泰国红色原鸡和中国红色原鸡mtDNA控制区遗传多态性和分类关系研究

对泰国红色原鸡Gallus gallus gallus亚种和中国红色原鸡Gallus gallus spadiceus亚种各16个个体mtDNAD-loop序列进行系统分析,测定线粒体D-loop部分序列大小约为560bp,A、C、G、T这4种核苷酸的平均比例分别为13.6%、43.2%、4.3%和38.9%,A+T含量高于G+C含量。结果共发现27个变异位点,颠换和转换之比为0.13,没有观测到插入/缺失情况。测定的6种单倍型中,2个红色原鸡亚种没有共享单倍型,单倍型多样度分别为0.250和0.695,平均核苷酸差异数分别为3.750和10.833,核苷酸多样度分别为0.954%和2.757%。泰国红色原鸡中性检验的Tajima'sD值为-1.800(P<0.05),不符合中性突变。2个红色原鸡亚种间核苷酸分歧度(Dxy)为2.847%,核苷酸净遗传距离(Da)为0.991%。序列群体间的方差组分(Va)占总变异的47.31%,Fst=0.473,差异极显著(P<0.01);群体间mtDNAD-loopFst值也差异显著(P=0.035)。红色原鸡2个亚种具有不同的群体遗传结构,群体之间存在明显的遗传分化,本研究支持这2个亚种并非是同一个亚种的观点。

Analysis on Genetic Diversity of Mitochondrial Control Region and Taxonomic Relationship of Red Jungle Fowl in Thailand and Red Jungle Fowl in China

Part of mtDNA D-loop among 32 individuals of red jungle fowl in Thailand (Gallus gallus gallus)and red jungle fowl in China(Gallus gallus spadiceus)were sequenced and analyzed. The results showed that the length of D-loop in this study was about 560 bp. Content of nucleotide A, C, G, T were 13.6%, 43.2%, 4.3% and 38.9%, respectively, showing the higher A+T of mtDNA D-loop in 2 populations. There were 27 polymorphic sites in this study, only transition and transversion but no insertion/deletion were found in this region, the ratio of transition and transversion was 0.13. There was no shared haplotypes between these two subspecies among 6 haplotypes,the average diversity of haplotypes of two subspecies were 0.250 and 0.695, respectively. The average number of nucleotide divergence(K) and average nucleotide diversity(Pi) were 3.750 and 10.833,0.954 and 2.757%, respectively. Tajima's D values was -1.800 (P <0.05) for Gallus gallus gallus, which showed significant difference from neutrality. Inter-population nucleotide divergence (Dxy) and net nucleotide divergence (Da) in two populations were 2.847% and 0.991%, respectively. Analysis of molecular variance showed that 47.31% of genetic variation was present between populations. Fst value was 0.473. The pair wise genetic differentiation index(Fst)of mtDNA D-loop was also significant (P = 0.035), all results indicated that there were different genetic structure and significant genetic differentiation between red jungle fowl in China and red jungle fowl in Thailand, and this provided enough support to identify these two red jungle fowl subspecies as the different subspecies.