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1.
J Biol Chem ; 299(9): 105066, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37468103

RESUMO

Among the rare venomous mammals, the short-tailed shrew Blarina brevicauda has been suggested to produce potent neurotoxins in its saliva to effectively capture prey. Several kallikrein-like lethal proteases have been identified, but the active substances of B. brevicauda remained unclear. Here, we report Blarina paralytic peptides (BPPs) 1 and 2 isolated from its submaxillary glands. Synthetic BPP2 showed mealworm paralysis and a hyperpolarization shift (-11 mV) of a human T-type Ca2+ channel (hCav3.2) activation. The amino acid sequences of BPPs were similar to those of synenkephalins, which are precursors of brain opioid peptide hormones that are highly conserved among mammals. However, BPPs rather resembled centipede neurotoxic peptides SLPTXs in terms of disulfide bond connectivity and stereostructure. Our results suggested that the neurotoxin BPPs were the result of convergent evolution as homologs of nontoxic endogenous peptides that are widely conserved in mammals. This finding is of great interest from the viewpoint of the chemical evolution of vertebrate venoms.


Assuntos
Canais de Cálcio Tipo T , Neurotoxinas , Peptídeos , Musaranhos , Animais , Humanos , Sequência de Aminoácidos , Neurotoxinas/química , Neurotoxinas/genética , Neurotoxinas/farmacologia , Peptídeos/síntese química , Peptídeos/genética , Peptídeos/isolamento & purificação , Peptídeos/farmacologia , Canais de Cálcio Tipo T/efeitos dos fármacos , Evolução Molecular , Musaranhos/classificação , Musaranhos/genética , Musaranhos/metabolismo , Tenebrio/efeitos dos fármacos , Células HEK293 , Eletrofisiologia
2.
J Therm Biol ; 104: 103193, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35180970

RESUMO

Ambient temperature has a substantial influence on the thermoregulation costs of small mammals due to their high surface-to-volume ratio. Shrews are among the smallest of mammals and have adopted different behavioral and physiological strategies to deal with cold temperatures. In this study, we assessed the use of an external heat source in the thermoregulatory strategy of two Crocidurinae species, Crocidura russula and C. suaveolens, and one Soricinae species, Sorex araneus. Crocidura russula inhabits western Europe and is better adapted to a Mediterranean climate; C. suaveolens inhabits central Europe; and S. araneus inhabits northern Europe and is better adapted to a Palearctic climate. We predicted that C. russula (most southern species) would spend larger amounts of time using an external heat source because it is the most cold-sensitive species, while S. araneus (most northern species) would spend less time using an external heat source or not respond to it. Shrews were experimentally tested in captivity inside a terrarium where they had access to a heat rock, which could be turned off (cold) or on (heated), depending on treatment. Our results confirmed our initial prediction: C. russula was the species that spent significantly more time on the heated rock, followed by C. suaveolens. Only a quarter of S. araneus individuals spent large amounts of time on the heat rock, which suggests this thermoregulation strategy is not generally adopted by this species, but may be rather associated with some individual personalities. We also analyzed the influence of the heat rock on rewarming from heterothermy, but heterothermy was not different between rock treatments. Overall, our results show that shrew species use external heat sources for thermoregulation according to their sensitivity to cold.


Assuntos
Regulação da Temperatura Corporal , Musaranhos/fisiologia , Adaptação Fisiológica , Animais , Temperatura Baixa , Europa (Continente) , Feminino , Temperatura Alta , Masculino , Musaranhos/classificação
3.
Zool Res ; 42(6): 739-745, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34636193

RESUMO

The small-eared shrew genus Cryptotis is the third largest in the family Soricidae and occurs in North, Central, and northern South America. In Mexico and Central and South America, most species inhabit geographically isolated moist, montane habitats at middle and high elevations in a typical sky-island pattern. The 49 recognized species have been partitioned into as many as six species groups based on morphological and molecular phylogenetic studies. The relationships among these species groups are poorly resolved, and their evolutionary histories, including migration patterns and locomotor adaptations, remain unclear. Herein, we provide a new phylogeny incorporating complete mitochondrial genomes (mitogenomes) and supermatrix approach. We compared different evolutionary scenarios using approximately unbiased (AU), Kishino-Hasegawa (KH), and Shimodaira-Hasegawa (SH) statistical tests. The phylogenetic hypothesis based on mitogenomes revealed novel relationships supporting a basal position for the Cryptotis parvus-group in the genus, and a close relationship between C. gracilis and one clade of the C. thomasi-group. The former relationship is consistent with the least derived humerus morphology and northern distribution of the species. The latter relationship implies multiple migrations between Central and South America. The lack of fine resolution for the species group relationships may be due partly to the lack of taxon sampling. In contrast, multi-approach analyses suggest that the unresolved relationships may be a result of rapid diversification during the early stages of Cryptotis evolution.


