File:Mouse- X-linked gene expression in primordial germ cells.jpg

Expression Patterns of X-Linked Genes in Mouse Primordial Germ Cells at Each Stage

A schematic shows the transition of gene expression patterns during PGC development. Each circle graph indicates the ratio of cells that are positive (yellow) and negative (black) for each gene, and biallelically (red) and monoallelically (blue) expressed in cells positive for each gene.

"X chromosome inactivation is a mechanism to compensate gene dosage difference between XY males and XX females in mammals. During early embryogenesis, one of two X chromosomes in every female cell is inactivated, and the inactive X chromosome is stably inherited through cell divisions of somatic cells. Although precise timing is not given, the inactive X chromosome is known to be reactivated during germ cell development. It is generally believed that the dynamics of X chromosome activity is tightly correlated with major genomic reprogramming events occurring during mammalian development. Therefore, elucidation of the X reactivation kinetics is important for understanding the mechanism of X chromosome inactivation/reactivation processes and the epigenetic reprogramming processes as well. Here we investigated when X reactivation is initiated during development of female mouse germ cells. Contrary to the previous suggestions, X reactivation already begins in nascent primordial germ cells in female mice and proceeds gradually requiring a prolonged period. The activity status of the X chromosomes of germ cells appears to vary from cell-to-cell and from gene-to-gene during the reactivation processes. These results indicate that the X reactivation coincides with the formation of germ cells and suggest that this involves slow passive steps."

Original file name: Figure 3. Journal.pgen.0030116.g003.jpg http://www.plosgenetics.org/article/slideshow.action?uri=info:doi/10.1371/journal.pgen.0030116&imageURI=info:doi/10.1371/journal.pgen.0030116.g003

Reference

<pubmed>17676999</pubmed>| PMC1950944 | PLoS Genet.

Copyright: © 2007 Sugimoto and Abe. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.