Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 793
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-32202175

RESUMO

In this paper, we investigate the genetic structure and phylogeography of Rhinolophus ferrumequinum, using the mitochondrial cytochrome b gene (1017 bp) in Iran and adjacent regions. The total haplotype and nucleotide diversity are 0.63 ± 0.055 and 0.0021 ± 0.00017, respectively which suggest that R. ferrumequinum exhibits low genetic diversity. AMOVA analysis shows that more variation of genetic differentiation is present among populations of phylogenetic groupings than within populations. Our phylogenetic results support the monophyly of R. ferrumequinum and suggest this taxon comprises three allopatric/parapatric phylogroups that are distributed in Europe-western Turkey, eastern Turkey-northern Iran, and southern Iran. The Europe-western Turkey lineage (clade 2) split from the eastern Turkey-Iran lineage (clade 1) during the middle Pleistocene (0.8534 (ca.I)-0.6454 (ca.II) Ma). The divergence time among subclades A and B occurred during the mid-Pleistocene (0.4849 (ca.I)-0.369 (ca.II) Ma). All phylogenetic analyses also indicate that the Iranian and eastern Turkey R. ferrumequinum diverged from Europe and western Turkey R. ferrumequinum, with the mean percentage sequence differences ranging from 0.92%-0.75% between them. We infer that long-term isolation of R. ferrumequinum in spatially distinct refugia in parts of southwestern and northeastern Iran has promoted distinct phylogeographic lineages during the Pleistocene.


Assuntos
Quirópteros/genética , Citocromos b/genética , Animais , Evolução Biológica , DNA Mitocondrial/genética , Evolução Molecular , Genes Mitocondriais/genética , Variação Genética/genética , Genética Populacional/métodos , Genoma Mitocondrial/genética , Haplótipos/genética , Irã (Geográfico) , Mitocôndrias/genética , Filogenia , Filogeografia/métodos , Análise de Sequência de DNA/métodos , Turquia
2.
J Med Virol ; 92(4): 433-440, 2020 04.
Artigo em Inglês | MEDLINE | ID: covidwho-17

RESUMO

The current outbreak of viral pneumonia in the city of Wuhan, China, was caused by a novel coronavirus designated 2019-nCoV by the World Health Organization, as determined by sequencing the viral RNA genome. Many initial patients were exposed to wildlife animals at the Huanan seafood wholesale market, where poultry, snake, bats, and other farm animals were also sold. To investigate possible virus reservoir, we have carried out comprehensive sequence analysis and comparison in conjunction with relative synonymous codon usage (RSCU) bias among different animal species based on the 2019-nCoV sequence. Results obtained from our analyses suggest that the 2019-nCoV may appear to be a recombinant virus between the bat coronavirus and an origin-unknown coronavirus. The recombination may occurred within the viral spike glycoprotein, which recognizes a cell surface receptor. Additionally, our findings suggest that 2019-nCoV has most similar genetic information with bat coronovirus and most similar codon usage bias with snake. Taken together, our results suggest that homologous recombination may occur and contribute to the 2019-nCoV cross-species transmission.


Assuntos
Betacoronavirus/genética , Quirópteros/virologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Reservatórios de Doenças , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Serpentes/virologia , Glicoproteína da Espícula de Coronavírus/genética , Animais , Betacoronavirus/classificação , Betacoronavirus/fisiologia , Bungarus/genética , Bungarus/virologia , Quirópteros/genética , Uso do Códon , Infecções por Coronavirus/epidemiologia , Surtos de Doenças , Evolução Molecular , Genoma Viral , Recombinação Homóloga , Especificidade de Hospedeiro , Humanos , Naja naja/genética , Naja naja/virologia , Filogenia , Pneumonia Viral/epidemiologia , Serpentes/genética , Zoonoses
3.
J Med Virol ; 92(4): 433-440, 2020 04.
Artigo em Inglês | MEDLINE | ID: covidwho-2245

