In vivo parthenogenetic activation of ovulated oocytes in a marsupial, Sminthopsis crassicaudata

Abstract

SummaryThe occurrence of in vivo parthenogenesis is documented for laboratory-bred individuals of the Australian dasyurid marsupial, Sminthopsis crassicaudata. About 30% of females that had been isolated from males for a greater period of time than the length of pregnancy were found, on dissection of their uteri, to have embryos present. The embryos were surrounded by a mucoid coat and shell membrane and at least the first two cleavage divisions occurred normally. After this time, however, unequal cleavage divisions appeared to result. The parthenogenesis that takes place may be initiated as a result of activation of ageing ovulated oocytes. Its frequent occurrence may prove useful in a study of maternal and paternal contributions to early embryonic development in this species.