【作者】 张婷；

【导师】 杨光；

【作者基本信息】 南京师范大学 ， 生物化学与分子生物学， 2005， 硕士

【摘要】 大熊猫(Ailuropoda melanoleuca)是我国特有的濒危物种。本文选取线粒体DNA(mitochondrial DNA,mtDNA)控制区和核DNA主要组织相容性复合体(maior histocompatibility complex,MHC)标记研究大熊猫的遗传多样性和与部分食肉目物种之间的进化关系。结果表明大熊猫个体之间存在广泛的遗传变异,推测可能由于近期大熊猫群体的逐渐增大,遗传多样性得到一定程度的恢复。线粒体DNA系统发生分析支持大熊猫和熊(Ursus thibetanus)有较近的亲缘关系。 伪虎鲸(Pseudorca crassidens)是世界范围内广泛分布的一种大型海豚,但迄今关于该物种遗传变异的研究很少。本文测定了黄海水域7头伪虎鲸线粒体DNA控制区5’端533bp的序列,共发现54个变异位点,定义了4种单元型。最大似然法和邻接法的系统树均把单元型聚为2分支。两支之间没有共享单元型且无姊妹关系。分支间的核苷酸序列差异显著地超过了其它海豚类种间的序列差异水平,提示传统意义上的伪虎鲸可能包括了具有显著遗传差别的不同物种,迫切需要开展进一步的研究。更多还原

【Abstract】 Giant panda, Ailuropoda melanoleuca, is a well-known endangered animal, which is distributed only in China. To understand the current genetic status as well as evolutionary relationship with some other carnivores, sequence variation at mtDNA D-Loop and nuclear MHC loci were surveyed in this study. Results suggest there is an extensive genetic variation in panda, probably due to recent population expansion. Phylogenetic analyses of mtDNA data support the giant panda have closer relationship with bear (U. thibetanus) than with red panda (A. fulgens).False killer whale, Pseudorca crassidens, is a larger dolphin, distributed all over the world. Five hundred and thirty three base pairs (bp) of the mitochondrial control region of seven false killer whales from the Yellow Sea in Chinese waters were sequenced in this study. Fifty four variable sites were determined and four haplotypes were identified. Phylogenetic analyses using maximum likelihood and neighbor-joining algorithms divided the haplotypes of false killer whales into two clades showing no sister relationship with each other. No shared haplotypes were found between the two clades. The average nucleotide divergence between the two clades is approximately 7.61%, much higher than those between Turisops species (5.58%) and between Delphinus species (1.09%), which suggested that the two clades probably represent two separate species. Further study is urgently needed.更多还原