Tetraspanin CD9 in bovine oocytes and its role in fertilization.
This study was conducted in bovine to investigate whether CD9 (a member of the tetraspanin superfamily of proteins) is present on oocytes and whether it functions in sperm-oocyte binding and fusion. First, the presence of CD9 in bovine matured oocytes was examined by immunofluorescence with the anti-CD9 monoclonal antibody (mAb) and fluorescein isothiocyanate-conjugated goat anti-mouse antibody, and the results showed that CD9 was expressed on the plasma membrane of matured oocytes. Sperm binding and fusion with oocytes was then examined by in vitro fertilization. When the zona pellucida-free matured oocytes were fertilized, both sperm binding to ooplasma and sperm penetrating into oocytes were significantly (P<0.01) reduced in anti-CD9 antibody-treated oocytes (6.3 +/- 0.7 per oocyte and 41.6%, respectively) compared with untreated control oocytes (19.0 +/- 0.7 per oocyte and 81.3%, respectively), indicating that the anti-CD9 mAb potentially inhibits sperm-oocyte binding and fusion. These results demonstrated that the CD9 present on bovine matured oocytes is involved in sperm-oocyte interaction during fertilization.
Zhou
Guang-Bin
GB
College of Animal Science and Technology and State Key Laboratory for Agrobiotechnology, China Agricultural University.
Liu
Guo-Shi
GS
Meng
Qing-Gang
QG
Liu
Ying
Y
Hou
Yun-Peng
YP
Wang
Xiao-Xu
XX
Li
Ning
N
Zhu
Shi-En
SE
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism* / Q000502:physiology*; D002417:Cattle; D002478:Cells, Cultured; D005260:Female; D005306:Fertilization / Q000502:physiology*; D005307:Fertilization in Vitro; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism* / Q000502:physiology*; D009865:Oocytes / Q000378:metabolism* / Q000502:physiology; D013084:Sperm-Ovum Interactions / Q000502:physiology; D060245:Tetraspanin 29
D015703:Antigens, CD; C554870:Cd9 protein, mouse; D008562:Membrane Glycoproteins; D060245:Tetraspanin 29