The male pronucleus was formed before releasing of the second polar body,and then the female pronucleus occurred quickly,the female and male pronuclei becoming together in the ovum center.

Studies on artificial induction of haploid gynogenesis in oyster Crassostrea hongkongensis;

The early embryonic development and the cytological observation of gynogenesis in sea urchin Hemicentrotus pulcherrimus artificially induced;

Identification of F_1 progeny of gynogenesis in common carp by RAPD analysis;