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Gauthier Dobigny - One of the best experts on this subject based on the ideXlab platform.
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Fossils know it best: Using a new set of fossil calibrations to improve the temporal phylogenetic framework of murid rodents (Rodentia: Muridae)
Molecular Phylogenetics and Evolution, 2018Co-Authors: Tatiana Aghova, Gauthier Dobigny, Laurent Granjon, Yuri Kimura, Josef Bryja, Gael KergoatAbstract:Murid rodents (Rodentia: Muridae) represent the most diverse and abundant mammalian family. In this study, we provide a refined set of fossil calibrations which is used to reconstruct a dated phylogeny of the family using a multilocus dataset (six nuclear and nine mitochondrial gene fragments) encompassing 161 species representing 82 murid genera from four extant subfamilies (Deomyinae, Gerbillinae, Lophiomyinae and Murinae). In comparison with previous studies on murid or muroid rodents, our work stands out for the implementation of nine robust fossil constraints within the Muridae thanks to a thorough review of the fossil record. Before being assigned to specific nodes of the phylogeny, all potential fossil constraints were carefully assessed; they were also subjected to several cross-validation analyses. The resulting phylogeny is consistent with previous phylogenetic studies on murids, and recovers the monophyly of all sampled murid subfamilies and tribes. Based on nine controlled fossil calibrations, our inferred temporal timeframe indicates that the murid family likely originated in the course of the Early Miocene, 22.0-17.0 million years ago (Ma), and that most major lineages (i.e. tribes) started diversifying ca. 10 Ma. Historical biogeography analyses support the tropical origin for the family, with an initial internal split (vicariance event) between Afrotropical and Oriental (Indomalaya and Philippines) lineages. During the course of their diversification, the biogeographic pattern of murids is marked by several dispersal events toward the Australasian and the Palearctic regions. The Afrotropical region was also secondarily colonized a least three times from the Indomalaya, indicating that the latter region has acted as a major centre of diversification for the family.
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Integrative taxonomy of a poorly known Sahelian rodent, Gerbillus nancillus (Muridae, Gerbillinae)
Zoologischer Anzeiger, 2014Co-Authors: Arame Ndiaye, Gauthier Dobigny, Karmadine Hima, Aliou Sow, Ambroise Dalecky, Massamba Thiam, Laurent GranjonAbstract:Aridification processes that affected the Sahelian area of West Africa during the last decades have induced significant changes in plant and animal communities of this region. In rodents, the genus Gerbillus characteristic of North African and Asian arid habitats has been affected by this climatic and environmental trends. Several species of this genus showed a southward range expansion in recent years into the Sahelian bioclimatic zone. Recent sampling in several localities of West Africa (Mali, Niger and Senegal) enabled us to collect numerous specimens of small gerbils. An integrative study of these samples using molecular, morphological and cytogenetical methods revealed that many of them were attributable to Gerbillus nancillus, a secretive and poorly known species. Gerbillus nancillus appears characterized by a well differentiated karyotype with 2n = 56 chromosomes, and to represent a unique genetic lineage within this genus. Body and skull measurements of G. nancillus were compared with those of the morphologically similar Gerbillus henleyi, which provided diagnostic clues between them. These new data significantly expand the distribution area of G. nancillus, which now ranges from Sudan in the East to Senegal in the West. G. nancillus is here reported from numerous new localities in Niger and Mali, and for the first time in Senegal, which raises questions about the origin of its presence and the colonization routes it followed to get there. We also show that G. henleyi and G. nancillus are sympatric and apparently often syntopic in the sub-Saharan part of the distribution of G. henleyi.
