| Tabanidae insects commonly known as “Gadfly”,“blind fly”,belonging to the Tabanidae,Brachycera,Diptera,Insecta,with a total of about 4 455 species in 144 genera.As an ectoparasite,the gadflies not only bites,bloodsucking,harassing humans and animals to cause skin damage or urticaria dermatitis,resulting in livestock weight loss;It also serves as an important biological vector for the transmission of a variety of zoonotic diseases,bringing harm to animal husbandry and public health security.Accurate identification is the basis of control,control and scientific research of gadflies.Morphological identification of gadflies mainly relies on traditional morphological methods,and the identification work is completely dependent on morphological experts.Molecular biological identification has some advantages in species identification,but there are relatively few molecular data about gadflies.Therefore,this study intends to comprehensively apply morphological identification and molecular identification to identify the collected gadflies,laying a foundation for further research on the gadflies.On the one hand,morphological identification was carried out on the gadflies collected from Northeast China(Heilongjiang,Jilin and Liaoning provinces).The shape of the basal scapula of the head,the length and width of antennae and the degree of dorsal protruding were observed,the color of the back plate on the abdomen and the pattern of the wings were identified.On the other hand,molecular biological identification was carried out for the gadflies.The complete mitochondrial(mt)genome sequences of six species of gadflies from four genera of Tabanidae were amplified and analyzed by PCR.The phylogenetic tree was constructed with 13 tandem protein-coding genes of mitochondria by Bayesian(BI),Maximum parsimony(MP)and Maximum likelihood method(ML),and the characteristics of mitochondrial genome and its relationship with other gadflies were analyzed.The results showed that we have identified Tabanus pleskei,Tabanus Chrysurus,Chrysops vanderwulpi,Chrysops dissectus,Haematopota turkestanica and Hybomitra sp.,a total of six species of gadflies.The complete mitochondrial genome of the six species of gadflies was circular,with the length of complete mitochondrial amplification of 15,851 to 16,107 base pairs(bp),and the content of AT ranged from 75.64% to 77.91%.The six complete mitochondrial genomes were composed of 13 protein-coding genes(PCG),2 ribosomal RNA genes(r RNA),22 transfer RNA genes(t RNA).In total,there are 37 functional subunits and a large non-coding region.ATT and ATG are the most common start codons,and TAA is the stop codon of almost all protein-coding genes.All trnas except trn Ser1 had a typical clover structure.Bayesian inference,Maximum likelihood tree and Maximum parsimony inference all show consistent results.This study supports the concept of monophyletic genera,which is consistent with the current classification results.In this study,complete mitochondrial genomes of six species of gadflies Tabanus pleskei,Tabanus Chrysurus,Chrysops vanderwulpi,Chrysops dissectus,Haematopota turkestanica and Hybomitra sp.were amplified for the first time and their sequence characteristics and evolutionary relationships were analyzed.It provides an effective genetic marker for molecular classification,systematics and genetics of Tabanidae.To fill in the genome database of Tabanidae and lay the foundation for further studies on pathogens. |
