Biology subjects

Talukdar, G.

Publications and source records attributed to Talukdar, G..

5 recordsLinked to original sources

bioRxiv2026

Mutant ATXN1 impacts human and mouse microglia and contributes to cognitive, mood, and motor deficits in SCA1 mice

Microglia, resident immune cells of the brain, are important players in neurodegeneration. While microglial activation is a hallmark of many neurodegenerative diseases, the specific role of microglia intrinsic factors in microglial activation and disease pathogenesis remains unknown. Spinocerebellar ataxia type-1 (SCA1) is an inherited autosomal dominant neurodegenerative disease characterized by severe neuronal loss and early microglial activation in the cerebellum. SCA1 is caused by CAG repeat expansion in the ubiquitously expressed ATAXIN1 (ATXN1) gene. Using human microglia differentiated from SCA1 patient derived iPSCs, we found that mutant ATXN1 is sufficient to alter morphology, gene and protein expression in human microglia in a cell-autonomous manner. Moreover, compared to controls, human SCA1 microglia exhibited increased phagocytosis and pro-inflammatory cytokine production, indicating an immune priming. To determine the extent to which mutant ATXN1 in microglia contributes to SCA1 pathogenesis and behavioral symptoms, we removed mutant ATXN1 from microglia and macrophages in a novel conditional SCA1 mouse model, f-ATXN1146Q/2Q mice. Microglial mutant ATXN1 reduction led to a marked correction in microglia phenotype, in particular in the transcriptomic signature of interferon type 1 mediated immune response, reduced microglial density and resulted in smaller microglia with reduced branching in the cerebellum. Pathology of Purkinje neurons and cerebellar astrogliosis were also ameliorated. Utilizing a battery of behavioral tests, we found that microglia and macrophage mutant ATXN1 reduction ameliorated cognitive, mood, and motor deficits in SCA1 mice. Together, these results indicate that mutant ATXN1 directly impacts microglial phenotype in SCA1, contributing to SCA1 pathology and behavioral deficits.

neuroscience↗

bioRxiv2020

"Tracking the Rain Bird": Modeling the monthly distribution of Pied cuckoo in India

Pied cuckoo Clamator jacobinus (Boddart, 1783) is a migratory, brood-parasitic bird found in the African and Indian Subcontinent. Although the southern Indian population is presumably resident, the North Indian Population migrates from Africa to India during the summer. The arrival of the bird is linked to the onset of monsoon in India from scientific literature to folklore. It is known to make its appearance in central and northern India in the last week of May or early June, indicating the imminent arrival of the monsoon with its unmistakably loud metallic calls. There have been few attempts to compile relevant information on the species migration in the early 1900s and citizen science approach by Bird-count India; little information is available on how environmental factors might be affecting its migration. Here, we have used Maximum Entropy modeling to identify the monthly and seasonal distribution patterns and major bioclimatic factors that might be influencing the distribution of the species in India. We have used E-Bird citizen science platform data, seven bioclimatic variables, and monthly NDVI of respective months for building the models. The predicted output shows the species presence throughout the year in southern India. In contrast, in northern India, the distribution is dynamic, peaking in summers in the Month of May-June and no presence in winter. The influence of bioclimatic variables used in SDM varied monthly; Water vapor pressure was the primary contributing variable in the months prior to species arrival. In July, it was NDVI (Higher NDVI suggests abundance of food resources for the species). In August-September, Windspeed and water vapor pressure (Factors might be responsible for the departure of the species) have contributed highest. Our approach provides a more concise understanding of Pied cuckoos monthly distributions throughout India, which helps understand the complex seasonal shifts in the distribution of such migratory birds.

ecology↗

bioRxiv2020

Soil bacterial community diversity and composition vary more with elevation than seasons in alpine habitats of western Himalaya

Soil heterotrophic respiration-driven CO2 emissions, its impact on global warming and the mechanistic roles of soil bacterial communities in this process have been an area of active research. However, our knowledge regarding the effects of environmental changes on soil bacterial communities is limited. To this end, the climate-sensitive high-altitude alpine ecosystems offer ideal opportunities to investigate relationship between climate change and bacterial communities. While data from several high-altitude mountain regions suggest that local environment factors and geological patterns govern bacterial communities, no information is available from the Himalaya. Here we provide baseline information on seasonal soil bacterial community diversity and composition along a 3200-4000 m elevation gradient covering four alpine habitats (subalpine forest, alpine scrub, alpine meadow and moraine) in Gangotri National Park, western Himalaya. Bacterial metabarcoding data from 36 field-collected samples showed no elevation trend in the bacterial richness and a non-monotonous decrease in their diversity. Further, their community diversity and composition varied significantly among habitats along elevation but were stable seasonally within each habitat. The richness was primarily influenced by soil inorganic carbon (SOC) and total nitrogen (TN), whereas temperature, SOC and TN affected diversity and composition patterns. Given the importance of the Himalaya in the context of global carbon cycle this information will help in accurate modeling of climate adaptation scenarios of bacterial niches and their downstream impacts towards climate warming.

genomics↗

bioRxiv2020

Assessing tiger corridor functionality with landscape genetics and modelling across Terai-Arc Landscape, India

India led the global tiger conservation initiatives since last decade and has doubled its wild tiger population to 2967 (2603-3346). The survival of these growing populations residing inside the continuously shrinking habitats is a major concern, which can only be tackled through focused landscape-scale conservation planning across five major extant Indian tiger landscapes. The Terai-Arc landscape (TAL) is one of the global priority tiger conservation landscapes holding 22% of the countrys wild tigers. We used intensive field-sampling, genetic analyses and GIS modelling to investigate tiger population structure, source-sink dynamics and functionality of the existing corridors across TAL. Genetic analyses with 219 tigers revealed three low, but sigficantly differentiated tiger subpopulations. Overall, we identified Seven source and 10 sink areas in TAL through genetic migrant and gene flow analyses. GIS modelling identified total 19 (10 high, three medium and six low conductance) corridors in this landscape, with 10 being critical to maintain landscape connectivity. We suggest urgent management attention towards 2707 sq. km. non-protected habitat, mitigation measures associated with ongoing linear infrastructure developments and transboundary coordination with Nepal to ensure habitat and genetic connectivity and long-term sustainability of tigers in this globally important landscape.

ecology↗

bioRxiv2019

A practive faeces collection protocol for multidisciplinary research in wildlife science

Faecal samples have become important non-invasive source of information in wildlife biology and ecological research. Despite regular use of faeces, there is no universal protocol available for faeces collection and storage to answer various questions in wildlife biology. We collected 1408 faeces from ten different species using a dry sampling approach, and achieved 94.87% and 86.02% success rate in mitochondrial and nuclear marker amplifications. We also suggest a universal framework to use the same samples for different use. This protocol provides an easy, quick and cheap option to collect non-invasive samples from species living at different environmental conditions to answer multidisciplinary questions in wildlife biology.

ecology↗