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

[7010 . 98]查尔斯沃斯许多物种的性别决定是由一对特殊的染色体——X和Y染色体控制的。Y染色体通常只有很少的活性基因。在一些物种中，“新性染色体”是由X或Y染色体与常规染色体融合形成的，导致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Y染色体退化的力量成为可能。米兰达果蝇（Drosophila miranda）是一个典型的例子，它的新y染色体上的一些基因已经退化。不同的退化过程可能对新y染色体基因的种间和种内变异模式有不同的影响。新y染色体基因的DNA序列将从D. miranda的不同个体和它的亲戚D. pseudobscura中获得，以找出发生了哪些过程。这项工作将阐明性染色体基本特征的起源，并增强对DNA序列变异的遗传机制的认识。由于性染色体在人类遗传疾病中起着重要作用，因此研究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.