title: Mitochondrial phylogeny reveals differential modes of chromosomal evolution in the genus Tatera (Rodentia: Gerbillinae) in Africa.
abstract: The African gerbils of the genus Tatera are widespread and abundant throughout sub-Saharan Africa. There is still today a certain controversy concerning the taxonomy of these rodents and very few attempts have been made to assess their systematic relationships. The present paper introduces findings based on the partial sequences of cytochrome b (495 bp) and the 16S rRNA (469 bp) mitochondrial genes of six (T. robusta, T. nigricauda, T. vicina, T. leucogaster, T. valida, and T. kempi) species together with two additional taxa. We also report the karyotypes of T. vicina and T. leucogaster. We propose that T. vicina should be considered as a valid species and show the monophyly of the robusta species group, with the exclusion of T. leucogaster. Our results show there is a different chromosomal evolutionary pattern within the two major lineages, which is recognizable through molecular phylogenetics. One is characterized by karyotype stability and the other by a considerable number of chromosomal rearrangements. The lineage divergence coincides with the formation of the East African Rift. The processes that led to the origin of the East African species seem to be related to the subsequent climatic changes, which caused cyclic contraction and expansion of the savannah biomes. Furthermore, geological activities that characterized East Africa during Plio-Pleistocene may also have contributed to lineage divergence.
authors.affiliation: Dipartimento di Biologia Animale e dell'Uomo, Università di Roma La Sapienza, Via Borelli 50, 00161 Roma, Italy. paolo.colangelo@uniroma1.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Colangelo
authors.forename: Marco
authors.initials: M
authors.lastname: Corti
authors.forename: Erik
authors.initials: E
authors.lastname: Verheyen
authors.forename: Flavia
authors.initials: F
authors.lastname: Annesi
authors.forename: Nicholas
authors.initials: N
authors.lastname: Oguge
authors.forename: Rhodes H
authors.initials: RH
authors.lastname: Makundi
authors.forename: Walter
authors.initials: W
authors.lastname: Verheyen
mesh_terms: D000349:Africa; D000818:Animals; D001483:Base Sequence; D033481:Chromosomes, Mammalian / Q000235:genetics*; D016000:Cluster Analysis; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D005843:Geography; D005849:Gerbillinae / Q000235:genetics*; D007621:Karyotyping; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial