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1.
Sci Rep ; 12(1): 842, 2022 01 17.
Article de Anglais | MEDLINE | ID: mdl-35039544

RÉSUMÉ

Five-toed jerboas of the subfamily Allactaginae comprise several complex taxa occurring over a wide distribution range covering a large part of the Eurasian arid belt. In this study, we employed current methods of molecular phylogenetics based on 15 nuclear genes and the mitochondrial gene cytb to revise relations and systematics within Allactaginae. We also applied species distribution modelling projected on paleo-environmental data to reconstruct the geographic patterns of speciation in Allactaginae. We elucidated the intergeneric relationships within this subfamily and clarified interspecies relations within the genus Scarturus. Moreover, our results demonstrate the species status of S. caprimulga; outline the currently understudied diversity within Orientallactaga, Allactaga, and Pygeretmus; and improve the divergence estimates of these taxa. Based on our results from modelling of geographic range fragmentation in allactagines, we suggest the dating and location of speciation events and present hypotheses regarding general habitat niche conservatism in small mammals.


Sujet(s)
Phylogenèse , Rodentia/génétique , Animaux , Écosystème , Union européenne , Variation génétique , Mitochondries/génétique , Rodentia/classification , Spécificité d'espèce
2.
Sci Rep ; 11(1): 24496, 2021 12 30.
Article de Anglais | MEDLINE | ID: mdl-34969948

RÉSUMÉ

Among seven species of the order Eulipotyphla (from southern Gansu and northern Sichuan Provinces, Central China) studied cytogenetically, karyotypes of one talpid species, Uropsilus aff. soricipes (2n = 36, NFa = 54), and three soricid species, Chodsigoa hypsibia (2n = 65, NFa = 66), Sorex cansulus (2n = 42, NFa = 64) and Sorex thibetanus (2n = 42, NFa = 60), are described cytogenetically for the first time. All four species are endemic to China with distribution ranges restricted to the Qinghai-Tibet Plateau and adjacent mountain ranges. The Ch. hypsibia karyotype consists of mostly acrocentric autosomes and one metacentric pair of autosomes; besides, a B chromosome was identified. No polymorphism was detected among karyotypes of other species, including shrews Sorex bedfordiae (2n = 26, NFa = 44), Anourosorex squamipes (2n = 48, NFa = 92) and Crocidura suaveolens (2n = 40, NFa = 44). The Chinese shrew mole U. aff. soricipes and three shrew species (S. bedfordiae, Ch. hypsibia and A. squamipes) represent autochthonous fauna of Central/Western China, whereas S. thibetanus, S. cansulus and C. suaveolens belong to phylogenetic groups occurring mostly to the north and west from China; therefore, they should be considered relatively recent colonisers. Thus, considering the relationships of the species within phylogenetic groups, our results on karyotypes are in good agreement with molecular genetic data.


Sujet(s)
/génétique , Animaux , Chine , Femelle , Variation génétique , Caryotype , Mâle , Phylogenèse , Tibet
3.
Sci Rep ; 11(1): 10557, 2021 05 18.
Article de Anglais | MEDLINE | ID: mdl-34006914

RÉSUMÉ

The genus status of Urocricetus was defined recently based on morphological and molecular data. Even though the amount of evidence for a separate phylogenetic position of this genus among Cricetinae continues to increase, there is still no consensus on its relationship to other groups. Here we give the first comprehensive description of the U. kamensis karyotype (2n = 30, NFa = 50) including results of comparative cytogenetic analysis and detailed examination of its phylogenetic position by means of numerous molecular markers. The molecular data strongly indicated that Urocricetus is a distant sister group to Phodopus. Comparative cytogenetic data showed significant reorganization of the U. kamensis karyotype compared to karyotypes of all other hamsters investigated earlier. The totality of findings undoubtedly means that Urocricetus belongs to a separate divergent lineage of Cricetinae.


Sujet(s)
Cricetinae/génétique , Caryotypage , Animaux , Zébrage chromosomique , Cricetinae/classification , Femelle , Mâle , Phylogenèse , Spécificité d'espèce
4.
PeerJ ; 9: e10759, 2021.
Article de Anglais | MEDLINE | ID: mdl-33520475

RÉSUMÉ

The Tianshan birch mouse Sicista tianschanica is an endemic of the Central Asian mountains and has previously been shown to include several karyomorphs ("Terskey", "Talgar", "Dzungar"); however, the taxonomic status of these forms has remained uncertain. We examined the genetic variation in S. tianschanica based on historical DNA samples from museum collections, including the type series. Mitochondrial and nuclear data indicated that the species complex includes two major clades: Northern (N) and Southern (S) (cytb distance 13%). The N clade corresponds to the "Dzungar" karyomorph (Dzungar Alatau, Tarbagatay). The S clade is comprised of four lineages (S1-S4) divergent at 6-8%; the relationships among which are resolved incompletely. The S1 lineage is found in eastern Tianshan and corresponds to the nominal taxon. The S2 is distributed in central and northern Tianshan and corresponds to the "Terskey" karyomorph. The S3 is restricted to Trans-Ili Alatau and belongs to the "Talgar" karyomorph. The S4 is represented by a single specimen from southeastern Dzungar Alatau with "Talgar" karyotype. No interlineage gene flow was revealed. The validity of S. zhetysuica (equivalent to the N clade) is supported. Based on genetic and karyotypic evidence, lineages S2 and S3 are described as distinct species. The status of the S4 requires further investigation.

5.
Zookeys ; 888: 133-158, 2019.
Article de Anglais | MEDLINE | ID: mdl-31754323

RÉSUMÉ

The first genetic study of the holotype of the Gansu short-tailed shrew, Blarinella griselda Thomas, 1912, is presented. The mitochondrial analysis demonstrated that the type specimen of B. griselda is close to several recently collected specimens from southern Gansu, northern Sichuan and Shaanxi, which are highly distinct from the two species of Asiatic short-tailed shrews of southern Sichuan, Yunnan, and Vietnam, B. quadraticauda and B. wardi. Our analysis of four nuclear genes supported the placement of B. griselda as sister to B. quadraticauda / B. wardi, with the level of divergence between these two clades corresponding to that among genera of Soricinae. A new generic name, Parablarinella, is proposed for the Gansu short-tailed shrew. Karyotypes of Parablarinella griselda (2n = 49, NFa = 50) and B. quadraticauda (2n = 49, NFa = 62) from southern Gansu are described. The tribal affinities of Blarinellini and Blarinini are discussed.

6.
Zookeys ; (795): 77-81, 2018.
Article de Anglais | MEDLINE | ID: mdl-30429659

RÉSUMÉ

The Hainan gymnure Neohylomyshainanensis (Mammalia, Lipotyphla), endemic to Hainan Island (China), is one of the rarest and least-known species within the family Galericidae. The IUCN Red List inferred it as an endangered species due to ongoing population decline caused by natural habitat loss. A recent biodiversity survey has revealed N.hainanensis to be rather common in northern Vietnam. This is the first record of the species outside Hainan Island. New data have allowed us to re-assess the conservation status of this poorly known mammal. The occurrence of N.hainanensis in mainland Vietnam also supports the hypothesis that Hainan Island could have been previously connected to Guangxi and northern Vietnam rather than to neighbouring Guangdong.

7.
PeerJ ; 6: e4543, 2018.
Article de Anglais | MEDLINE | ID: mdl-29576991

RÉSUMÉ

We hypothesize the phylogenetic relationships of the agamid genus Phrynocephalus to assess how past environmental changes shaped the evolutionary and biogeographic history of these lizards and especially the impact of paleogeography and climatic factors. Phrynocephalus is one of the most diverse and taxonomically confusing lizard genera. As a key element of Palearctic deserts, it serves as a promising model for studies of historical biogeography and formation of arid habitats in Eurasia. We used 51 samples representing 33 of 40 recognized species of Phrynocephalus covering all major areas of the genus. Molecular data included four mtDNA (COI, ND2, ND4, Cytb; 2,703 bp) and four nuDNA protein-coding genes (RAG1, BDNF, AKAP9, NKTR; 4,188 bp). AU-tests were implemented to test for significant differences between mtDNA- and nuDNA-based topologies. A time-calibrated phylogeny was estimated using a Bayesian relaxed molecular clock with nine fossil calibrations. We reconstructed the ancestral area of origin, biogeographic scenarios, body size, and the evolution of habitat preference. Phylogenetic analyses of nuDNA genes recovered a well-resolved and supported topology. Analyses detected significant discordance with the less-supported mtDNA genealogy. The position of Phrynocephalus mystaceus conflicted greatly between the two datasets. MtDNA introgression due to ancient hybridization best explained this result. Monophyletic Phrynocephalus contained three main clades: (I) oviparous species from south-western and Middle Asia; (II) viviparous species of Qinghai-Tibetan Plateau (QTP); and (III) oviparous species of the Caspian Basin, Middle and Central Asia. Phrynocephalus originated in late Oligocene (26.9 Ma) and modern species diversified during the middle Miocene (14.8-13.5 Ma). The reconstruction of ancestral areas indicated that Phrynocephalus originated in Middle East-southern Middle Asia. Body size miniaturization likely occurred early in the history of Phrynocephalus. The common ancestor of Phrynocephalus probably preferred sandy substrates with the inclusion of clay or gravel. The time of Agaminae radiation and origin of Phrynocephalus in the late Oligocene significantly precedes the landbridge between Afro-Arabia and Eurasia in the Early Miocene. Diversification of Phrynocephalus coincides well with the mid-Miocene climatic transition when a rapid cooling of climate drove progressing aridification and the Paratethys salinity crisis. These factors likely triggered the spreading of desert habitats in Central Eurasia, which Phrynocephalus occupied. The origin of the viviparous Tibetan clade has been associated traditionally with uplifting of the QTP; however, further studies are needed to confirm this. Progressing late Miocene aridification, the decrease of the Paratethys Basin, orogenesis, and Plio-Pleistocene climate oscillations likely promoted further diversification within Phrynocephalus. We discuss Phrynocephalus taxonomy in scope of the new analyses.

8.
Cytogenet Genome Res ; 152(2): 65-72, 2017.
Article de Anglais | MEDLINE | ID: mdl-28719894

RÉSUMÉ

Sokolov's dwarf hamster (Cricetulus sokolovi) is the least studied representative of the striped hamsters (Cricetulus barabensis species group), the taxonomy of which remains controversial. The species was described based on chromosome morphology, but neither the details of the karyotype nor the phylogenetic relationships with other Cricetulus are known. In the present study, the karyotype of C. sokolovi was examined using cross-species chromosome painting. Molecular and cytogenetic data were employed to determine the phylogenetic position of Sokolov's hamster and to analyze the potential pathways of chromosome evolution in Cricetulus. Both the chromosome and molecular data support the species status of Sokolov's hamster. Phylogenetic analysis of the CYTB data placed C. sokolovi as sister to all other striped hamsters (sequence divergence of 8.1%). FISH data revealed that the karyotype of C. sokolovi is highly rearranged, with the most parsimonious scenario of its origin implying at least 4 robertsonian events and a centromere shift. Comparative cytogenetic data on Cricetinae suggest that their evolutionary history includes both periods of chromosomal conservatism and episodes of rapid chromosomal change.


Sujet(s)
Peinture chromosomique/méthodes , Chromosomes de mammifère/génétique , Cricetulus/génétique , Caryotype , Phylogenèse , Animaux , Haplotypes/génétique
9.
Zootaxa ; 4232(2): zootaxa.4232.2.5, 2017 Feb 15.
Article de Anglais | MEDLINE | ID: mdl-28264392

RÉSUMÉ

We analyzed the complete mitochondrial cytochrome b (cytb) gene and fragments of four nuclear loci: ApoB, RAG2, IRBP1 and BRCA1. These data allowed us to provide new insights into the diversity of the Asiatic water shrews of Indochina. A new, highly divergent genetic lineage of Chimarrogale was found in southern Vietnam, and this lineage included specimens from the provinces of Kon Tum, Dak Lak, and Lam Dong. Such finding represents the newest and southernmost records of Chimarrogale in Indochina. Morphological analysis classified the specimens from southern Vietnam as C. varennei proper, which is restricted to that region, whereas the polymorphic C. himalayica, which contained at least four cytochrome b haplogroups, occurred in central and northern Vietnam and southern China. This distinct C. varennei lineage closely related to the C. platycephalus + C. leander clade suggests the existence of an unknown glacial refuge in Tay Nguyen Plateau, southern Vietnam. Because the Bornean C. phaeura (i) was sister-group of the rest of Chimarrogale sensu lato and (ii) had a high genetic divergence (~15% for cytochrome b) and geographical isolation, we suggest that C. phaeura be placed into a separate genus, Crossogale Thomas, 1921. This genus should also include C. sumatrana (Sumatra) and C. hantu (Peninsular Malaysia). On those grounds, we propose a new classification system for Asiatic water shrews.


Sujet(s)
Analyse de séquence d'ADN , Musaraignes , Animaux , Asie du Sud-Est , Chine , ADN mitochondrial , Femelle , Phylogenèse , Vietnam
10.
Chromosome Res ; 15(3): 283-97, 2007.
Article de Anglais | MEDLINE | ID: mdl-17333534

RÉSUMÉ

The evolutionary success of rodents of the superfamily Muroidea makes this taxon the most interesting for evolution studies, including study at the chromosomal level. Chromosome-specific painting probes from the Chinese hamster and the Syrian (golden) hamster were used to delimit homologous chromosomal segments among 15 hamster species from eight genera: Allocricetulus, Calomyscus, Cricetulus, Cricetus, Mesocricetus, Peromyscus, Phodopus and Tscherskia (Cricetidae, Muroidea, Rodentia). Based on results of chromosome painting and G-banding, comparative maps between 20 rodent species have been established. The integrated maps demonstrate a high level of karyotype conservation among species in the Cricetus group (Cricetus, Cricetulus, Allocricetulus) with Tscherskia as its sister group. Species within the genera Mesocricetus and Phodopus also show a high degree of chromosomal conservation. Our results substantiate many of the conclusions suggested by other data and strengthen the topology of the Muroidea phylogenetic tree through the inclusion of genome-wide chromosome rearrangements. The derivation of the muroids karyotypes from the putative ancestral state involved centric fusions, fissions, addition of heterochromatic arms and a great number of inversions. Our results provide further insights into the karyotype relationships of all species investigated.


Sujet(s)
Analyse cytogénétique/méthodes , Phylogenèse , Animaux , Zébrage chromosomique , Cartographie chromosomique , Peinture chromosomique , Cricetinae , Caryotypage , Mutagenèse
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