Activation of the Complementary sex determiner (Csd) protein by amino acid polymorphism

在提出的项目中，我们试图了解互补性别决定的分子机制。一些初始的性别决定信号已经在一些模型系统中被识别出来，然而，到目前为止，我们对这些初始信号如何在分子上首先建立性别决定状态知之甚少。在蜜蜂中，来自两个等位基因（杂合性）的sd蛋白通过fem基因的性剪接激活雌性分化。从单个等位基因或相同等位基因表达的sd蛋白导致雄性分化。我们仍然缺乏理解的过程，通过少数氨基酸的差异可以控制ON和OFF活性状态。这是一个迷人的、基本的调控原则，在多种特异性中共享。到目前为止，我们的工作已经确定了识别等位基因特异性所需的结合域。在拟议的项目中，我们将测试必需结合域和氨基酸在激活开关进入女性决定状态中的作用。这项工作也将增加我们对这种新的主要信号在进化过程中所采取的分子路径的理解。最后，我们将描述对性别互补决定至关重要的其他遗传因素。

In the proposed project we seek to understand the molecular mechanism of complementary sex determination. Some initial sex determination signals have been identified in few model systems, however, we have thus far very little understanding how these initial signals molecularly establish sexual determined states in the first place. In the honeybee Csd-proteins that are derived from two alleles (heterozygosity) activate female differentiation through the sexual splicing of the fem gene. Csd-proteins that are expressed from a single allele or same alleles result in male differentiation. We still lack an understanding of the processes through which few amino acid differences can control ON and OFF activity states. This is a fascinating, basic regulatory principle that is shared among the multiple specificities. Our work has so far identified binding domains that are required to recognize the allele specificity. In the proposed project we will test the role of essential binding domains and amino acids in activating the switch into the female-determining state. This work will also add to our understanding of the molecular path which was taken during the evolutionary rise of this new primary signal. Finally, we will characterize other genetic factors essential for complementary sex determination.