Biology subjects

Garg, T.

Publications and source records attributed to Garg, T..

4 recordsLinked to original sources

bioRxiv2023

The relationship between object-based spatial ability and virtual navigation performance

Spatial navigation is a multi-faceted behaviour drawing on many different aspects of cognition. Visuospatial abilities, such as spatial working memory and mental rotation, in particular, may be key factors. A range of tests have been developed to assess visuospatial processing and memory, but how such tests relate to navigation ability remains unclear. This understanding is important to advance tests of navigation for disease monitoring in Alzheimers Disease, where disorientation is an early symptom. Here, we report the use of an established mobile gaming app, Sea Hero Quest, as a measure of navigation ability. We used three separate tests of navigation embedded in the game: wayfinding, path integration and spatial memory in a radial arm maze. In the same participants, we also collected measures of mental rotation (Mental Rotation Test), visuospatial processing (Design Organization Test) and visuospatial working memory (Digital Corsi). We found few strong correlations across our measures. Being good at wayfinding in a virtual navigation test does not mean an individual will rate themself as a confident navigator, be good at path integration, or have a superior memory in a radial arm maze. However, those good at wayfinding tend to perform well on the three visuospatial tasks examined here, and to also use a landmark strategy in the radial maze task. These findings help clarify the inter-relationships between different abilities supporting visuospatial and navigation skills. HighlightsO_LIThree navigation tests embedded in the game Sea Hero Quest were examined in relation to three object-based visuospatial tasks, and self-ratings of navigation ability and stress during navigation. C_LIO_LINo associations were observed among performance on wayfinding, path integration and radial arm maze levels of Sea Hero Quest. C_LIO_LIObject-based visuospatial abilities were selectively correlated with performance on wayfinding levels of Sea Hero Quest. C_LIO_LIGameplay stress and navigation strategy were not associated with performance on Sea Hero Quest navigation tasks. C_LI

neuroscience↗

bioRxiv2022

In vitro and in vivo activity of Gepotidacin against drug-resistant mycobacterial infections

Mycobacterial pathogens including Non-tuberculous mycobacteria (NTM) and M. tuberculosis (Mtb), are pathogens of significant worldwide interest owing to inherent drug resistance to a wide variety of FDA-approved drugs as well as causing a broad range of serious infections. Identifying new antibiotics active against mycobacterial pathogens is an urgent unmet need, especially those antibiotics that can bypass existing resistance mechanisms. In this study, we demonstrate that Gepotidacin, a first-in-class triazaacenapthylene topoisomerase inhibitor, shows potent activity against Mtb and M. fortuitum as well as against other NTMs species, including fluoroquinolone-resistant M. abscessus. Furthermore, Gepotidacin exhibits concentration-dependent bactericidal activity against various mycobacterial pathogens, synergizes with several drugs utilized for their treatment, and reduces bacterial load in macrophages in the intracellular killing assay comparable to amikacin. Additionally, M. fortuitum ATCC 6841 was unable to generate resistance to Gepotidacin in vitro. When tested in a murine neutropenic M. fortuitum infection model, Gepotidacin caused a significant reduction in bacterial load in various organs at 10 fold lower concentration than amikacin. Taken together, Gepotidacin possesses a potentially new mechanism of action that enables it to escape existing resistance mechanisms. Thus, it can be projected as a potent novel lead for the treatment of mycobacterial infections, particularly for NTM, where present therapeutic interventions are very limited.

microbiology↗

bioRxiv2021

Auxin-responsive (phospho)proteome analysis reveals regulation of cell cycle and ethylene signaling during rice crown root development

The rice root system, which primarily consists of adventitious/crown roots (AR/CR) developed from the coleoptile base, is an excellent model system for studying shoot-to-root trans-differentiation process. We reveal global changes in protein and metabolite abundance, and protein phosphorylation in response to an auxin stimulus during CR development. Global proteome and metabolome analyses of developing crown root primordia (CRP) and emerged CRs uncovered that the biological processes associated with chromatin conformational change, gene expression, and cell cycle were translationally regulated by auxin signaling. Spatial gene expression pattern analysis of differentially abundant proteins disclosed their stage-specific dynamic expression pattern during CRP development. Further, our tempo-spatial gene expression and functional analyses revealed that auxin creates a regulatory feedback module during CRP development and activates ethylene biosynthesis exclusively during CRP initiation. Ethylene signaling promotes CR formation by repressing the cytokinin response regulator, OsRR2. Additionally, the (phospho)proteome analysis identified differential phosphorylation of the Cyclin-dependent kinase G-2 (OsCDKG;2), and cell wall proteins, in response to auxin signaling, suggesting that auxin-dependent phosphorylation may be required for cell cycle activation, and cell wall synthesis during root organogenesis. Thus, our study provides evidence for the translational and post-translational regulation during CRP trans-differentiation downstream of the auxin signaling pathway. HighlightGlobal (phospho)proteome and metabolic profiling of rice CRP and CRs uncover differential proteins and metabolites associated with gene expression, cell cycle, ethylene signaling and cell wall synthesis during CR development.

plant biology↗

bioRxiv2020

Genome-Wide High Resolution Expression Map and Functions of Key Cell Fate Determinants Reveal the Dynamics of Crown Root Development in Rice

Shoot borne adventitious/crown roots (AR/CR) shape up the root architecture in grasses. Mechanisms underlying initiation and subsequent outgrowth of CR remain largely unknown. Here, we provide genome-wide modulation in the landscape of transcriptional signatures during distinct developmental stages of CR formation in highly derived grass species, rice. Our studies implicate the role of potential epigenetic modifiers, transcription factors and cell division regulators in priming the initiation of CR primordia followed by progressive activation of conserved transcription regulatory modules to ensure their outgrowth. In depth analysis of spatio-temporal expression patterns of key cell fate determinants and functional analyses of rice WUSCHEL RELATED HOMEOBOX10 (OsWOX10) and PLETHORA (OsPLT1) genes reveal their unprecedented role in controlling root architecture. We further show that OsPLT1 activates local auxin biosynthesis and forms an integral part of ERF3-OsWOX11-OsRR2 regulatory module during CR primordia development. Interestingly, OsPLT genes, when expressed in the transcriptional domain of root-borne lateral root primordia of Arabidopsis plt mutant, rescued their outgrowth demonstrating the conserved role of PLT genes in root primordia outgrowth irrespective of their developmental origin. Together, these findings unveil the molecular framework of cellular reprogramming during trans-differentiation of shoot tissue to root leading to culmination of robust root architecture in grass species which got evolutionary diverged from dicots.

plant biology↗