Assuntos
Especiação Genética , Genômica , Filogenia , Musaranhos/classificação , Musaranhos/genética , Animais
4.
Sci Rep ; 11(1): 9416, 2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33941819

RESUMO

We discovered a new Crocidura species of shrew (Soricidae: Eulipotyphla) from Narcondam Island, India by using both morphological and molecular approaches. The new species, Crocidura narcondamica sp. nov. is of medium size (head and body lengths) and has a distinct external morphology (darker grey dense fur with a thick, darker tail) and craniodental characters (braincase is rounded and elevated with weak lambdoidal ridges) in comparison to other close congeners. This is the first discovery of a shrew from this volcanic island and increases the total number of Crocidura species catalogued in the Indian checklist of mammals to 12. The newly discovered species shows substantial genetic distances (12.02% to 16.61%) to other Crocidura species known from the Indian mainland, the Andaman and Nicobar Archipelago, Myanmar, and from Sumatra. Both Maximum-Likelihood and Bayesian phylogenetic inferences, based on mitochondrial (cytochrome b) gene sequences showed distinct clustering of all included soricid species and exhibit congruence with the previous evolutionary hypothesis on this mammalian group. The present phylogenetic analyses also furnished the evolutionary placement of the newly discovered species within the genus Crocidura.


Assuntos
Musaranhos , Animais , Citocromos b/genética , Ecossistema , Genoma/genética , Índia , Ilhas , Mitocôndrias/genética , Mianmar , Musaranhos/anatomia & histologia , Musaranhos/classificação , Musaranhos/genética
5.
Hist Philos Life Sci ; 43(1): 31, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33629158

RESUMO

More than a century ago, Edward W. Nelson and Edward A. Goldman spent 14 years (1892-1906) traveling across much of Mexico in one of the most critical biological expeditions ever undertaken by two naturalists. This long-term survey was a cornerstone in Mexican mammalogy development; however, their specific role in discovering taxa that were practically unknown before the expedition is not yet necessarily recognized. In a time when the historical aspect of knowledge on mammals is being ignored for the new generations of mammalogists, a detailed analysis of the legacy of the survey is essential. Here I focus on shrews (Eulipotyphla, Soricidae) to analyze how the fieldwork and the specimens they collected have contributed to the current knowledge of shrews in the country. Nelson and Goldman collected 474 specimens of shrews, representing 31 of the 40 species that have currently been recognized. This collection has been key to building taxonomic, evolutionary, and biogeographic knowledge of shrews in the country. The success of the expedition was primarily due to the epistemic role of novel methods and approaches in natural history research at the time. The collection also offers the opportunity to document the loss of species and ecological interactions as indirect consequences of human activities, especially in montane regions. I argue that the value of this expedition can still increase with the use of modern biodiversity study tools and the digitization and access of ancient material such as photographs, field notes, and correspondence.


Assuntos
Distribuição Animal , Biodiversidade , Traços de História de Vida , História Natural/história , Musaranhos , Animais , História do Século XIX , História do Século XX , México , Filogenia , Musaranhos/classificação , Musaranhos/fisiologia
6.
Sci Rep ; 11(1): 1011, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441654

