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1.
Indian J Med Microbiol ; 45: 100384, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37573057

RESUMEN

PURPOSE: Compared to nasopharyngeal/oropharyngeal swabs (N/OPS-VTM), non-invasive saliva samples have enormous potential for scalability and routine population screening of SARS-CoV-2. In this study, we investigate the efficacy of saliva samples relative to N/OPS-VTM for use as a direct source for RT-PCR based SARS-CoV-2 detection. METHODS: We collected paired nasopharyngeal/oropharyngeal swabs and saliva samples from suspected positive SARS-CoV-2 patients and tested using RT-PCR. We used generalized linear models to investigate factors that explain result agreement. Further, we used simulations to evaluate the effectiveness of saliva-based screening in restricting the spread of infection in a large campus such as an educational institution. RESULTS: We observed a 75.4% agreement between saliva and N/OPS-VTM, that increased drastically to 83% in samples stored for less than three days. Such samples processed within two days of collection showed 74.5% test sensitivity. Our simulations suggest that a test with 75% sensitivity, but high daily capacity can be very effective in limiting the size of infection clusters in a workspace. Guided by these results, we successfully implemented a saliva-based screening in the Bangalore Life Sciences Cluster (BLiSC) campus. CONCLUSION: These results suggest that saliva may be a viable alternate source for SARS-CoV-2 surveillance if samples are processed immediately. Although saliva shows slightly lower sensitivity levels when compared to N/OPS-VTM, saliva collection is logistically advantageous. We strongly recommend the implementation of saliva-based screening strategies for large workplaces and in schools, as well as for population-level screening and routine surveillance as we learn to live with the SARS-CoV-2 virus.


Asunto(s)
COVID-19 , Saliva , Humanos , SARS-CoV-2 , Análisis Costo-Beneficio , COVID-19/diagnóstico , India , Nasofaringe , Manejo de Especímenes
2.
Biol Rev Camb Philos Soc ; 98(6): 2114-2135, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37449566

RESUMEN

Intraguild interactions among carnivores have long held the fascination of ecologists. Ranging from competition to facilitation and coexistence, these interactions and their complex interplay influence everything from species persistence to ecosystem functioning. Yet, the patterns and pathways of such interactions are far from understood in tropical forest systems, particularly across countries in the Global South. Here, we examined the determinants and consequences of competitive interactions between dholes Cuon alpinus and the two large felids (leopards Panthera pardus and tigers Panthera tigris) with which they most commonly co-occur across Asia. Using a combination of traditional and novel data sources (N = 118), we integrate information from spatial, temporal, and dietary niche dimensions. These three species have faced catastrophic declines in their extent of co-occurrence over the past century; most of their source populations are now confined to Protected Areas. Analysis of dyadic interactions between species pairs showed a clear social hierarchy. Tigers were dominant over dholes, although pack strength in dholes helped ameliorate some of these effects; leopards were subordinate to dholes. Population-level spatio-temporal interactions assessed at 25 locations across Asia did not show a clear pattern of overlap or avoidance between species pairs. Diet-profile assessments indicated that wild ungulate biomass consumption by tigers was highest, while leopards consumed more primate and livestock prey as compared to their co-predators. In terms of prey offtake (ratio of wild prey biomass consumed to biomass available), the three species together harvested 0.4-30.2% of available prey, with the highest offtake recorded from the location where the carnivores reach very high densities. When re-examined in the context of prey availability and offtake, locations with low wild prey availability showed spatial avoidance and temporal overlap among the carnivore pairs, and locations with high wild prey availability showed spatial overlap and temporal segregation. Based on these observations, we make predictions for 40 Protected Areas in India where temporally synchronous estimates of predator and prey densities are available. We expect that low prey availability will lead to higher competition, and in extreme cases, to the complete exclusion of one or more species. In Protected Areas with high prey availability, we expect intraguild coexistence and conspecific competition among carnivores, with spill-over to forest-edge habitats and subsequent prey-switching to livestock. We stress that dhole-leopard-tiger co-occurrence across their range is facilitated through an intricate yet fragile balance between prey availability, and intraguild and conspecific competition. Data gaps and limitations notwithstanding, our study shows how insights from fundamental ecology can be of immense utility for applied aspects like large predator conservation and management of human-carnivore interactions. Our findings also highlight potential avenues for future research on tropical carnivores that can broaden current understanding of intraguild competition in forest systems of Asia and beyond.


