Genetic Resources Of Rhynchocypris Oxycephalus

Rhynchocypris oxycephalus(Teleostei:Cyprinidae)is a typical small cold water fish,which is distributed widely and mainly inhabit in East Asia.Rhynchocypris oxycephalus usually inhabits a stream at a higher altitude,a lower water temperature,a certain water flow rate,a clear and dissolved oxygen content,and a source of sand or stone.It is of great value both in economics and biology.The classification of the genus Rhynchocypris is very complicated,and the phylogenetic relationship of the genus Rhynchocypris is one of the long-standing controversial scientific problems in the classification relationship of the subfamily Leuciscinae.So the identification and determination of the big genus is the key of its genetic resources,and the first step in the study of germplasm.Aquatic animal genetic resources are an important material basis for the sustainable development of aquatics industry,and the classification and identification of aquatic animal genetic resources is the prerequisite for the development and utilization of aquatic animal genetic resources.Nowadays,some natural and human factors,Aquatic genetic resources in China are being seriously damaged.Therefore,the protection and rational use of aquatic genetic resources is the key to maintaining a healthy and sustainable development of aquatic industry in China.Due to the great controversy in the classification and identification of the genus Rhynchocypris,it restricts the development and utilization of the genus Rhynchocypris.So the purpose of this study is to identify species of the genus Rhynchocypris,providing basic scientific information for its development and utilization of genetic resources.Here,we sequenced and determined the complete mitochondrial genome of Rhynchocypris oxycephalus and studied its phylogenetic implication.Rhynchocypris oxycephalus mitogenome is 16,609 bp in length(GenBank accession No:MH885043)and it contains 13 protein-coding genes(PCGs),two rRNA genes,22 tRNA genes,and two non-coding regions(the control region and the putative origin of light strand replication).12 PCGs started with ATG,while COI used GTG as the start codon.The secondary structure of tRNA-Ser(AGN)lacks the dihydrouracil(DHU)arm.The control region is 943bp in length,with a termination associated sequence,six conserved sequence blocks(CSB-1,CSB-2,CSB-3,CSB-D,CSB-E,CSB-F)and a repetitive sequence(AT).Phylogenetic analysis was performed with Maximum Likelihood and Bayesian methods based on the concatenated nucleotide sequence of 13 PCGs and the complete sequence without control region,and the result revealed that the relationship between Rhynchocypris oxycephalus and Rhynchocypris percnurus is closest,while and the relationship with Rhynchocypris kumgangensis is farthest.The genus Rhynchocypris is revealed as a polyphyletic group and Rhynchocypris kumgangensis had distant relationship with other Rhynchocypris species.In addition,we selected six PCGs(COⅠ,COⅢ,ND2,ND4,ND5,Cytb)as potential DNA barcodes for the genus Rhynchocypris.COI and ND2 genes are considered as the fittest DNA barcoding gene in genus Rhynchocypris.This work provides additional data support for the study of genetic resources and rational development of the Rhynchocypris oxycephalus.