Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Journal of Biogeography 2237-2250 Africa Mastomys erythroleucus mtDNA phylogeography Quaternary history rodent savanna sub-Sahara 2009 fdi:010048401 ENG Journal of Biogeography 0305-0270 ISI:000271902200006 12 10.1111/j.1365-2699.2009.02184.x https://www.documentation.ird.fr/hor/fdi:010048401 https://www.documentation.ird.fr/intranet/publi/2009/12/010048401.pdf 36 Horizon (IRD) Aim To investigate the phylogeographical structure of the Guinea multimammate mouse, Mastomys erythroleucus (Temminck, 1853), a widespread murid rodent in sub-Saharan (Sahel and Sudan) savannas, for a better understanding of the impacts of geographical and historical factors on the evolutionary history of this species, in the context of the growing database of phylogeographical studies of African savanna mammal species. Location Sahel and Sudan savannas, Africa. Methods We sequenced the whole cytochrome b gene in 211 individuals from 59 localities distributed from Senegal to Ethiopia. Sequence data were analysed using both phylogenetic (several rooted tree-construction methods, median-joining networks) and population genetic methods (spatial analyses of molecular variance, mismatch distributions). Results Haplotypes were distributed into four major monophyletic groups corresponding to distinct geographical regions across a west-east axis. Diversification events were estimated to have occurred between 1.16 and 0.18 Ma. Main conclusions Vicariance events related to the fragmentation of savanna habitats during the Pleistocene era may explain the phylogeographical patterns observed. Genetic structure was consistent with a role of major Sahelian rivers as significant barriers to west-east dispersal. Recent demographic expansions probably occurred during arid phases of the Holocene with the southward expansion of savannas. 080 UR022