Rates of DNA Sequence Change on Avian Chromosomes: A Test of the Replicative Division Hypothesis

禽类染色体 DNA 序列变化率：复制分裂假说的检验

• 批准号: 9306823
• 负责人: Thomas Quinn
• 金额: $ 7.8万
• 依托单位: University of Denver
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-09-01 至 1996-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9306823&HistoricalAwards=false
• 关键词: Rates; DNA; Sequence; Change; Avian

9306823 Quinn The proposed research will investigate the rate of single copy DNA divergence in the sex and autosomal chromosomes of birds. The replicative division hypothesis suggests that the number of rounds of replicative division in germ line cells per unit chronological time determines the rate of DNA sequence change. Birds provide an excellent model for testing this interesting hypothesis because in birds the heterogametic sex is reversed from that seen in mammals. Microdissection of avian chromosome metaphase spreads and DNA amplification and cloning techniques will be used to isolate single copy DNA from the W, Z, and autosomal chromosomes of several waterfowl, and the nucleotide sequence of these clones will be determined. These data will be used to compare rates on different chromosome type in relation to the number of replicative divisions that particular chromosome undergoes. %%% The replicative division hypothesis and the repair mechanism hypothesis address the basic pattern of heritable mutational change in DNA. Unfortunately, these hypotheses cannot be tested using mammalian chromosomes. This proposal utilizes some well designed experimental procedures, an appropriate model system (birds), and state of the art chromosome and molecular techniques to provide a powerful test for these two opposing hypotheses. The results have several implications. First, sex specific markers will be obtained, and these markers can be used in breeding programs of endangered species that do not show sexual dimorphism. Second, the results of W chromosome rates of change can be compared to existing information on maternally inherited mtDNA sequences, and these data may have important implications to systematic biology. Finally, some very important molecular techniques will be refined, and these offer great potential to other studies of comparative chromosome mapping. ***

小行星9306823 拟议的研究将调查鸟类性别和常染色体中单拷贝DNA分歧的比率。 复制分裂假说认为，生殖系细胞每单位时间内复制分裂的轮数决定了DNA序列变化的速率。 鸟类为检验这一有趣的假说提供了一个极好的模型，因为鸟类的异配性别与哺乳动物的相反。 显微解剖的鸟类染色体中期蔓延和DNA扩增和克隆技术将被用来分离单拷贝DNA的W，Z，和常染色体的几个水禽，这些克隆的核苷酸序列将被确定。 这些数据将用于比较不同染色体类型与特定染色体经历的复制分裂次数的比率。复制分裂假说和修复机制假说阐述了DNA中可遗传突变的基本模式。 不幸的是，这些假设不能用哺乳动物的染色体来检验。 该建议利用一些精心设计的实验程序，适当的模型系统（鸟类），以及最先进的染色体和分子技术，为这两个相反的假设提供了一个强大的测试。 这些结果有几个含义。 首先，将获得性别特异性标记，这些标记可用于不显示性二型性的濒危物种的育种计划。 第二，W染色体变化率的结果可以与母系遗传mtDNA序列的现有信息进行比较，这些数据可能对系统生物学具有重要意义。 最后，一些非常重要的分子技术将被完善，这些比较染色体定位的其他研究提供了巨大的潜力。***