Complete mitochondrial genome of Sitotroga cerealella (Insecta: Lepidoptera: Gelechiidae)

Abstract

In this study, we have sequenced the complete mitochondrial genome of Sitotroga cerealella, which is 15,312 bp and contains 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and a control region. Twenty-three genes were found to be encoded by the majority strand and the other 14 genes by minority strand, it is similar to Lepidoptera insects. The nucleotide compositions 39.60% of A, 11.80% of C, 40.90% of T, and 7.70% of G.

Keywords:

• Mitochondrial genome
• Gelechiidae
• Sitotroga cerealella

The Angoumois grain moth, Sitotroga cerealella (Lepidoptera: Gelechiidae), is a major pest of many stored grains including barley, wheat, and rice at field and post-harvest conditions (Weston et al. 1993; Weston and Rattlingourd 2000). Such damage leads to considerable quantitative and qualitative economic losses and usually infested seeds never germinate (Crombie 1943; Yang et al. 2012). Prior to this study, mitochondrial genome of seven species have been sequenced in the Gelechiidae family (Ma et al. 2016; Park et al. 2016; Ramírez-Ríos et al. 2016). Here, we have sequenced the complete mitochondrial genome of S. cerealella based on the samples collected from Huaxi District in Guizhou, China (geographic coordinate: N26°23′41.1394571745972″, E106°40′46.096659178428″), which would facilitate our understanding of the mitochondrial genome, phylogeography and the phylogenic relationship of the Gelechiidae family. The adult stage of S. cerealella was washing with 70% ethanol first, and then those were stored in 95% ethanol, the mitochondrial DNA was extracted using De Novo sequencing library, and DNA sequencing at Berry Genomic, Beijing, China. The voucher specimen’s genome DNA is deposited in the Institute of Entomology, Guizhou University, Guizhou Province, China.

The complete sequences of S. cerealella mitochondrial genome (GenBank accession no. MH433621) is 15,312 bp in length, consisting of 13 protein-coding genes, 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a control region. Twenty-three genes (trnI, trnM, nad2, trnW, cox1, trnL2, cox2, trnK, trnD, atp8, atp6, cox3, trnG, nad3, trnA, trnR, trnN, trnS1, trnE, trnT, nad6, cytB, and trnS2) were found to be encoded by the majority strand (J-strand) and the other 14 genes (trnQ, trnC, trnY, trnF, nad5, trnH, nad4, nad4L, trnP, nad1, trnL1, rrnL, trnV, and rrnS) by minority strand (N-strand), those similar to Biston marginata (Zheng et al. 2018). Overall nucleotide compositions are 39.60% of A, 11.80% of C, 40.90% of T, and 7.70% of G, with an AT content of 80.50%. Most protein-coding genes begin with ATN, such as cox2, cytB nad1, nad4, and nad4L genes employing ATG, while the rest using ATA as a start codon. And the exception of nad4, which terminates with a single T, nad4L and nad1 are terminated with TAG, others with TAA as the stop codon. The rrnL is located between trnL1 and trnV, whereas rrnS is between trnV and control region. The 22 tRNA genes vary from 65 to 71bp in length. The secondary structure of tRNAs exhibited typical clover-leaf structure are same as others insect. The size of the control region is only 80bp (42.50% A, 0 G, 8.80% T, 3.8% C, with an AT content of 96.20%), and it located between rrnS and trnI, and the gene order model was same with other reported Ephestia elutella (Liu et al. 2018).

The phylogenetic relationships of the S. cerealella mitogenome assembly references and 16 other Lepidoptera taxas from GenBank, were reconstructed using maximum-likelihood (ML) method (Chen et al. 2016) analysis based upon the concatenated nucleotide sequences of the 13 PCGs (Figure 1). Sitotroga cerealella is part of the Gelechiidae, all members of which are clustered into a clade.

Figure 1. The ML phylogenetic tree of 17 Lepidoptera taxas. The phylogenetic tree was constructed by MEGA 6.0 and Bootstrap support is shown at nodes.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

The project supported by The Provincial Key Project for Agricultural Science and Technology of Guizhou (20172579), the Science and Technology Foundation of Guizhou Province (J- [2015] 2041), the Study on Occurrence and Control of Tobacco Pests in Guiyang City (Building Smoke Division [2015] No. 01), the Provincial Outstanding Graduate Program for Agricultural Entomology and Pest Control (ZYRC- [2013] 010).