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intrageneric relationships within gerbilliscus rodentia muridae Gerbillinae with characterization of an additional west african species
Zootaxa, 2012Co-Authors: Laurent Granjon, Gauthier Dobigny, Paolo Colangelo, Caroline Tatard, Marc Colyn, Violaine NicolasAbstract:The systematics of the African rodent genus Gerbilliscus is still a matter of debate. At the genus level it has been said toinclude the related genus Gerbillurus, and at the species level some species still need to be definitely recognized as dis-tinct. To tackle these questions, we gathered and analyzed mitochondrial (cytochrome b) and nuclear (BRCA1) gene se-quences in a number of specimens representing ten species of Gerbilliscus and three species of Gerbillurus. Phylogeneticreconstructions confirm that Gerbillurus should be considered a synonym of Gerbilliscus. They also clearly show that spe-cies diversity in this group is spatially organized, with geographically well-defined species groups covering major areasof sub-Saharan Africa, namely Southern, Eastern and Western Africa. In the latter area, a well-supported genetic lineageappears to correspond to a hitherto overlooked species, also characterized by a distinctive karyotype. This species is char-acterized by an overall large size, a relatively long tail, a distinct karyotype, and represents a well-differentiated geneticcluster. It ranges from Benin to Guinea in Sudano-Guinean forest-savanna mosaic habitats, where it can be sympatric withthe congeneric species G. kempi and G. guineae. Detailed body and skull morphological and biometrical analyses per-formed on samples of the West African species, including type specimens described in this region, suggest that this speciesmay correspond to G. kempi. If confirmed, this would imply that what is currently named G. kempi would deserve another species name, the most likely of which would be G. giffardi.
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unusually extensive karyotype reorganization in four congeneric gerbillus species muridae Gerbillinae
Cytogenetic and Genome Research, 2006Co-Authors: V M Aniskin, Gauthier Dobigny, T Benazzou, Laurent Granjon, Larisa S Biltueva, V. VolobouevAbstract:Comparative analysis of the G- and C-banding patterns in four morphologically poorly differentiated Gerbillus species (G. pyramidum, G. perpallidus, G. tarabuli and G. occiduus) was carried out. These gerbils have similar karyotype morphology with 2n and NF equal to 38/76, 40/76, 40/78 and 40/80, respectively. Our study revealed that possibly 70 Robertsonian (Rb) fusions, two pericentric inversions, one tandem translocation and at least 13 non-identified rearrangements have occurred during the karyotypic evolution of these species. The number of chromosomal changes by which any of these species differ from each other ranges from 33 to 49. One Rb fusion was common to two of the species, with only a single autosome-gonosome translocation shared by all four, suggesting a monophyletic origin of these karyotypically highly divergent species. Based on the chromosomal data obtained here, the systematic and geographic implications for these North African species are also discussed.
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Recent radiation in West African Taterillus (Rodentia, Gerbillinae): the concerted role of chromosome and climatic changes
Heredity, 2005Co-Authors: Gauthier Dobigny, L Granjon, V Aniskin, R Cornette, V. VolobouevAbstract:West African gerbils of the genus Taterillus constitute a complex of seven sibling species distributed from sudano-guinean to saharo-sahelian regions. They display radically rearranged karyotypes despite low genic divergence and a very recent differentiation, that is, within the last 0.4 Myr for the six most derived species. We here provide a comparison of the seven specific karyotypes and perform a cladistic analysis using chromosomal rearrangements character states. When a posteriori polarized mutations were mapped onto the phylogenetic tree, 38 rearrangements were identified as fixed during the evolution of these rodents. This makes Taterillus one of the most striking examples of accelerated chromosomal evolution within placental mammals. Taking into account the types of chromosomal changes involved, divergence times between lineages, genetic distances, as well as reassessed geographic distributions, we suggest that (1) speciation in West African Taterillus was driven by chromosomal changes, and (2) the paleoclimatic oscillations of the Sahara desert have played a major role in their evolution. In particular, elevated plasticity of the Taterillus genome, as suggested by the patterns observed for some repetitive elements, would have led to a higher probability of mutation. We hypothesize that the process underpinning cladogenesis most probably involved highly underdominant genomic rearrangements that were fixed following pronounced populational bottlenecks resulting from drastic climatic and subsequent environmental changes. Major African rivers formed significant barriers to dispersal, limiting expansion during the more moist and so favorable periods. This scenario would explain the current parapatric species distributions and their relationship to the West African hydrographic features.