Asunto(s)
Canidae , Ecosistema , Humanos , Animales , Asia , Biomasa , Ecología , Ganado
3.
Ecol Evol ; 13(5): e10129, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37250448

RESUMEN

Studying the genetic variation among different species distributed across their core and range-edge habitats can provide valuable insights into how genetic variation changes across the species' distribution range. This information can be important for understanding local adaptation, as well as for conservation and management efforts. In this study, we have carried out genomic characterization of six species of Asian Pikas distributed along their core and range-edge habitats in the Himalayas. We utilized a population genomics approach using ~28,000 genome-wide SNP markers obtained from restriction-site associated DNA sequencing. We identified low nucleotide diversity and high inbreeding coefficients in all six species across their core and range-edge habitats. We also identified evidence of gene flow among genetically diverse species. Our results provide evidence of reduced genetic diversity in Asian pikas distributed across the Himalayas and the neighboring regions and indicate that recurrent gene flow is possibly a key mechanism for maintaining genetic diversity and adaptive potential in these pikas. However, full-scale genomics studies that utilize whole-genome sequencing approaches will be needed to quantify the direction and timing of gene flow and functional changes associated with introgressed regions in the genome. Our results represent an important step toward understanding the patterns and consequences of gene flow in species, sampled at the least studied, yet climatically vulnerable part of their habitat that can be further used to inform conservation strategies that promote connectivity and gene flow between populations.

4.
Ecol Evol ; 13(5): e10100, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37214618

RESUMEN

Human demographic expansion has confined wildlife to fragmented habitats, often in proximity to human-modified landscapes. Such interfaces facilitate increased interactions between feral or domesticated animals and wildlife, posing a high risk to wild species. This is especially relevant for free-ranging dogs (Canis lupus familiaris) and wild canids like gray wolves (Canis lupus) and golden jackals (Canis aureus). Wolf-dog hybridization may lead to a significant reduction of specific adaptations in wolves that could result in the decline of wolf populations. Detection and genetic discrimination of hybrids between dogs and wolves are challenging because of their complex demographic history and close ancestry. Citizen scientists identified two phenotypically different-looking individuals and subsequently collected non-invasive samples that were used by geneticists to test wolf-dog hybridization. Genomic data from shed hair samples of suspected hybrid individuals using double-digest restriction-site-associated DNA (ddRAD) sequencing resulted in 698 single nucleotide polymorphism (SNP) markers. We investigated the genetic origin of these two individuals analyzed with genetically known dogs, wolves, and other canid species including jackals and dholes (Cuon alpinus). Our results provide the first genetic evidence of one F2 hybrid and the other individual could be a complex hybrid between dogs and wolves. Our results re-iterate the power of next-generation sequencing (NGS) for non-invasive samples as an efficient tool for detecting hybrids. Our results suggest the need for more robust monitoring of wolf populations and highlight the tremendous potential for collaborative approaches between citizens and conservation scientists to detect and monitor threats to biodiversity.

5.
Lancet Reg Health Southeast Asia ; 11: 100151, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36688230

RESUMEN

Background: Environmental surveillance (ES) of a pathogen is crucial for understanding the community load of disease. As an early warning system, ES for SARS-CoV-2 has complemented routine diagnostic surveillance by capturing near real-time virus circulation at a population level. Methods: In this longitudinal study conducted between January 2022 and June 2022 in 28 sewershed sites in Bengaluru city (∼11 million inhabitants), we quantified weekly SARS-CoV-2 RNA concentrations to track infection dynamics and provide evidence of change in the relative abundance of emerging variants. Findings: We describe an early warning system using the exponentially weighted moving average control chart and demonstrate how SARS-CoV-2 RNA concentrations in wastewater correlated with clinically diagnosed new COVID-19 cases, with the trends appearing 8-14 days earlier in wastewater than in clinical data. This was further corroborated by showing that the estimated number of infections is strongly correlated with SARS-CoV-2 RNA copies detected in the wastewater. Using a deconvolution matrix, we detected emerging variants of concern up to two months earlier in wastewater samples. In addition, we found a huge diversity in variants detected in wastewater compared to clinical samples. The findings from this study have been discussed regularly with local authorities to inform policy-making decisions. Interpretation: Our study highlights that quantifying viral titre, correlating it with a known number of cases in the area, and combined with genomic surveillance helps in tracking variants of concern (VOC) over time and space, enabling timely and making informed policy decisions. Funding: This work has been supported by funding from the Rockefeller Foundation grant to National Centre for Biological Sciences, TIFR) and the Indian Council of Medical Research grant to (FI) Tata Institute for Genetics and Society and Tata Trusts.

