Gongora Jaime, Moran Chris
Centre for Advanced Technologies in Animal Genetics and Reproduction, Faculty of Veterinary Science, Gunn Building B19, University of Sydney, NSW 2006, Australia.
Mol Phylogenet Evol. 2005 Jan;34(1):181-9. doi: 10.1016/j.ympev.2004.08.021.
The three extant peccary species, the Chacoan (Catagonus wagneri), the White-lipped (Tayassu pecari) and the Collared (Pecari tajacu), are morphologically and chromosomally distinct and confined to the New World. There is ongoing paleontological, cytogenetic, and molecular debate about phylogenetic relationships among them. To contribute to the understanding of Tayassuidae phylogeny, three mitochondrial (control region, cytochrome b, and 12S rRNA) and five nuclear (K-casein, thyrotropin, tyrosinase, and swine short interspersed nuclear elements PRE-1 P27 and P642) peccary DNA fragments were amplified, cloned and sequenced from Chacoan, White-lipped, and Collared peccaries. Phylogenetic analyses were performed using maximum likelihood and neighbor joining methods. K-casein, thyrotropin, and tyrosinase sequences did not resolve the phylogeny, while control region, cytochrome b, 12S rRNA, and PRE-1 P27 and P642 sequences were more informative in deciphering phylogenetic relationships. When pig and warthog were used as an outgroup, Chacoan and White-lipped peccaries clustered distinct from Collared peccaries. Furthermore, control region and cytochrome b sequence variation within Collared peccaries was as extreme as that between White-lipped and Chacoan peccaries, supporting subspecific and possibly even specific variation within the widely distributed Collared peccary. This study supports the existence of two independent genera within the Tayassuidae family consisting of Collared and Chacoan/White-lipped peccaries, in contrast with classical morphological taxonomy which clusters White-lipped and Collared peccaries in the genus Tayassu or which alternatively clusters the Collared peccary in the genus Dicotyles as a related sister clade of the Chacoan peccary (genus Catagonus).
现存的三种西猯科动物,即查科豚鼠(Catagonus wagneri)、白唇西猯(Tayassu pecari)和领西猯(Pecari tajacu),在形态和染色体方面存在差异,且都分布于新大陆。关于它们之间的系统发育关系,古生物学、细胞遗传学和分子学领域一直存在争论。为了有助于理解西猯科的系统发育,从查科豚鼠、白唇西猯和领西猯中扩增、克隆并测序了三个线粒体(控制区、细胞色素b和12S rRNA)和五个核(K-酪蛋白、促甲状腺激素、酪氨酸酶以及猪短散在核元件PRE-1 P27和P642)西猯DNA片段。使用最大似然法和邻接法进行了系统发育分析。K-酪蛋白、促甲状腺激素和酪氨酸酶序列未能解析系统发育,而控制区、细胞色素b、12S rRNA以及PRE-1 P27和P642序列在解读系统发育关系方面提供了更多信息。当猪和疣猪作为外类群时,查科豚鼠和白唇西猯聚为一类,与领西猯不同。此外,领西猯内部的控制区和细胞色素b序列变异程度与白唇西猯和查科豚鼠之间的变异程度一样大,这支持了广泛分布的领西猯内部存在亚种甚至可能是种的变异。这项研究支持西猯科家族中存在两个独立的属,分别由领西猯和查科豚鼠/白唇西猯组成,这与传统形态分类学不同,传统形态分类学将白唇西猯和领西猯归为塔亚苏属(Tayassu),或者将领西猯归为双领西猯属(Dicotyles),作为查科豚鼠属(Catagonus)的相关姐妹进化枝。