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The role of inducible nitric oxide synthase in gamete interaction and fertilization: A comparative study on knockout mice of three NOS isoforms
Author(s) -
Yang Jian Zhi,
Ajonuma Louis Chukwuemeka,
Rowlands Dewi Kenneth,
Tsang Lai Ling,
Ho Lok Sze,
Lam Sun Yee,
Chen Wen Yin,
Zhou Chen Xi,
Chung Yiu Wa,
Cho Cheuk Yin,
Tse John Yeuk Hoi,
James Anthony Edward,
Chan Hsiao Chang
Publication year - 2005
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1016/j.cellbi.2005.05.005
Subject(s) - nitric oxide synthase , gene isoform , knockout mouse , gamete , nitric oxide , microbiology and biotechnology , chemistry , human fertilization , biology , biochemistry , genetics , endocrinology , gene
Nitric oxide (NO), which is produced from l ‐arginine by three isoforms of NO synthase (NOS), has been implicated in reproductive functions. However, the specific role of NOS isoforms in gamete function and fertilization is not clear. Three types of NOS knockout mice were super ovulated and fertilized in vitro and in vivo. The sperm count and motility, in vivo and in vitro fertilization rate as indicated by two‐cell embryos and blastocyst rate were examined. The sperm count and motility from all three knockout mice were not significantly different from that of the wild type. Inducible NOS (iNOS) knockout mice were found to have the largest number of two‐cell embryos/mouse collected after fertilization in vivo ( P < 0.01), but the rate of blastocyst formation from two‐cell embryos in vitro was similar for all three knockouts. The rate of in vitro fertilization using either iNOS‐deficient sperm or oocytes, but not those deficient in the other two NOS isoforms, was significantly elevated when compared to that in the wild type ( P < 0.001). While all three types of NOS do not seem to play a significant role in pre‐ejaculated sperm function, iNOS may play an inhibitory role in sperm and oocyte functions affecting the process of fertilization and early embryo development.