Diversification and evolutionary history of the African laminated-toothed rats (Rodentia, Otomyini)

Claudine Montgelard; Tanguy Muller; Véronique Arnal; Sarita Maree; Peter J Taylor; Arthur F Sands; Terence J Robinson; Conrad A Matthee

doi:10.1016/j.ympev.2023.107779

Diversification and evolutionary history of the African laminated-toothed rats (Rodentia, Otomyini)

Mol Phylogenet Evol. 2023 Jun:183:107779. doi: 10.1016/j.ympev.2023.107779. Epub 2023 Apr 3.

Authors

Claudine Montgelard¹, Tanguy Muller², Véronique Arnal², Sarita Maree³, Peter J Taylor⁴, Arthur F Sands⁵, Terence J Robinson⁶, Conrad A Matthee⁶

Affiliations

¹ CEFE, PSL-EPHE (Biogéographie et Ecologie des Vertébrés), CNRS, Univ. Montpellier, Univ. Paul Valéry Montpellier 3, IRD, Montpellier, France; Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Johannesburg, South Africa. Electronic address: claudine.montgelard@cefe.cnrs.fr.
² CEFE, PSL-EPHE (Biogéographie et Ecologie des Vertébrés), CNRS, Univ. Montpellier, Univ. Paul Valéry Montpellier 3, IRD, Montpellier, France.
³ Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa.
⁴ Department of Zoology and Entomology, Afromontane Research Unit, University of the Free State, Qwa Qwa Campus, Phuthaditjhaba, South Africa.
⁵ Evolutionary Genomics Group, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa; Area of Ecology and Biodiversity School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong SAR.
⁶ Evolutionary Genomics Group, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa.

PMID: 37019420
DOI: 10.1016/j.ympev.2023.107779

Abstract

The African continent was subjected to periodic climatic shifts during the Pliocene and Pleistocene. These habitat changes greatly affected the evolutionary processes and tempo of diversification in numerous, widely distributed mammals. The Otomyini (Family Muridae) comprises three African rodent genera, Parotomys, Otomys and Myotomys, characterized by unique laminated-shaped molars. Species within this tribe generally prefer open-habitat and show low dispersal capabilities, with previous studies suggesting that their diversification was closely associated with climatic oscillations over the last four million years. Our phylogenetic reconstructions, based on three mitochondrial (mtDNA) genes (Cytb, COI and 12S) and four nuclear introns (EF, SPTBN, MGF and THY), identified eight major genetic clades that are distributed across southern, eastern and western Africa. Our data permit the re-examination of the taxonomic status of the three genera as well as the previously proposed mesic-arid dichotomy of the 10 South African species. Moreover, multiple mtDNA species delimitation methods incorporating 168 specimens estimated the number of Otomyini species to be substantially higher than the ∼ 30 recognized, suggesting that the current taxonomy will necessitate an integrative approach to delimit extant species diversity within the Otomyini. The data suggests that the origin of the tribe can be dated back to ∼ 5.7 million years ago (Ma) in southern Africa. The distribution and phylogenetic associations among the eight major otomyine evolutionary lineages can best be explained by several waves of northward colonization from southern Africa, complemented by independent reversed dispersals from eastern back to southern Africa at different time periods. There is strong support for the hypothesis that the radiation, dispersion, and diversification of the otomyine rodents is closely linked to recent Plio-Pleistocene climatic oscillations.

Keywords: Barcoding analyses; Mitochondrial genes; Nuclear introns; Otomyini; Otomys, Paratomys, Myotomys; Plio-Pleistocene climatic oscillations.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Biological Evolution*
DNA, Mitochondrial / genetics
Ecosystem*
Murinae / genetics
Phylogeny
Rats

Substances

DNA, Mitochondrial