Phylogeny Of The Subfamily Eristalinae Based On The Mitochondrial Genomes

Eristalinae belongs to the family Syrphidae,it is truly a rich subfamily with the highest species diversity and biological value.The research about phylogenetic relationship among Eristalinae always based on morphological evidences and a few molecular datas,but some species had similarities,a few datas just can provide less genetic information.Beacause of this,the phylogenetic relationship among tribes in this group were still unclear.Mitochondrial genome with some characteristics such as s Tableility,high evolution rate and maternal inheritance made it was sui Tablele for phylogentic research.It provides a new direction for phylogenetic relationship analysis in the Eristalinae.This project based on Next-generation sequencing,has sequenced mitochondrial geonomes including 8 species belonging to the subfamily Eristalinae,1 species belonging to the subfamily Syrphinae and 1 species belonging to the subfamily Pipizinae.Has combined with 24 genomes(23 species of Eristalinae and one of Syrphinae)from Gen Bank,based on 4 datasets and 2 methods constructing phylogenetic tree.At the same time,this research got some 28 S r RNA genes from Gen Bank for phylogenetic analysis.The major results are as follows:1.Sequenced 10 species,finished assembling,gene annotation,gene alignment and relevant analysis.2.All genomes were closed double-stranded circular molecules.The length of all mitochondrial genomes were range from 15719 bp to 15965 bp.All genomes were made of 13 protein-coding genes(PCGs),22 transfer RNA(t RNAs),two ribosomal RNA genes(r RNAs)and a Non-coding region.3.Gene order of the sequenced species were consistent with Drosophila yakuba mitochondrial genome.There was no gene rearrangement,but gene overlap and interval in the genomes were ferquent.4.All genomes showed high AT content and significantly higher than GC content.All genomes showed significantly AT bias.The AT contents were range from79.7%-81.3%.5.The start codons of protein-coding genes were ATN(ATT,ATG,ATC,ATA).Among these,the start condons of COX1 always were CGA and CAA,ND5 always were GTG,ND1 always were TTG.The stop codons of them were TAA or TAG,but the stop codons of COX1,ND5 and ND1 were always a single T or uncomplete TA.6.t RNA-Ser1(AGN)lost dihydrouridine(DHU)arm.All the other t RNA genes can folded into the typical clover secondary structure.There were many base pair mismatches in the t RNA genes,the major type of base pair mismatch were U-U(44times).Moreover,there were other 3 types: U-C,A-A and A-C.7.Based on 5 different datasets of 34 species and 2 methods constructing phylogenetic tree.All the 34 species could be divided into 3 major clades: Eristalinae,Syrphinae and Pipizinae.The Eristalinae was still monophyly.The phylogenetic tree based on 28 S r RNA genes indicated that the Eristalinae was polyphyly.8.The ML and BI phylogenetic tree based on PCG12 dataset of 34 species had the same structure.The phylogenetic among the subfamily of Eristalinae was:((Rhingiini +((Volucellini +(Brachyopini + Merodontini)+ Milesiini + Eritalini)).9.The phylogenetic tree based on the Complete mitogenomes,PCG and PCGRNA dataset supported the genus Xylota become the tribe Xylotini.The phylogenetic tree based on the PCG12 and PCG12 RNA dataset supported the genus Xylota belongs to the tribe Milesiini.