Interspecies Introgressive Of Quasipaa And Genetic Characteristics Of Hybrid Tadpole

Hybridization and introgression hybridization have an important influence on speciation and contribute to the formation of genetic diversity.The genus Quasipaa(Dicroglossidae family)is a unique amphibian in Asian.Based on mitochondrial and nuclear gene study on the gene introgression of the secondary contact area of Quasipaa,which have detected a large scale of gene introgression,except Quasipaa spinosa and O.boulengeri(lots of similar morphology and domain distribution).In order to further verify the previous hypothesis and detect the divergence of genetic diversity between hybrid tadpoles and their parents(Q.spinosa and Q.shini).In this paper,we use the mtDNA(COI)and microsatellite gene to investigate the gene hybridization between Q.spinosa and Q.boulengeri,and detect the level of divergence of genetic diversity between hybrid tadpoles and parents.The main conclusions are as following:1)Take sampes of the overlapping area:In the five overlapping area of Quasipaa(Longshen,Guangxi;Anhua,Hunan;Jinhua,Zhejiang;Yichun and Lushan,Jiangxi),collected 3 species of Quasipaa(Q.spinose,119;Q.boulengeri,106;Q.shini,27).2)Microsatellite primer screening:Nine pairs of microsatellite gene primers were successfully screened from sixty-eight microsatellite primers of Quasipaa,which could be used to study the related species of Quasipaa.3)The genetic structure and differentiation of Quasipaa:Using 9 pairs of microsatellite loci detected a total of 152 alleles loci,a high level of genetic diversity in Quasipaa(NA:5.80±0.50,3.11?8.44;NE:3.031±0.28,1.81-4.48;Ho:0.52±0.56,0.38?0.88;HE:0.53±0.41,0.32?0.72;PIC:0.49±0.37,0.29?0.65),the species of Quasipaa in Longsheng and Jinhua have the highest genetic diversity,followed by the species of Anhua and Yichun.Average genetic differentiation index 0.3168±0.138(0.0137?0.5212),the population of Anhua has a lower level of differentiation.Interspecific genetic distance(0.0378)between Q.spinosa and Q.boulengeri in Anhua was the lowest in all populations,and have the high genetic distance between with another population.The source of geneticvariation in populations mainly comes from that of intraspecific individuals.Q.spinosa(Longsheng and Jinhua),Q.boulengeri(Anhua)and Hybrid tadpoles experienced the bottleneck effect,the other populations did not experience the bottleneck period.4)Introgression hybridization:Based on the mitochondrial COI(amplified fragment:434bp)screening haplotypes,construction of phylogenetic trees using Bayesian(BI)and Maximum Likelihood(ML),and using MEGA6.0 to analyze genetic distances of interspecific and intraspecific between Quasipaa.microsatellite gene analysis,genetic diversity and genetic variation in various populations.The results show that two-way mitochondrial gene introgression between Q.spinosa and Q.boulengeri in Anhua of Hunan province,one-way mitochondrial gene introgression between Q.spinosa and Q boulengeri in Longsheng of Guangxi province.Q.spinosa can be divided into the eastern,central and western three branches.5)Genetic characteristics of hybrid offspring:Based on microsatellite gene,analysis average alleles,average effective alleles,average observed heterozygosity,average expected heterozygosity of hybrids and their parents,constructed NJ phylogenetic relationships of population.Mitochondrial gene screening haplotype and BI phylogenetic relationships,genetic variations analysis in three populations by MEGA6.0.The genetic diversity level of the hybrids is similar to that of Q.shini,and the phylogenetic relationships is closer to Q.spinose.Only three genetic variation sites are the same between Q.spinosa and Q.shini,which may be exist gene introgression in the ancestors of Q.spinosa and Q.shini of the evolutionary process.