不同地区褐黄血蜱的基因变异及遗传进化分析

为探究不同区域褐黄血蜱的基因变异情况及其遗传进化关系，试验以采集自湖南、河南省的20只褐黄血蜱为研究对象，通过PCR扩增其内转录间隔区Ⅱ（ITS-2）和烟酰胺脱氢酶亚基Ⅰ（nad1）基因序列，并对所获序列进行基因变异分析；在所获ITS-2和nad1基因序列的基础上，对不同地区褐黄血蜱的遗传进化关系进行分析，并利用ITS-2和nad1基因序列分别构建褐黄血蜱的系统进化树。结果显示，褐黄血蜱ITS-2基因序列长度均为1 160 bp，nad1基因序列长度均为285 bp；两省褐黄血蜱ITS-2及nad1基因的种内差异分别为0~1.9%和0~0.4%；湖南省褐黄血蜱的种内差异分别为0~1.4%和0~0.4%，而河南省的种内差异分别为0~1.2%和0~0.4%；两省褐黄血蜱ITS-2及nad1基因的种间差异分别为37.0%~52.0%和13.6%~24.8%。系统进化树结果显示，所有来自于两省的褐黄血蜱共处于同一分支上。结果表明，来自于两省的褐黄血蜱之间均存在基因变异的现象，但湖南省褐黄血蜱的基因变异程度和遗传多样性均高于河南省；两省褐黄血蜱之间的亲缘关系较近，暗示两省褐黄血蜱之间有基因交流，未出现遗传分化。

Genetic Variation and Phylogenetic Evolution of Haemaphysalis flava from Different Geographical Areas in China

To explore the genetic variation and phylogenetic evolution of Haemaphysalis flava (H. flava) collected from different geographical areas in China,a total of 20 H. flava from Hunan and Henan provinces were used in this study,their internal transcribed spacer Ⅱ (ITS-2) and NADH dehyd ogenase subunit Ⅰ (nad1) sequences were amplified by PCR,and the genetic variations in the obtained sequences were analyzed.Moreover,the phylogenetic relationship of H. flava from two provinces was analyzed,and two phylogenetic trees were established using the obtained ITS-2 and nad1 genes sequence.The results showed that the intra-specific sequence variations of ITS-2 and nad1 genes within H. flava from Hunan and Henan provinces were 0 to 1.9% and 0 to 0.4%,respectively.The intra-specific sequence variations of ITS-2 and nad1 genes within H. flava from Hunan province were 0 to 1.4% and 0 to 0.4%,respectively.The intra-specific sequence variations of ITS-2 and nad1 genes within H. flava from Henan province were 0 to 1.2% and 0 to 0.4%,respectively.The inter-specific sequence variations of ITS-2 and nad1 genes of H. flava were 37.0% to 52.0% and 13.6% to 24.8%,respectively.The phylogenetic analysis showed that all samples are on a clades in two phylogenetic trees established by ITS-2 and nad1 genes sequence.The results indicated that there was genetic variation between H. flava from Hunan and Henan provinces,but the genetic variation and genetic diversity of H. flava from Henan province were higher than that from Hunan province.The phylogenetic relationship of H. flava from Hunan and Henan provinces was closed.The results suggested that there was gene exchange within H. flava from Hunan and Henan provinces,and no genetic differentiation between all samples.