Genetic conflict and evolution of mammalian X‐chromosome inactivation

The existence of parentally imprinted gene expression in the somatic tissues of mammals and plants can be explained by a theory of intragenomic genetic conflict, which is a logical extension of classical parent‐offspring conflict theory. This theory unites conceptually the phenomena of autosomal imprinting and X‐chromosome inactivation. We argue that recent experimental studies of X‐chromosome inactivation and andro‐genetic development address previously published predictions of the conflict theory, and we discuss possible explanations for the occurrence of random X‐inactivation in the somatic tissues of eutherians. © 1995 Wiley‐Liss, Inc.