On the phylogeny of Mustelidae subfamilies: analysis of seventeen nuclear non-coding loci and mitochondrial complete genomes

Background: Mustelidae, as the largest and most-diverse family of order Carnivora, comparises eight subfamilies. Phylogenetic relationships among these Mustelidae subfamilies remain argumentative subjects in recent years. One speciation even. Prior investigation has been concentrated on the applicaiton of different mitochodrial (mt) sequence and nuclear protein-coding data, herein we employ 17 nuclear non-coding (> 15 kb), in conjunction with mt complete genome data (> 16 kb), to clarify these enigmatic problems. Results: The combined nuclear intron and mt genome analyses both robustly support that Taxidiinae diverged first, followed by Meliane. Lutrinae and Mustelinae are grouped together in all analyses with strong supports. The position of Helictidinae. however, is enigmatic because the mt genome analysis places it to the clade uniting Lutrinae and Mustelinae. whereas the nuclear intron analysis favores a novel view supporting a closer relationship of Helictidinae to Mustelinae. This finding emphasizes a need to add more data and include more taxa to resolve this problem. In addition. the molecular dating provides into the time scale of origin and diversification of the Mustelidae subfamilies. Finally, the phylogenetic performances and limits of nuclear introns and mt genes are discussed in the context of Mustelidae phylogeny. Conclusion: Our study not only brings new perspectives on the perviously obscured phylogenetic relationships among Mustelidae subfamilies, but also provides another example demonstrating the effectiveness of nuclear non-coding loci for reconstructing evolutionary histories in a group that has undergone rapid bursts of speciation.