Department of Biochemistry and Molecular Biology, University of Texas M. D. Anderson Hospital and Tumor Institute, Houston, Texas 77030.
Genetics. 1987 Nov;117(3):477-85. doi: 10.1093/genetics/117.3.477.
Dosage compensation is a mechanism that equalizes the expression of X chromosome linked genes in males, who have one X chromosome, with that in females, who have two. In Drosophila, this is achieved by the relative hyperactivation of X-linked genes in males, as was first shown by Muller using a phenotypic assay based on adult eye color. Several genes involved in regulating dosage compensation have been identified through the isolation of mutations that are sex-specific lethals. However, because of this lethality it is not straightforward to assay the relative roles of these genes using assays based on adult phenotypes. Here this problem is circumvented using an assay based on embryonic phenotypes. These experiments indicate that dosage compensation is established early in development and demonstrate that the daughterless and Sex-lethal gene products are involved in regulating X chromosome activity at the blastoderm stage of embryogenesis.
剂量补偿是一种机制，可使男性（只有一条 X 染色体）中与 X 染色体连锁的基因表达与女性（有两条 X 染色体）中该基因的表达相平等。在果蝇中，这是通过雄性中 X 连锁基因的相对超活化来实现的，这最初是 Muller 利用基于成年眼色的表型测定法证明的。通过分离性别特异性致死突变，已经鉴定出几种参与调节剂量补偿的基因。然而，由于这种致死性，使用基于成年表型的测定法来直接测定这些基因的相对作用并不简单。在这里，使用基于胚胎表型的测定法来解决这个问题。这些实验表明，剂量补偿在发育早期就已建立，并证明了无活性和性致死基因产物参与调节胚胎发生中胚泡阶段的 X 染色体活性。