V. Volobouev - One of the best experts on this subject based on the ideXlab platform.
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chromosome banding study in Gerbillinae rodentia i comparative analysis of gerbillus poecilops g henleyi and g nanus
Journal of Zoological Systematics and Evolutionary Research, 2009Co-Authors: V. Volobouev, M Lombard, M. Tranier, Bernard DutrillauxAbstract:An analysis was made of the R- and C-banding of chromosomes of the following Gerbillus species (Rodentia, Gerbillidae): G. poecilops (Taif, Saudi Arabia), G. henleyi (Oursi, Burkina Faso; Kairouan, Tunisia), and G. nanus (Taif and Hofuf, Saudi Arabia; Sind desert, Pakistan). Their karyotypes show the same chromosome number (2n – 52), but a different N.F.a. (number of autosomal arms), ranging from 58 to 62 in the species overall, and from 58 to 60 among G. nanus forms, due to pericentric inversions involving chromosomes 1 and 4. Moreover, large inter-individual variations of heterochromatin segments of chromosomes 25, X, and Y were found. Considering morphology and karyotype, G. poecilops and G. henleyi appear to be rather monomorphous species, whereas G. nanus produces a series of forms as a consequence of speciation, in which both chromosomal and morphological differentiations occur that do not correlate. Resume Marquage chromosomique des Gerbillinae (Rodentia). I. L'analyse comparee de Gerbillus poecilops, G. henleyi et G. nanus L'analyse du marquage chromosomique en bandes R et C de Gerbillus poecilops, en provenance de Taif (Arabie Saoudite), G. henleyi, en provenance de Oursi (Burkina Faso) et de Kairouan (Tunisie) et de G. nanus, en provenance de Taif et Hofuf (Arabie Saoudite) et du desert de Sind (Pakistan) a revele que les trois especes ont un nombre chromosomique 2n = 52 mais les N.F.a. varient de 58 a 62 selon les especes, et de 58 a 60 dans l'espece G. nanus, en raison d'inversions pericentriques impliquant les chromosomes 1 et 4. La paire 25 et les chromosomes X et Y, possedent un grand segment d'heteochromatine, ont une taille variable selon les individus. G. poecilops et G. henleyi paraissent monomorphes morphologiquement et caryotypiquement alors que G. nanus est probablement constitute d'une serie de formes en voie de speciation, ou les debuts de differenciations morphologique et karyotypique s'ajoutent sans Etre apparemment correles. Zusammenfassung Untersuchungen an Chromosomen von Springmaus-Arten (Gerbillinae, Rodentia) mit Hilfe von Banderungs-Techniken. I. Vergleich von Gerbillus poecilops, G. henleyi und G. nanus Eine Analyse der Chromosomen von Gerbillus poecilops (Herkunft Taif, Saudi-Arabien), G. henleyi (Herkunft Oursi, Burkina Faso, und Kairoun, Tunesien) und G. nanus (Herkunft Taif und Hofuf, Saudi-Arabien und Sind-Wuste, Pakistan) zeigt nach R- und C-Banderung, das alle drei Arten 52 Chromosomen (2n = 52) besitzen, das aber die Zahl der Chromosomen-Arme der Autosomen (N.F.a.) variiert; zwischen 58 und 62, wenn alle drei Arten verglichen werden, und zwischen 58 und 60 innerhalb der Art G. nanus. Ursache dafur sind perizentrische Inversionen auf den Chromosomen 1 und 4. Das Homologenpaar 25 und die Chromosomen X und Y besitzen grose heterochromatische Abschnitte, die von Individuum zu Individuum stark schwanken. G. poecilops und G. henleyi erwiesen sich morphologisch und karyologisch als monomorphe Arten, wahrend sich G. nanus vermutlich als Folge von beginnender Artaufspaltung aus einer Reihe von unterschiedlichen Formen zusammensetzte, wobei die morphologischen und die karyologischen Differenzierungen aber keine Korrelation erkennen liesen.
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unusually extensive karyotype reorganization in four congeneric gerbillus species muridae Gerbillinae
Cytogenetic and Genome Research, 2006Co-Authors: V M Aniskin, Gauthier Dobigny, T Benazzou, Laurent Granjon, Larisa S Biltueva, V. VolobouevAbstract:Comparative analysis of the G- and C-banding patterns in four morphologically poorly differentiated Gerbillus species (G. pyramidum, G. perpallidus, G. tarabuli and G. occiduus) was carried out. These gerbils have similar karyotype morphology with 2n and NF equal to 38/76, 40/76, 40/78 and 40/80, respectively. Our study revealed that possibly 70 Robertsonian (Rb) fusions, two pericentric inversions, one tandem translocation and at least 13 non-identified rearrangements have occurred during the karyotypic evolution of these species. The number of chromosomal changes by which any of these species differ from each other ranges from 33 to 49. One Rb fusion was common to two of the species, with only a single autosome-gonosome translocation shared by all four, suggesting a monophyletic origin of these karyotypically highly divergent species. Based on the chromosomal data obtained here, the systematic and geographic implications for these North African species are also discussed.
