Molecular evolution of the family Camelidae: a mitochondrial DNA study

Abstract

We report the first molecular evolutionary analysis of the family Camelidae by analysing the full DNA sequence of the mitochondrial cytochrome b gene. Estimates for the time of divergence of the Old World (Camelini) and New World (Lamini) tribes obtained from sequence data are in agreement with those derived from the fossil record. The DNA sequence data were also used to test current hypotheses concerning the ancestors of the domesticated llama and alpaca. The results show that hybridization has occurred in the ancestry of both domesticated camelids, obscuring the origin of the domestic species.

Genetic analysis reveals the wild ancestors of the llama and the alpaca

“…The phylogenetic a¤liations of the llama and alpaca were ¢rst con¢rmed by sequencing a short (158 bp) but highly informative region of the cytochrome b gene of the mitochondrial genome sensu Stanley et al (1994) (GenBank accession numbers U06425^U06430). In total, 211 South American camelids were analysed from throughout the geographical range (comprising 21 guanaco, 42 vicu·a, 54 llama, 84 alpaca and the 10 hybrids described in table 1).…”

“…DNA samples were stored in TE bu¡er (10 mM Tris-HCl, 1mM EDTA, pH 8.0). The cytochrome b primers L14724 and H14900 were used for polymerase chain reaction (PCR), which was carried out as in Stanley et al (1994). PCR products were puri¢ed and DNA sequencing was carried out as previously described (Stanley et al 1994).…”

“…One Arabian camel was also analysed. Brie£y, DNA was extracted from blood or skin using standard proteinase-K digestion followed by organic extraction using phenol and phenol^chloroform, and total DNA was precipitated in 100% ethanol (Stanley et al 1994;Bruford et al 1998). DNA samples were stored in TE bu¡er (10 mM Tris-HCl, 1mM EDTA, pH 8.0).…”

“…The guanaco and vicu·a diverged from a common ancestor around two million years ago, and are the only representatives of the lamini to survive the Pleistocene period (Stanley et al 1994;Wheeler 1995). Archaeozoological evidence from the central Peruvian Andes links alpaca origins to the vicu·a at 6000^7000 years before present (Wheeler 1995).…”

Comparison of uteroplacental glycosylation in the camel (Camelus dromedarius) and alpaca (Lama pacos)

“…This was the first viable hybridization between the Old and New world camelids , and the result of 50 attempts to produce a cross between species that diverged 11 million years ago (Stanley et al, 1994). Jones et al (2000) suggested that glycan-glycan interactions at the fetomaternal interface may play a role in successful implantation and subsequent maintenance of pregnancy, and that interspecies differences in glycosylation may be one mechanism for blocking inappropriate hybridization.…”