Abstract
Sarcophaga ruficornis (Pape Citation1996) plays a significant role in medicolegal application for postmortem interval (PMI) estimation. The mitochondrial genome (mitogenome) has been broadly applied to phylogenetic analyses and species identification as a genetic marker. The complete mitogenome of S. ruficornis was first sequenced and analyzed. This study would strengthen our understanding of its phylogenetic relationship and contribute to taxonomic diagnosis.
Sarcophaga ruficornis (Diptera: Sarcophagidae) is a well-known flesh fly species of forensic importance (Suwannayod et al. Citation2013), whereas species identification is a crucial step in PMI estimation from entomological evidence. Molecular identification is a credible and rapid alternative method to identify species with lower standard of sample preserving, comparing to traditional morphological method (Ren et al. Citation2018).
The species of S. ruficornis occurs to distribute worldwide, which was collected in June 2018 in Changsha, China (28°90′N; 112°54′E) and then was stored at −80 °C in Guo's lab (Changsha city). The species was identified based on morphology. Genomic DNA extraction was conducted using the CTAB method. The complete mitogenome was conducted on an Illumina HiSeq 2500 Platform (Illumina, San Diego, CA). De novo assembly and annotation were performed by combining the results of MITOS and SOAPdenovo v. 2.0.
The complete mitogenome of S. ruficornis (GenBank accession no. MH937749) has typical gene arrangement with ancestral insect mitogenome order. It consists of 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a putative control region, which is 15,029 bp in length. According to the translations in the invertebrate mitochondrial codes, 12 of the 13 PCGs initiate with a typical initiation codon (ATN) in eight sacrophagids mitogenomes, in addition to the COI with the start codon of TCG. Moreover, except that the incomplete termination codon of T is used in COI, COII, ND4 and ND5 gene, the complete termination codons commonly used in the remaining PCGs are TAN. Among the 22 tRNAs, 21 of them can be folded into typical clover-leaf structure by tRNAScan-SE software except the tRNASer (AGN) could not be predicted for lacking a discernible dihydrouridine (DHU) stem, but it has been common in other metazoan mitogenomes.
The phylogenetic analysis indicated that S. ruficornis was closely related to the species of Sarcophaga portschinskyi (Pape Citation1996). Moreover, the genus Sarcophaga was clustered together into a monophyletic group (). Our data give considerable new insights into the phylogeny of S. ruficornis, and it can be used in further studies of species identification, evolutionary biology.
Figure 1. Phylogenetic analyse was constructed using neighbour-joining (NJ) method based on 13 protein-coding genes.
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The authors report no conflicts of interest.
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References
- Pape T. 1996. Catalogue of the Sarcophagidae of the World (Insecta: Diptera). Florida: Associated Publishers.
- Ren LP, Shang YJ, Chen W, Meng FM, Cai JF, Zhu GH, Chen LS, Wang Y, Deng JQ, Guo YD. 2018. A brief review of forensically important flesh flies (Diptera: Sarcophagidae). Forensic Sci Res. 3:16–26.
- Suwannayod S, Sanit S, Sukontason K, Sukontason KL. 2013. Parasarcophaga (Liopygia) ruficornis (Diptera:Sarcophagidae): a flesh fly species of medical importance. Trop Biomed. 30:174–180.