X chromosome inactivation: when dosage counts.
How do mammals count their X chromosomes and keep only one X active per cell? In this issue, Jonkers et al. (2009) show that Rnf12/RLIM, encoded by the X-linked gene Rnf12, induces X chromosome inactivation only when present above a certain threshold, a condition fulfilled when at least two Xs are active.
Nora
Elphège P
EP
Institut Curie, CNRS UMR3215, INSERM U934, 75724 Paris Cedex 05, France.
Heard
Edith
E
D000818:Animals; D018628:Gene Dosage; D050172:Genes, X-Linked; D006801:Humans; D012097:Repressor Proteins / Q000378:metabolism; D014960:X Chromosome / Q000378:metabolism*; D049951:X Chromosome Inactivation
D012097:Repressor Proteins