RESUMO

The current outbreak of viral pneumonia in the city of Wuhan, China, was caused by a novel coronavirus designated 2019-nCoV by the World Health Organization, as determined by sequencing the viral RNA genome. Many initial patients were exposed to wildlife animals at the Huanan seafood wholesale market, where poultry, snake, bats, and other farm animals were also sold. To investigate possible virus reservoir, we have carried out comprehensive sequence analysis and comparison in conjunction with relative synonymous codon usage (RSCU) bias among different animal species based on the 2019-nCoV sequence. Results obtained from our analyses suggest that the 2019-nCoV may appear to be a recombinant virus between the bat coronavirus and an origin-unknown coronavirus. The recombination may occurred within the viral spike glycoprotein, which recognizes a cell surface receptor. Additionally, our findings suggest that 2019-nCoV has most similar genetic information with bat coronovirus and most similar codon usage bias with snake. Taken together, our results suggest that homologous recombination may occur and contribute to the 2019-nCoV cross-species transmission.


Assuntos
Betacoronavirus/genética , Quirópteros/virologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Reservatórios de Doenças , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Serpentes/virologia , Glicoproteína da Espícula de Coronavírus/genética , Animais , Betacoronavirus/classificação , Betacoronavirus/fisiologia , Bungarus/genética , Bungarus/virologia , Quirópteros/genética , Uso do Códon , Infecções por Coronavirus/epidemiologia , Surtos de Doenças , Evolução Molecular , Genoma Viral , Recombinação Homóloga , Especificidade de Hospedeiro , Humanos , Naja naja/genética , Naja naja/virologia , Filogenia , Pneumonia Viral/epidemiologia , Serpentes/genética , Zoonoses
4.
J Med Virol ; 92(4): 433-440, 2020 04.
Artigo em Inglês | MEDLINE | ID: covidwho-1298

RESUMO

The current outbreak of viral pneumonia in the city of Wuhan, China, was caused by a novel coronavirus designated 2019-nCoV by the World Health Organization, as determined by sequencing the viral RNA genome. Many initial patients were exposed to wildlife animals at the Huanan seafood wholesale market, where poultry, snake, bats, and other farm animals were also sold. To investigate possible virus reservoir, we have carried out comprehensive sequence analysis and comparison in conjunction with relative synonymous codon usage (RSCU) bias among different animal species based on the 2019-nCoV sequence. Results obtained from our analyses suggest that the 2019-nCoV may appear to be a recombinant virus between the bat coronavirus and an origin-unknown coronavirus. The recombination may occurred within the viral spike glycoprotein, which recognizes a cell surface receptor. Additionally, our findings suggest that 2019-nCoV has most similar genetic information with bat coronovirus and most similar codon usage bias with snake. Taken together, our results suggest that homologous recombination may occur and contribute to the 2019-nCoV cross-species transmission.


Assuntos
Betacoronavirus/genética , Quirópteros/virologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Reservatórios de Doenças , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Serpentes/virologia , Glicoproteína da Espícula de Coronavírus/genética , Animais , Betacoronavirus/classificação , Betacoronavirus/fisiologia , Bungarus/genética , Bungarus/virologia , Quirópteros/genética , Uso do Códon , Infecções por Coronavirus/epidemiologia , Surtos de Doenças , Evolução Molecular , Genoma Viral , Recombinação Homóloga , Especificidade de Hospedeiro , Humanos , Naja naja/genética , Naja naja/virologia , Filogenia , Pneumonia Viral/epidemiologia , Serpentes/genética , Zoonoses
5.
PLoS Negl Trop Dis ; 14(1): e0007952, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31961874

RESUMO

The significance of the integral membrane protein Niemann-Pick C1 (NPC1) in the ebolavirus entry process has been determined using various cell lines derived from humans, non-human primates and fruit bats. Fruit bats have long been purported as the potential reservoir host for ebolaviruses, however several studies provide evidence that Mops condylurus, an insectivorous microbat, is also an ebolavirus reservoir. NPC1 receptor expression in the context of ebolavirus replication in microbat cells remains unstudied. In order to study Ebola virus (EBOV) cellular entry and replication in M. condylurus, we derived primary and immortalized cell cultures from 12 different organs. The NPC1 receptor expression was characterized by confocal microscopy and flow cytometry comparing the expression levels of M. condylurus primary and immortalized cells, HeLa cells, human embryonic kidney cells and cells from a European microbat species. EBOV replication kinetics was studied for four representative cell cultures using qRT-PCR. The aim was to elucidate the suitability of primary and immortalized cells from different tissues for studying NPC1 receptor expression levels and their potential influence on EBOV replication. The NPC1 receptor expression level in M. condylurus primary cells differed depending on the organ they were derived from and was for most cell types significantly lower than in human cell lines. Immortalized cells showed for most cell types higher expression levels than their corresponding primary cells. Concluding from our infection experiments with EBOV we suggest a potential correlation between NPC1 receptor expression level and virus replication rate in vitro.


