X-inactivation: it takes two to count.
Mammals balance X-linked gene dosage by silencing one X chromosome in female cells, a process that begins with counting the number of X chromosomes. Recent reports suggest homologous X chromosome pairing may be a prerequisite for silencing, providing a basis for counting by ensuring that silencing only occurs in cells with two X chromosomes.
Royce-Tolland
Morgan
M
Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158, USA.
Panning
Barbara
B
D000818:Animals; D005260:Female; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics; D014960:X Chromosome / Q000235:genetics / Q000378:metabolism*; D049951:X Chromosome Inactivation / Q000502:physiology*
D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; C465658:Tsix transcript, mouse