| Eristalini belongs to the subfamily Eristalinae of family Syrphidae in Diptera,it is a relatively rich group with high species diversity.Adults feed pollen and nectar and are an important pollinator.There are about 1000 species in 42 genera under Eristalini known around the world,and 14 genera with 100 species occured in China.The research on the phylogenetic relationship among genera of Eristalini is usually based on the cox1 and Cytb genes in most cases,it leads the results not comprehensive and unconvincing,.It is necessary to select a genome that contains a large amount of genetic information due to single gene or few genes combination can provides less genetic information.Mitochondrial genomes play an important role in reconstruction of insect phylogeny relationship because of the characteristics of maternal inheritance,a low molecular,fast evolution rate,and stable gene composition.Up to February of 2021,the Gen Bank,DYRAD,and GSA databases have released 7 complete mitochondrial genomes of tribe Eristalini,which represented only 2 genera,and it lacks of sufficient data and representativeness to compare and analyze the basic structural features of mitochondrial genomes of Eristalini and understanding phylogenetic relationships.Therefore,14 complete mitochondrial genomes of Eristalini species belonged in 7 genera were sequenced in this study,combining with the published mitochondrial genome of Syrphidae in Gen Bank database to constructed phylogenetic relationship of genera among Eristalini based on four datasets.The main results are follows:1.The 14 complete mitochondrial genomes from 6 genera of the tribe Eristalini were sequenced and assembled.2.Totally 21 complete mitochondrial genomes of the tribe Eristalini were comparative analysis including 7 complete mitochondrial genomes from Gen Bank:(1)The total length of the mitochondrial genome of Eristalini is from 15,348 to 16,245 bp.The bases composition shows a strong AT bias.(2)The 21 mitochondrial genomes are conserved in gene composition,location direction,they are same to the Drosophila yakuba mitochondrial genome.There are no gene rearrangements.(3)The start codons of 13 protein-coding genes are ATN,GTG,TCG and TTG.Gene nad1 among all 21 species use TTG as the start codon always.The stop codons are TAA,TAG and the incomplete stop codon T or TA.(4)Except for t RNA-Ser1,the secondary structures of t RNA genes are loverleaf structure.The secondary structure of 16 S r RNA contains 5 domains(I,II,IV,V and VI)and 43stem-loop structures;the secondary structure of 12 S r RNA contains 3 domains(I,II and III)and 24 stem-loops structures.(5)The mitochondrial control region(CR)of the tribe Eristalini contains relatively scattered repeat sequences;there is always a stable stem-loop structure(Stem-loop)near one-third or one-fourth of the 3' end.3.Phylogenetic relationship of Syrphidae was generated based on 36 mitochondrial genome sequences in this study.The 8 phylogenetic topologies were consistent and supported that Syrphinae is a monophyletic and Eristalinae is a non-monophyletic.The monophyly of Eristalini is well supported,both Eristalis and Phytomia are monophyly,however,Mallota and Eristalinus may be polyphyletic,and still needs to be further discussed.The phylogenetic relationship among the genera of Eristalini is: Helophilus +(Parhelophilus +(Mesembrius +(Mallota +(Eristalis +(Phytomia + Eristalinus))))). |
PDF Full Text Request