title: Sampling strategies in a linguistic isolate: results from mtDNA analysis.
abstract: OBJECTIVE
  Sampling strategies are crucial issues in population genetics and anthropological studies. The sampling choice is related to the research question and the type of markers used. In this research, we compared two different sampling strategies in the Sardinian linguistic isolate of Carloforte (Italy).
  
  
  METHODS
  A first sampling (N = 49) was carried out through grandparents criterion: individuals selected for the study were born and resident in Carloforte, and unrelated for at least three generations. A second sampling (N = 50) was based on founders surnames (FS): selected participants were proved to be descendants of the village founders, and to have no ancestors in common, at least up to the grandparental generation.
  
  
  RESULTS
  The group selected through FS showed a greater gene diversity, which was confirmed by both network and haplogroup analysis. Among the shared haplogroups, we find clear differences in their frequencies. Sampling through grandparents criterion showed essentially the same haplogroups found in Sardinia, and with similar frequencies. Interesting results came from genetic tree. The FS sampling clustered with Northern African populations and it is located very far from Italian and Sardinian populations, whereas the grandparents criterion sampling clustered with Italian populations and it is located close to the other Sardinian populations.
  
  
  CONCLUSIONS
  Results showed that different sampling strategies can lead to contrasting results. As sampling through grandparents criterion is influenced by recent gene flow, we hypothesize that the difference observed with the two sampling strategies is due to the merging of Carloforte with Sardinian populations.
authors.affiliation: Department of Experimental Biology, University of Cagliari, 09042 Monserrato, Italy.
authors.forename: Carla Maria
authors.initials: CM
authors.lastname: Calò
authors.forename: Laura
authors.initials: L
authors.lastname: Corrias
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vona
authors.forename: Valeria
authors.initials: V
authors.lastname: Bachis
authors.forename: Renato
authors.initials: R
authors.lastname: Robledo
mesh_terms: D000328:Adult; D004272:DNA, Mitochondrial / Q000032:analysis*; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population / Q000379:methods*; D006239:Haplotypes; D006801:Humans; D007558:Italy; D007802:Language; D008037:Linguistics / Q000379:methods; D008297:Male; D012494:Sampling Studies
chemical_list: D004272:DNA, Mitochondrial