'Escaping' the X chromosome leads to increased gene expression in the male germline of Drosophila melanogaster

Genomic analyses of Drosophila species suggest that the X chromosome presents an unfavourable environment for the expression of genes in the male germline. A previous study in D. melanogaster used a reporter gene driven by a testis-specific promoter to show that expression was greatly reduced when the gene was inserted onto the X chromosome as compared with the autosomes. However, a limitation of this study was that only the expression regulated by a single, autosomal-derived promoter was investigated. To test for an increase in expression associated with ‘escaping’ the X chromosome, we analysed reporter gene expression driven by the promoters of three X-linked, testis-expressed genes (CG10920, CG12681 and CG1314) that were inserted randomly throughout the D. melanogaster genome. In all cases, insertions on the autosomes showed significantly higher expression than those on the X chromosome. Thus, even genes whose regulation has adapted to the X-chromosomal environment show increased mal...

对果蝇物种的基因组分析显示，X染色体对于雄性生殖系中的基因表达并非适宜环境。此前一项针对黑腹果蝇（D. melanogaster）的研究，借助睾丸特异性启动子驱动的报告基因（reporter gene），证实当该基因插入X染色体时，其表达水平相较于常染色体显著降低。但该研究存在一处局限：仅探究了单一常染色体来源启动子所调控的基因表达。为验证与‘逃逸’X染色体相关的表达上调现象，我们分析了由三个X连锁（X-linked）睾丸表达基因（CG10920、CG12681与CG1314）的启动子驱动的报告基因表达情况，这些报告基因被随机插入黑腹果蝇基因组的各处位点。所有实验均显示，常染色体上的插入片段的表达水平显著高于X染色体上的插入片段。因此，即便那些调控机制已适应X染色体环境的基因，其表达也会在...