The complete mitochondrial genome of the firefly, Luciola curtithorax (Coleoptera: Lampyridae)

Abstract We report the complete mitochondrial genome of firefly, Luciola curtithorax. The circular genome of 16,882 bp has a base composition of A (44.98%), C (11.84%), G (8.15%), and T (35.03%). Our sequence is similar to other Metazoa, which contains 13 protein-coding genes. All 13 protein-coding genes were initiated by the ATN (ATT, ATA, and ATG) codon. Ten protein-coding genes stopped with TAA or TAG codon and the other three genes have an incomplete termination codon, a single T––. We sequenced the mitochondrial genome of fireflies to analyze phylogenetic relationships and deduce the evolution of their flashing signals.

Fireflies are a family of insects in the beetle order Coleoptera. Using morphological characters, 12 species of genus Luciola had known from Taiwan (Matsumura 1928;Pic 1928;Jeng et al. 2003). Luciola curtithorax Pic, 1928 is found in Taiwan, China (Pic 1928). It is distributed from Vietnam, and it is also widely distributed in adjacent Chinese provinces of Hainan, Hubei, Hongkong, and Taiwan (Fu 2014).
Mitochondrial genome sequences are essential to a comprehensive understanding of the evolution of Lampyridae and other luminescent beetles (Ermakov et al. 2006). Here, we elucidate the mtDNA genome of L. curtithorax.
These male fireflies used in this study were collected from Xiapu Town, Tongshan County, Hubei Province, China, in 13 July 2016, and were stored in Natural History Museum, Huazhong Agricultural University, Wuhan, Hubei, China (its accession no. is LC2016071301). L. curtithorax's habits, flashing signals, and some morphology have been studied in detail (Pic 1928). However, there is no genetic research information about L. curtithorax.
Specific primers were designed based on these conserved regions sequences. The PCR reaction was carried out with LA Taq polymerase for 35 cycles at 94 C for 30 s, and annealed at 50 C for 30 s, followed by extension at 72 C for 1 min per 1 kb. Sequences were assembled using the software DNAstar v7.1 (Madison, WI) and adjusted manually to generate the complete sequence of mitochondrial DNA.
The phylogenetic tree among the eight species based on mitochondrial genome sequences were aligned in MEGA 5 (Phoenix, AZ) (with 1000 bootstrap replicates) to construct a Neighbour-Joining tree (Figure 1).
The result shows that L. curtithorax is most closely related to L. cruciata, which belongs to an entirely different genus in the Lampyridae.
In conclusion, the complete mitochondrial genome sequence of L. curtithorax provides an important molecular framework for further phylogenetic analyses of fireflies. These data are essential for comprehensive understanding of the