Three genetically divergent lineages of the Oryx in eastern Africa: Evidence for an ancient introgressive hybridization

Abstract

Phylogeographic and population genetic studies using sequence information are frequently used to infer species boundaries and history; and to assess hybridization and population level processes. In this study, partial mitochondrial DNA (mtDNA) control region (423 bp) and cytochrome b sequences (666 bp) of Oryx beisa sampled from five isolated localities in its entire current range in Africa were analyzed to investigate the extent of genetic variation and differentiation between populations. We observed high nucleotide diversity at the control region in the total sample (6.3%) but within populations, it varied considerably ranging from 1.6% to 8.1%. Population pairwise genetic differentiation was generally significantly high (ranging from F ST = 0.15, P<0.01 to F ST = 0.54, P<0.001). In the total sample, 29 and 12 haplotypes were observed in the control region and the cytochrome b data sets respectively. For both data sets, the haplotypes cluster into three distinct clades (sequence divergence ranged from 6.0%-12.9% to 0.8%-1.0% for the control region and cytochrome b sequences, respectively) that do not correspond to sampling locations. Two of these clades are found in the same localities (Samburu and Marsabit), which represent the O.beisa beisa subspecies, whereas the last clade represents the fringe-eared oryx (O. beisa callotis). We interpret these findings in terms of an ancient hybridization and introgression between two formerly isolated taxa of Oryx beisa.

The genetic status of two subspecies of Rhodeus atremius, an endangered bitterling in Japan

“…Therefore, in the completely admixed populations, one MU based on MS (Moritz 1994) seems most appropriate for conservation management than two ESUs based on mtDNA (Ryder 1986). Note that a comparable case was reported in Oryx beisa (Masembe et al 2006) and Pelophylax esculentus (Holsbeek et al 2009). Lineages III and IV based on mtDNA approximately coincided with groups B and C using MS respectively (Figs.…”

Application of mitochondrial genes sequences for measuring the genetic diversity of Arabian oryx

“…Thus, the existing population of Arabian oryx is comprised of different lineages originating from the founders animals. Recently, Masembe et al (2006) have pointed out the importance of conservation efforts for preserving the genetic identity of various oryx groups.…”

Genetic analysis of southern African gemsbok (Oryx gazella) reveals high variability, distinct lineages and strong divergence from the East African Oryx beisa

“…Amplification of a partial sequence of the mitochondrial control region was carried out with the primer pair MT4 (5 -CCTCCCTAAGACTCAAGGAAG-3 ; Arnason et al, 1993) and B16168H (5 -GGTTGCTGGTTTCACGCGGCATG-3 , Simonsen et al, 1998) as previously described for Oryx beisa by Masembe et al (2006). PCR reactions were carried out in a total volume of 75 l, including primers, dNTPs, reaction buffer, MgCl 2 , purified water, Promega Taq DNA-polymerase and 2 l DNA isolate.…”

“…in the Limpopo province in the north-east of South Africa (Knight, 1999), mainly on private game farms for the purpose of trophy and venison hunting. Previous studies have been carried out with respect to the genetic make-up of the northern oryx species (Masembe et al, 2006;Iyengar et al, 2007), but to date no population genetic analysis of the gemsbok has been done. The present study aims at filling this gap by addressing the following questions:…”