title: Genetic structure of fragmented southern populations of African Cape buffalo (Syncerus caffer caffer).
abstract: BACKGROUND
  African wildlife experienced a reduction in population size and geographical distribution over the last millennium, particularly since the 19th century as a result of human demographic expansion, wildlife overexploitation, habitat degradation and cattle-borne diseases. In many areas, ungulate populations are now largely confined within a network of loosely connected protected areas. These metapopulations face gene flow restriction and run the risk of genetic diversity erosion. In this context, we assessed the "genetic health" of free ranging southern African Cape buffalo populations (S.c. caffer) and investigated the origins of their current genetic structure. The analyses were based on 264 samples from 6 southern African countries that were genotyped for 14 autosomal and 3 Y-chromosomal microsatellites.
  
  
  RESULTS
  The analyses differentiated three significant genetic clusters, hereafter referred to as Northern (N), Central (C) and Southern (S) clusters. The results suggest that splitting of the N and C clusters occurred around 6000 to 8400 years ago. Both N and C clusters displayed high genetic diversity (mean allelic richness (A r ) of 7.217, average genetic diversity over loci of 0.594, mean private alleles (P a ) of 11), low differentiation, and an absence of an inbreeding depression signal (mean F IS = 0.037). The third (S) cluster, a tiny population enclosed within a small isolated protected area, likely originated from a more recent isolation and experienced genetic drift (F IS = 0.062, mean A r = 6.160, P a = 2). This study also highlighted the impact of translocations between clusters on the genetic structure of several African buffalo populations. Lower differentiation estimates were observed between C and N sampling localities that experienced translocation over the last century.
  
  
  CONCLUSIONS
  We showed that the current genetic structure of southern African Cape buffalo populations results from both ancient and recent processes. The splitting time of N and C clusters suggests that the current pattern results from human-induced factors and/or from the aridification process that occurred during the Holocene period. The more recent S cluster genetic drift probably results of processes that occurred over the last centuries (habitat fragmentation, diseases). Management practices of African buffalo populations should consider the micro-evolutionary changes highlighted in the present study.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Smitz
authors.forename: Daniel
authors.initials: D
authors.lastname: Cornélis
authors.forename: Philippe
authors.initials: P
authors.lastname: Chardonnet
authors.forename: Alexandre
authors.initials: A
authors.lastname: Caron
authors.forename: Michel
authors.initials: M
authors.lastname: de Garine-Wichatitsky
authors.forename: Ferran
authors.initials: F
authors.lastname: Jori
authors.forename: Alice
authors.initials: A
authors.lastname: Mouton
authors.forename: Alice
authors.initials: A
authors.lastname: Latinne
authors.forename: Lise-Marie
authors.initials: LM
authors.lastname: Pigneur
authors.forename: Mario
authors.initials: M
authors.lastname: Melletti
authors.forename: Kimberly L
authors.initials: KL
authors.lastname: Kanapeckas
authors.forename: Jonathan
authors.initials: J
authors.lastname: Marescaux
authors.forename: Carlos Lopes
authors.initials: CL
authors.lastname: Pereira
authors.forename: Johan
authors.initials: J
authors.lastname: Michaux
mesh_terms: D000353:Africa, Southern; D000818:Animals; D005075:Biological Evolution; D002020:Buffaloes / Q000235:genetics*; D033481:Chromosomes, Mammalian; D003247:Conservation of Natural Resources; D017753:Ecosystem; D051456:Gene Flow; D040961:Genetic Drift; D014644:Genetic Variation; D005828:Genetics, Population; D018895:Microsatellite Repeats; D014998:Y Chromosome