Birchler J A
Biological Laboratories, Harvard University, Cambridge, MA 02138.
Genet Res. 1992 Feb;59(1):11-8. doi: 10.1017/s0016672300030123.
At the white eye colour locus, there are a number of alleles that have altered expression between males and females. To test these regulatory mutations of the white eye colour locus for their phenotypic expression in metafemales (3X; 2A) compared to diploid females and males, eleven alleles or transduced copies of white were analysed. Two alleles that exhibit dosage compensation between males and females (apricot, blood) also exhibit dosage compensation in metafemales. White-ivory and white-eosin, which fail to dosage compensate in males compared to females, but that are distinct physical lesions, also show a dosage effect in metafemales. Two alleles with greater expression in males than females (spotted, spotted-55) exhibit even lower expression in metafemales. Lastly, five transduced copies of white carrying three different lengths of the white promoter, but that all exhibit higher expression in males, show reduced expression in metafemales, exhibiting an inverse correlation between the level of expression and the dosage of the X chromosome. Because these alleles of white respond to dosage compensation in metafemales as a continuum of the male and female responses, it is concluded that the same basic mechanism of dosage compensation is involved and that the dosage of the X chromosome conditions the sexually dimorphic expression.
在白眼颜色基因座上，有许多等位基因在雄性和雌性之间的表达有所改变。为了测试白眼颜色基因座的这些调控突变在超雌（3X；2A）中的表型表达，并与二倍体雌性和雄性进行比较，对11个白眼等位基因或转导拷贝进行了分析。在雄性和雌性之间表现出剂量补偿的两个等位基因（杏色、血红色）在超雌中也表现出剂量补偿。与雌性相比，在雄性中未能进行剂量补偿的白象牙色和白曙红色，但它们是不同的物理损伤，在超雌中也显示出剂量效应。在雄性中表达高于雌性的两个等位基因（斑点、斑点-55）在超雌中的表达更低。最后，携带三种不同长度白眼启动子的五个白眼转导拷贝，它们在雄性中均表现出较高的表达，但在超雌中表达降低，显示出表达水平与X染色体剂量之间呈负相关。由于这些白眼等位基因在超雌中的剂量补偿反应是雄性和雌性反应的连续统一体，因此得出结论，涉及相同的基本剂量补偿机制，并且X染色体的剂量决定了性别二态性表达。