RESUMO

Afrotheria is a clade of African-origin species with striking dissimilarities in appearance and habitat. In this study, we compared whole proteome sequences of six Afrotherian species to obtain a broad viewpoint of their underlying molecular make-up, to recognize potentially unique proteomic signatures. We find that 62% of the proteomes studied here, predominantly involved in metabolism, are orthologous, while the number of homologous proteins between individual species is as high as 99.5%. Further, we find that among Afrotheria, L. africana has several orphan proteins with 112 proteins showing < 30% sequence identity with their homologues. Rigorous sequence searches and complementary approaches were employed to annotate 156 uncharacterized protein sequences and 28 species-specific proteins. For 122 proteins we predicted potential functional roles, 43 of which we associated with protein- and nucleic-acid binding roles. Further, we analysed domain content and variations in their combinations within Afrotheria and identified 141 unique functional domain architectures, highlighting proteins with potential for specialized functions. Finally, we discuss the potential relevance of highly represented protein families such as MAGE-B2, olfactory receptor and ribosomal proteins in L. africana and E. edwardii, respectively. Taken together, our study reports the first comparative study of the Afrotherian proteomes and highlights salient molecular features.


Assuntos
Eutérios/classificação , Eutérios/genética , Animais , Sequência Conservada , Bases de Dados de Proteínas , Elefantes/classificação , Elefantes/genética , Elefantes/metabolismo , Eutérios/metabolismo , Evolução Molecular , Ouriços/classificação , Ouriços/genética , Ouriços/metabolismo , Anotação de Sequência Molecular , Toupeiras/classificação , Toupeiras/genética , Toupeiras/metabolismo , Filogenia , Domínios Proteicos , Proteínas/química , Proteínas/genética , Proteínas/metabolismo , Proteoma/genética , Proteômica , Musaranhos/classificação , Musaranhos/genética , Musaranhos/metabolismo , Especificidade da Espécie , Trichechus manatus/classificação , Trichechus manatus/genética , Trichechus manatus/metabolismo
7.
Mol Phylogenet Evol ; 154: 107001, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33130298

RESUMO

Giant sengis, or elephant-shrews (Macroscelidea; Macroscelididae; Rhynchocyon), are small-bodied mammals found in central and eastern African forests. Studies have provided contrasting views of the extent and direction of introgression among species. We generated full mitochondrial genomes, and compiled publically available mtDNA 12S and nuclear vWF sequences from Rhynchocyon cirnei, R. petersi and R. udzungwensis that had not previously been analyzed in concert, to elucidate the phylogenetic and population-specific context of potential introgression. Our spatially and phylogenetically broad sampling across species revealed substantial, unidirectional mitochondrial introgression of the R. petersi lineage into R. cirnei reichardi and R. udzungwensis, and from R. udzungwensis into R. c. reichardi. All introgression was highly localized and found only in the eastern Udzungwa Mountains forests in Tanzania. The nuclear data showed another pattern, with R. petersi haplotypes in R. cirnei cirnei and R. c. reichardi. No individuals showed both mitochondrial and nuclear introgression. Our results suggest higher levels of hybridization among giant sengi species than previously recognized, but also highlight the need for further genome-wide analysis and increased spatial sampling to clarify the many aspects of diversification and introgression in this group.


Assuntos
Musaranhos/classificação , Musaranhos/genética , Animais , Núcleo Celular/genética , DNA Intergênico/genética , DNA Mitocondrial/genética , Genoma Mitocondrial , Geografia , Haplótipos/genética , Hibridização Genética , Filogenia , Tanzânia
8.
Genes Genet Syst ; 95(4): 201-210, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33012772

RESUMO

The soricid water shrew Chimarrogale platycephalus is a mammalian species endemic to the Japanese Islands. The animals inhabit the islands of Honshu and Kyushu, and are considered to be extinct in Shikoku. Information on this water shrew from Honshu and Kyushu is scarce, and C. platycephalus is registered on many local governments' red lists as an endangered species. There are very few studies on their ethology, ecology or phylogenetics, due to difficulties related to the shrews being both nocturnal and aquatic: to study C. platycephalus, field research must be conducted in mountain streams at night. To overcome these challenges, we previously established a genetic analysis method using the feces of C. platycephalus, as a result of which the amount of phylogenetic and phylogeographic data has increased and our understanding of the species has improved. In this study, microsatellite markers were developed, and analyses using markers for 21 loci were performed. Moreover, to confirm the ability of these 21 microsatellite markers to differentiate individuals, all markers were tested using fecal and tissue specimens from 12 individuals reared separately in an aquarium. Using as few as 12 of these loci, individual differentiation with 100% accuracy should be achievable. The development of microsatellite markers in this study and the establishment of individual identification methods should greatly contribute to future ecological, ethological, population genetics and biogeographical research on C. platycephalus.


