【作者】 李建华；

【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， 2004， 硕士

【摘要】 本试验测定了在我国家鹅杂交育种中广泛应用的六个家鹅品种线粒体ND4基因的部分核苷酸序列(621bp)，发现其平均GC含量为45.8％，偏倚不严重，在密码子的三个位点上，核苷酸组成的偏倚也不严重，但密码子的使用存在严重偏倚；序列间发生转换的碱基对明显大于发生颠换的碱基对(si／sv=3.8)，转换主要发生在密码子第三位点上，颠换则全部发生在密码子第三位点上；同义替换速率(ds)和非同义替换速率(dn)分别为0.2633和0.0134，差异极显著，表明鹅线粒体ND4基因在进化过程中经历了净化选择的作用；共检测到了4种单倍型，4种单倍型的频率分别为0.467、0.0333、0.467、0.0333，单倍型多样性为0.582；各品种间的核苷酸分化系数(Nst)在0至1之间，家鹅群体的遗传分化主要是由灰雁家鹅与鸿雁家鹅品种间的遗传分化造成的；六个家鹅各品种内核苷酸多样性(Pi)很低，在0至0.01417之间，各品种间的遗传距离(D)很小，在0至0.02475之间，遗传相似度高(F：0.97525至1)，而且同属于灰雁或鸿雁的家鹅品种之间的遗传相似度比分属于灰雁、鸿雁的家鹅品种之间的遗传相似度更高。更多还原

【Abstract】 DNA sequences (621bp) in Mitochondrial ND4 gene of six domestic geese that are widely used as the material of crossbreed in China were sequenced. The average percent value of G+C was 45.8%, the bias is not prominence; the bias of nucleotide composition is not prominence in each position of codens also, but the bias of the frequency of coden usage is very prominence. The transitionsal pairs are more than tranversional pairs (si/sv=3.8) among sequences; Most transitions and all tranversions were found in 3rd coden positions; The significant difference between Synonymous Subtitution (ds=0.2633) and Nonsynonymous Substitution (dn=0.0134) indicate that goose Mitochondrial ND4 gene undergo the effect of purie selection in the process of evolution. Four haplotypes were found and the haplotype diversity is 0.582; Frequence of the four haplotypes is 0.467, 0.0333, 0.467 and 0.0333 respectively. The Index of Nucleotide Differentiation (Nst) among six-goose breeds variety between 0 to 1 and the genetic diversity between breeds of Anser anser to breeds of Anser cygnoides is the main reason of the genetic diversity in all six-goose breeds. The Nucleotide Diversity in each breeds of the six geese is very low (Pi: 0 to 0.01417). The genetic distance between breeds of the six geese is close (D:0 to 0.02475) and the genetic identification is high (F: 0.97525 to 1). The genetic identification between breeds in Anser anser or in Anser cygnoides is higher than the genetic identification between breeds of Anser anser to breeds of Anser cygnoides.更多还原