X-chromosome inactivation in extra-embryonic membranes of diploid parthenogenetic mouse embryos demonstrated by differential staining

Abstract

X chromosome activity in the separated yolk sac layers of diploid parthenogenetic mouse embryos in which both X chromosomes are maternally derived were studied. X inactivation occurs in somatic cells of diploid parthenogenetic embryos. A modification of Kanda''s method, which renders the presumptive inactive X dark staining, reveals an inactive X chromosome in both endoderm and mesoderm layers of separated yolk sacs from parthenogenones. Even in tissues in which there is normally total non-random paternal X inactivation, in the absence of a paternally derived X chromosome a maternally derived X can be inactivated.