Assuntos
Código de Barras de DNA Taxonômico/métodos , Repetições de Microssatélites , Musaranhos/genética , Animais , Código de Barras de DNA Taxonômico/normas , Espécies em Perigo de Extinção , Limite de Detecção , Filogenia , Musaranhos/classificação
9.
BMC Evol Biol ; 20(1): 106, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32811443

RESUMO

BACKGROUND: The Caribbean offers a unique opportunity to study evolutionary dynamics in insular mammals. However, the recent extinction of most Caribbean non-volant mammals has obstructed evolutionary studies, and poor DNA preservation associated with tropical environments means that very few ancient DNA sequences are available for extinct vertebrates known from the region's Holocene subfossil record. The endemic Caribbean eulipotyphlan family Nesophontidae ("island-shrews") became extinct ~ 500 years ago, and the taxonomic validity of many Nesophontes species and their wider evolutionary dynamics remain unclear. Here we use both morphometric and palaeogenomic methods to clarify the status and evolutionary history of Nesophontes species from Hispaniola, the second-largest Caribbean island. RESULTS: Principal component analysis of 65 Nesophontes mandibles from late Quaternary fossil sites across Hispaniola identified three non-overlapping morphometric clusters, providing statistical support for the existence of three size-differentiated Hispaniolan Nesophontes species. We were also able to extract and sequence ancient DNA from a ~ 750-year-old specimen of Nesophontes zamicrus, the smallest non-volant Caribbean mammal, including a whole-mitochondrial genome and partial nuclear genes. Nesophontes paramicrus (39-47 g) and N. zamicrus (~ 10 g) diverged recently during the Middle Pleistocene (mean estimated divergence = 0.699 Ma), comparable to the youngest species splits in Eulipotyphla and other mammal groups. Pairwise genetic distance values for N. paramicrus and N. zamicrus based on mitochondrial and nuclear genes are low, but fall within the range of comparative pairwise data for extant eulipotyphlan species-pairs. CONCLUSIONS: Our combined morphometric and palaeogenomic analyses provide evidence for multiple co-occurring species and rapid body size evolution in Hispaniolan Nesophontes, in contrast to patterns of genetic and morphometric differentiation seen in Hispaniola's extant non-volant land mammals. Different components of Hispaniola's mammal fauna have therefore exhibited drastically different rates of morphological evolution. Morphological evolution in Nesophontes is also rapid compared to patterns across the Eulipotyphla, and our study provides an important new example of rapid body size change in a small-bodied insular vertebrate lineage. The Caribbean was a hotspot for evolutionary diversification as well as preserving ancient biodiversity, and studying the surviving representatives of its mammal fauna is insufficient to reveal the evolutionary patterns and processes that generated regional diversity.


Assuntos
Tamanho Corporal , Fósseis , Musaranhos/classificação , Animais , DNA Antigo/análise , Filogenia , Índias Ocidentais
10.
BMC Evol Biol ; 20(1): 29, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-32059644

RESUMO

BACKGROUND: Crocidura, the most speciose mammalian genus, occurs across much of Asia, Europe and Africa. The taxonomy of Chinese representatives has been studied primarily based on cursory morphological comparisons and their molecular phylogenetic analyses remain unexplored. In order to understand the phylogeny of this group in China, we estimated the first multilocus phylogeny and conducted species delimitation, including taxon sampling throughout their distribution range. RESULTS: We obtained one mitochondrial gene (cytb) (~ 1, 134 bp) and three nuclear genes (ApoB, BRCA1, RAG1) (~ 2, 170 bp) for 132 samples from 57 localities. Molecular analyses identified at least 14 putative species that occur within two major well-supported groups in China. Polyphyletic C. wuchihensis appears to be composed of two putative species. Two subspecies, C. rapax rapax and C. rapax kurodai should be elevated to full species status. A phylogenetic tree based on mitochondrial gene from Asian Crocidura species showed that the C. rapax rapax is embedded within C. attenuata, making the latter a paraphyletic group. Three strongly supported undescribed species (C. sp.1, C. sp.2 and C. sp.3) are revealed from Zada County of Tibet (Western China), Hongjiang County of Hunan Province (Central China) and Dongyang County of Zhejiang Province (Eastern China), Motuo County of Tibet, respectively. The divergence time estimation suggested that China's Crocidura species began to diversify during the late Pliocene (3.66 Ma) and the Early Pleistocene (2.29 Ma), followed by a series of diversifications through the Pleistocene. CONCLUSIONS: The cryptic diversity found in this study indicated that the number of species is strongly underestimated under the current taxonomy. We propose that the three undescribed species should be evaluated using extensive taxon sampling and comprehensive morphological and morphometric approaches. Climate change since the late Pliocene and the uplift of the Qinghai-Tibet Plateau may result in the diversification and speciation of China's Crocidura species. In short, the underestimated diversity underlines the need for a taxonomic revision of Chinese Crocidura species.


