@article {564061,
	title = {Postmeiotic sex chromatin in the male germline of mice.},
	journal = {Curr Biol},
	volume = {16},
	number = {7},
	year = {2006},
	month = {2006 Apr 4},
	pages = {660-7},
	abstract = {
	In mammals, the X and Y chromosomes are subject to meiotic sex chromosome inactivation (MSCI) during prophase I in the male germline, but their status thereafter is currently unclear. An abundance of X-linked spermatogenesis genes has spawned the view that the X must be active . On the other hand, the idea that the imprinted paternal X of the early embryo may be preinactivated by MSCI suggests that silencing may persist longer . To clarify this issue, we establish a comprehensive X-expression profile during mouse spermatogenesis. Here, we discover that the X and Y occupy a novel compartment in the postmeiotic spermatid and adopt a non-Rabl configuration. We demonstrate that this postmeiotic sex chromatin (PMSC) persists throughout spermiogenesis into mature sperm and exhibits epigenetic similarity to the XY body. In the spermatid, 87\% of X-linked genes remain suppressed postmeiotically, while autosomes are largely active. We conclude that chromosome-wide X silencing continues from meiosis to the end of spermiogenesis, and we discuss implications for proposed mechanisms of imprinted X-inactivation.

},
	keywords = {Animals, Chromatin, Chromosome Positioning, Male, Meiosis, Mice, Oligonucleotide Array Sequence Analysis, Spermatids, Spermatogenesis, Spermatozoa, X Chromosome, X Chromosome Inactivation, Y Chromosome},
	issn = {0960-9822},
	doi = {10.1016/j.cub.2006.01.066},
	author = {Namekawa, Satoshi H and <b>Park, Peter J</b> and Zhang, Li-Feng and Shima, James E and McCarrey, John R and Griswold, Michael D and Lee, Jeannie T}
}
