【作者】 王慧娟；

【导师】 刘中来；

【作者基本信息】 华中师范大学 ， 生物化学与分子生物学， 2006， 硕士

【摘要】 神农架白熊是我国神农架山地特有的珍稀动物,自1954年以来,世界上仅发现神农架白熊10余只,目前全世界圈养的仅有两只,它是比大熊猫还要珍贵的动物。由于神农架白熊外形像亚洲黑熊,但又有所不同,而其生活习性却有些像大熊猫。因此,自被发现起至今,神农架白熊的分类地位一直存在争议,主要有两种说法:一部分人认为它是黑熊的白化型,大多数人认为神农架白熊是远古残遗至今的一个独立的熊种。 针对神农架白熊的分类地位问题,本文以神农架白熊的毛发和粪便为材料,进行了非损伤性样品DNA的提取和线粒体DNA中细胞色素b、12S rRNA、控制区(control region,D-loop)的扩增,结合GenBank里其他熊类的同源基因片段进行比较,分析了碱基组成频率、替代数、变异位点、简约信息位点数、转换/颠换比率、相似指数和分化指数。用MEGA(3.0)中的邻接法(NJ)和最大节约法(MP)对线粒体Cyt b基因、12S rRNA、D-loop构建了分子系统树,并且用DNASTAR软件的J.Hein法和Clustal W方法对D-loop基因构建了分子系统树。这些结果都显示,神农架白熊与亚洲黑熊的亲缘关系最近,与大熊猫的亲缘关系较远。结果提示:神农架白熊可能是亚洲黑熊的白化型或者是一个独立的熊种,而与大熊猫的亲缘关系较远。更多还原

【Abstract】 The Shennongjia white bear is a rare species which only dwell in mountainous region of Shennongjia, China. Since 1954, only 10 of these animals have been spotted. Now there are merely two of them in the zoos. This species is more precious than giant panda. The aspect of Shennongjia white bear is similar to Asia black bear, but the behavior of it is similar to panda. Since the discovery of Shennongjia white bear there are dispute about its classification. Someone believes that it is the albinism of Asiatic black bear, but the majority believes that it is a independent epibiotic species from high antiquity.In order to investigate the phylogenetic relationship of Shennongjia white bear and other bears, total DNA of Shennongjia white bear was extracted and sequenced from hair and feces of Shennongjia white bear. Based on the partial Cyt b、 12S rRNA and D-loop gene sequences obtained from the samples, the authors aligned them using the Clustal W software program. The MEGA software was used to analyze the divergences and base substitutions of the mtDNA genes among the 11 species: Shennongjia white bear, Selenarctos thibetanus(Asiatic black bear), American black bear (Euarctos americanus), sun bear (Helarctos malayanus), brown bear (Ursus arctos), polar bear (Thalarctos maritimus), sloth bear (Melursus ursinus), raccoon (Procyon lotor), giant panda (Ailuropoda melanoleuca), lesser panda (Ailurus fulgens) and spectacled bear (Tremarctos ornatus). The phylogenetic trees constructed by multiple methods (NJ and MP) supported nearly the same topology. And the phylogenetic tree of D-loop gene also constructed by J.Hein method and Clustal W method. Our molecular results show that the sequence divergence between Shennongjia white bear and Asiatic black bear (Selenarctos thibetanus) is lower than that between other species.更多还原