摘要
Comparisons of vertebrate mitochondrial genomes(mitogenomes)may yield significant insights into the evolution of organisms and genomes.However,no complete mitogenome from the snake family Psammophiidae has been reported.In this study,we sequenced and annotated the complete mitogenome of Psammophis lineolatus,representing the first mitogenome of Psammophiidae.The total length is 17166 bp,consisting of 13 protein-coding genes(PCGs),22 transfer RNAs(tRNAs),two ribosomal RNAs(12 S rRNA and16 S rRNA),and duplicate control regions(CRs).This gene arrangement belongs to the TypeⅢpattern,which is a widely shared gene order in Alethinophidian snakes.All tRNAs exhibit cloverleaf structures with the exception of tRNA-Ser^(AGY) and tRNA-Pro,which lack a dihydrouridine(DHU)arm/stem and TΨC loop,respectively.The 13 PCGs include five start codons(ATG,GTG,ATA,ATT,and ATC),two complete stop codons(TAA and AGG),and two incomplete stop codon(T--and TA-).In addition,the Ka/Ks ratios indicate that all PCGs had undergone a strong purifying selection.Four types of CR domains rearrangement occurred among eight species of Elapoidea.The phylogenetic reconstructions with both Bayesian inference and maximum likelihood methods support the placement of Psammophiidae in the Elapoidea superfamily,with Homalopsidae being the sister taxon to Elapoidea and Colubroidea.However,the sister taxon of Psammophiidae is unclear due to the availability of Elapoidea mitogenomes being limited to the family Elapidae.More mitogenomes from different taxonomic groups in Elapoidea are needed to better understand the phylogenetic relationships within Elapoidea.
基金
supported by the National Natural Science Foundation of China(Nos.31672270,32070433)
supported by grant from the National Natural Science Foundation of China(No.31560591)。
