Inactivation of the x-chromosome.
D000483:Alleles; D000818:Animals; D002478:Cells, Cultured; D002999:Clone Cells; D005260:Female; D005796:Genes; D006801:Humans; D051379:Mice; D009024:Morphogenesis; D010063:Ovum / Q000166:cytology; D012729:Sex Chromosome Aberrations; D012730:Sex Chromosomes