Sequencing and analysis of the complete mitochondrial genome of Changeondelphax velitchkovskyi (Hemiptera: Fulgoroidea)

Abstract We determined the complete mitochondrial genome sequence of Changeondelphax velitchkovskyi (Melichar 1913). The complete mitogenome sequence of C. velitchkovskyi was observed to be a circular molecule 16,449 bp long and consists of 13 protein-coding genes (PCG), two ribosomal RNA (rRNA) genes and 22 transfer RNA (tRNA) genes (GenBank accession no. MG049916). This nucleotide composition is biased toward adenine and thymine (75.7% A + T). The A + T-rich region is found between rrnS and trnI, and this entire region was 1781 bp long.

Changeondelphax velitchkovskyi (Melichar 1913) is widely distributed in the Palaearctic Region. Unlike most delphacids that feed on Poaceae, it feeds on both Poaceae and Typhaceae (Kwon 1982;Ding 2006). However, the mitogenome sequence of C. velitchkovskyi remain unknown so far. Here, we sequenced the complete mitochondrial DNA genome of C. velitchkovskyi to provide more comprehensive data toward establishing its relationship within the family Delphacidae.
Adult C. velitchkovskyi males were collected from LONGFENG wetland in Daqing City (N 46 30 0 41.54 00 and E 125 06 0 58.78 00 ), Heilongjiang, China in August of 2014. Voucher specimens were deposited in the Key Laboratory of Plant Protection Resources and Pest Management of the Ministry of Education, Entomological Museum, Northwest A&F University (NWAFU).
The complete mitochondrial genome of C. velitchkovskyi was sequenced using an Illumina HiSeq2000 system made by the Shanghai Personal Biotechnology Limited Company (Shanghai, China). The annotation was carried out in Geneious 8.1.3 (Kearse et al. 2012). Protein-coding genes (PCG) were determined by the open reading frames; rRNAs and tRNAs were identified using MITOS (Bernt et al. 2013).
The C. velitchkovskyi mitochondrial genome is 16,449 bp (GenBank accession no. MG049916) in length with a total A þ T content of 75.7% that is heavily biased toward the A and T nucleotides. It encodes the complete set of 37 genes which are usually found in animal mitogenomes. The gene arrangement in the mitochondrial genome of C. velitchkovskyi is conserved, similar to other mitogenomes in the Delphacidae, with the exception of Nilaparvata lugens (Zhang et al. 2013). In the mitogenome of C. velitchkovskyi, a total of 19 bp overlaps have been found at six gene junctions (trnQ and trnM share a nucleotide; atp8 and atp6 share seven nucleotides; nad3 and trnA share two nucleotides; trnN and trnS 1 share one nucleotide; trnS 1 and trnE share one nucleotide, and nad4 and nad4L share seven nucleotides). The mitogenome is loose and has a total of 486 bp intergenic sequences without the putative A þ T-rich region. The intergenic sequences are at 15 locations ranging from 1 to 217 bp, with the longest one located between trnS 2 and nad1. The A þ T-rich region of the C. velitchkovskyi is 1781 bp long and located between the rrnS and trnI genes.
All 22 tRNA genes usually found in the mitogenomes of insects are present in C. velitchkovskyi. The nucleotide length of tRNA genes ranges from 58 bp (trnS 2 ) to 71 bp (trnK), and A þ T content ranges from 66.7% (trnI) to 86.7% (trnE). These two rRNA genes have been identified on the N-strand in the C. velitchkovskyi mitogenome.
We analyzed the nucleotide sequences of 13 PCGs using the maximum likelihood (ML) method to understand the phylogenetic relationship of C. velitchkovskyi with other Auchenorrhyncha species. The mitogenome sequence of Aphis gossypii was used as the outgroup. Our results show that C. velitchkovskyi belongs to the superfamily Fulgoroidea and is clustered into a branch of Delphacidae (Figure 1). The family Delphacidae is monophyletic and C. velitchkovskyi is nested within the delphacids.