Rex-Induced Recombination in the rDNA of Drosophila

果蝇的异染色质和其他真核生物一样，占基因组的很大一部分，但对其组织和功能知之甚少。REX(核糖体交换)是已发现的极少数异染色质基因座之一，它的分析将大大增加我们对异染色质的理解。该基因座位于X染色体的基底异染色质上，是母体效应显性基因，促进了雌霸王后代早期有丝分裂过程中核糖体RNA基因的重组。对Rex和Rex产生的重组体的分子和遗传分析将集中在解剖Rex，并了解其诱导rDNA交换的机制。这个项目将增加我们对染色体异染色质区域的理解。过去，异染色质很难分析。这个项目使用了别处找不到的独特方法。对果蝇异染色质的了解将很容易在原则上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.