Experimental study reveals severe female infertility driven by failed sperm-egg fusion in CD9-deficient mice, indicating CD9 is essential for membrane fusion.
Key Points
Investigate the functional role of the membrane protein CD9 in mammalian fertilization and sperm-egg fusion.
Generated CD9-knockout mice (CD9-/-) via homologous recombination.
Evaluated female fertility mechanisms through in vitro fertilization and assisted microfertilization with direct intracytoplasmic sperm injection.
CD9-deficient mice were viable and healthy, but CD9-/- females exhibited severe infertility with litter sizes less than 2% of wild-type controls.
In vitro fertilization assays demonstrated that the reproductive failure in CD9-/- oocytes occurred specifically at the sperm-egg fusion stage.
Assisted microfertilization bypassed the fusion defect, enabling fertilized CD9-/- oocytes to successfully develop to full term.