6.
Gigascience ; 122022 12 28.
Artículo en Inglés | MEDLINE | ID: mdl-36576130

RESUMEN

The tiger, a poster child for conservation, remains an endangered apex predator. Continued survival and recovery will require a comprehensive understanding of genetic diversity and the use of such information for population management. A high-quality tiger genome assembly will be an important tool for conservation genetics, especially for the Indian tiger, the most abundant subspecies in the wild. Here, we present high-quality near-chromosomal genome assemblies of a female and a male wild Indian tiger (Panthera tigris tigris). Our assemblies had a scaffold N50 of >140 Mb, with 19 scaffolds corresponding to the 19 numbered chromosomes, containing 95% of the genome. Our assemblies also enabled detection of longer stretches of runs of homozygosity compared to previous assemblies, which will help improve estimates of genomic inbreeding. Comprehensive genome annotation identified 26,068 protein-coding genes, including several gene families involved in key morphological features such as the teeth, claws, vision, olfaction, taste, and body stripes. We also identified 301 microRNAs, 365 small nucleolar RNAs, 632 transfer RNAs, and other noncoding RNA elements, several of which are predicted to regulate key biological pathways that likely contribute to the tiger's apex predatory traits. We identify signatures of positive selection in the tiger genome that are consistent with the Panthera lineage. Our high-quality genome will enable use of noninvasive samples for comprehensive assessment of genetic diversity, thus supporting effective conservation and management of wild tiger populations.


Asunto(s)
Conducta Predatoria , Tigres , Animales , Femenino , Masculino , Cromosomas , Genoma , Genómica , Tigres/genética
7.
J Indian Inst Sci ; 102(2): 711-730, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36093274

RESUMEN

The current pandemic caused by the SARS CoV-2, tracing back its origin possibly to a coronavirus associated with bats, has ignited renewed interest in understanding zoonotic spillovers across the globe. While research is more directed towards solving the problem at hand by finding therapeutic strategies and novel vaccine techniques, it is important to address the environmental drivers of pathogen spillover and the complex biotic and abiotic drivers of zoonoses. The availability of cutting-edge genomic technologies has contributed enormously to preempt viral emergence from wildlife. However, there is still a dearth of studies from species-rich South Asian countries, especially from India. In this review, we outline the importance of studying disease dynamics through environmental sampling from wildlife in India and how ecological parameters of both the virus and the host community may play a role in mediating cross-species spillovers. Non-invasive sampling using feces, urine, shed hair, saliva, shed skin, and feathers has been instrumental in providing genetic information for both the host and their associated pathogens. Here, we discuss the advances made in environmental sampling protocols and strategies to generate genetic data from such samples towards the surveillance and characterization of potentially zoonotic pathogens. We primarily focus on bat-borne or small mammal-borne zoonoses and propose a conceptual framework for non-invasive strategies to tackle the threat of emerging zoonotic infections.

