tailieunhanh - Báo cáo y học: "Regional differences in dosage compensation on the chicken Z chromosome"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài:Regional differences in dosage compensation on the chicken Z chromosome. | Open Access Research Regional differences in dosage compensation on the chicken Z chromosome Esther Melamed and Arthur P Arnold Address Department of Physiological Science and Laboratory of Neuroendocrinology of the Brain Research Institute University of California Los Angeles CA 90095-1606 USA. Correspondence Arthur P Arnold. Email arnold@ Published 27 September 2007 Genome Biology 2007 8 R202 doi gb-2007-8-9-r202 The electronic version of this article is the complete one and can be found online at http 2007 8 9 R202 Received 31 May 2007 Revised 19 September 2007 Accepted 27 September 2007 2007 Melamed and Arnold licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Most Z chromosome genes in birds are expressed at a higher level in ZZ males than in ZW females and thus are relatively ineffectively dosage compensated. Some Z genes are compensated however by an unknown mechanism. Previous studies identified a non-coding RNA in the male hypermethylated MHM region associated with sex-specific histone acetylation which has been proposed to be involved in dosage compensation. Results Using microarray mRNA expression analysis we find that dosage compensated and noncompensated genes occur across the Z chromosome but a cluster of compensated genes are found in the MHM region of chicken chromosome Zp whereas Zq is enriched in non-compensated genes. The degree of dosage compensation among Z genes is predicted better by the level of expression of Z genes in males than in females probably because of better compensation of genes with lower levels of expression. Compensated genes have different functional properties than noncompensated genes suggesting that dosage compensation has evolved .