zona pellucida protein 3 (ZP3)Cretransgene produce fewer pups primarily due to a reduction in ovulation rate. Here, we show that the ovulation rate of mutant females is decreased due to aberrant development of preovulatory follicles. After a superovulatory regime of 48 h pregnant mare's serum (PMSG) and 9 h human chorionic gonadotropin (hCG), mutant ovaries weighed less and contained ∼60% fewer preovulatory follicles and more atretic and abnormal follicles than controls. Unlike controls, a proportion of mutant follicles underwent premature luteinization. In addition, mutant preovulatory oocytes exhibited gross abnormalities with ∼36% being blebbed or zona-free. While 97% of wild-type oocytes had a perivitelline space at the preovulatory stage, ∼54% of mutant oocytes did not. The cumulus mass surrounding mutant oocytes was also smaller with a decreased number of proliferating cells compared with controls, although hyaluronan around mutant oocytes was similar to controls. In addition, cumulus cells surrounding mutant eggs were resistant to removal by either hyaluronidase or incubation with capacitated sperm. Therefore, the absence of complex and hybridN-glycans on oocyte glycoproteins leads to abnormal folliculogenesis resulting in a decreased ovulation rate.Keywords
This publication has 36 references indexed in Scilit:
- Sperm surface arylsulfatase A can disperse the cumulus matrix of cumulus oocyte complexesJournal of Cellular Physiology, 2007
- Fertilization in mouse does not require terminal galactose or N-acetylglucosamine on the zona pellucida glycansJournal of Cell Science, 2007
- Hyalp1 in Murine Sperm Function: Evidence for Unique and Overlapping Functions With Other Reproductive HyaluronidasesJournal of Andrology, 2007
- Mouse testicular hyaluronidase-like proteins SPAM1 and HYAL5 but not HYALP1 degrade hyaluronanBiochemical Journal, 2006
- Inactivation of the Mgat1 Gene in Oocytes Impairs Oogenesis, but Embryos Lacking Complex and Hybrid N-Glycans Develop and ImplantMolecular and Cellular Biology, 2004
- Selective assembly of connexin37 into heterocellular gap junctions at the oocyte/granulosa cell interfaceJournal of Cell Science, 2004
- Cellular and molecular mechanisms leading to cortical reaction and polyspermy block in mammalian eggsMicroscopy Research and Technique, 2003
- Perivitelline space: Does it play a role in blocking polyspermy in mammals?Microscopy Research and Technique, 2003
- Intercellular Communication in the Mammalian Ovary: Oocytes Carry the ConversationScience, 2002
- Mutant female mice carrying a singlemZP3allele produce eggs with a thin zona pellucida, but reproduce normallyProceedings. Biological sciences, 1997