Assuntos
Quirópteros/genética , Reservatórios de Doenças/virologia , Ebolavirus/fisiologia , Proteína C1 de Niemann-Pick/genética , Proteína C1 de Niemann-Pick/metabolismo , Receptores Virais/genética , Animais , Quirópteros/metabolismo , Quirópteros/virologia , Humanos , Receptores Virais/metabolismo , Internalização do Vírus
6.
J Med Virol ; 92(4): 433-440, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31967321

RESUMO

The current outbreak of viral pneumonia in the city of Wuhan, China, was caused by a novel coronavirus designated 2019-nCoV by the World Health Organization, as determined by sequencing the viral RNA genome. Many initial patients were exposed to wildlife animals at the Huanan seafood wholesale market, where poultry, snake, bats, and other farm animals were also sold. To investigate possible virus reservoir, we have carried out comprehensive sequence analysis and comparison in conjunction with relative synonymous codon usage (RSCU) bias among different animal species based on the 2019-nCoV sequence. Results obtained from our analyses suggest that the 2019-nCoV may appear to be a recombinant virus between the bat coronavirus and an origin-unknown coronavirus. The recombination may occurred within the viral spike glycoprotein, which recognizes a cell surface receptor. Additionally, our findings suggest that 2019-nCoV has most similar genetic information with bat coronovirus and most similar codon usage bias with snake. Taken together, our results suggest that homologous recombination may occur and contribute to the 2019-nCoV cross-species transmission.


Assuntos
Betacoronavirus/genética , Quirópteros/virologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Reservatórios de Doenças , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Serpentes/virologia , Glicoproteína da Espícula de Coronavírus/genética , Animais , Betacoronavirus/classificação , Betacoronavirus/fisiologia , Bungarus/genética , Bungarus/virologia , Quirópteros/genética , Uso do Códon , Infecções por Coronavirus/epidemiologia , Surtos de Doenças , Evolução Molecular , Genoma Viral , Recombinação Homóloga , Especificidade de Hospedeiro , Humanos , Naja naja/genética , Naja naja/virologia , Filogenia , Pneumonia Viral/epidemiologia , Serpentes/genética , Zoonoses
7.
Gen Comp Endocrinol ; 286: 113321, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31733210

RESUMO

Growing evidence shows that sex steroids not only act within the individual whose glands produce them; they can also act on proximate conspecifics. Previous studies show that exogenous 17ß-estradiol (E2) can be absorbed both nasally and percutaneously, arriving in blood, neural, reproductive, and peripheral tissues. When male bats were injected with radiolabeled E2 (3H-E2) and housed with females during the mating season, radioactivity was reliably measured in the females' tissues. The present study was designed to compare E2 transfer from male to female bats at three time points in the annual reproductive cycle: spring (ovulation and fertilization), summer (maternal season), and autumn (mating season). Pairs of mature female bats were housed with a mature 3H-E2-treated male (50 µCi). Following 48 h of communal housing, radioactivity was measured in the tissues of female bats. Higher levels of radioactivity were present in the uterus and other tissues during the spring and autumn seasons compared to the summer season. We also measured natural levels of bioactive, unconjugated E2 in the urine of male bats using enzyme immunoassays, and found that it was present in all three seasons but at lower levels during the summer. Male-excreted E2 could transfer to females within the close confines of a roost, potentially influencing their reproductive physiology and behavior. These results suggest increased E2 transfer coincides with female reproduction, with urine as a likely vector. We suggest that sex steroid transfer among interacting individuals may explain several mammalian phenomena historically viewed as "pheromonal".


