大围山微型鸡、云龙矮脚鸡和拉伯高脚鸡mtDNA D-loop遗传多样性分析

Genetic Diversity of Daweishan Mini,Yunlong Short Leg and La-bai High Leg Chickens in Yunnan Based on Mitochondrial DNA D-loop Sequences

大围山微型鸡、云龙矮脚鸡和拉伯高脚鸡是近年在云南发现的地方鸡遗传资源,具有优良的种质特性,为了阐明其群体遗传背景,采用mtDNA D-loop区序列为遗传标记,对采自3个地方鸡的共257个样品进行了检测分析。结果表明:大围山微型鸡、云龙矮脚鸡和拉伯高脚鸡的单倍型多样度分别为0.083±0.018、0.851±0.029和0.784±0.039;核苷酸多样度分别为0.014 67±0.000 45、0.013 42±0.000 80、0.011 66±0.001 55;群体内遗传距离分别为0.014±0.003、0.014±0.003、0.012±0.003。中介网络分析显示:本研究检测的257个样品分布在A、B、C、D、E、F和G等7个世系中,其中大围山微型鸡包含A、B、C、D、E、F和G等7个世系,B、D世系为其主要世系;云龙矮脚鸡包含A、B、C、E、F和G等6个世系,E世系为其主要世系;拉伯高脚鸡包含A、B、E和G等4个世系,G世系为其主要世系。AMOVA分析表明:3个群体间遗传分化指数(Fst)分别为0.120 84、0.239 46、0.263 68(P<0.01),群体内遗传变异占80.61%,群体间变异为19.39%(P<0.01)。本研究结果揭示3个地方鸡群体遗传多样性较丰富,都含有多个母系血统,支持家鸡多个母系起源的观点,但它们之间存在较大的遗传分化。

Daweishan mini, Yunlong short leg and La-bai high leg chickens are three indigenous chicken genetic resources with excellent breed characteristics, which have been found in recent years in Yunnan Province, China. To evaluate their genetic background information, the variation in a total of 257 individuals sampled from the three chicken populations was assessed by using the mitochondrial DNA （mtDNA） D-loop sequences as genetic marker. The results showed that the haplotype diversity, nucleotide diversity and average genetic distance within the population of Daweishan mini chicken were 0. 083±0. 018, 0. 014 67±0. 000 45 and 0. 014 ±0. 003, respectively. These three indexes for Yun- long short leg chickens were 0. 851 ±0.029,0. 013 42 ±0.000 80 and 0. 014 ±0. 003, respectively. And for La-bai high leg chicken were 0. 784±0. 039, 0. 011 66 ±0. 001 55 and 0. 012 ±0. 003, re- spectively. Median-joining network displayed that all 257 individuals distributed in maternal lineage A, B, C, D, E, F and G. Daweishan mini chicken contained the all seven lineages, of which the main lineages were lineage D and B. Yunlong short leg chicken included A, B, C, E, F and G linea- ges, and the lineage E was of the highest percentage in this population. La-bai high leg chicken only contained four lineages, A, B, E and G, which mainly consisted of lineage G. The analysis of molecu- lar variance （AMOVA） showed that genetic differentiation indexes （Fst） were respectively 0. 120 84, 0. 239 46 and 0. 263 68 among the three indigenous populations （ P 〈 0. 01 ）, and the percentage of variation among populations and within populations were 80. 61% and 19. 39% （P 〈0.01 ） , respec- tively. This study suggests that there are relatively abundant genetic diversity in Daweishan mini, Yun- long short leg and La-bai high leg chickens and they all contain multiple maternal lineage, which sup- ports the views of multiple maternal origin of chicken, but there are significant genetic divergences be- tween them.