Assuntos
Variação Genética , Musaranhos/classificação , Musaranhos/genética , África , Animais , Ásia , China , DNA Mitocondrial/genética , Europa (Continente) , Genes Mitocondriais , Tipagem de Sequências Multilocus/métodos , Tipagem de Sequências Multilocus/veterinária , Filogenia , Filogeografia , Tibet
11.
J Hum Evol ; 140: 102694, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31759619

RESUMO

Excavations at Kanapoi in north-western Kenya have yielded the most numerically abundant and taxonomically diverse early Pliocene (4.19 Ma) terrestrial small mammal assemblage known from Kenya. A minimum of 15 species are reported, including soricids, sengis, leporids, and rodents: all taxa are referable to extant genera, with the exception of the murine rodent, Saidomys. The majority of the terrestrial small mammals are derived from a bone bed at Nzube's Mandible Site, closely associated with the holotype mandible of Australopithecus anamensis. A smaller number were surface-collected or obtained from screening at several other sites, including the Bat Site. Most small mammals from Nzube's Mandible Site and the Bat Site likely represent prey accumulated as regurgitated pellets from owls, in particular barn owls or giant eagle owls. The small mammal fauna is dominated by the spiny mouse, Acomys: the next most commonly recovered taxa are the multimammate mouse, Mastomys, and the African gerbil, Gerbilliscus. Comparisons of the Kanapoi fauna to other eastern African late Miocene-Pliocene (and one Pleistocene) faunas at the generic level suggest the greatest similarity is to Lemudong'o, Kenya, and Omo B and Aramis, Ethiopia. Further similarities with other localities such as Laetoli, Tanzania, and Hadar, Ethiopia, suggest the existence of a corridor for dispersal along the East African Rift Valley between Ethiopia, Kenya, and Tanzania in the early Pliocene. Further comparisons of the relative abundances of individuals in different families (or subfamilies) emphasize the distinctiveness of the Kanapoi small mammal fauna. The Kanapoi fauna is likely derived from a heterogeneous but relatively arid environment.


Assuntos
Distribuição Animal , Biota , Meio Ambiente , Fósseis , Lagomorpha , Roedores , Musaranhos , Animais , Fósseis/anatomia & histologia , Quênia , Lagomorpha/anatomia & histologia , Lagomorpha/classificação , Paleontologia , Roedores/anatomia & histologia , Roedores/classificação , Musaranhos/anatomia & histologia , Musaranhos/classificação
12.
Proc Natl Acad Sci U S A ; 116(51): 25745-25755, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31772017

RESUMO

Venom systems are key adaptations that have evolved throughout the tree of life and typically facilitate predation or defense. Despite venoms being model systems for studying a variety of evolutionary and physiological processes, many taxonomic groups remain understudied, including venomous mammals. Within the order Eulipotyphla, multiple shrew species and solenodons have oral venom systems. Despite morphological variation of their delivery systems, it remains unclear whether venom represents the ancestral state in this group or is the result of multiple independent origins. We investigated the origin and evolution of venom in eulipotyphlans by characterizing the venom system of the endangered Hispaniolan solenodon (Solenodon paradoxus). We constructed a genome to underpin proteomic identifications of solenodon venom toxins, before undertaking evolutionary analyses of those constituents, and functional assessments of the secreted venom. Our findings show that solenodon venom consists of multiple paralogous kallikrein 1 (KLK1) serine proteases, which cause hypotensive effects in vivo, and seem likely to have evolved to facilitate vertebrate prey capture. Comparative analyses provide convincing evidence that the oral venom systems of solenodons and shrews have evolved convergently, with the 4 independent origins of venom in eulipotyphlans outnumbering all other venom origins in mammals. We find that KLK1s have been independently coopted into the venom of shrews and solenodons following their divergence during the late Cretaceous, suggesting that evolutionary constraints may be acting on these genes. Consequently, our findings represent a striking example of convergent molecular evolution and demonstrate that distinct structural backgrounds can yield equivalent functions.


