title: Genetic variation and population structure in the endangered Hermann's tortoise: the roles of geography and human-mediated processes.
abstract: The Hermann's tortoise (Testudo hermanni) is an endangered land tortoise distributed in disjoint populations across Mediterranean Europe. We investigated its genetic variation by typing 1 mitochondrial locus and 9 nuclear microsatellites in approximately 300 individuals from 22 localities. Our goal was to understand the relative impact of natural and human-mediated processes in shaping the genetic structure and to identify the genetic priorities for the conservation of this species. We found that 1) all geographic areas are highly differentiated, mainly as a function of their distance but with a clear genetic discontinuity (F st values larger than 0.4) between the Eastern and the Western subspecies; 2) the contact zone between subspecies is located farthest to the west than previously believed, and it probably coincides with the delta of the largest Italian river; 3) extinction events due to climatic conditions in the Upper Palaeolithic and subsequent human-mediated translocations in the Neolithic possibly explain the unexpected similarity among Spain, Sicily, and Corsica. For conservation purposes, the large majority of genetic pools appears native although hybridization among subspecies, related to extensive 20th century trade of tortoises across Europe, is observed in Spain and some Italian samples. Most populations do not seem at immediate risk of low genetic variation, except the French population, which has very low nuclear genetic diversity (heterozygosity = 0.25) and where 50 out of 51 sampled animals shared the same mitochondrial sequence. In general, restocking and reintroduction plans should carefully consider the genetic background of the individuals.
authors.affiliation: Muséum National d'Histoire Naturelle, Département Systématique et Evolution, Université Pierre & Marie Curie, 75231 Paris cedex 05, France.
authors.forename: Melanie
authors.initials: M
authors.lastname: Perez
authors.forename: Barbara
authors.initials: B
authors.lastname: Livoreil
authors.forename: Sara
authors.initials: S
authors.lastname: Mantovani
authors.forename: Marie-Catherine
authors.initials: MC
authors.lastname: Boisselier
authors.forename: Barbara
authors.initials: B
authors.lastname: Crestanello
authors.forename: Jawad
authors.initials: J
authors.lastname: Abdelkrim
authors.forename: Céline
authors.initials: C
authors.lastname: Bonillo
authors.forename: Vassilis
authors.initials: V
authors.lastname: Goutner
authors.forename: Josie
authors.initials: J
authors.lastname: Lambourdière
authors.forename: Massimo
authors.initials: M
authors.lastname: Pierpaoli
authors.forename: Bogoljub
authors.initials: B
authors.lastname: Sterijovski
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Tomovic
authors.forename: Sibelle T
authors.initials: ST
authors.lastname: Vilaça
authors.forename: Stefano
authors.initials: S
authors.lastname: Mazzotti
authors.forename: Giorgio
authors.initials: G
authors.lastname: Bertorelle
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources; D004272:DNA, Mitochondrial / Q000235:genetics / Q000302:isolation & purification*; D005602:France; D056426:Genetic Loci; D014644:Genetic Variation; D006824:Hybridization, Genetic; D015810:Linkage Disequilibrium; D018895:Microsatellite Repeats; D058974:Phylogeography; D017422:Sequence Analysis, DNA; D014426:Turtles / Q000145:classification* / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial
keywords: Testudo hermanni; conservation; microsatellites; mtDNA; phylogeography; translocations