Assuntos
Quirópteros/genética , Estradiol/urina , Animais , Feminino , Masculino , Estações do Ano
8.
Zool Res ; 41(1): 70-77, 2020 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-31840951

RESUMO

During a survey in 2014, several tube-nosed bats (Vespertilionidae: Murininae: Murina) were collected in Sichuan Province. Based on morphological characters, these bats did not match any species previously recorded from China. Morphometric analyses and phylogenetic inference based on mitochondrial and nuclear gene sequences indicated that they represented a new species, named here as Murina jinchui sp. nov. Although the new species is presently known only from Wolong National Nature Reserve, it is unlikely to be a rare species in the area based on our capture frequencies.


Assuntos
Quirópteros/anatomia & histologia , Nariz/anatomia & histologia , Distribuição Animal , Animais , China , Quirópteros/classificação , Quirópteros/genética , Feminino , Masculino , Especificidade da Espécie
9.
Curr Biol ; 29(24): R1299-R1300, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-31846673

RESUMO

Anthropogenic activities have propelled the Earth into a crisis characterized by unprecedented levels of environmental degradation and habitat loss, generating changes in global climatic regimes and initiating the planet's Sixth Extinction Catastrophe [1]. Loss of population genetic diversity is known to be a harbinger of local and global extinction events [2]. However, there is a lack of direct empirical evidence of historic losses of genetic diversity through periods of anthropogenically linked environmental degradation. We present genomic DNA information from a population of Sunda fruit bats (Cynopterus brachyotis) from Singapore, an exceptionally well-studied tropical rainforest island that has undergone substantial environmental degradation and fragmentation through the Anthropocene of the 1930-1950s [3]. As an effective pollinator and seed disperser, C. brachyotis represents an important keystone species in Singapore's ecosystem [4]. Here we show that comparison of historic DNA from individuals collected in 1931 with modern specimens reveals a nearly 30-fold reduction in effective population size and corresponding levels of decline in genetic diversity estimates. Coalescent population models indicate that Singapore's C. brachyotis bats underwent a continuous decline in genetic diversity followed by a stark bottleneck in approximately the 1940s, consistent with the estimated onset of the Anthropocene [5]. C. brachyotis continues to be considered common across Singapore [4], yet our results reveal large-scale impacts of the Anthropocene on biotic communities, even in those species thought to be tolerant to the effects of environmental degradation.


Assuntos
Quirópteros/genética , Conservação dos Recursos Naturais/tendências , Variação Genética/genética , Animais , Conservação dos Recursos Naturais/métodos , Ecossistema , Genética Populacional/métodos , Polinização , Densidade Demográfica , Floresta Úmida , Singapura , Especificidade da Espécie
10.
PLoS One ; 14(11): e0224969, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31725795

RESUMO

DNA metabarcoding assays are powerful tools for delving into the DNA in wildlife feces, giving unprecedented ability to detect species, understand natural history, and identify pathogens for a range of applications in management, conservation, and research. Next-generation sequencing technology is developing rapidly, which makes it especially important that predictability and reproducibility of DNA metabarcoding assays are explored together with the post-depositional ecology of the target taxon's fecal DNA. Here, we defined the constraints of an assay called 'Species from Feces' used by government agencies, research groups, and non-governmental organizations to identify bat species from guano. We tested assay sensitivity by examining how time and humidity affect the ability to recover and successfully sequence DNA in guano, assessing whether a fecal pellet from a rare bat species could be detected in a background of feces from other bat species, and evaluating the efficacy of Species from Feces as a survey tool for bat roosts in temperate and tropical areas. We found that the assay performs well with feces over two years old in dry, cool environments, and fails by 12 months at 100% relative humidity. We also found that it reliably identifies rare DNA, has great utility for surveying roosts in temperate and tropical regions, and detects more bat species than do visual surveys. We attribute the success of Species from Feces to characteristics of the assay paired with application in taxa that are particularly well-suited for fecal DNA survival. In a time of rapid evolution of DNA metabarcoding approaches and their use with feces, this study illustrates the strengths and limitations of applied assays.


