The ubiquitin-conjugating enzyme HR6B is required for maintenance of X chromosome silencing in mouse spermatocytes and spermatids

BMC Genomics

Research Article

Marja Ooms¹  Willy M Baarends²  J Anton Grootegoed²  Esther Sleddens-Linkels²  Jos W Hoogerbrugge²  Eskeatnaf Mulugeta Achame²  Evelyne Wassenaar²  Wilfred FJ van IJcken³  Zu-Wen Sun⁴ 

[1] Department of Biochemistry and Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, USA;Department of Reproduction and Development Erasmus MC, Rotterdam, The Netherlands;Erasmus Center for Biomics, Erasmus MC, Rotterdam, The Netherlands;null;

关键词: Meiotic Prophase;    Round Spermatid;    Average Expression Level;    Pachytene Spermatocyte;    Centromeric Chromatin;   

DOI  :  10.1186/1471-2164-11-367

 received in 2010-03-03, accepted in 2010-06-10,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe ubiquitin-conjugating enzyme HR6B is required for spermatogenesis in mouse. Loss of HR6B results in aberrant histone modification patterns on the trancriptionally silenced X and Y chromosomes (XY body) and on centromeric chromatin in meiotic prophase. We studied the relationship between these chromatin modifications and their effects on global gene expression patterns, in spermatocytes and spermatids.ResultsHR6B is enriched on the XY body and on centromeric regions in pachytene spermatocytes. Global gene expression analyses revealed that spermatid-specific single- and multicopy X-linked genes are prematurely expressed in Hr6b knockout spermatocytes. Very few other differences in gene expression were observed in these cells, except for upregulation of major satellite repeat transcription. In contrast, in Hr6b knockout spermatids, 7298 genes were differentially expressed; 65% of these genes was downregulated, but we observed a global upregulation of gene transcription from the X chromosome. In wild type spermatids, approximately 20% of the single-copy X-linked genes reach an average expression level that is similar to the average expression from autosomes.ConclusionsSpermatids maintain an enrichment of repressive chromatin marks on the X chromosome, originating from meiotic prophase, but this does not interfere with transcription of the single-copy X-linked genes that are reactivated or specifically activated in spermatids. HR6B represses major satellite repeat transcription in spermatocytes, and functions in the maintenance of X chromosome silencing in spermatocytes and spermatids. It is discussed that these functions involve modification of chromatin structure, possibly including H2B ubiquitylation.

【 授权许可】

Unknown   
© Achame et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.