Early development and X-chromosome inactivation in mouse parthenogenetic embryos.
Early development and X-chromosome inactivation were studied in ethanol-induced mouse parthenogenones. About 24% of oocytes transferred to 0.5-day pseudopregnant recipients successfully implanted. However, only 49%, 20%, and 16% of implanted parthenogenones survived 5, 6, and 7 days later, respectively. Abnormal development was evident in every parthenogenone as early as 5 days after activation with the degenerating polar trophectoderm. These embryos were destined to become either small disorganized embryos or embryonic ectoderm vesicles bounded by the visceral endoderm. Only 2 of 51 representative 6- to 8-day parthenogenones sectioned had morphology of the normal egg cylinder, although growth retardation was evident. Spontaneous LT/Sv parthenogenones shared similar morphological features. In late blastocysts, the frequency of cells with an apparently inactivated X chromosome was lower in parthenogenones than in fertilized embryos. The failure of X-inactivation in the trophectoderm seems to contribute to the defective development of parthenogenones.
Tada
T
T
Research Center for Molecular Genetics, Hokkaido University, Sapporo, Japan.
Takagi
N
N
D000818:Animals; D002454:Cell Differentiation; D004171:Diploidy; D004303:Dosage Compensation, Genetic; D004624:Embryo Transfer; D000431:Ethanol / Q000494:pharmacology; D005260:Female; D008297:Male; D051379:Mice; D010312:Parthenogenesis; D011247:Pregnancy
D000431:Ethanol