8.
Philos Trans R Soc Lond B Biol Sci ; 377(1852): 20200418, 2022 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-35430878

RESUMEN

Unprecedented advances in sequencing technology in the past decade allow a better understanding of genetic variation and its partitioning in natural populations. Such inference is critical to conservation: to understand species biology and identify isolated populations. We review empirical population genetics studies of Endangered Bengal tigers within India, where 60-70% of wild tigers live. We assess how changes in marker type and sampling strategy have impacted inferences by reviewing past studies, and presenting three novel analyses including a single-nucleotide polymorphism (SNP) panel, genome-wide SNP markers, and a whole-mitochondrial genome network. At a broad spatial scale, less than 100 SNPs revealed the same patterns of population clustering as whole genomes (with the exception of one additional population sampled only in the SNP panel). Mitochondrial DNA indicates a strong structure between the northeast and other regions. Two studies with more populations sampled revealed further substructure within Central India. Overall, the comparison of studies with varied marker types and sample sets allows more rigorous inference of population structure. Yet sampling of some populations is limited across all studies, and these should be the focus of future sampling efforts. We discuss challenges in our understanding of population structure, and how to further address relevant questions in conservation genetics. This article is part of the theme issue 'Celebrating 50 years since Lewontin's apportionment of human diversity'.


Asunto(s)
Tigres , Animales , Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Variación Genética , Genética de Población , India , Estudios Prospectivos , Tigres/genética
9.
Conserv Biol ; 2022 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-35288989

RESUMEN

As ecological data and associated analyses become more widely available, synthesizing results for effective communication with stakeholders is essential. In the case of wildlife corridors, managers in human-dominated landscapes need to identify both the locations of corridors and multiple stakeholders for effective oversight. We synthesized 5 independent studies of tiger (Panthera tigris) connectivity in central India, a global priority landscape for tiger conservation, to quantify agreement on landscape permeability for tiger movement and potential movement pathways. We used the latter analysis to identify connectivity areas on which studies agreed and stakeholders associated with these areas to determine relevant participants in corridor management. Three or more of the 5 studies' resistance layers agreed in 63% of the study area. Areas in which all studies agree on resistance were of primarily low (66%, e.g., forest) and high (24%, e.g., urban) resistance. Agreement was lower in intermediate resistance areas (e.g., agriculture). Despite these differences, the studies largely agreed on areas with high levels of potential movement: >40% of high average (top 20%) current-flow pixels were also in the top 20% of current-flow agreement pixels (measured by low variation), indicating consensus connectivity areas (CCAs) as conservation priorities. Roughly 70% of the CCAs fell within village administrative boundaries, and 100% overlapped forest department management boundaries, suggesting that people live and use forests within these priority areas. Over 16% of total CCAs' area was within 1 km of linear infrastructure (437 road, 170 railway, 179 transmission line, and 339 canal crossings; 105 mines within 1 km of CCAs). In 2019, 78% of forest land diversions for infrastructure and mining in Madhya Pradesh (which comprises most of the study region) took place in districts with CCAs. Acute competition for land in this landscape with globally important wildlife corridors calls for an effective comanagement strategy involving local communities, forest departments, Appendix 1 and infrastructure planners. This article is protected by copyright. All rights reserved.

10.
Mol Phylogenet Evol ; 168: 107414, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35032646

RESUMEN

The leopard gecko, Eublepharis macularius, is a widely used model organism in laboratory and experimental studies. The high phenotypic diversity in the pet trade, the fact that the provenance of different breeding lines is unknown, and that distinct Eublepharis species are known to hybridize, implies that the continued use of E. macularius as a model requires clarity on the origin of the lineages in the pet trade. We combine multi-locus sequence data and the first range-wide sampling of the genus Eublepharis to reconstruct the evolutionary history of the Eublepharidae and Eublepharis, with an updated time-tree for the Eublepharidae. Our sampling includes five of the six recognized species and additional nominal taxa of uncertain status comprising 43 samples from 34 localities plus 48 pet-trade samples. The Eublepharidae began diversifying in the Cretaceous. Eublepharis split from its sister genera in Africa in the Palaeocene-Eocene, and began diversifying in the Oligocene-Miocene, with late Miocene-Pliocene cladogenesis giving rise to extant species. The current species diversity within this group is moderately underestimated. Our species delimitation suggests 10 species with four potentially unnamed divergent lineages in Iran, India and Pakistan. All 30 individuals of E. macularius that we sampled from the pet trade, which include diverse morphotypes, come from a few shallow E. macularius clades, confirming that lab and pet trade strains are part of a single taxon. One of the wild-caught haplotypes of E. macularius, from near Karachi, Pakistan, is identical to (10) pet-trade samples and all other captive populations are closely related to wild-caught animals from central/southern Pakistan (0.1-0.5 % minimum pairwise uncorrected ND2 sequence divergence).


