Publications by authors named "Uma Ramakrishnan"

SWI/SNF chromatin remodelers hydrolyze ATP to modulate chromatin accessibility and are mutated in up to 20 % of human cancers. The development of ATPase inhibitors and proteolysis targeting chimeras (PROTACs) have shown that SWI/SNF complexes can be therapeutic targets against cancers that require MYC expression for their survival (e.g.

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Bacterial infections account for a large proportion of zoonoses. Our current understanding of zoonotic spillover, however, is largely based on studies from viral systems. Small mammals such as rodents and their ectoparasites present a unique system for studying several bacterial pathogens and mapping their spillover pathways.

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Land-use change and increased human-livestock-wildlife interactions have generated numerous possibilities for viral spillover, demanding enhanced surveillance in biodiverse regions. We investigated adenovirus diversity in small mammals, an understudied host taxon, from a forest-plantation mosaic in the Western Ghats biodiversity hotspot. We observed high prevalence (up to 39.

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Nucleocytoplasmic large DNA viruses (NCLDVs) have massive genome and particle sizes compared to other known viruses. NCLDVs, including poxviruses, encode ATPases of the FtsK/HerA superfamily to facilitate genome encapsidation. However, their biochemical and structural characteristics are yet to be discerned.

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Article Synopsis
  • Genetic variation in a population is often viewed positively, seen as a way to enhance survival and adaptability.
  • However, not all genetic variants are beneficial; some can be neutral or harmful, creating what is known as 'genetic load'.
  • Advances in technology are now allowing scientists to gain deeper insights into how this genetic load affects the health and survival of wild species.
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Interview with Uma Ramakrishnan, who studies the genetics of Indian biodiversity at the National Centre for Biological Sciences, Tata Institute of Fundamental Research.

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Asian elephants (Elephas maximus) are the largest extant terrestrial megaherbivores native to Asia, with 60% of their wild population found in India. Despite ecological and cultural importance, their population genetic structure and diversity, demographic history, and ensuing implications for management/conservation remain understudied. We analyzed 34 whole genomes (between 11× and 32×) from most known elephant landscapes in India and identified five management/conservation units corresponding to elephants in Northern (Northwestern/Northeastern), Central, and three in Southern India.

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Article Synopsis
  • Scientists are studying the DNA of tigers to understand their genetic diversity and help protect them, especially since many tigers in the wild are endangered.
  • This research looks at tigers that are kept in captivity, like privately owned ones in the U.S., known as "Generic" tigers, which might have mixed ancestry from different tiger types.
  • The study found that these Generic tigers have similar genetic diversity to wild tigers and can help conservation efforts by creating a new way to identify tiger ancestry using less expensive genetic testing methods.
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  • Humans have significantly altered natural habitats, leading to isolated patches that threaten genetic diversity and increase the risk of inbreeding among species.
  • The study focuses on gaur and sambar populations in central India, using innovative genomic techniques to analyze how habitat fragmentation affects gene flow and connectivity.
  • Results show that gaur populations are highly fragmented and genetically distinct, while sambar populations display variable genetic structure, indicating that different species respond uniquely to landscape changes, emphasizing the need for multi-species conservation strategies.
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  • This study compares saliva samples to traditional nasopharyngeal/oropharyngeal swabs for detecting SARS-CoV-2 using RT-PCR, highlighting saliva's potential for scalable screening.
  • Results show a 75.4% agreement between the two methods, which increases to 83% for samples stored less than three days, indicating saliva can be effective if processed quickly.
  • The findings support implementing saliva-based screening in workplaces and schools for routine surveillance, acknowledging that while slightly less sensitive than swabs, saliva collection is more logistically favorable.
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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.

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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.

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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.

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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 () and wild canids like gray wolves () and golden jackals ().

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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Delhi, the national capital of India, experienced multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreaks in 2020 and reached population seropositivity of >50% by 2021. During April 2021, the city became overwhelmed by COVID-19 cases and fatalities, as a new variant, B.1.

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