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Recent radiation in West African Taterillus (Rodentia, Gerbillinae): the concerted role of chromosome and climatic changes
Heredity, 2005Co-Authors: Gauthier Dobigny, L Granjon, V Aniskin, R Cornette, V. VolobouevAbstract:West African gerbils of the genus Taterillus constitute a complex of seven sibling species distributed from sudano-guinean to saharo-sahelian regions. They display radically rearranged karyotypes despite low genic divergence and a very recent differentiation, that is, within the last 0.4 Myr for the six most derived species. We here provide a comparison of the seven specific karyotypes and perform a cladistic analysis using chromosomal rearrangements character states. When a posteriori polarized mutations were mapped onto the phylogenetic tree, 38 rearrangements were identified as fixed during the evolution of these rodents. This makes Taterillus one of the most striking examples of accelerated chromosomal evolution within placental mammals. Taking into account the types of chromosomal changes involved, divergence times between lineages, genetic distances, as well as reassessed geographic distributions, we suggest that (1) speciation in West African Taterillus was driven by chromosomal changes, and (2) the paleoclimatic oscillations of the Sahara desert have played a major role in their evolution. In particular, elevated plasticity of the Taterillus genome, as suggested by the patterns observed for some repetitive elements, would have led to a higher probability of mutation. We hypothesize that the process underpinning cladogenesis most probably involved highly underdominant genomic rearrangements that were fixed following pronounced populational bottlenecks resulting from drastic climatic and subsequent environmental changes. Major African rivers formed significant barriers to dispersal, limiting expansion during the more moist and so favorable periods. This scenario would explain the current parapatric species distributions and their relationship to the West African hydrographic features.
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a new sibling species of taterillus muridae Gerbillinae from west africa
Mammalian Biology, 2003Co-Authors: Gauthier Dobigny, Laurent Granjon, V M Aniskin, V. VolobouevAbstract:Modern systematics can now rely on powerful discriminating techniques, such as cytogenetics. As a result, a growing number of sibling species has been described in a variety of taxa. Among mammals, this is particularly true in rodents. Here, we describe a new species of Taterillus (Rodentia, Gerbillinae), namely Taterillus tranieri sp. n. based on specimens from Mali and Mauritania. Neither external and cranial morphology nor morphometrics taking size and shape into account could lead to a satisfying diagnosis of this species relative to the four West African species known in this genus. Conversely, this new species could be characterized by a very specific karyotype (with 2N = 14/15, the lowest diploid number in gerbilline rodents, NFa = 22-24) differing from that of its closest relative Taterillus petteri (2N = 18/19, NFa = 28) by two tandem translocations accompanied by 2 centromere activations/desactivations, one non reciprocal translocation, and three pericentric inversions. In addition to providing non-ambiguous arguments in favour of the description of this taxon as a new biological species, these chromosomal results confirm the complex karyoty-pic evolution of Taterillus. Furthermore, this study illustrates how cytogenetics can contribute to the description of sibling species and hence to biodiversity. These cryptic taxa also constitute valuable support for evolutionary studies, especially concerning speciation processes. They also represent important issues in applied research such as in conservation biology or pest species control. The routine use of cytogenetics for species characterization will undoubtedly constitute a powerful diagnostic tool in these contexts.