Assuntos
Eutérios , Evolução Molecular , Genoma/genética , Musaranhos , Peçonhas/genética , Animais , Eutérios/classificação , Eutérios/genética , Eutérios/fisiologia , Duplicação Gênica , Masculino , Filogenia , Proteômica , Musaranhos/classificação , Musaranhos/genética , Musaranhos/fisiologia , Calicreínas Teciduais/genética
13.
C R Biol ; 342(3-4): 108-117, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31056422

RESUMO

The taxonomy of African shrew species is still unresolved due to their conserved morphology. This also affects knowledge concerning their geographic distribution. In Nigeria, using mitochondrial Cytochrome b gene sequences, we carried out a survey for shrews from the genus Crocidura across various ecological zones to determine taxa that are present and also to assess their phylogeographic structure. Our analyses include 183 specimens collected with Sherman traps from 19 localities around the country. We detected six taxa: Crocidura olivieri lineages II, III and IV, C. hildegardeae, C. jouvenetae, and C. foxi. Among these, C. hildegardeae and C. jouvenetae are reported in Nigeria for the first time. Phylogenetic comparison of our genetic sequences to those generated from other parts of Africa demonstrate that all species in our study, as currently defined, are in need of taxonomic revision. Geographically, Nigeria seems to represent the easternmost boundary for C. olivieri lineage II and C. jouvenetae, and the western distribution limit of C. olivieri lineage IV and C. hildegardeae. The Niger River appears to be the most significant topographical barrier restricting these taxa. This information is vital to preserving the diversity but also managing the epidemiological potential of these small mammals.


Assuntos
Citocromos b/genética , Genes Mitocondriais , Filogenia , Musaranhos/classificação , Animais , Ecologia , Nigéria , Filogeografia
14.
Virology ; 531: 162-170, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30884426

RESUMO

Limited sampling means that relatively little is known about the diversity and evolutionary history of mammalian members of the Hepadnaviridae (genus Orthohepadnavirus). An important case in point are shrews, the fourth largest group of mammals, but for which there is limited knowledge on the role they play in viral evolution and emergence. Here, we report the discovery of a novel shrew hepadnavirus. The newly discovered virus, denoted shrew hepatitis B virus (SHBV), is divergent to be considered a new species of Orthohepadnavirus. Phylogenetic analysis revealed that these viruses were usually most closely related to TBHBV (tent-making bat hepatitis B virus), known to be able to infect human hepatocytes, and had a similar genome structure, although SHBV fell in a more basal position in the surface protein phylogeny. In sum, these data suggest that shrews are natural hosts for hepadnaviruses and may have played an important role in their long-term evolution.


Assuntos
Evolução Molecular , Infecções por Hepadnaviridae/veterinária , Infecções por Hepadnaviridae/virologia , Hepadnaviridae/isolamento & purificação , Musaranhos/virologia , Sequência de Aminoácidos , Animais , China , Genoma Viral , Hepadnaviridae/química , Hepadnaviridae/classificação , Hepadnaviridae/genética , Infecções por Hepadnaviridae/transmissão , Hepatócitos/virologia , Humanos , Orthohepadnavirus/classificação , Orthohepadnavirus/genética , Orthohepadnavirus/isolamento & purificação , Filogenia , Alinhamento de Sequência , Musaranhos/classificação , Proteínas Virais/química , Proteínas Virais/genética
15.
Zool Res ; 39(5): 321-334, 2018 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-29976842

