Dosage compensation of Z sex chromosome genes in avian fibroblast cells. Dosage compensation of Z sex chromosome genes in avian fibroblast cells

Sex in birds is genetically determined, molecular mechanism of which is not well-understood. Their Z sex chromosome (chrZ) lacks whole chromosome inactivation as known for mammalian chrX. To investigate the extent of chrZ dosage compensation and its role in somatic cell’s sex specification, we used a highly-quantitative method and analyzed transcriptional activities of male and female fibroblasts from seven birds. Our data indicate for the first time that ¾ of chrZ genes are strictly compensated, similar to that observed in chrX. We also describe non-compensated chrZ genes and identify Ribosomal Protein S6 (RPS6) as a candidate for universal, sex-dimorphic genes in birds. Overall design: Embryonic fibroblast cultures for seven bird species (chicken, quail, turkey, peacock, duck, zebra finch, and emu) obtained from males and females. At least two replicates.

鸟类的性别由遗传因素决定，但其分子机制尚未完全明晰。其Z性染色体（chrZ）并不像哺乳动物的X染色体（chrX）那样存在整条染色体的失活现象。为探究chrZ剂量补偿的程度及其在体细胞性别特化中的作用，我们采用高精度定量分析方法，对7种鸟类的雌雄成纤维细胞的转录活性进行了检测与分析。本研究首次证实，有四分之三的chrZ基因存在严格的剂量补偿效应，这与哺乳动物chrX中观察到的现象高度相似。我们同时描述了未发生剂量补偿的chrZ基因，并将核糖体蛋白S6（Ribosomal Protein S6, RPS6）鉴定为鸟类通用性别二态性基因的候选靶标。
整体实验设计：获取7种鸟类（鸡、鹌鹑、火鸡、孔雀、鸭、斑胸草雀及鸸鹋）的雌雄胚胎成纤维细胞进行体外培养，每组至少设置2个生物学重复。