Biology subjects

Ganguly, I.

Publications and source records attributed to Ganguly, I..

4 recordsLinked to original sources

bioRxiv2025

"Decoding Mobile Genetic Elements, Virulence Factors, and Antibiotic Resistance Genes Driving Biofilm Formation in MRSA via Network Analysis"

This study aimed to analyze the genome of the Methicillin-resistant Staphylococcus aureus (MRSA) strain d1418m22 through whole-genome sequencing (WGS) and comprehensive bioinformatics analysis with six references strains. De novo assembly resulted in 61 scaffolds with a total genome size of 2.78 Mb. Functional annotation revealed 2,625 predicted genes, including those involved in metabolism, cellular processes, and virulence. Comparative genomic analysis identified 20 antibiotic resistance genes, including those conferring resistance to beta-lactams, fluoroquinolones, and aminoglycosides. In addition, 21 virulence factors (VFs) were identified, including Panton-Valentine leukocidin (PVL) and various enterotoxins. The presence of staphylococcal cassette chromosome mec (SCCmec) type IVa and mobile genetic elements (MGEs), such as prophages and transposons, underscored the role of horizontal gene transfer (HGT) in the evolution and transmission of resistance and virulence factors. Interaction network analysis identified key hub genes involved in various cellular processes, including biofilm formation. This comprehensive genomic analysis provides valuable insights into the genetic makeup of MRSA strain d1418m22, contributing to a better understanding of its pathogenicity and potential public health implications. Six reference MRSA strains were isolated from (MRSA-AMRF4 and MRSA-AMRF5) eye infections, (MRSA and MRSA-15) wound pus, (VMRSA-WC071, and VMRSA-WC081) urine samples. The analysis identified resistance genes, virulence factors, GC content, ANI values, and SCCmec elements, which were found to be similar to those present in the resistant MRSA d1418m22 strain genome.

genomics↗

bioRxiv2023

Diversity of visual inputs to Kenyon cells of the Drosophila mushroom body

The arthropod mushroom body is well-studied as an expansion layer that represents olfactory stimuli and links them to contingent events. However, 8% of mushroom body Kenyon cells in Drosophila melanogaster receive predominantly visual input, and their tuning and function are poorly understood. Here, we use the FlyWire adult whole-brain connectome to identify inputs to visual Kenyon cells. The types of visual neurons we identify are similar across hemispheres and connectomes with certain inputs highly overrepresented. Many visual projection neurons presynaptic to Kenyon cells receive input from large swathes of visual space, while local visual interneurons, providing smaller fractions of input, receive more spatially restricted signals that may be tuned to specific features of the visual scene. Like olfactory Kenyon cells, visual Kenyon cells receive sparse inputs from different combinations of visual channels, including inputs from multiple optic lobe neuropils. The sets of inputs to individual visual Kenyon cells are consistent with random sampling of available inputs. These connectivity patterns suggest that visual coding in the mushroom body, like olfactory coding, is sparse, distributed, and combinatorial. However, the expansion coding properties appear different, with a specific repertoire of visual inputs projecting onto a relatively small number of visual Kenyon cells.

neuroscience↗

bioRxiv2022

A high-speed, modular display system for diverse neuroscience applications

Visual stimulation of animals in the laboratory is a powerful technique for studying sensory control of complex behaviors. Since commercial displays are optimized for human vision, we established a novel display system based on custom-built modular LED panels that provides millisecond refresh, precise synchronization, customizable color combinations, and varied display configurations. This system simplifies challenging experiments. With variants of this display, we probed the speed limits of motion vision and examined the role of color vision in behavioral experiments with tethered flying Drosophila. Using 2-photon calcium imaging, we comprehensively mapped the tuning of visual projection neurons across the flys field of view. Finally, using real-time behavior analysis, we developed low-latency interactive virtual environments and found that flying flies can independently control their navigation along two dimensions. This display system uniquely addresses most technical challenges of small animal vision experiments and is thoroughly documented for replicability.

neuroscience↗

bioRxiv2021

Mushroom body input connections form independently of sensory activity in Drosophila melanogaster

Associative brain centers, such as the insect mushroom body, need to represent sensory information in an efficient manner. In Drosophila melanogaster, the Kenyon cells of the mushroom body integrate inputs from a random set of olfactory projection neurons, but some projection neurons -- namely those activated by a few ethologically meaningful odors -- connect to Kenyon cells more frequently than others. This biased and random connectivity pattern is conceivably advantageous, as it enables the mushroom body to represent a large number of odors as unique activity patterns while prioritizing the representation of a few specific odors. How this connectivity pattern is established remains largely unknown. Here, we test whether the mechanisms patterning the connections between Kenyon cells and projection neurons depend on sensory activity or whether they are hardwired. We mapped a large number of mushroom body input connections in anosmic flies -- flies lacking the obligate odorant co-receptor Orco -- and in wildtype flies. Statistical analyses of these datasets reveal that the random and biased connectivity pattern observed between Kenyon cells and projection neurons forms normally in the absence of most olfactory sensory activity. This finding supports the idea that even comparatively subtle, population-level patterns of neuronal connectivity can be encoded by fixed genetic programs and are likely to be the result of evolved prioritization of ecologically and ethologically salient stimuli.

neuroscience↗