Genetic Variability Of Psoroptes Ovis Var. Cuniculi Determined By The Full-length Of Mitochondrial 12S,16S And ATP6 Gene In China

Psoroptes ovis var.cuniculi is mainly parasitic on the skin surface of the rabbit external auditory canal.The typical features of this chronic contact skin infection are emaciation,with scab formed in the external auditory canal volume patterns,and cause huge economic losses to the rabbit warren.Mitochondrial genes evolve rapidly and have good genetic stability.They are often used as molecular markers to study molecular identification and population genetics of species.Currently,there are few studies on the mitochondrial geneand population heredity of Psoroptes ovis.In this study,PCR sequencing techniques were used to compare and analyze the complete sequence of mitochondrial 12 S gene,16 Sgene,ATP6 gene of P.ovis var.cuniculi of Rex-Rabbit and Meat-Rabbitin isolates from 5 geographical regions(HuaDong,HuaZhong,HuaBei,XiBei,and XiNan)in China to explore the genetic diversitiy and genetic structure of P.ovis var.cuniculi.The main results are summarized as follows:1.Genetic diversity of Psoroptes ovis var.cuniculi of rabbits in China based on mitochondrial 12 S and 16 S genesTo explore the genetic diversitiy and genetic structure of P.ovis var.cuniculi,the complete sequence of mitochondrial 12 S,16S and combined12S+16S genes of P.ovis var.cuniculi isolates from 5 geographical regions(HuaBei,HuaDong,HuaZhong,XiBei,and XiNan)in China,were obtained by PCR sequencing techniques,and analyzed the genetic diversity of P.ovis population.We successfully obtained 89 12S(657bp),83 16S(1025bp)and 63 12S+16S(1682bp)sequences,dividing into 50,52 and 56 haplotypes respectively.The values of haplotypes diversitiy(Hd)and nucleotide diversity(?)(12S:0.931054and0.00559;16S:0.95827 and 0.00686;12S+16S:0.99130 and 0.00633),showed high genetic diversity.Analysis of molecular variance(AMOVA)indicated that the genetic variation mainly occurred within the overall China populations(12S:95.77%;16S:71.03%;12S+16S:76.31%).Moreover,genetic diversity analysis showed that there was a certain genetic diversity across the population(Fst: 12S=0.04232;16S=0.28972;12S+16S=0.23685)and more frequent gene exchange(Nm:12S=5.65737;16S=1.2258;12S+16S=0.80552).The positive neutrality tests(T ajima's D and Fu's Fs)and mismatch distribution diagram with amulti-peak phenomenon indicated that P.ovis var.cuniculi population was a stable population.Haplotype network diagram and NJ tree were both revealed that the clustering of P.ovis var.cuniculi haplotypes was not related to rabbit species,temperature zone or geographical origin.2.Genetic diversity of Psoroptes ovis var.cuniculi population of rabbits in China based on mitochondrial ATP6 geneThe goal of this study was to further understand genetic variation of Psoroptes ovis var.cuniculi population in China.ATP6 gene of P.ovis var.cuniculi samples in rabbits collected from 5 geographical regions in China were amplified,sequenced and analyzed.We successfully obtained 88 ATP6(672bp)gene sequences,including 41 haplotypes.The values of haplotypes diversitiy(Hd)and nucleotide diversity(?)were 0.92581 and0.01494,showing high genetic diversity.Analysis of molecular variance(AMOVA)indicated that the genetic variation mainly occurred within the overall China populations(97.92%).Moreover,genetic diversity analysis showed that there was a certain genetic diversity across the population(Fst=0.02081)and very frequent gene exchange(Nm=11.7635).The positive neutrality tests(T ajima's D and Fu's Fs)and mismatch distribution diagram with a multi-peak phenomenon indicated that P.ovis var.cuniculi population was a stable population.Haplotype network diagram and NJ tree were both revealed that the clustering of P.ovis var.cuniculi haplotypes was not related to rabbit species,temperature zone or geographical origin.Research results show that,P.ovis var.cuniculi population was a stable population which hadthe high genetic diversity and frequent gene exchange,and the clustering of P.ovis var.cuniculi haplotypes was not related to rabbit species,temperature zone or geographical origin.