阿坝藏鸡三个品系线粒体DNA编码分析

Study on DNA Barcoding of Three Lines of Aba Tibetan Chicken by mtDNA Genes

试验旨在通过对阿坝藏鸡三个品系进行深入研究,利用COX1和D-LOOP基因某一特定区段作为DNA条形码对阿坝藏鸡三个品系进行分子鉴定,分析其遗传多态性并探讨DNA条形码在藏鸡分支鉴定工作的可行性和有效性。以阿藏1系、阿藏2系、阿藏3系三个品系作为研究对象,利用DNA测序技术测定了COX1和D-LOOP基因的部分序列。两基因在三个品系的单倍型数量、平均核苷酸差异数(K)均不相同,阿藏3系的平均核苷酸差异数高于阿藏1系和阿藏2系;三个品系核苷酸多态度(Pi)相差不大,其中阿藏2系COX1基因核苷酸多态度略高于其他两品系。三个品系内COX1和D-LOOP两基因测算得出的遗传距离分别为2.21~2.40、4.02~4.34,且各品系间相差不大。通过构建两基因的UPGMA树显示,三品系间存在一定程度的基因交流。利用COX1和D-LOOP基因某一特定区段作为DNA条形码的基础,各有其优势特点,两基因工具搭配使用可提高品系鉴定的准确性。

The aim of the study was to analysis the polymorphismof three lines in Aba prefecture by using a specific section of the COX1 and D-LOOP gene as DNA barcodes,and explore the feasibility and effectiveness of DNA barcode identification in Aba Tibetan chicken.The partial sequences of the COX1 and D-LOOP gene of three lines in Aba prefecture was amplified by using PCR and sequencing.The number of haplotypes and the average number of nucleotide differences(K)of the two genes were totally different among the three lines.The average nucleotide difference of Azang 3 line was higher than Azang 1 and Azang 2 line.The nucleotide polymorphism(Pi)of the three lines were similar,and the nucleotide expression of the COX1 gene of Azang 2 was slightly higher than the others.The genetic distances of COX1 and D-LOOP in the three lines were 2.21 to 2.40 and 4.02 to 4.34,respectively,and the differences between the lines were not significant.There was a certain degree of gene communication among the three lines by constructing the UPGMA tree of the two genes.The specific segment of the COX1 and D-LOOP gene could be used as the basis of DNA barcodes and had its own strength,and the combination of two gene tools could improve the accuracy of the variety identification.