Geographic patterns of genetic variation in the greater Egyptian jerboa Jaculus orientalis (Dipodidae, Rodentia) from Tunisia

• We analyzed the genetic diversity and population structure of Jaculus orientalis in Tunisia using mitochondrial cytochrome b gene.
• Two major mitochondrial DNA clades corresponding to two haplogroups were recognized.
• The first clade included populations from northern and central Tunisia, while the second comprised the southern populations.
• High genetic differentiation and geographic structure between populations of the two clades were found.
• Importance of natural habitat, genetic variability and isolation on population structure were discussed.

The biogeographic area of Tunisia is characterized by several geographic and climatic zones that shaped the spatial distribution and genetic differentiation in many species. Despite the merit studies carried out on different species in this region, yet the distribution patterns of genetic diversity and taxonomy of many taxa remain unresolved. This study aimed to elucidate the geographic patterns of genetic variation in one of the endemic species of Tunisia, the greater Egyptian jerboa, Jaculus orientalis. The extent of phylogeographic patterns and molecular genetic diversity (mitochondrial cytochrome b gene) were addressed in a survey of 65 specimens from 11 localities. Twenty-four haplotypes were identified among populations which organized them into two well-supported clades separated by a higher genetic divergence (K2P = 1%; Фct = 0.65; P < 0.05). The first, clade I, included populations from the northern and central parts of Tunisia, while the second, clade II, comprised only populations from the southern part. Divergence between populations of the two clades would have occurred by Middle Pleistocene (ca. 0.71 Mya). Barrier Software showed that the populations of the two clades were separated by a geographical barrier, namely Chott El Jerid, located in the middle zone. Additionally, the clear distinction between the northern and central populations from those of the southern part was probably due to a Libyan origin of the latter.