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evolution of rrna gene clusters and telomeric repeats during explosive genome repatterning in taterillus x rodentia Gerbillinae
Cytogenetic and Genome Research, 2003Co-Authors: Gauthier Dobigny, C Ozoufcostaz, C Bonillo, V. VolobouevAbstract:A survey of 28S and 5S rRNA gene clusters, and telomeric repeats was performed using single and double FISH in the Taterillus genus (Rodentia, Muridae, Gerbillinae). Taterillus was previously demonstrated to have undergone a very recent and extensive chromosomal evolution. Our FISH results demonstrate that rRNA genes can vary in location and number irrespective of the phylogenetic relationships. Telomeric repeats were detected in pericentromeric and interstitial regions of several chromosomes, thus providing nonambiguous evolutionary footprints of Robertsonian and tandem translocation events. These footprints are discussed in reference to the molecular process of these karyotypical changes. Also, examples of colocation of rDNA clusters and telomeric repeats lend support to their possible involvement in nucleolus formation. Finally, the presence of rRNA genes, and the extensive amplification of telomeric repeats at specific loci within a double X-autosome translocated element which were not observed on the homologous Y1 and Y2, served as basis for an epigenomic hypothesis on X-autosome translocation viability in mammals.
Paolo Colangelo - One of the best experts on this subject based on the ideXlab platform.
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intrageneric relationships within gerbilliscus rodentia muridae Gerbillinae with characterization of an additional west african species
Zootaxa, 2012Co-Authors: Laurent Granjon, Gauthier Dobigny, Paolo Colangelo, Caroline Tatard, Marc Colyn, Violaine NicolasAbstract:The systematics of the African rodent genus Gerbilliscus is still a matter of debate. At the genus level it has been said toinclude the related genus Gerbillurus, and at the species level some species still need to be definitely recognized as dis-tinct. To tackle these questions, we gathered and analyzed mitochondrial (cytochrome b) and nuclear (BRCA1) gene se-quences in a number of specimens representing ten species of Gerbilliscus and three species of Gerbillurus. Phylogeneticreconstructions confirm that Gerbillurus should be considered a synonym of Gerbilliscus. They also clearly show that spe-cies diversity in this group is spatially organized, with geographically well-defined species groups covering major areasof sub-Saharan Africa, namely Southern, Eastern and Western Africa. In the latter area, a well-supported genetic lineageappears to correspond to a hitherto overlooked species, also characterized by a distinctive karyotype. This species is char-acterized by an overall large size, a relatively long tail, a distinct karyotype, and represents a well-differentiated geneticcluster. It ranges from Benin to Guinea in Sudano-Guinean forest-savanna mosaic habitats, where it can be sympatric withthe congeneric species G. kempi and G. guineae. Detailed body and skull morphological and biometrical analyses per-formed on samples of the West African species, including type specimens described in this region, suggest that this speciesmay correspond to G. kempi. If confirmed, this would imply that what is currently named G. kempi would deserve another species name, the most likely of which would be G. giffardi.
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Morphometric analysis of six Gerbillus species (Rodentia, Gerbillinae) from Tunisia.
Comptes rendus biologies, 2010Co-Authors: Awatef Abiadh, Ernesto Capanna, Paolo Colangelo, Taher Lamine-cheniti, M’barek ChetouiAbstract:Size and shape changes in the skull of the genus Gerbillus were investigated using geometric morphometrics. Six species from Tunisia were studied (G. gerbillus, G. campestris, G. nanus, G. tarabuli, G. simoni and G. latastei). Statistical analyses of shape variability allowed us to discriminate three morphological groups which are congruent with the three groups suggested by previous morphological and molecular studies. However, our results contrast with previous molecular investigations. In fact, according to results obtained by the use of principal component analysis, canonical variate analysis and UPGMA, we found a higher degree of divergence between the subgenus Dipodillus and the other two subgenera Gerbillus and Hendecapleura. This fact suggests that the morphometric differences observed among species within the genus Gerbillus are not mainly related to phylogeny. To reconciliate the molecular and morphological approaches, we propose a hypothesis of differential rates of phenotypic evolution in the genus Gerbillus. In this view, the species belonging to the subgenus Dipodillus evolved apomorphic features of the skull likely related to a higher degree of habitat specialization. By contrast, the more generalist Gerbillus and Hendecapleura subgenera show less differentiated plesiomorphic morphology.
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Molecular phylogenetics of the genus Gerbillus (Rodentia, Gerbillinae): Implications for systematics, taxonomy and chromosomal evolution.
