Phylogenetic studies of sinipercid fish (Perciformes: Sinipercidae) based on multiple genes, with first application of an immune-related gene, the virus-induced protein (viperin) gene.

The sinipercid fish represent a group of 12 species of freshwater percoid fish endemic to East Asia. To date published morphological and molecular phylogenetics hypotheses of sinipercid fish are part congruent, and there are some areas of significant disagreement with respect to species relationships. The present study used separate and combined methods to analyze 7307 bp of data from three mitochondrial genes (cyt b, CO1 and 16S rRNA; approximately 2312 bp) and three nuclear genes (viperin, the first two introns of S7 ribosomal protein gene; approximately 4995 bp) for the attempts to estimate the relationships among sinipercids and to assess the phylogenetic utility of these markers. Phylogenetic trees were reconstructed using maximum parsimony, maximum likelihood and partitioned Bayesian analyses. Despite the detection of significant heterogeneity of phylogenetic signal between the mitochondrial and nuclear partitions, the combined data analysis represented the best-supported topology of all data. The sinipercid fish form a monophyletic group with two distinct clades, one corresponding to the genus Siniperca and the other to Coreoperca. Coreoperca whiteheadi is the sister taxon to Coreoperca herzi plus Coreoperca kawamebari. In the Siniperca, Siniperca undulata is the sister taxon to the other members of Siniperca, within the subclade containing the other members of the genus, Siniperca chuatsi and Siniperca kneri are sister species, next joined by Siniperca obscura, Siniperca roulei, Sinipercascherzeri and finally by Siniperca fortis. The potential utilities of six different genes for phylogenetic resolution of closely related sinipercid species were also evaluated, with special interest in that of the novel virus-induced protein (viperin) gene.