Co-evolution of X-chromosome inactivation and imprinting in mammals.
Recent studies have revealed mechanistic parallels between imprinted X-chromosome inactivation and autosomal imprinting. We suggest that neither mechanism was present in ancestral egg-laying mammals, and that both arose when the evolution of the placenta exerted selective pressure to imprint growth-related genes. We also propose that non-coding RNAs and histone modifications were adopted for the imprinting of growth suppressors on the X chromosome and on autosomes. This provides a unified hypothesis for the evolution of X-chromosome inactivation and imprinting.
Reik
Wolf
W
Laboratory of Developmental Genetics and Imprinting, The Babraham Institute, Cambridge CB2 4AT, United Kingdom. wolf.reik@bbsrc.ac.uk
Lewis
Annabelle
A
D000818:Animals; D004303:Dosage Compensation, Genetic; D019143:Evolution, Molecular; D018392:Genomic Imprinting; D008322:Mammals / Q000235:genetics; D014960:X Chromosome / Q000235:genetics*