Phylogenetic utility of nuclear introns in interfamilial relationships of Caniformia (order Carnivora).
The monophyletic group Caniformia (dog-like carnivores) in the order Carnivora comprises 9 families. Except for the general consensus for the earliest divergence of Canidae and the grouping of Procyonidae and Mustelidae, conflicting phylogenetic hypotheses exist for the other caniformian families. In the present study, a data set comprising > 22 kb of 22 nuclear intron loci from 16 caniformian species is used to investigate the phylogenetic utility of nuclear introns in resolving the interfamilial relationships of Caniformia. Our phylogenetic analyses support Ailuridae as the sister taxon to a clade containing Procyonidae and Mustelidae, with Mephitinae being the sister taxon to all of them. The unresolved placements of Ursidae and Pinnipeds here emphasize a need to add more data and include more taxa to resolve this problem. The present study not only resolves some of the ambiguous relationships in Caniformia phylogeny but also shows that the noncoding nuclear markers can offer powerful complementary data for estimating the species tree. None of the newly developed introns here have previously been used for phylogeny reconstruction, thus increasing the spectrum of molecular markers available to mammalian systematics. Interestingly, all the newly developed intron data partitions exhibit intraindividual allele heterozygotes (IIAHs). There are 115 cases of IIAHs in total. The incorporation of IIAHs into phylogenetic analysis not only provides insights into the interfamilial relationships of Caniformia but also identifies two potential hybridization events occurred within Ursidae and Otariidae, respectively. Finally, the powers and pitfalls of phylogenetics using nuclear introns as markers are discussed in the context of Caniformia phylogeny.
Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, China. yuli1220@yahoo.com.cn
Li
L
Yu
Peng-Tao
PT
Luan
Wei
W
Jin
Oliver A
OA
Ryder
Leona G
LG
Chemnick
Heidi A
HA
Davis
Ya-Ping
YP
Zhang
D000818:Animals; D002335:Carnivora / Q000145:classification* / Q000235:genetics*; D002467:Cell Nucleus / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D007438:Introns; D010802:Phylogeny