Qinling Region In Asia Agkistrodon Genus Phylogeny And Its Geographical Evolution

Pit-viper(Gloydius),as a colony of viper,is the largest number and is widely distributed in china.Their live environments are diversiform:jokuls,altiplanos,hills and plains.Pit-viper is highly adapt to a variety of environmental conditions.Abundant Pit-viper is distributed in China has,but little is known about the genetic diversity and their geographical distribution pattern of Pit-viper.In this paper,We used mitochondrial DNA cytochrome b(Cytb)gene and NADH dehydrogenase subunit 4(ND4)gene as molecular marker in order to reveal their genetic diversity and geographical distribution pattern.We sequenced Cytb and ND4 gene sequences of G. brevicaudus from five geographic populations(Yangxian County,Ningshan County,Hanyin County and Qishan County in Shaanxi province,Huangshan in Anhui province),one geographic population G.intermedius(Yanan Baota District in shaanxi province),one geographic population G. qinlingensis(Taibai County in shaanxi province)and two geographic populations Trimeresurus jerdonii(Ningshan County and Taibai in shaanxi province).We have compared two kinds of genes for which a gene sequence analysis and molecular marker gene.On this basis,Phylogenetic trees of ML,NJ,MP and Bayesian tree based on mitochondrial Cytb,ND4 gene and combined gene data were built respectively.In addition,Combined with the geographical distribution of pit-viper morphological characteristics in the Qinling area,We analysed the phylogenetic relationships,the geographical distribution pattern and the reasons of evolution of pit-vipers.In order to provide information to the relationship,distribution pattern,geographic evolution reasons of the process of evolution on the territory of Shaanxi Province.The main results and conclusions as follows:1.The variable sites of Cytb(1067bp)and ND4(819bp)gene sequences were 259 and 182,parsimony informative sites were 135 and 144,conservative sites were 808 and 637 respectively.In 38 sequences what we obtained(including the outgroup),There are 19 Cytb gene sequences(10 haplotypes),the average content of T,C,A,G,was 28.3%,11.3%,28.1%,32.2% respectively.There are 19 ND4 gene sequences(11 haplotypes),the average content of T,C,A,G, was 32.9%,12.5%,24.8%,29.8%respectively.Content of A and T(56.4%,57.7%) was significantly higher than the content of G and C(43.5%,42.5%) in two gene sequences,The composition of two gene sequences composition were characteristic of a typically high A+T content.2.We can see that interspecific relationship of G.brevieaudus that in different geographical clustering relationship is consistent Completely phylogenetic trees of ML,NJ,MP and Bayesian tree based on mitochondrial Cytb.ND4 gene and combined gene data were built respectively.In the four phylogenetic trees which built based on ND4 and Bayesian tree was constructed by Cytb, G.brevicaudus from different geographic populations with G.qinlingensis of Taibai County clustering a first big branch,then clustering with Yanan G.intermedius.In the phylogenetic trees of ML,NJ,MP based on mitochondrial Cytb and four phylogenetic trees builted by combined gene data of Cytb and ND4,G.qinlingensis of Taibai County forming a big branch with Yanan G. intermedius,then clustering with G.brevicaudus of different geographic populations.3.The results of the analyses for the ratio of transitions and transversions of Cytb and ND4 showed that the R values both are obvious bigger than parameter 2.The mutation of two gene-types are not saturation,which indicates that they are lesser affected by evolution noise and suitable to rebuild phylogenetic tree.After analyzing the component of gene sequences,we found that two genes have intraspecific mutation in viperidae,which can be act as marker gene to study the geographical distribution of Pit-viper.4.In comparison to ND4,Cytb is more conservative and there is a low evolution speed.For rebuild the phylogenetic relationship of Pit-viper,ND4 is obvious better than Cytb.The interspecific genetic distance is significantly bigger than intraspecific genetic distance in ND4 gene,while the stability of interspecific ramose structure and clustering relationship of Cytb are less than ND4.Therefore,ND4 is much more suitable than Cytb for confirming the interspecific phylogenetic relationship.5.Integrated with the analyses of gene sequences of Cytb and ND4 and clustering relation in phylogenetic relationships,geographic distribution and morphological characteristics,we suggest that G.qinlingensis has a near relative relation with G.brevicaudus,but has a far relative relation with G.intermedius.6.The geographic distribution of G.brevicaudus was obvious divided to two colonies in Qinling area,One colony lives in north hillside of Qin-ling mountain,Qishan wuzhangyuan for example,another colony lives in south hillside of Qinling mountains,such as tongchewan in Ningshan County,Huayang in Yangxian County and Chengguanzhen in Hanyin County.7.In conclusion,based on the analyses of geographic distribution,morphological characteristics and phylogenetic relationships of G.brevicaudus and G.qinlingensis,G. qinlingensis is evolved from G.brevicaudus and is the ecological substitution species which can acclimatize themselves to live in high altitude areas.