Rex-Induced Recombination in the rDNA of Drosophila

和其他真核生物一样，果蝇的异染色质占基因组的很大一部分，但人们对其组织和功能知之甚少。Rex（核糖体交换）是少数已被鉴定的异染色质位点之一，它的分析将大大增加我们对异染色质的理解。该基因座是位于X染色体基底异染色质上的母系显性基因，在雷克斯雌性后代早期有丝分裂中促进核糖体RNA基因的重组。对Rex及其产生的重组体的分子和遗传分析将集中于对Rex的解剖，以及对其诱导rDNA交换的机制的理解。这个项目将增加我们对染色体异色区的认识。过去，异染色质很难分析。这个项目使用了其他地方没有的独特方法。对果蝇中异染色质的理解，原则上可以很容易地转移到包括人类在内的所有哺乳动物中发现的大部分异染色质。

The heterochromatin of Drosophila, as of other eukaryotes, accounts for a substantial fraction of the genome, but its organization and function is little understood. Rex (Ribosomal exchange) is one of very few heterochromatic loci that have been identified, and its analysis will provide a significant increase in our understanding of heterochromatin. This locus is a maternal-effect dominant located in the basal heterochromatin of the X chromosome that promotes recombination of the ribosomal RNA genes during early mitotic divisions in offspring of Rex females. Molecular and genetic analysis of Rex and of Rex-generated recombinants will focus on dissecting Rex, and on understanding the mechanism by which it induces rDNA exchange. This project will increase our understanding of the heterochromatic regions of chromosomes. Heterochromatin has been difficult to analyze in the past. This project uses unique methods not found elsewhere. An understanding of heterochromatin in fruit flies will be readily transferable in principle to the large fraction of heterochromatin found in all mammals including man.