Asunto(s)
Lagartos , Fitomejoramiento , África , Animales , Especiación Genética , Lagartos/genética , Filogenia
11.
Bioinformation ; 18(9): 739-741, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-37426502

RESUMEN

Lantana camara L. is an invasive species of global concern. An ornamental plant originating from central America, it has now spread across natural and human-dominated habitats across tropical and subtropical regions globally. Understanding the population and evolutionary genetics of this species could help gain deeper insights into invasion biology, and provide tools for more effective management. Such investigation would require a relatively good quality genome assembly. While there have been reports of a transcriptome, it has been challenging to construct the genome assembly because of the large genome size. We present here the first draft genome assembly of Lantana camara L. which has an N50 value of 62 Kb, genome completeness of 99.3% and genome coverage of 74.3%. We hope that such an assembly will help researchers study colonization history, the genetic basis of adaptation and invasiveness, and help design strategies to contain the invasiveness of this plant, allowing biodiversity recovery in several parts of the globe.

12.
Heredity (Edinb) ; 128(2): 88-96, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34857925

RESUMEN

Identification of genetic structure within wildlife populations have implications in their conservation and management. Accurately inferring population genetic structure requires whole-genome data across the geographical range of the species, which can be resource-intensive. A cheaper strategy is to employ a subset of markers that can efficiently recapitulate the population genetic structure inferred by the whole genome data. Such ancestry informative markers (AIMs), have rarely been developed for endangered species such as tigers utilizing single nucleotide polymorphisms (SNPs). Here, we first identify the population structure of the Indian tiger using whole-genome sequences and then develop an AIMs panel with a minimum number of SNPs that can recapitulate this structure. We identified four population clusters of Indian tigers with North-East, North-West, and South Indian tigers forming three separate groups, and Terai and Central Indian tigers forming a single cluster. To evaluate the robustness of our AIMs, we applied it to a separate dataset of tigers from across India. Out of 92 SNPs present in our AIMs panel, 49 were present in the new dataset. These 49 SNPs were sufficient to recapitulate the population genetic structure obtained from the whole genome data. To the best of our knowledge, this is the first-ever SNP-based AIMs panel for big cats, which can be used as a cost-effective alternative to whole-genome sequencing for detecting the biogeographical origin of Indian tigers. Our study can be used as a guideline for developing an AIMs panel for the management of other endangered species where obtaining whole genome sequences are difficult.


Asunto(s)
Tigres , Animales , Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Variación Genética , Genética de Población , Genoma , Tigres/genética
13.
Proc Natl Acad Sci U S A ; 118(49)2021 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-34848534

RESUMEN

Increasing habitat fragmentation leads to wild populations becoming small, isolated, and threatened by inbreeding depression. However, small populations may be able to purge recessive deleterious alleles as they become expressed in homozygotes, thus reducing inbreeding depression and increasing population viability. We used whole-genome sequences from 57 tigers to estimate individual inbreeding and mutation load in a small-isolated and two large-connected populations in India. As expected, the small-isolated population had substantially higher average genomic inbreeding (FROH = 0.57) than the large-connected (FROH = 0.35 and FROH = 0.46) populations. The small-isolated population had the lowest loss-of-function mutation load, likely due to purging of highly deleterious recessive mutations. The large populations had lower missense mutation loads than the small-isolated population, but were not identical, possibly due to different demographic histories. While the number of the loss-of-function alleles in the small-isolated population was lower, these alleles were at higher frequencies and homozygosity than in the large populations. Together, our data and analyses provide evidence of 1) high mutation load, 2) purging, and 3) the highest predicted inbreeding depression, despite purging, in the small-isolated population. Frequency distributions of damaging and neutral alleles uncover genomic evidence that purifying selection has removed part of the mutation load across Indian tiger populations. These results provide genomic evidence for purifying selection in both small and large populations, but also suggest that the remaining deleterious alleles may have inbreeding-associated fitness costs. We suggest that genetic rescue from sources selected based on genome-wide differentiation could offset any possible impacts of inbreeding depression.


Asunto(s)
Variación Genética , Genómica , Endogamia , Tigres/genética , Distribución Animal , Animales , Conservación de los Recursos Naturales , Genoma , India
15.
Bioscience ; 71(9): 964-976, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34475806

RESUMEN

Global conservation policy and action have largely neglected protecting and monitoring genetic diversity-one of the three main pillars of biodiversity. Genetic diversity (diversity within species) underlies species' adaptation and survival, ecosystem resilience, and societal innovation. The low priority given to genetic diversity has largely been due to knowledge gaps in key areas, including the importance of genetic diversity and the trends in genetic diversity change; the perceived high expense and low availability and the scattered nature of genetic data; and complicated concepts and information that are inaccessible to policymakers. However, numerous recent advances in knowledge, technology, databases, practice, and capacity have now set the stage for better integration of genetic diversity in policy instruments and conservation efforts. We review these developments and explore how they can support improved consideration of genetic diversity in global conservation policy commitments and enable countries to monitor, report on, and take action to maintain or restore genetic diversity.

16.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-34518374

RESUMEN

Most endangered species exist today in small populations, many of which are isolated. Evolution in such populations is largely governed by genetic drift. Empirical evidence for drift affecting striking phenotypes based on substantial genetic data are rare. Approximately 37% of tigers (Panthera tigris) in the Similipal Tiger Reserve (in eastern India) are pseudomelanistic, characterized by wide, merged stripes. Camera trap data across the tiger range revealed the presence of pseudomelanistic tigers only in Similipal. We investigated the genetic basis for pseudomelanism and examined the role of drift in driving this phenotype's frequency. Whole-genome data and pedigree-based association analyses from captive tigers revealed that pseudomelanism cosegregates with a conserved and functionally important coding alteration in Transmembrane Aminopeptidase Q (Taqpep), a gene responsible for similar traits in other felid species. Noninvasive sampling of tigers revealed a high frequency of the Taqpep p.H454Y mutation in Similipal (12 individuals, allele frequency = 0.58) and absence from all other tiger populations (395 individuals). Population genetic analyses confirmed few (minimal number) tigers in Similipal, and its genetic isolation, with poor geneflow. Pairwise FST (0.33) at the mutation site was high but not an outlier. Similipal tigers had low diversity at 81 single nucleotide polymorphisms (mean heterozygosity = 0.28, SD = 0.27). Simulations were consistent with founding events and drift as possible drivers for the observed stark difference of allele frequency. Our results highlight the role of stochastic processes in the evolution of rare phenotypes. We highlight an unusual evolutionary trajectory in a small and isolated population of an endangered species.


Asunto(s)
Evolución Biológica , Flujo Genético , Variación Genética , Genética de Población , Melanosis/genética , Fenotipo , Tigres/fisiología , Secuencia de Aminoácidos , Animales , Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Genoma , Genotipo , India , Repeticiones de Microsatélite , Homología de Secuencia , Tigres/genética
17.
J Indian Inst Sci ; 101(2): 115-116, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34248302
18.
PLoS Negl Trop Dis ; 15(3): e0009178, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33705398

RESUMEN

Bartonella species are recognized globally as emerging zoonotic pathogens. Small mammals such as rodents and shrews are implicated as major natural reservoirs for these microbial agents. Nevertheless, in several tropical countries, like India, the diversity of Bartonella in small mammals remain unexplored and limited information exists on the natural transmission cycles (reservoirs and vectors) of these bacteria. Using a multi-locus sequencing approach, we investigated the prevalence, haplotype diversity, and phylogenetic affinities of Bartonella in small mammals and their associated mites in a mixed-use landscape in the biodiverse Western Ghats in southern India. We sampled 141 individual small mammals belonging to eight species. Bartonella was detected in five of the eight species, including three previously unknown hosts. We observed high interspecies variability of Bartonella prevalence in the host community. However, the overall prevalence (52.5%) and haplotype diversity (0.9) was high for the individuals tested. Of the seven lineages of Bartonella identified in our samples, five lineages were phylogenetically related to putative zoonotic species-B. tribocorum, B. queenslandensis, and B. elizabethae. Haplotypes identified from mites were identical to those identified from their host species. This indicates that these Bartonella species may be zoonotic, but further work is necessary to confirm whether these are pathogenic and pose a threat to humans. Taken together, these results emphasize the presence of hitherto unexplored diversity of Bartonella in wild and synanthropic small mammals in mixed-use landscapes. The study also highlights the necessity to assess the risk of spillover to humans and other incidental hosts.


