Chromosome-wide profiling of X-inactivation status and epigenetic regulation in fetal brain

ABSTRACT: Evidence from a few genes of diverse species suggests that marsupial X-chromosome inactivation (XCI) is characterized by exclusive, but leaky, inactivation of the paternally derived X chromosome. To comprehensively study the mechanism of marsupial XCI, we profiled parent-of-origin-specific-allele expression, DNA methylation, and histone modifications in opossum fetal brain and extra-embryonic membranes. The majority (152/176) of X-linked genes exhibited paternally imprinted expression with nearly 100% maternal allele expression, whereas 24 loci (14%) escaped inactivation showing varying levels of biallelic expression. In addition to regulation by the non-coding RSX transcript, strong depletion of H3K27me3 at escaper gene loci indicates that histone states also influence opossum XCI. Notably, the opossum does not show an association between X-linked gene expression and promoter DNA methylation. Our study provides the first comprehensive catalogue of parent-of-origin expression status for X-linked genes in a marsupial and sheds light on the regulation and evolution of imprinted XCI in mammals.

ORGANISM(S): Monodelphis domestica

PROVIDER: GSE45186 | GEO | 2013/09/23

SECONDARY ACCESSION(S): PRJNA193185

REPOSITORIES: GEO