【作者】 刘安芳；

【导师】 王继文；

【作者基本信息】 四川农业大学 ， 动物遗传育种与繁殖， 2003， 硕士

【摘要】 本研究采用PCR和DNA测序技术测定了6个中国家鹅品种和2个欧洲鹅品种25个个体线粒体DNA（mitochondrial DNA，mtDNA）部分序列，分析了序列的相似性及雁属鹅种间的遗传多样性、2个tRNA基因(tRNA^Pro、tRNA^Thr)的二级结构和细胞色素b（cytochrome b，Cyt b）跨膜螺旋结构及序列的变异特征。结果表明：得到的家鹅线粒体DNA1401bp序列包括ND5基因部分序列77bp、细胞色素b基因全序列1143bp、tRNA^Thr全序列68bp和tRNA^Pro全序列69bp；线粒体DNA1401bp序列与基因库中白额雁（Anser albifrons）、钻水鸭（Aythya americana）的序列相似率分别为97％、88％，灰雁和鸿雁家鹅Cyt b的氨基酸序列与白额雁的相似率分别为99.7％和100％，表明本次实验所测序列是真实可靠的；2个tRNA基因三叶草结构的氨基酸臂、反密码子环在鸿雁、灰雁和白额雁种间没有发生变异；家鹅Cyt b基因的核苷酸序列在膜内、膜间和膜外的变异位点数分别为12、9和10，膜内、膜间的变异均属同义替换，而膜外有两个位点发生了非同义替换，表明跨膜螺旋的膜外区域变异程度高于膜间和膜内，但膜间亲水氨基酸的比例为5.26％，远小于膜外（鸿雁16.58％、灰雁16.31％）和膜内（17.38％）；8个家鹅品种25条序列（1401bp）共检测到22个变异位点，3种单倍型，单倍型多样度和核苷酸多样度分别为0.547和0.00775，核苷酸平均差异数为10.86；支持家鹅具有两种不同起源的观点；用线粒体DNA细胞色素b及相邻的tRNA作为分子标记，能准确检测出雁属鹅种间的遗传变异，却不能检测出种内品种间的遗传多样性。更多还原

【Abstract】 The mtDNA of altogether 25 individuals in 6 breeds of Chinese goose and 2 breeds of domestic Europe goose were extractioned and the entire cytochrome b (Cyt b) gene (1143bp), ND5 gene partial sequences (77bp) along with 2tRNA gene (137bp) were sequenced. Comparability of these sequences and the cloverleaf structure of 2tRNA gene and the transmembrane helices structure of the entire Cyt b gene and variation of sequence were analysed hi the paper. The results indicated as follow:The analogical percentage between determined sequences of gooseand white-front goose (Anser albifrons), dabbling duck(Aythya Americana) inGenbank was 97%, 88% respectively. The analogical percentage between domestic goose and white-front goose in Genbank about ammo acid list of Cyt b was more than 99%, The reliability of the sequence was testified by comparability and the cloverleaf structure of 2tRNA and the transmembrane helices structure of the entire Cyt b gene between domestic geese and white-front goose; The amino acid arm and anticodon loop of cloverleaf structure of 2tRNA is very conservative among Anser albifrons and Anser cmser and Anser cygnoides. The sequence in the intermembrane domain of Cyt b transmemb helices was relatively conservative among Anser albifrons and Anse anser eand Anser cygnoides;variable sites in matrix domain, in the intermembrane domain and outer membrane was 12, 9 and 10 respectively, variation both in matrix domain and in the intermembrane domain were synonymious substitution, two various site were nonsynonymious substitution outer membrane, the difference outer membrane was more severity than matrix domain and in the intermembrane. 22 variable sites and 3 haplotypes was detected in 25 sequences, nucleotide diversity (Pi), haplotype diversity (H) and average number of nucleotide differences(K) were estimated to be 0.00775,0.547,10.86 respectively; There are two origins in domestic geese breeds, namely Xingjiang Yili breed and Landoise breed along with Rhin breed originated from Anser anser and other 5 Chinese goose breeds originated from Anser cygnoides; The genetic differentiation interspecific of goose could be examined by the molecule marker with the partial sequence of mtDNA including the entire cytochrome b (Cyt b) gene (1143bp), ND5 gene partial list (77bp) along with 2tRNA gene (137bp),whereas the genetic differentiation among geese breeds could not be checked up by the molecule marker.更多还原