Assuntos
Quirópteros/genética , Fezes/química , Testes Genéticos/métodos , Animais , Arqueologia , Umidade , Mineração , Reprodutibilidade dos Testes , Sudoeste dos Estados Unidos , Especificidade da Espécie , Fatores de Tempo
11.
Proc Natl Acad Sci U S A ; 116(42): 21094-21103, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31570615

RESUMO

Distantly related species entering similar biological niches often adapt by evolving similar morphological and physiological characters. How much genomic molecular convergence (particularly of highly constrained coding sequence) contributes to convergent phenotypic evolution, such as echolocation in bats and whales, is a long-standing fundamental question. Like others, we find that convergent amino acid substitutions are not more abundant in echolocating mammals compared to their outgroups. However, we also ask a more informative question about the genomic distribution of convergent substitutions by devising a test to determine which, if any, of more than 4,000 tissue-affecting gene sets is most statistically enriched with convergent substitutions. We find that the gene set most overrepresented (q-value = 2.2e-3) with convergent substitutions in echolocators, affecting 18 genes, regulates development of the cochlear ganglion, a structure with empirically supported relevance to echolocation. Conversely, when comparing to nonecholocating outgroups, no significant gene set enrichment exists. For aquatic and high-altitude mammals, our analysis highlights 15 and 16 genes from the gene sets most affected by molecular convergence which regulate skin and lung physiology, respectively. Importantly, our test requires that the most convergence-enriched set cannot also be enriched for divergent substitutions, such as in the pattern produced by inactivated vision genes in subterranean mammals. Showing a clear role for adaptive protein-coding molecular convergence, we discover nearly 2,600 convergent positions, highlight 77 of them in 3 organs, and provide code to investigate other clades across the tree of life.


Assuntos
Quirópteros/genética , Quirópteros/fisiologia , Ecolocação/fisiologia , Proteínas/genética , Baleias/genética , Baleias/fisiologia , Adaptação Fisiológica/genética , Adaptação Fisiológica/fisiologia , Substituição de Aminoácidos/genética , Animais , Evolução Molecular , Genoma/genética , Genômica/métodos , Audição/genética , Audição/fisiologia , Filogenia , Seleção Genética/genética
12.
Immunogenetics ; 71(8-9): 575-587, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31520134

RESUMO

The major histocompatibility complex (MHC) is one of the most diverse genetic regions under pathogen-driven selection because of its central role in antigen binding and immunity. The highest MHC variability, both in terms of the number of individual alleles and gene copies, has so far been found in passerine birds; this is probably attributable to passerine adaptation to both a wide geographic range and a diverse array of habitats. If extraordinary high MHC variation and duplication rates are adaptive features under selection during the evolution of ecologically and taxonomically diverse species, then similarly diverse MHC architectures should be found in bats. Bats are an extremely species-rich mammalian group that is globally widely distributed. Many bat species roost in multitudinous groups and have high contact rates with pathogens, conspecifics, and allospecifics. We have characterized the MHC class I diversity in 116 Panamanian Seba's short-tailed bats (Carollia perspicillata), a widely distributed, generalist, neotropical species. We have detected a remarkable individual and population-level diversity of MHC class I genes, with between seven and 22 alleles and a unique genotype in each individual. This diversity is comparable with that reported in passerine birds and, in both taxonomic groups, further variability has evolved through length polymorphisms. Our findings support the hypothesis that, for species with a geographically broader range, high MHC class I variability is particularly adaptive. Investigation of the details of the underlying adaptive processes and the role of the high MHC diversity in pathogen resistance are important next steps for a better understanding of the role of bats in viral evolution and as carriers of several deadly zoonotic viruses.


Assuntos
Quirópteros/genética , Evolução Molecular , Antígenos de Histocompatibilidade Classe I/genética , Polimorfismo Genético , Seleção Genética , Sequência de Aminoácidos , Animais , Quirópteros/imunologia , Éxons , Frequência do Gene , Geografia , Antígenos de Histocompatibilidade Classe I/imunologia , Filogenia , Homologia de Sequência
13.
BMC Evol Biol ; 19(1): 166, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31434566

