Dynamics of the two heterochromatin types during imprinted X chromosome inactivation in vole Microtus levis

• Published in: PloS one Vol. 9; no. 2; p. e88256
• Main Authors: Vaskova, Evgeniya A, Dementyeva, Elena V, Shevchenko, Alexander I, Pavlova, Sophia V, Grigor'eva, Elena V, Zhelezova, Antonina I, Vandeberg, John L, Zakian, Suren M
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 04.02.2014; Public Library of Science (PLoS)
• Subjects: Animals; Arvicolinae - genetics; Biology; Book publishing; Chromatin; Chromosomes; Deactivation; Embryonic Development - genetics; Embryos; Female; Genetic research; Genomic Imprinting - genetics; Heterochromatin; Heterochromatin - genetics; Histones - genetics; Histones - metabolism; Inactivation; Jeans (Clothing); Mammals; Marsupials; Meiosis; Meiosis - genetics; Microtus levis; Sex chromatin; Sex Chromatin - genetics; Stem Cells - metabolism; Tissues; Trophoblasts - metabolism; X Chromosome - genetics; X Chromosome Inactivation - genetics; X Chromosomes; X-Chromosome inactivation; Y Chromosome - genetics
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0088256

In rodent female mammals, there are two forms of X-inactivation - imprinted and random which take place in extraembryonic and embryonic tissues, respectively. The inactive X-chromosome during random X-inactivation was shown to contain two types of facultative heterochromatin that alternate and do not overlap. However, chromatin structure of the inactive X-chromosome during imprinted X-inactivation, especially at early stages, is still not well understood. In this work, we studied chromatin modifications associated with the inactive X-chromosome at different stages of imprinted X-inactivation in a rodent, Microtus levis. It has been found that imprinted X-inactivation in vole occurs in a species-specific manner in two steps. The inactive X-chromosome at early stages of imprinted X-inactivation is characterized by accumulation of H3K9me3, HP1, H4K20me3, and uH2A, resembling to some extent the pattern of repressive chromatin modifications of meiotic sex chromatin. Later, the inactive X-chromosome recruits trimethylated H3K27 and acquires the two types of heterochromatin associated with random X-inactivation.