摘要
In the evolutionary model of dosage compensation,per-allele expression level of the X chromosome has been proposed to have twofold up-regulation to compensate its dose reduction in males(XY)compared to females(XX).However,the expression regulation of X-linked genes is still controversial,and comprehensive evaluations are still lacking.By integrating multi-omics datasets in mammals,we investigated the expression ratios including X to autosomes(X:AA ratio)and X to orthologs(X:XX ratio)at the transcriptome,translatome,and proteome levels.We revealed a dynamic spatial-temporal X:AA ratio during development in humans and mice.Meanwhile,by tracing the evolution of orthologous gene expression in chickens,platypuses,and opossums,we found a stable expression ratio of X-linked genes in humans to their autosomal orthologs in other species(X:XX1)across tissues and developmental stages,demonstrating stable dosage compensation in mammals.We also found that different epigenetic regulations contributed to the high tissue specificity and stage specificity of X-linked gene expression,thus affecting X:AA ratios.It could be concluded that the dynamics of X:AA ratios were attributed to the different gene contents and expression preferences of the X chromosome,rather than the stable dosage compensation.
基金
supported by the National Natural Science Foundation of China(Grant No.31871305)
the Opening Foundation of State Key Laboratory of Freshwater Ecology and Biotechnology,China(Grant No.2020FB08)
the Fundamental Research Funds for the Central Universities,China(Grant Nos.2662018PY021 and 2662019PY003)
the Huazhong Agricultural University Scientific&Technological Self-innovation Foundation,China(Grant No.2016RC011).