Characterization of the First Complete Mitochondrial Genome of Cyphonocerinae (Coleoptera: Lampyridae) with Implications for Phylogeny and Evolution of Fireflies

Abstract

Simple Summary

The classification of Lampyridae has been extensively debated. Although some recent efforts have provided deeper insight into it, few genes have been analyzed for Cyphonocerinae in the molecular phylogenies, which undoubtedly influence elucidating the relationships of fireflies. In this study, we generated the first complete mitochondrial genome for Cyphonocerinae, with Cyphonocerus sanguineus klapperichi as the representative species. The comparative analyses of the mitogenomes were made between C . sanguineus klapperichi and that of well-characterized species. The results showed that the mitogenome of Cyphonocerinae was conservative in the organization and characters, compared with all other fireflies. Like most other insects, the cox1 gene was most converse, and the third codon positions of the protein-coding genes were more rate-heterogeneous than the first and second ones in the fireflies. The phylogenetic analyses suggested that Cyphonocerinae as an independent lineage was more closely related to Drilaster (Ototretinae). Nevertheless, more sampler species are needed in the reconstruction of fireflies’ phylogeny to verify this result.

Abstract

Complete mitochondrial genomes are valuable resources for phylogenetics in insects. The Cyphonoceridae represents an important lineage of fireflies. However, no complete mitogenome is available until now. Here, the first complete mitochondrial genome from this subfamily was reported, with Cyphonocerus sanguineus klapperichi as a representative. The mitogenome of C. sanguineus klapperichi was conserved in the structure and comparable to that of others in size and A+T content. Nucleotide composition was A+T-biased, and all genes exhibited a positive AT-skew and negative GC-skew. Two types of tandem repeat sequence units were present in the control region (136 bp × 2; 171 bp × 2 + 9 bp). For reconstruction of Lampyridae’s phylogeny, three different datasets were analyzed by both maximum likelihood (ML) and Bayesian inference (BI) methods. As a result, the same topology was produced by both ML analysis of 13 protein-coding genes and 2rRNA and BI analysis of 37 genes. The results indicated that Lampyridae, Lampyrinae, Luciolinae (excluding Emeia) were monophyletic, but Ototretinae was paraphyletic, of which Stenocladius was recovered as the sister taxon to all others, while Drilaster was more closely related to Cyphonocerinae; Phturinae + Emeia were included in a monophyletic clade, which comprised sister groups with Lampyridae. Vesta was deeply rooted in the Luciolinae.