RESUMO

BACKGROUND: The Old World insectivorous bat genus Rhinolophus is highly speciose. Over the last 15 years, the number of its recognized species has grown from 77 to 106, but knowledge of their interrelationships has not kept pace. Species limits and phylogenetic relationships of this morphologically conservative group remain problematic due both to poor sampling across the Afrotropics and to repeated instances of mitochondrial-nuclear discordance. Recent intensive surveys in East Africa and neighboring regions, coupled with parallel studies by others in West Africa and in Southern Africa, offer a new basis for understanding its evolutionary history. RESULTS: We investigated phylogenetic relationships and intraspecific genetic variation in the Afro-Palearctic clade of Rhinolophidae using broad sampling. We sequenced mitochondrial cytochrome-b (1140 bp) and four independent and informative nuclear introns (2611 bp) for 213 individuals and incorporated sequence data from 210 additional individuals on GenBank that together represent 24 of the 33 currently recognized Afrotropical Rhinolophus species. We addressed the widespread occurrence of mito-nuclear discordance in Rhinolophus by inferring concatenated and species tree phylogenies using only the nuclear data. Well resolved mitochondrial, concatenated nuclear, and species trees revealed phylogenetic relationships and population structure of the Afrotropical species and species groups. CONCLUSIONS: Multiple well-supported and deeply divergent lineages were resolved in each of the six African Rhinolophus species groups analyzed, suggesting as many as 12 undescribed cryptic species; these include several instances of sympatry among close relatives. Coalescent lineage delimitation offered support for new undescribed lineages in four of the six African groups in this study. On the other hand, two to five currently recognized species may be invalid based on combined mitochondrial and/or nuclear phylogenetic analyses. Validation of these cryptic lineages as species and formal relegation of current names to synonymy will require integrative taxonomic assessments involving morphology, ecology, acoustics, distribution, and behavior. The resulting phylogenetic framework offers a powerful basis for addressing questions regarding their ecology and evolution.


Assuntos
Quirópteros/classificação , Quirópteros/genética , Filogenia , África , Animais , Núcleo Celular/genética , Citocromos b/genética , DNA Mitocondrial/genética , Íntrons , Simpatria
14.
Genome Biol Evol ; 11(10): 2741-2749, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31424505

RESUMO

In mammals, social and reproductive behaviors are mediated by chemical cues encoded by hyperdiverse families of receptors expressed in the vomeronasal organ. Between species, the number of intact receptors can vary by orders of magnitude. However, the evolutionary processes behind variation in receptor number, and its link to fitness-related behaviors are not well understood. From vomeronasal transcriptomes, we discovered the first evidence of intact vomeronasal type-1 receptor (V1r) genes in bats, and we tested whether putatively functional bat receptors were orthologous to those of related taxa, or whether bats have evolved novel receptors. Instead of lineage-specific duplications, we found that bat V1rs show high levels of orthology to those of their relatives, and receptors are under comparative levels of purifying selection as non-bats. Despite widespread vomeronasal organ loss in bats, V1r copies have been retained for >65 million years. The highly conserved nature of bat V1rs challenges our current understanding of mammalian V1r function and suggests roles other than conspecific recognition or mating initiation in social behavior.


Assuntos
Quirópteros/metabolismo , Receptores de Feromonas/metabolismo , Órgão Vomeronasal/metabolismo , Comunicação Animal , Animais , Sequência de Bases , Quirópteros/genética , Sequência Conservada , Evolução Molecular , Filogenia , Receptores de Feromonas/genética
15.
Mol Biol Evol ; 36(10): 2171-2183, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31311032

RESUMO

Diet is a key factor in determining and structuring animal diversity and adaptive radiations. The mammalian fossil record preserves phenotypic evidence of many dietary shifts, whereas genetic changes followed by dietary diversification in mammals remain largely unknown. To test whether living mammals preserve molecular evidence of dietary shifts, we examined the trehalase gene (Treh), which encodes an enzyme capable of digesting trehalose from insect blood, in bats and other mammals with diverse diets. Bats represent the largest dietary radiation among all mammalian orders, with independent origins of frugivory, nectarivory, carnivory, omnivory, and even sanguivory in an otherwise insectivorous clade. We found that Treh has been inactivated in unrelated bat lineages that independently radiated into noninsectivorous niches. Consistently, purifying selection has been markedly relaxed in noninsectivorous bats compared with their insectivorous relatives. Enzymatic assays of intestinal trehalase in bats suggest that trehalase activity tends to be lost or markedly reduced in noninsectivorous bats compared with their insectivorous relatives. Furthermore, our survey of Treh in 119 mammal species, which represent a deeper evolutionary timeframe, additionally identified a number of other independent losses of Treh in noninsectivorous species, recapitulating the evolutionary pattern that we found in bats. These results document a molecular record of dietary diversification in mammals, and suggest that such molecular signatures of dietary shifts would help us understand both historical and modern changes of animal diets.


