Mitochondrial DNA Variation in Southern Tunisian Populations.

Due to its complex history of migrations and colonization of African, European, and Asian people, the Tunisian territory is an ideal area to study the effects of cultural change on the genetic structure of human populations. This study investigated genetic variation in the mitochondrial DNA of Tunisian populations to detect the possible impact of recent historical events on their gene pool. Two Arab and three Berber communities were analyzed using a comparison data set of 45 other populations comprising African, Arabian, Asian, European, and Near Eastern groups. Results were compared with those produced using a large panel of autosomal single-nucleotide polymorphisms. We observed a slight but important difference between the populations that inhabit the southern and central-northern areas of Tunisia. Furthermore, robust signatures of genetic isolation were detected in two Berber populations (Nouvelle Zraoua and Tamezret) and in the R'Baya people, a seminomadic Arab group. This investigation suggests that the genetic structure of investigated southern Tunisian populations retains signatures of historical events that occurred between the 7th and 17th centuries, particularly the trans-Saharan slave trade and the emigration of Berbers in remote areas of the south during the Arab conquest. [ABSTRACT FROM AUTHOR]