Asunto(s)
Infecciones por Bartonella/veterinaria , Bartonella/clasificación , Mamíferos/microbiología , Ácaros/microbiología , Animales , Bartonella/genética , Infecciones por Bartonella/epidemiología , ADN Bacteriano , Haplotipos/genética , India/epidemiología , Mamíferos/parasitología , Infestaciones por Ácaros/veterinaria , Filogenia , Reacción en Cadena de la Polimerasa , Prevalencia
19.
Mol Biol Evol ; 38(6): 2366-2379, 2021 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-33592092

RESUMEN

Species conservation can be improved by knowledge of evolutionary and genetic history. Tigers are among the most charismatic of endangered species and garner significant conservation attention. However, their evolutionary history and genomic variation remain poorly known, especially for Indian tigers. With 70% of the world's wild tigers living in India, such knowledge is critical. We re-sequenced 65 individual tiger genomes representing most extant subspecies with a specific focus on tigers from India. As suggested by earlier studies, we found strong genetic differentiation between the putative tiger subspecies. Despite high total genomic diversity in India, individual tigers host longer runs of homozygosity, potentially suggesting recent inbreeding or founding events, possibly due to small and fragmented protected areas. We suggest the impacts of ongoing connectivity loss on inbreeding and persistence of Indian tigers be closely monitored. Surprisingly, demographic models suggest recent divergence (within the last 20,000 years) between subspecies and strong population bottlenecks. Amur tiger genomes revealed the strongest signals of selection related to metabolic adaptation to cold, whereas Sumatran tigers show evidence of weak selection for genes involved in body size regulation. We recommend detailed investigation of local adaptation in Amur and Sumatran tigers prior to initiating genetic rescue.


Asunto(s)
Evolución Biológica , Flujo Genético , Endogamia , Selección Genética , Tigres/genética , Animales , Conservación de los Recursos Naturales , Variación Genética , Genoma , India , Filogeografía
20.
Sci Rep ; 10(1): 18705, 2020 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-33127966

RESUMEN

Phylogenetically closely related species are often assumed to have similar responses to environmental conditions, but species-specific responses have also been described. These two scenarios may have different conservation implications. We tested these two hypotheses for Prionailurus cats (P. rubiginosus, P. bengalensis, P. viverrinus) in the Indian subcontinent and show its implications on species current protected area coverage and climatic suitability trends through time. We fitted ecological niche models with current environmental conditions and calculated niche overlap. In addition, we developed a model for the Jungle Cat Felis chaus to compare species responses and niche overlap estimates within Prionailurus with those for a related sympatric small cat species. Then we estimated the proportion of current suitable environment covered by protected area and projected climatic models from past (last interglacial) to future (2070; RCP4.5 and RCP8.5) conditions to show implications on population management and conservation. The hypothesis of a similar response and niche overlap among closely related species is not supported. Protected area coverage was lowest for P. viverrinus (mean = 0.071, SD = 0.012) and highest for P. bengalensis (mean = 0.088, SD = 0.006). In addition, the proportion of the subcontinent with suitable climate varied through time and was species-specific. For P. bengalensis, climatic suitability shrunk since at least the mid-Holocene, a trend that can be intensified by human-induced climate warming. Concerning P. viverrinus, most predictions show stable future climatic suitability, but a few indicated potential loss. Climatic suitability for P. rubiginous was predicted to remain stable but the species exhibited a negative association with intensive agriculture. Similar responses to environmental change by phylogenetically closely related species should not be assumed and have implications on protected area coverage and natural trends of species climatic suitability over time. This should be taken into account during conservation and management actions.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Felidae/fisiología , Agricultura , Animales , Clima , Cambio Climático , Análisis por Conglomerados , Felidae/clasificación , Geografía , India , Filogenia , Especificidad de la Especie
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