Norman R A, Doane W W
Department of Zoology, Arizona State University, Tempe 85287-1501.
Biochem Genet. 1990 Dec;28(11-12):601-13. doi: 10.1007/BF00553953.
The functional locus for alpha-amylase (Amy) in Drosophila miranda is in the evolutionarily new X2 chromosome. X2 evolved from an autosome in response to an ancestral autosome-Y translocation that gave rise to the "neo-Y" chromosome of this species. Y-linked Amy, if still present in the ancestrally translocated element, is unexpressed. Dosage compensation for amylase activity was examined in larvae of the S 204 strain. Since dietary glucose is known to repress Amy expression in Drosophila melanogaster, dosage compensation of amylase activity in male larvae of D. miranda was tested by rearing larvae of both sexes on yeast diets with or without a glucose supplement. The WT 10 strain of Drosophila persimilis, a sibling species in which Amy is autosomally linked, was used as a reference for tests of amylase activity differences between the sexes. On the diet with glucose, Amy expression was repressed in both WT 10 and S 204 larvae and male larvae of S 204 displayed dosage compensation for amylase activity. On the nonrepressing diet consisting of yeast alone, S 204 continued to display dosage compensation.
黑腹拟果蝇中α-淀粉酶（Amy）的功能基因座位于进化上较新的X2染色体上。X2是由一条常染色体进化而来，这是对一次祖先常染色体 - Y染色体易位的响应，该易位产生了该物种的“新Y”染色体。如果祖先易位元件中仍存在Y连锁的Amy，它是不表达的。在S 204品系的幼虫中检测了淀粉酶活性的剂量补偿。由于已知饮食中的葡萄糖会抑制黑腹果蝇中Amy的表达，因此通过在添加或不添加葡萄糖补充剂的酵母饲料上饲养雌雄幼虫，来测试黑腹拟果蝇雄性幼虫中淀粉酶活性的剂量补偿。黑腹果蝇的WT 10品系是Amy位于常染色体上的近缘物种，被用作测试两性之间淀粉酶活性差异的参考。在含有葡萄糖的饲料上，WT 10和S 204幼虫中的Amy表达均受到抑制，并且S 204的雄性幼虫表现出淀粉酶活性的剂量补偿。在仅由酵母组成的非抑制性饲料上，S 204继续表现出剂量补偿。
