Choosing the Active X: The Human Version of X Inactivation

Publication date: Available online 5 October 2017 Source:Trends in Genetics Author(s): Barbara R. Migeon Humans and rodents differ in how they carry out X inactivation (XI), the mammalian method to compensate for the different number of X chromosomes in males and females. Evolutionary changes in staging embryogenesis and in mutations within the XI center alter the process among mammals. The mouse model of XI is predicated on X counting and subsequently choosing the X to ‘inactivate’. However, new evidence suggests that humans initiate XI by protecting one X in both sexes from inactivation by XIST, the noncoding RNA that silences the inactive X. This opinion article explores the question of how the active X is protected from silencing by its own Xist locus, and the possibility of different solutions for mouse and human.

Source: Trends in Genetics - November 8, 2017 Category: Genetics & Stem Cells Source Type: research