ABSTRACT
Quasipaa boulengeri, an Asian spiny frog that belongs to Neobatrachia, has been reported as a de novo case of chromosomal rearrangements. In this paper, we determined the whole mitochondrial DNA (mtDNA) sequence of Q. boulengeri. The complete mtDNA sequence of Q. boulengeri is 17,741 bp in length, which contains 13 protein-coding genes (PCGs), two rRNAs, 23 tRNAs and one control region. The overall nucleotides base composition of the complete mtDNA is A (28.86%), G (14.43%), C (26.09%), T (30.62%), with a much higher A + T content. Compared to other Neobatrachia species, the mtDNA genome of Q. boulengeri shows a novel gene order at WANCY region.
Subject(s)
Anura/genetics , Genome, Mitochondrial , Animals , Chromosomes , Codon , DNA, Mitochondrial/genetics , Gene Rearrangement , Molecular Sequence Data , RNA, Ribosomal/genetics , RNA, Transfer/genetics , Sequence Analysis, DNA , Sequence Analysis, RNAABSTRACT
The 5' region of the mitochondrial DNA (mtDNA) gene cytochrome c oxidase I (COI) is the standard marker for DNA barcoding. However, because COI tends to be highly variable in amphibians, sequencing is often challenging. Consequently, another mtDNA gene, 16S rRNA gene, is often advocated for amphibian barcoding. Herein, we directly compare the usefulness of COI and 16S in discriminating species of hynobiid salamanders using 130 individuals. Species identification and classification of these animals, which are endemic to Asia, are often based on morphology only. Analysis of Kimura 2-parameter genetic distances (K2P) documents the mean intraspecific variation for COI and 16S rRNA genes to be 1.4% and 0.3%, respectively. Whereas COI can always identify species, sometimes 16S cannot. Intra- and interspecific genetic divergences occasionally overlap in both markers, thus reducing the value of a barcoding gap to identify genera. Regardless, COI is the better DNA barcoding marker for hynobiids. In addition to the comparison of two potential markers, high levels of intraspecific divergence in COI (>5%) suggest that both Onychodactylus fischeri and Salamandrella keyserlingii might be composites of cryptic species.
