PDF(Pubmed)
Abstract：
Heteromorphic sex chromosomes (XY or ZW) present problems of gene dosage imbalance between sexes and with autosomes. A need for dosage compensation has long been thought to be critical in vertebrates. However, this was questioned by findings of unequal mRNA abundance measurements in monotreme mammals and birds. Here, we demonstrate unbalanced mRNA levels of X genes in platypus males and females and a correlation with differential loading of histone modifications. We also observed unbalanced transcripts of Z genes in chicken. Surprisingly, however, we found that protein abundance ratios were 1:1 between the sexes in both species, indicating a post-transcriptional layer of dosage compensation. We conclude that sex chromosome output is maintained in chicken and platypus (and perhaps many other non therian vertebrates) via a combination of transcriptional and post-transcriptional control, consistent with a critical importance of sex chromosome dosage compensation.
摘要：
异形性染色体（XY或ZW）存在性别之间和常染色体之间基因剂量失衡的问题。对于剂量补偿的需要一直被认为在脊椎动物中是关键的。然而,在单类哺乳动物和鸟类中mRNA丰度测量不相等的发现对此提出了质疑。这里,我们证明了鸭嘴兽雄性和雌性中X基因的mRNA水平不平衡，并且与组蛋白修饰的差异负荷相关。我们还观察到鸡中Z基因的不平衡转录本。令人惊讶的是,然而,我们发现两个物种的性别之间的蛋白质丰度比为1:1，表明剂量补偿的转录后层。我们得出的结论是，通过转录和转录后控制的组合，在鸡和鸭嘴兽（以及许多其他非脊椎动物）中保持性染色体输出。与性染色体剂量补偿的关键重要性一致。
