Characterization of the complete mitochondrial genome of the Oriental armyworm, Mythimna separata (Lepidoptera: Noctuidae)

Qiu-Ning Liu,Bao-Ming Ge,Chun-Lin Zhou,Dan-Dan Bian,Bo-Ping Tang,Sen-Hao Jiang

doi:10.14411/eje.2015.055

Abstract

The complete mitochondrial genome (mitogenome) of Mythimna separata (Lepidoptera: Noctuidae) was determined to be 15,329 bp, including 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and an A+T-rich region. The AT skew of this mitogenome was slightly negative and the nucleotide composition was also biased toward A+T nucleotides (81.00%). All PCGs were initiated by ATN codons, except for cytochrome c oxidase subunit 1 (cox1) gene, which was initiated by CGA. Five of the 13 PCGs have the incomplete termination codon, T or TA. All the tRNA genes displayed a typical clover-leaf structure of mitochondrial tRNA. The A+T-rich region of the mitogenome was 372 bp in length and consisted of several features common to the Noctuidae. Phylogenetic analysis confirmed the placement of M. separata within the Noctuidae.

Highlights

The insect mitochondrial genome is a circular molecule, 14–19 kb in size and contains 22 transfer RNA genes and two ribosomal RNA genes encoding the small and large subunit rRNAs that are involved in the translation of 13 protein coding genes (PCGs), ATPase subunits 6 and 8, cytochrome c oxidase subunits 1–3, cytochrome B, NADH dehydrogenase subunits 1–6 and 4L, and a large non-coding element termed the A+T-rich region, containing both the origin for replication and transcription (Moritz et al, 1987; Wolstenholme, 1992; Cameron, 2014)
The complete mitogenome of M. separata was sequenced and the mitogenome was subjected to phylogenetic analyses, involving comparison with selected species belonging to the orders Lepidoptera, Orthoptera and Diptera
The gene content is typical of other insect mitochondrial genomes, including 22 transfer RNA (tRNA) genes, 13 PCGs, two mitochondrial ribosomal RNAs, and a major non-coding region known as the A+T

Summary

Introduction

The insect mitochondrial genome (mitogenome) is a circular molecule, 14–19 kb in size and contains 22 transfer RNA (tRNA) genes and two ribosomal RNA genes encoding the small and large subunit rRNAs (rrnS and rrnL) that are involved in the translation of 13 protein coding genes (PCGs), ATPase subunits 6 and 8 (atp6 and atp8), cytochrome c oxidase subunits 1–3 (cox1–cox3), cytochrome B (cob), NADH dehydrogenase subunits 1–6 and 4L (nad1–6 and nad4L), and a large non-coding element termed the A+T-rich region, containing both the origin for replication and transcription (Moritz et al, 1987; Wolstenholme, 1992; Cameron, 2014). The gene content is typical of other insect mitochondrial genomes, including 22 tRNA genes (one for each amino acid, two for leucine and serine), 13 PCGs (cox1–3, nad1–6, nad4L, cob, atp6 and atp8), two mitochondrial ribosomal RNAs (rrnS and rrnL), and a major non-coding region known as the A+T- The mitogenome of M. sepa rata contains 162 bp of intergenic spacer sequence spread over 16 regions, ranging in size from 1 to 50 bp (Table 3), which is considerably longer than that of other Lepido ptera species, including Manduca sexta (L.) (115 bp over 13 regions), A. selene (137 bp over 13 regions), but shorter than Coreana raphaelis (Oberthür).

Results

Conclusion