Complete mitochondrial genome of the laced fritillary Argyreus hyperbius (Lepidoptera: Nymphalidae).

Abstract

We investigated the complete mitochondrial genome (mitogenome) of Argyreus hyperbius. The 15156 bp long genome harbored the gene content (13 protein coding genes, 22 tRNA genes, 2 rRNA genes and an A+T-rich region) and the gene arrangement was identical to all known lepidopteran mitogenomes. Mitogenome sequence nucleotide organization and codon usage analyses showed that the genome had a strong A+T bias, accounting for A+T content of 80.8%, with a small negative AT skew (-0.019). Eleven intergenic spacers totaling 96 bp, and 14 overlapping regions totaling 34 bp were scattered throughout the whole genome. As has been observed in other lepidopteran species, 12 of the 13 protein-coding genes (PCGs) were initiated by ATN codons, while the COI gene was tentatively designated by the CGA codon. A total of 11 PCGs harbored the complete termination codon TAA, while the COI and COII genes ended at a single T residue. All of the 22 tRNA genes showed typical clover structures except that the tRNA(Ser(AGN)) lacks the dihydrouridine (DHU) stem which is replaced by a simple loop. The intergenic spacer sequence between the tRNA(Ser(AGN)) and ND1 also contained the ATACTAA motif, which is conserved in all other lepidopterans as well. Additionally, the 349 bp A+T-rich region was not comprised of large tandem repetitive sequences, but harbored a few structures common to other lepidopteran insects, such as the motif ATAGA followed by a 20 bp poly-T stretch, a microsatellite-like (AT)(9) element preceded by the ATTTA motif, and a 5 bp poly-A site present immediately upstream of tRNA(Met). The mitochondrial genomic sequence features found in this study not only contribute to genetic diversity information of the group, but also are useful in future studies of the endangered nymphalid butterfly in population genetic dynamics, species conservation, phylogeography and evolution.