Dissertation Research: Inferring the Mechanism of Y Chromosome Degeneration From the Newly Evolving Sex Chromosomes in Drosophila miranda

9701098在许多物种中，查尔斯沃斯性别决定是由一对特殊的染色体控制的，即X和Y染色体。Y染色体通常没有多少活性基因。在一些物种中，“新性染色体”是由一条X或Y染色体与一条规则染色体融合而成的，这使得这条染色体以与真正的性染色体相同的方式传播。这使得研究导致Y染色体退化的作用力成为可能。果蝇Miranda就是一个经典的例子，它的neo-Y染色体上的一些基因已经退化。可能导致退化的不同过程对新Y染色体基因在物种间和物种内的变异模式有不同的后果。为了找出发生了哪些过程，将从不同的米兰达及其近缘的米兰达毛虫身上获得neo-Y染色体基因的DNA序列。这项工作将阐明性染色体基本特征的起源，并加强对控制DNA序列变异的遗传机制的了解。由于性染色体在人类遗传性疾病中起着重要作用，这一结果将有助于我们对这些疾病的理解。

9701098 Charlesworth Sex determination in many species is controlled by a special pair of chromosomes, the X and Y chromosomes. The Y chromosome usually has few active genes. In some species, "neo-sex chromosomes" have been formed by the fusion of an X or Y chromosome to a regular chromosome, causing this chromosome to be transmitted in the same way as the true sex chromosomes. This allows study of the forces responsible for the degeneration of the Y chromosome. The fruitfly Drosophila miranda is a classic example, in which some of the genes on the neo-Y chromosome have degenerated. Different processes that might be responsible for degeneration have different consequences for the patterns of between- and within-species variation of neo-Y chromosome genes. The DNA sequences of neo-Y chromosome genes will be obtained from different individuals of D. miranda, and from its relative D. pseudoobscura, in order to find out which processes are occurring. This work will illuminate the origin of the basic features of sex chromosomes, and enhance knowledge of the genetic mechanisms controlling variation in DNA sequences. Since sex chromosomes play an important role in human genetic diseases, the results will aid our understanding of these diseases.