Molecular phylogenetics and evolution, 2010Co-Authors: Awatef Abiadh, Ernesto Capanna, M’barek Chetoui, Taher Lamine-cheniti, Paolo ColangeloAbstract:Although gerbils forms an important component of the mammalian fauna of arid and semi-arid area, the taxonomic and phylogenetic relationship within the species of the genus Gerbillus are still ambiguous. The present paper introduces findings based on the whole cytochrome b (1140 bp) mitochondrial genes of seven species (Gerbillus campestris, G. latastei, G. nanus, G. tarabuli, G. gerbillus, G. simoni and G. nigeriae) six of which are present in Tunisia. Our results show that all the Gerbillus species are monophyletic. Moreover, molecular phylogeny rejects the genus rank for the taxon Dipodillus. Gebillus nanus, a species belonging to the subgenus Hendecapleura, early diverged from the other species which are divided into two clades: the subgenus Dipodillus, including G. campestris and G. simoni and the subgenus Gerbillus including G. gerbillus, G. nigeriae, G. tarabuli and G. latastei. These results are congruent with morphological and karyological evidences. According to molecular clock, the appearance of the genus Gerbillus coincides with the Miocene-Pliocene expansion of African arid biomes. Extensive intraspecific chromosomal changes evolved in a relatively narrow lapse of time, like in the case of G. latastei, allowing the fixations of different chromosomal variants due to pericentric inversion.
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Evolutionary systematics in African gerbilline rodents of the genus Gerbilliscus: Inference from mitochondrial genes
'Elsevier BV', 2007Co-Authors: Paolo Colangelo, Laurent Granjon, Peter J. Taylor, Marco CortiAbstract:Gerbilliscus has recently been proposed as an endemic African rodent genus distinct from the Asian Tatera. A molecular phylogeny of the genus, including nine species from southern, western and eastern Africa, is presented here based on the analysis of the cytochrome b and 16S mitochondrial genes. With an adequate taxonomic sampling over a wide geographic range, we here provide a clear picture of the phylogenetic relationships between species and species groups in this genus. Three distinct clades were resolved, corresponding to major geographical subdivisions: an eastern clade that possibly diverged first, then a southern and a western clades which appeared later. We suggest two possible hypotheses concerning the dispersal of the genus across Africa, considering also the patterns of karyotypic variation. Finally, we discuss the taxonomic status of G. gambianus and the relationships between Gerbillurus and Gerbilliscus, as previous studies have suggested that the former should be included in the latter. Our data seem to support the synonymy of the two taxa and suggest that Gerbillurus and Gerbilliscus lineages diverged from a common ancestor appeared in eastern Africa. (c) 2006 Elsevier Inc. All rights reserved
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mitochondrial phylogeny reveals differential modes of chromosomal evolution in the genus tatera rodentia Gerbillinae in africa
Molecular Phylogenetics and Evolution, 2005Co-Authors: Paolo Colangelo, Marco Corti, Erik Verheyen, Flavia Annesi, Nicholas Oguge, Rhodes H. Makundi, Walter VerheyenAbstract: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.
Laurent Granjon - One of the best experts on this subject based on the ideXlab platform.
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Fossils know it best: Using a new set of fossil calibrations to improve the temporal phylogenetic framework of murid rodents (Rodentia: Muridae)
Molecular Phylogenetics and Evolution, 2018Co-Authors: Tatiana Aghova, Gauthier Dobigny, Laurent Granjon, Yuri Kimura, Josef Bryja, Gael KergoatAbstract:Murid rodents (Rodentia: Muridae) represent the most diverse and abundant mammalian family. In this study, we provide a refined set of fossil calibrations which is used to reconstruct a dated phylogeny of the family using a multilocus dataset (six nuclear and nine mitochondrial gene fragments) encompassing 161 species representing 82 murid genera from four extant subfamilies (Deomyinae, Gerbillinae, Lophiomyinae and Murinae). In comparison with previous studies on murid or muroid rodents, our work stands out for the implementation of nine robust fossil constraints within the Muridae thanks to a thorough review of the fossil record. Before being assigned to specific nodes of the phylogeny, all potential fossil constraints were carefully assessed; they were also subjected to several cross-validation analyses. The resulting phylogeny is consistent with previous phylogenetic studies on murids, and recovers the monophyly of all sampled murid subfamilies and tribes. Based on nine controlled fossil calibrations, our inferred temporal timeframe indicates that the murid family likely originated in the course of the Early Miocene, 22.0-17.0 million years ago (Ma), and that most major lineages (i.e. tribes) started diversifying ca. 10 Ma. Historical biogeography analyses support the tropical origin for the family, with an initial internal split (vicariance event) between Afrotropical and Oriental (Indomalaya and Philippines) lineages. During the course of their diversification, the biogeographic pattern of murids is marked by several dispersal events toward the Australasian and the Palearctic regions. The Afrotropical region was also secondarily colonized a least three times from the Indomalaya, indicating that the latter region has acted as a major centre of diversification for the family.
