Emilie Lecompte^1,2, Ken Aplin³, Christiane Denys¹, François Catzeflis⁴, Marion Chades⁴ and Pascale Chevret^4,5

¹UMR CNRS 5202, Origine, Structure et Evolution de la Biodiversité, Département Systématique et Evolution, Muséum National d'Histoire Naturelle, 55 rue Buffon, 75005 Paris, France

²UMR CNRS/UPS 5174 "Evolution et Diversité Biologique" EDB, Université Paul Sabatier, Bat. 4R3, 118 route de Narbonne, 31062 Toulouse cedex 9, France

³Australian National Wildlife Collection, CSIRO Division of Sustainable Ecosystems, GPO Box 284, Canberra, ACT 2601, Australia

⁴Laboratoire de Paléontologie, Phylogénie et Paléobiologie – CC064, Institut des Sciences de l'Evolution (UMR 5554/CNRS), Université Montpellier II, Place E. Bataillon, 34 095 Montpellier Cedex 05, France

⁵Equipe Zoologie Moléculaire, Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, CNRS, INRA, ENS de Lyon 46, Allée d'Italie 69007 Lyon, France

BMC Evolutionary Biology 2008, 8:199. An Open Access article distributed under the terms of the Creative Commons Attribution License.

Abstract

Background

Within the subfamily Murinae, African murines represent 25% of species biodiversity, making this group ideal for detailed studies of the patterns and timing of diversification of the African endemic fauna and its relationships with Asia. Here we report the results of phylogenetic analyses of the endemic African murines through a broad sampling of murine diversity from all their distribution area, based on the mitochondrial cytochrome b gene and the two nuclear gene fragments (IRBP exon 1 and GHR).

Results

A combined analysis of one mitochondrial and two nuclear gene sequences consistently identified and robustly supported ten primary lineages within Murinae. We propose to formalize a new tribal arrangement within the Murinae that reflects this phylogeny. The diverse African murine assemblage includes members of five of the ten tribes and clearly derives from multiple faunal exchanges between Africa and Eurasia. Molecular dating analyses using a relaxed Bayesian molecular clock put the first colonization of Africa around 11 Mya, which is consistent with the fossil record. The main period of African murine diversification occurred later following disruption of the migration route between Africa and Asia about 7–9 Mya. A second period of interchange, dating to around 5–6.5 Mya, saw the arrival in Africa of Mus (leading to the speciose endemic Nannomys), and explains the appearance of several distinctive African lineages in the late Miocene and Pliocene fossil record of Eurasia.

Conclusion

Our molecular survey of Murinae, which includes the most complete sampling so far of African taxa, indicates that there were at least four separate radiations within the African region, as well as several phases of dispersal between Asia and Africa during the last 12 My. We also reconstruct the phylogenetic structure of the Murinae, and propose a new classification at tribal level for this traditionally problematic group.