RESUMO

Blarinellini is a tribe of soricine shrews comprised of nine fossil genera and one extant genus. Blarinelline shrews were once widely distributed throughout Eurasia and North America, though only members of the Asiatic short-tailed shrew genus Blarinella currently persist (mostly in southwestern China and adjacent areas). Only three forms of Blarinella have been recognized as either species or subspecies. However, recent molecular studies indicated a strikingly deep divergence within the genus, implying the existence of a distinct genus-level lineage. We sequenced the complete mitochondrial genomes and one nuclear gene of three Asiatic short-tailed and two North American shrews and analyzed them morphometrically and morphologically. Our molecular analyses revealed that specimens ascribed to B. griselda formed two deeply diverged lineages, one a close relative to B. quadraticauda, whereas the other - comprised of topotype specimens from southern Gansu - diverged from other Blarinella in the middle Miocene (ca. 18.2 million years ago (Ma), 95% confidence interval=13.4-23.6 Ma). Although the skulls were similarly shaped in both lineages, we observed several diagnostic characteristics, including the shape of the upper P4. In consideration of the molecular and morphological evidence, we recognize B. griselda as the sole species of a new genus, namely, Pantherina gen. nov. Interestingly, some characteristics of Pantherina griselda are more similar to fossil genera, suggesting it represents an evolutionarily more primitive form than Blarinella. Recognition of this new genus sheds light on the systematics and evolutionary history of the tribe Blarinellini throughout Eurasia and North America.


Assuntos
Musaranhos/anatomia & histologia , Animais , Evolução Biológica , China , Mitocôndrias/genética , América do Norte , Análise de Sequência de DNA , Musaranhos/classificação , Musaranhos/genética , Crânio/anatomia & histologia
16.
Mol Phylogenet Evol ; 125: 188-195, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29608962

RESUMO

The red-toothed shrews (Soricinae) are the most widespread subfamily of shrews, distributed from northern South America to North America and Eurasia. Within this subfamily, the tribe Nectogalini includes the fossil species Nesiotites hidalgo recorded from the Late Pleistocene to Holocene of the Balearic Islands (Western Mediterranean). Although there is a consensus about the close relationship between the extinct red-toothed shrew genera Nesiotites and Asoriculus based on morphology, molecular data are necessary to further evaluate the phylogenetic relationships of the Balearic fossils. We obtained a near complete mitochondrial genome of N. hidalgo, allowing the first molecular phylogenetic analysis of this species. Analyses based on 15,167 bp of the mitochondrial genome placed N. hidalgo as close relative to the extant Himalayan shrew (Soriculus nigrescens), and a combined analysis using molecular and morphological data confirm that N. hidalgo and Asoriculus gibberodon are sister-taxa with S. nigrescens as the immediate outgroup. Molecular clock and divergence estimates suggest that the split between N. hidalgo and its closest living relative occurred around 6.44 Ma, which is in agreement with the previously proposed colonisation of the Balearic Islands from mainland Europe by nectogaline shrews during the Messinian Salinity Crisis (5.97-5.33 My ago). Our results highlight that it is possible to retrieve genetic data from extinct small mammals from marginal environments for DNA preservation. Additional finds from the fossil record of Soricinae from the Eurasian Late Miocene/Early Pliocene are needed to shed further light on the still confusing taxonomy and paleobiogeography of this clade.


Assuntos
Filogenia , Salinidade , Musaranhos/classificação , Animais , Teorema de Bayes , Calibragem , Cavernas , DNA Mitocondrial/genética , Evolução Molecular , Fósseis , Genoma Mitocondrial , Musaranhos/genética
17.
Genetica ; 146(2): 211-226, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29441472

RESUMO

Many peninsulas in the temperate zone played an important role as refugia of various flora and fauna, and the southern Korean Peninsula also served as a refugium for many small mammals in East Asia during the Pleistocene. The Asian lesser white-toothed shrew, Crocidura shantungensis, is a widely distributed species in East Asia, and is an appropriate model organism for exploring the role of the Korean Peninsula as a refugium of small mammals. Here, we investigated phylogenetic relationships and genetic diversity based on the entire sequence of the mitochondrial cytochrome b gene (1140 bp). A Bayesian tree for 98 haplotypes detected in 228 C. shantungensis specimens from East Asia revealed the presence of three major groups with at least 5 subgroups. Most haplotypes were distributed according to their geographic proximity. Pairwise FST's and analysis of molecular variance (AMOVA) revealed a high degree of genetic differentiation and variance among regions as well as among populations within region, implying little gene flow among local populations. Genetic evidence from South Korean islands, Jeju-do Island of South Korea, and Taiwan leads us to reject the hypothesis of recent population expansion. We observed unique island-type genetic characteristics consistent with geographic isolation and resultant genetic drift. Phylogeographic inference, together with estimates of genetic differentiation and diversity, suggest that the southern most part the Korean Peninsula, including offshore islands, played an important role as a refugium for C. shantungensis during the Pleistocene. However, the presence of several refugia on the mainland of northeast Asia is also proposed.