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Taxonomic hypotheses regarding the genus Gerbillus (Rodentia, Muridae, Gerbillinae) based on molecular analyses of museum specimens
ZooKeys, 2016Co-Authors: Arame Ndiaye, Caroline Tatard, William T. Stanley, Laurent GranjonAbstract:Methodological improvements now allow routine analyses of highly degraded DNA samples as found in museum specimens. Using these methods could be useful in studying such groups as rodents of the genus Gerbillus for which i) the taxonomy is still highly debated, ii) collection of fresh specimens may prove difficult. Here we address precise taxonomic questions using a small portion of the cytochrome b gene obtained from 45 dry skin/skull museum samples (from 1913 to 1974) originating from two African and three Asian countries. The specimens were labelled Gerbillus gerbillus, Gerbillus andersoni, Gerbillus nanus, Gerbillus amoenus, Gerbillus perpallidus and Gerbillus pyramidum, and molecular results mostly confirmed these assignations. The close relationship between Gerbillus nanus (Asian origin) and Gerbillus amoenus (African origin) confirmed that they represent vicariant sibling species which differentiated in allopatry on either side of the Red Sea. In the closely related Gerbillus perpallidus and Gerbillus pyramidum, specimens considered as belonging to one Gerbillus pyramidum subspecies (Gerbillus pyramidum floweri) appeared closer to Gerbillus perpallidus suggesting that they (Gerbillus pyramidum floweri and Gerbillus perpallidus) may represent a unique species, distributed on both sides of the Nile River, for which the correct name should be Gerbillus floweri. Furthermore, the three other Gerbillus pyramidum subspecies grouped together with no apparent genetic structure suggesting that they may not yet represent genetically differentiated lineages. This study confirms the importance of using these methods on museum samples, which can open new perspectives in this particular group as well as in other groups of interest.
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dae) from West Africa
2015Co-Authors: Laurent GranjonAbstract:ABSTRACT. Three chromosomally well-differentiated but morphologically similar species of the Gerbilline rodent genus Tatera occur in West Africa, namely T. gambiana, T. guineae and T. kempi. In order to find reliable diagnostic characters, morphological and morphometrical analyses were performed on samples of these three species from Mali, the only country where they are known to occur sympatrically. Body measurement comparisons show that T. guineae has a longer tail and hindfoot, and T. gambiana a shorter ear, relative to the two other species. Skull meas-urements are less variable between species as only a larger upper tooth row characterizes T. kempi, and a shorter tympanic bulla length T. guineae. Conversely, geographically distant samples of T. kempi from Mali and Chad differ mainly for skull measurements. There is a wide overlap between the ranges of values recorded in the three species. Principal Component and Discriminant Analyses of skull measurements highlight the distinctiveness of T. guineae, whose sample is clearly separated from those of T. kempi and T. gambiana. All these results validate the status of morphologically cryptic species for T. kempi and T. gambiana, long treated as synonymous. Tatera guineae is the most differentiated, but the diagnosis of an individual specimen may prove difficult due to the observed interspe-cific overlap in all the characters considered
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Integrative taxonomy of a poorly known Sahelian rodent, Gerbillus nancillus (Muridae, Gerbillinae)
Zoologischer Anzeiger, 2014Co-Authors: Arame Ndiaye, Gauthier Dobigny, Karmadine Hima, Aliou Sow, Ambroise Dalecky, Massamba Thiam, Laurent GranjonAbstract:Aridification processes that affected the Sahelian area of West Africa during the last decades have induced significant changes in plant and animal communities of this region. In rodents, the genus Gerbillus characteristic of North African and Asian arid habitats has been affected by this climatic and environmental trends. Several species of this genus showed a southward range expansion in recent years into the Sahelian bioclimatic zone. Recent sampling in several localities of West Africa (Mali, Niger and Senegal) enabled us to collect numerous specimens of small gerbils. An integrative study of these samples using molecular, morphological and cytogenetical methods revealed that many of them were attributable to Gerbillus nancillus, a secretive and poorly known species. Gerbillus nancillus appears characterized by a well differentiated karyotype with 2n = 56 chromosomes, and to represent a unique genetic lineage within this genus. Body and skull measurements of G. nancillus were compared with those of the morphologically similar Gerbillus henleyi, which provided diagnostic clues between them. These new data significantly expand the distribution area of G. nancillus, which now ranges from Sudan in the East to Senegal in the West. G. nancillus is here reported from numerous new localities in Niger and Mali, and for the first time in Senegal, which raises questions about the origin of its presence and the colonization routes it followed to get there. We also show that G. henleyi and G. nancillus are sympatric and apparently often syntopic in the sub-Saharan part of the distribution of G. henleyi.
