Sequence Analysis And Phylogenetic Study Of The Whole Mitochondrial Genomes Of Six Species Of Spotted Moth

Zygaenoidea is a species rich superfamily of Ditrysia Lepidoptera with a world-wide distribution,being most diverse in tropical and subtropical Asia and the Palaearctic region.Zygaenoid larvae like eating plant leaves or drill stems cavity,is mainly pest of agriculture,forestry and animal husbandry.Zygaenoid attracts a lot of lepidopterists due to its interesting chemical defense system.In this study,we sequenced the complete mitochondrial genomes of Amesia sanguiflua,Elcysma delavayi,Erasmia pulchella,Histia flabellicornis,Neochalcosia remota,Phauda flammans by PCR with primer walking method.After the sequences were assembled and annotated,the gene arrangement,base composition,relative codon usage of protein coding genes,rRNAs,tRNAs and the control region were analyzed in details.We combined the six new complete mitochondrial genomes with that of other Zygaenoide species deposited in GenBank to reconstruct the phylogenetic relationship of Zygaenoidea.The main results are showed as following.1.The complete mitochondrial genome of A.sanguiflua,E.delavayi,E.pulchella,H.flabellicornis,N.remota,P.flammans respectively are 15203 bp,15235 bp,15198 bp,15201 bp,15255 bp,15427 bp in length,the varying length is due to the control region.The mitochondrial genome contained a common set of 37 mitochondrial genes including two rRNA genes,13 PCGs,22 tRNA genes,and a control region.The mitochondrial genes arrangement of A.sanguiflua,E.delavayi,E.pulchella,H.flabellicornis,N.remota is consistent with Chalcosiinae species deposited in GenBank,tRNASer(AGN)-tRNAGln in the mitochondrial genome of P.flammans is different with others.2.The base composition of A.sanguiflua,E.delavayi,E.pulchella,H.flabellicornis,N.remota,P.flammans showed a strong the A+T bias.The coding genes tendency of base A+T content is the control region>rRNAs>tRNAs>PCGs.3.There were two common overlapping nucleotides region of the six Zygaenoidea species,the region was between tRNATrp and tRNACys which including "AAGCCTTA",the region was between ATP8 and ATP6 which including"ATGATAA".The longest intergenic spacer was located between tRNAGln and ND2,the common intergenic spacer was between tRNASer(UCN)and ND1 which including conservative sequence"ATACTAA".4.The arrangement of 13 PCGs of the six Zygaenoidea species was ND2-CO?-CO?-ATP8-ATP6-CO?-ND3-ND5-ND4-ND4L-ND6-CYTB-ND1,ND2?CO??CO??ATP8?ATP6?CO? ND3?ND6?CYTB were coded on the majority strand(J-strand),ND5?ND4?ND4L?ND1were coded on the minority strand(N-strand).COI of the mitochondrial genome of A.sanguiflua,E.delavayi,E.pulchella,H.flabellicornis used CGA as start codon,other PCGs started with typical ATN codons.The usage of codons also showed bias towards A and T nucleotides.5.The length of 22 tRNAs in six Zygaenoidea species ranged from 62 to 74 bp.All tRNAs had the typial cloverleaf secondary structure except for tRNASer(AGN)which lacked the DHU stem.There were some unmatched base pairs in tRNA secondary structure,such as G-U,A-C,U-U.The rRNA genes(rrnS,rrnL)were located between tRNALeu(CUN)and the control region,rrnS and rrnL were separated by tRNA Val.6.The A+T-rich region of A.sanguiflua,E.delavayi,E.pulchella,H.flabellicornis,N.remota,P.flammans was located between 12SrRNA(rrnS)and tRNAMet,their lengths respectively were 346 bp,365 bp,332 bp,367 bp,375 bp,362 bp.The control region of six Zygaenoidea species contained origin of replication,tandem repeat sequences,microsatellite elements and poly-A or poly-T.7.Phylogenetic analysis of Zygaenoidea based on the 13 PCGs dataset of 43 Lepidoptera species using the BI and ML methods.The phylogenetic results revealed the monophyly of Zygaenoidea and Phaudidae was a separate family.The phylogenetic relationships of BI was:((((((((Bombycoidea+(Noctuoidea+Geometroidea)+Pyraloidea)+Papilionoidea)+Gelechioidea)+Zygaenoidea+Cossoidea)+Tortricoidea)+Yponomeutoi dea).