Phylogenetic divisions among Collared peccaries (Pecari tajacu) detected using mitochondrial and nuclear sequences

Abstract

The Collared peccary (Pecari tajacu) is one of the three extant recognised species of the family Tayassuidae, living in the Americas. To understand phylogenetic relationships among Collared peccaries, the entire mitochondrial DNA control region and cytochrome b as well as partial nuclear GPIP and PRE-1 P27, PRE-1 P642 and TYR sequences from specimens from Colombia, Argentina, Bolivia, Mexico, United States and Australian zoo animals of unknown origin were analysed. Separate and combined analyses of the mitochondrial sequences provided good resolution of Collared peccary relationships. Nuclear sequences were partially informative when combined sequence analyses were performed. Maximum Likelihood analyses of mitochondrial sequences showed that Collared peccaries clustered in two major clades, representing North-Central American and South American specimens. Collared peccaries from Colombia are paraphyletic. Statistical Parsimony analysis of combined nuclear sequences showed a distribution of DNA variants consistent with mitochondrial sequence analyses. However, there is an uncoupling of nuclear and mitochondrial sequence variation in two specimens from Colombia. The present study suggests the recent contact of isolated populations within Colombia and possible mitochondrial introgression between the North/Central clade and the South clade. Pairwise genetic distances comparison of mitochondrial sequences show that divergence between the two major clades of the Collared peccary was higher and comparable respectively with that within and between the other two recognised peccary species. Divergence between the two major clades of the Collared peccary was also higher than that observed within and even between recognised species of the Suidae family. The divergence within the major clades of the Collared peccary showed comparable values with those observed within the other two species of Tayassuidae and within six species of Suidae. The results show that the geographically widespread and phenotypically diverse Collared peccary consists of two species or at least subspecies with implications for management of wild, zoo and captive populations.