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intrageneric relationships within gerbilliscus rodentia muridae Gerbillinae with characterization of an additional west african species
Zootaxa, 2012Co-Authors: Laurent Granjon, Gauthier Dobigny, Paolo Colangelo, Caroline Tatard, Marc Colyn, Violaine NicolasAbstract:The systematics of the African rodent genus Gerbilliscus is still a matter of debate. At the genus level it has been said toinclude the related genus Gerbillurus, and at the species level some species still need to be definitely recognized as dis-tinct. To tackle these questions, we gathered and analyzed mitochondrial (cytochrome b) and nuclear (BRCA1) gene se-quences in a number of specimens representing ten species of Gerbilliscus and three species of Gerbillurus. Phylogeneticreconstructions confirm that Gerbillurus should be considered a synonym of Gerbilliscus. They also clearly show that spe-cies diversity in this group is spatially organized, with geographically well-defined species groups covering major areasof sub-Saharan Africa, namely Southern, Eastern and Western Africa. In the latter area, a well-supported genetic lineageappears to correspond to a hitherto overlooked species, also characterized by a distinctive karyotype. This species is char-acterized by an overall large size, a relatively long tail, a distinct karyotype, and represents a well-differentiated geneticcluster. It ranges from Benin to Guinea in Sudano-Guinean forest-savanna mosaic habitats, where it can be sympatric withthe congeneric species G. kempi and G. guineae. Detailed body and skull morphological and biometrical analyses per-formed on samples of the West African species, including type specimens described in this region, suggest that this speciesmay correspond to G. kempi. If confirmed, this would imply that what is currently named G. kempi would deserve another species name, the most likely of which would be G. giffardi.
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identification and characterization of a novel subtype of tula virus in microtus arvalis obscurus voles sampled from xinjiang china
Infection Genetics and Evolution, 2019Co-Authors: Jintao Chen, Jing Qin, Xiaoping Wang, Alexander Plyusnin, Wei Hou, Yongzhen ZhangAbstract:Although most of Arvicolinae associated hantaviruses can not cause disease in humans, hemorrhagic fever with renal syndrome (HFRS) cases caused by Tula virus (TULV) have been described in Europe since 2002. In addition to Europe, TULV was also identified in the Microtus arvalis obscurus voles sampled from Kazakhstan, which shares borders with China. To gain more insight into the molecular epidemiology of TULV, a total of 365 rodents representing 7 species of 4 subfamily (Arvicolinae, Murinae, Gerbillinae, and Cricetinae) were captured in Qapqal county, Xinjiang, northwest China. Hantavirus RNA was recovered from 40 lung tissue samples of M. arvalis obscurus, with the prevalence of 10.96%. Genetic analysis revealed that all recovered viral sequences were most closely related to those of TULV, but exhibited >11% nucleotide differences from all currently known TULV, suggesting that they may represent a new subtype of TULV. In the S tree, the newly identified viruses formed a distinct lineage and showed a close evolutionary relationship with those sampled from Southwestern Siberia and Kazakhstan. However, they exhibited a different clustering pattern in both the M and the L trees, suggesting the possibility of genetic reassortment. Finally, the recombination event was also observed in Xinjiang TULV viruses. In sum, all these data reveal a complex evolutionary history of TULV in Central Asia.