Assuntos
Evolução Biológica , Quirópteros/genética , Dieta , Trealase/genética , Animais , Quirópteros/metabolismo , Trealase/metabolismo
16.
Nat Commun ; 10(1): 2820, 2019 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-31249297

RESUMO

Bats are unusual mammals, with the ability to fly, and long lifespans. In addition, bats have a low incidence of cancer, but the mechanisms underlying this phenomenon remain elusive. Here we discovered that bat cells are more resistant than human and mouse cells to DNA damage induced by genotoxic drugs. We found that bat cells accumulate less chemical than human and mouse cells, and efficient drug efflux mediated by the ABC transporter ABCB1 underlies this improved response to genotoxic reagents. Inhibition of ABCB1 triggers an accumulation of doxorubicin, DNA damage, and cell death. ABCB1 is expressed at higher levels in several cell lines and tissues derived from bats compared to humans. Furthermore, increased drug efflux and high expression of ABCB1 are conserved across multiple bat species. Our findings suggest that enhanced efflux protects bat cells from DNA damage induced by genotoxic compounds, which may contribute to their low cancer incidence.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Quirópteros/genética , Quirópteros/metabolismo , Dano ao DNA/efeitos dos fármacos , Mutagênicos/toxicidade , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Doxorrubicina/toxicidade , Humanos , Camundongos
17.
Mol Phylogenet Evol ; 139: 106544, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31252069

RESUMO

Species delimitation and evolutionary reconstruction remain challenging for non-model species that have experienced reticulate evolution and exhibit conflicting patterns of differentiation among multiple lines of evidence, such as mitochondrial and nuclear data and phenotypes. Here, we applied an integrative taxonomic approach to a case study of Rhinolophus macrotis complex, whose taxonomic status remains controversial, to provide insight into the systematics and evolutionary history of these species. By integrating traditional genetic markers with different modes of inheritance, genome-wide SNPs as well as phenotypic characteristics, we clarified the presence of three closely related species, R. episcopus, R. siamensis, and R. osgoodi, within this complex, and proposed a new taxonomic treatment for R. osgoodi. Our results suggested that hybridization and introgression are the main causes of low mtDNA divergence in these species. Combined with the demographic inference, we deduced that glacial-interglacial cycles drove geographic isolation and secondary contacts of these species, then promoted hybridization and lineage fusion among them, finally resulting in a reticulate evolutionary pattern. Overall, our study highlights the importance of combining multiple types of data to delimit species, especially those with conserved morphology, and to reveal the sophisticated processes of speciation.


Assuntos
Quirópteros/classificação , Animais , Quirópteros/genética , DNA Mitocondrial/química , Marcadores Genéticos , Especiação Genética , Hibridização Genética , Fenótipo , Filogenia , Polimorfismo de Nucleotídeo Único
18.
Philos Trans R Soc Lond B Biol Sci ; 374(1777): 20180249, 2019 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-31154984

RESUMO

Animal microbiomes play an important role in dietary adaptation, yet the extent to which microbiome changes exhibit parallel evolution is unclear. Of particular interest is an adaptation to extreme diets, such as blood, which poses special challenges in its content of proteins and lack of essential nutrients. In this study, we assessed taxonomic signatures (by 16S rRNA amplicon profiling) and potential functional signatures (inferred by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt)) of haematophagy in birds and bats. Our goal was to test three alternative hypotheses: no convergence of microbiomes, convergence in taxonomy and convergence in function. We find a statistically significant effect of haematophagy in terms of microbial taxonomic convergence across the blood-feeding bats and birds, although this effect is small compared to the differences found between haematophagous and non-haematophagous species within the two host clades. We also find some evidence of convergence at the predicted functional level, although it is possible that the lack of metagenomic data and the poor representation of microbial lineages adapted to haematophagy in genome databases limit the power of this approach. The results provide a paradigm for exploring convergent microbiome evolution replicated with independent contrasts in different host lineages. This article is part of the theme issue 'Convergent evolution in the genomics era: new insights and directions'.


