【作者】 薛辉；

【导师】 吴孝兵；

【作者基本信息】 安徽师范大学 ， 动物学， 2005， 硕士

【摘要】 扬子鳄(Alligator sinensis)是我国特有珍稀物种,是世界现存23种鳄类中最濒危的一个种。对于扬子鳄的保护,除了重建扬子鳄的生境外,其遗传保护也同样重要。遗传变异性是遗传保护研究的主要内容,在小种群中,往往由于瓶颈效应、近亲繁殖、奠基者效应和遗传漂变等使得遗传变异性减少。线粒体控制区DNA序列分析是研究种群遗传结构的优良分子标记之一,本文通过PCR扩增分析扬子鳄控制区500bp序列,并研究了扬子鳄种群遗传结构,发现扬子鳄种群内遗传变异已处于极低的水平(π=0.00024±0.00016),64个个体中仅发现4个单倍型,其中单倍型A为绝大多数个体所共享。不但是饲养种群,在野生扬子鳄个体的研究中也发现同样的现象,提示扬子鳄这一珍稀物种在历史上经历了强烈的瓶颈效应。扬子鳄放归自然项目已启动,野放鳄的种群亦需进行遗传管理,这对回归自然的扬子鳄今后种群增长是十分必要的。本文利用密河鳄的10对微卫星引物对初选的13条放归自然试验中的野放鳄进行遗传相似度分析,结果密河鳄微卫星引物在扬子鳄个体中的适用效果不是很好,仅发现两个微卫星位点(Amiμ8和Amiμ18)是杂合的,适用于遗传分析。为了给扬子鳄遗传分析提供足够的微卫星分子标记,本文又利用微卫星富集文库法从扬子鳄基因组中共筛选出了17个微卫星位点以供进一步研究。更多还原

【Abstract】 Chinese alligator (Alligator sinensis) is a endemic rare species in China and also a most threatened one of Crocodilian. For Chinese alligator’s conservation, genetic conservation is as important as habitat conservation. Genetic variation is major study content in conservation genetics. In small population, genetic variation loss because of bottleneck effect, inbreeding, founder effect, and genetic drift. Control region sequence of Mitochondrial DNA is good genetic markers for population genetic structure study, with amplification and analysis of control region sequences of Chinese alligator individuals we found only four haplotypes appear in the 64 specimens and Chinese alligator is at low genetic variation level not only in captive breeding population but also in wild individuals ( π =0.00024±0.00016) , which indicates that the rare species has experienced a strong bottleneck effect in history. Reintroduction plan for Chinese alligator has been performed and genetic management for released individuals become study content. We analysis the genetic similarity of 13 pre-selective Chinese alligator for reintroduction experiment, with mtDNA control region sequence and 10 pairs microsatellite primers of American alligator (Alligator mississippiensis). Result indicates that the control region sequences has low resolution for genetic similarity and microsatellite loci of American alligator is not effective for Chinese alligator, just 2 pair of primers are polymorphism and suitable for genetic analysis. To own enough mircosatellite loci for genetic analysis of Chinese alligator, we isolate 17 loci from Chinese alligator genomics with enrichment library method.更多还原