Diploid and haploid mouse parthenogenetic development following in vitro activation and embryo transfer

Parthenogenetic mouse embryos were selected following in vitro activation, and transferred to the oviducts of pseudopregnant recipients. Decidua was evoked by 50–56 % of diploid parthenogenones compared to 35·1 % of haploid embryos with a single pronucleus, 37·5 % of immediate cleavage eggs and 77 % of fertilized eggs (controls). On day 4, 58·7 % of diploid parthenogenones were morphologically normal morulae or blastocysts; over 90 % of these ‘normal’ embryos evoked decidua when retransferred to recipients compared to 8·9 % of abnormal embryos flushed from the ‘transfer’ sides, suggesting that only ‘normal’ embryos could evoke decidua. Potentially diploid parthenogenones remained diploid on chromosomal examination on day 4.