Abstract
The complete mitochondrial (mt) genome of Neptune subdilatata was determined using genome walking techniques in this study. The total length of the mt genome sequence of N. subdilatata was 15,402 bp, including 13 protein-coding genes, 17 transfer RNA genes, and two ribosomal RNA genes. The overall composition of the mitogenome was estimated to be 30.59% for A, 38.42% for T, 15.19% for C and 15.73% for G, respectively, indicating that an A + T (69.01%)-rich feature occurs in the N. subdilatata mitogenome. The phylogenetic relationships of 12 mollusc species were constructed based on the complete mtDNA sequences by the neighbour-joining method using MEGA 5.0 and DNAMAN 6.0 software.
The Neptune whelk, Neptune subdilatata belongs to the family Buccinidae and is delicious with potential commercial value. However, its distribution area is very small, and it is only be found in northern parts Yellow Sea of China (Hou et al. Citation2013). The population of wild N. subdilatata is too small, which results in difficulty to collect samples for experiment. In addition, the research about N. subdilatata is rare. In order to restore and protect the wild N. subdilatata resources, it is necessary to carry out wild resource investigation and germplasm analysis. In this study, we report the complete sequence of mitochondrial (mt) genome for N. subdilatata (GenBank accession no. MG827217). The findings will provide useful information for further studies on population genetics, phylogenetic construction and other relevant studies in N. subdilatata.
One N. subdilatata individual was collected from Tahe Bay, Dalian City, Liaoning Province, China (38°51′32″ N, 121°25′37″ E). The total genomic DNA was extracted from foot muscle by a modification of standard phenol–chloroform procedure. The complete mitogenome of N. subdilatata was sequenced by primer walking. The gene annotation was performed following the methods described by Hao et al. (Citation2016) and Online software (GeneMarker, tRNAscan, ORFfinder). At present, the specimen is stored in the herbarium of Dalian Ocean University.
The total length of the hybrid of N. subdilatata mt genome was 15,402 bp, with the base composition of 30.59% A, 38.42% T, 15.19% C, and 15.73% G. It is comprised of two ribosomal RNA genes, 13 protein-coding genes, and 18 transfer RNA genes. All the mitogenome genes were encoded on the heavy strand except for six tRNA genes (tRNA-Met, tRNA-Tyr, tRNA-Sup, tRNA-Gly, tRNA-Glu, and tRNA-Thr).
The phylogenetic analysis showed that the complete mt sequence of N. subdilatata was phylogenetically closer to N. arthritica cumingii by 99% bootstrap support, and formed the Buccinidae clade (). Our result was consistent with the previous researches, both in traditional morphological and molecular-based phylogeny studies. We expect that the present result can contribute to construct molecular identification of this species and be helpful to explore the phylogeny of Buccinidae.
Figure 1. Consensus neighbour-joining tree based on the complete mitochondrial sequence of N. subdilatata and other 12 mollusc species. The phylogenetic tree was constructed using MEGA 5.0 and DNAMAN 6.0 software by the neighbour-joining method. The numbers at the tree nodes indicate the percentage of bootstrapping after 1000 replicates.
Disclosure statement
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.
Additional information
Funding
References
- Hao Z, Yang L, Zhan Y, Tian Y, Wang L, Mao J, Chang Y. 2016. The complete mitochondrial genome of Neptunea arthritica cumingii Crosse, (Gastropoda: Buccinidae). Mitochondrial DNA B Resour. 1:220–221.
- Hou L, Dahms H, Dong C, Chen Y, Hou H, Yang W, Zou X. 2013. Phylogenetic positions of some genera and species of the family Buccinidae (Gastropoda Mollusca) from China based on ribosomal RNA and COI sequences. Chin Sci. 58:2315–2322.