Assuntos
Variação Genética , Musaranhos/genética , Animais , Citocromos b/genética , Haplótipos , Coreia (Geográfico) , Filogeografia , Musaranhos/classificação
18.
Mol Phylogenet Evol ; 118: 306-317, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28963083

RESUMO

Phylogeographic research on endemic primates and amphibians inhabiting the Indonesian island of Sulawesi revealed the existence of seven areas of endemism (AoEs). Here, we use phylogenetic and population genetic analyses of one mitochondrial gene and 15 nuclear loci to assess geographic patterns of genetic partitioning in a shrew (Crocidura elongata) that is endemic to Sulawesi, but occurs across the island. We uncover substantial genetic diversity in this species both between and within AoEs, but we also identify close relationships between populations residing in different AoEs. One of the earliest divergences within C. elongata distinguishes a high-elevation clade from low-elevation clades. In addition, on one mountain, we observe three distinct genetic groups from low, middle, and high elevations, suggesting divergence along a single elevational gradient. In general, our results show that C. elongata, like several other Sulawesi endemic taxa, harbors extensive genetic diversity. This diversity is structured in part by known AoE boundaries, but also by elevational gradients and geographic isolation within AoEs.


Assuntos
Musaranhos/classificação , Animais , Sequência de Bases , DNA/química , DNA/isolamento & purificação , DNA/metabolismo , Fluxo Gênico , Variação Genética , Genética Populacional , Indonésia , Ilhas , Mitocôndrias/genética , Filogenia , Filogeografia , Alinhamento de Sequência , Análise de Sequência de DNA
19.
Mitochondrial DNA A DNA Mapp Seq Anal ; 29(2): 170-174, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28093009

RESUMO

To understand the dietary ecology of the leopard cat (Prionailurus bengalensis), DNA analysis was performed to identify prey species using DNA isolated from teeth harvested from the faeces of this feline species. From 70 DNA samples, a total of 52 mitochondrial DNA (mtDNA) cytochrome b (cytb) gene sequences of mammals were identified. The results of a sequence identity test indicated that those sequences were derived from four rodent species (Apodemus agrarius, Apodemus peninsulae, Eothenomys regulus and Tamias sibiricus) and two shrew species (Crocidura lasiura and Crocidura shantungensis). The sequences contained nine unique cytb sequences from site 1 and 13 from site 2. These results indicate that the leopard cat hunts rodents and shrews, and at least nine animals at site 1 and 13 animals at site 2 were eaten. These findings suggest that the animal molecular signatures that remain undigested in the faeces may provide useful ecological information about food items and may contribute to a better understanding of the leopard cat's feeding ecology.


Assuntos
Citocromos b/genética , Felidae/fisiologia , Roedores/classificação , Musaranhos/classificação , Dente/anatomia & histologia , Animais , Carnivoridade , DNA Mitocondrial/genética , Espécies em Perigo de Extinção , Fezes/química , Filogenia , Comportamento Predatório , Roedores/anatomia & histologia , Roedores/genética , Análise de Sequência de DNA , Musaranhos/anatomia & histologia , Musaranhos/genética , Dente/química
20.
Dokl Biol Sci ; 474(1): 93-97, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28702725

RESUMO

Genetic diversity of the genus Blarinella was studied using one mitochondrial and four nuclear genes as examples. The first genotyping of shrews from the southeast of Gansu province (China), which is a typical habitat of B. griselda, has been performed. Molecular genetic analysis showed that Blarinella sp. from southern Gansu stand apart among the other representatives of the genus and can be assigned to neither of the known species.


Assuntos
Variação Genética/genética , Musaranhos/genética , Animais , Ecossistema , Evolução Molecular , Variação Genética/fisiologia , Genótipo , Filogenia , Musaranhos/classificação
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