Assuntos
Bactérias/genética , Aves/genética , Quirópteros/genética , Microbioma Gastrointestinal , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Evolução Biológica , Aves/microbiologia , Aves/fisiologia , Quirópteros/microbiologia , Quirópteros/fisiologia , DNA Bacteriano/genética , Comportamento Alimentar , Filogenia , RNA Ribossômico 16S/genética
19.
Proc Natl Acad Sci U S A ; 116(21): 10418-10423, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31061126

RESUMO

Local adaptations can determine the potential of populations to respond to environmental changes, yet adaptive genetic variation is commonly ignored in models forecasting species vulnerability and biogeographical shifts under future climate change. Here we integrate genomic and ecological modeling approaches to identify genetic adaptations associated with climate in two cryptic forest bats. We then incorporate this information directly into forecasts of range changes under future climate change and assessment of population persistence through the spread of climate-adaptive genetic variation (evolutionary rescue potential). Considering climate-adaptive potential reduced range loss projections, suggesting that failure to account for intraspecific variability can result in overestimation of future losses. On the other hand, range overlap between species was projected to increase, indicating that interspecific competition is likely to play an important role in limiting species' future ranges. We show that although evolutionary rescue is possible, it depends on a population's adaptive capacity and connectivity. Hence, we stress the importance of incorporating genomic data and landscape connectivity in climate change vulnerability assessments and conservation management.


Assuntos
Adaptação Fisiológica/genética , Quirópteros/genética , Variação Genética/genética , Animais , Mudança Climática , Ecossistema , Previsões/métodos , Modelos Biológicos
20.
BMC Evol Biol ; 19(1): 98, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31064342

RESUMO

BACKGROUND: The Micronycterinae form a subfamily of leaf-nosed bats (Phyllostomidae) that contains the genera Lampronycteris Sanborn, 1949, and Micronycteris Gray, 1866 (stricto sensu), and is characterized by marked karyotypic variability and discrepancies in the phylogenetic relationships suggested by the molecular versus morphological data. In the present study, we investigated the chromosomal evolution of the Micronycterinae using classical cytogenetics and multidirectional chromosome painting with whole-chromosomes probes of Phyllostomus hastatus and Carollia brevicauda. Our goal was to perform comparative chromosome mapping between the genera of this subfamily and explore the potential for using chromosomal rearrangements as phylogenetic markers. RESULTS: The Micronycterinae exhibit great inter- and intraspecific karyotype diversity, with large blocks of telomere-like sequences inserted within or adjacent to constitutive heterochromatin regions. The phylogenetic results generated from our chromosomal data revealed that the Micronycterinae hold a basal position in the phylogenetic tree of the Phyllostomidae. Molecular cytogenetic data confirmed that there is a low degree of karyotype similarity between Lampronycteris and Micronycteris specimens analyzed, indicating an absence of synapomorphic associations in Micronycterinae. CONCLUSIONS: We herein confirm that karyotypic variability is present in subfamily Micronycterinae. We further report intraspecific variation and describe a new cytotype in M. megalotis. The cytogenetic data show that this group typically has large blocks of interstitial telomeric sequences that do not appear to be correlated with chromosomal rearrangement events. Phylogenetic analysis using chromosome data recovered the basal position for Micronycterinae, but did not demonstrate that it is a monophyletic lineage, due to the absence of common chromosomal synapomorphy between the genera. These findings may be related to an increase in the rate of chromosomal evolution during the time period that separates Lampronycteris from Micronycteris.


Assuntos
Quirópteros/classificação , Quirópteros/genética , Evolução Molecular , Cariótipo , Filogenia , Animais , Teorema de Bayes , Mapeamento Cromossômico , Coloração Cromossômica/métodos , Cromossomos de Mamíferos/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA