Biology subjects

Mehta, T.

Publications and source records attributed to Mehta, T..

5 recordsLinked to original sources

bioRxiv2026

Camus: a video-based framework for continuous behavioral monitoring in the mouse home-cage

Home-cage activity is a window into the spontaneous behavioral repertoire of mice. These behaviors are organized across the circadian cycle, and disruptions in their duration, frequency, or organization may provide sensitive measures of neurological or psychiatric dysfunction. While continuous monitoring can help track the dynamics of spontaneous behavior, video recording in conventional laboratory cages is limited by compact cage geometry, opaque cage tops, and obstructed views of animals, food, and water. We therefore developed Camus, a Camera for home-cage recordings of Mus musculus mice. Camus integrates off-the-shelf USB cameras with infrared illumination and custom 3D-printed components for access to food and water without obstructed views. The modular design pairs continuous video acquisition with a manually validated computer-vision model to quantify locomotion, feeding, drinking, and nesting-related behavior across multiday recordings. A single desktop computer can record as many as 20 cages in parallel at an incremental cost of approximately $250 per cage, recording more than 99% of expected frames at 640x360-pixel resolution and 30 frames per second. Camus captured circadian structure in locomotion, feeding, and drinking. Camus also captured nest-building and sex-specific differences in nest dynamics. Using Camus with transgenic 5xFAD mice overexpressing amyloid revealed selective, age-progressive deficits in nesting behavior. Camus provides a scalable, open-source platform that combines accessible hardware, automated video monitoring, and machine-learning based analysis for continuous and potentially longitudinal behavioral phenotyping.

animal behavior and cognition↗

bioRxiv2025

High-quality genome assembly for the genetically improved Abbassa Nile tilapia enables the reconstruction of X and Y haplotypes

The success of the Nile tilapia (Oreochromis niloticus) as an aquaculture species is partly the result of continuous selective breeding leading to high performing strains. These elite strains have been derived from breeding populations of diverse origins and crosses with other Oreochromis species. Owing to the complex and unique evolutionary histories of each strain, existing reference genomes of wild populations are unsuitable to implement genomic selection for beneficial traits such as growth or environmental resilience in aquaculture programmes. Here we generated a high-quality genome assembly and annotation of the WorldFish Genetically Improved Abbassa Nile tilapia (GIANT) elite strain using a combination of PacBio HiFi, and Omni-C Illumina sequencing. As a male Abbassa Nile tilapia was used for the generation of the genome assembly, we reconstructed both X and Y haplotypes, identifying both amhY and amh{Delta}y on LG23 indicating that Abbassa likely shares the same sex determination system as GIFT, and thereby differs from the existing reference genome, whose sex determination loci are located on LG1.

genomics↗

bioRxiv2025

Impaired Myelination in Multiple Sclerosis Organoids: p21 Links Oligodendrocyte Dysfunction to Disease Subtype

Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system. The cause of the disease is unknown but both genetic and environmental factors are strongly implicated in its pathogenesis. We derived cerebral and spinal cord organoids from induced pluripotent stem cells (iPSC) from healthy controls as well as from primary progressive MS (PPMS), secondary progressive MS (SPMS) and relapsing-remitting MS (RRMS) patients to investigate and compare oligodendrocyte differentiation and myelination capacity in healthy subjects and MS subtypes. In MS organoids, particularly in PPMS, we observed a decrease in p21 expression associated with a dysregulation of PAK1 and E2F1 expression. In parallel, a decrease in oligodendrocyte maturation was detected in long-term cultured cerebral and spinal cord organoids, especially in PPMS, leading to a reduced myelination capacity. Disruption of astrocyte and neuronal populations was also observed. Our findings demonstrate that in MS, inherent deficits in the p21 pathway may alter glial and neuronal cell populations and may contribute to the disease pathogenesis by reducing the capacity for myelin repair. Summary StatementUsing cerebral and spinal cord organoids derived from multiple sclerosis patients, we found an innate disruption of oligodendrocyte differentiation and myelination capacity as well as excitotoxicity, associated with PAK1 and E2F1-induced p21 dysregulation.

neuroscience↗

bioRxiv2024

Analyzing Biodiversity in Protected vs. Unprotected Tide Pools

This study assessed the efficacy of marine protected areas (MPAs) by comparing tide pool biodiversity in Half Moon Bay, California between a protected site (Fitzgerald Marine Reserve) and an unprotected site (Mavericks Beach). Samples were collected through random quadrat surveys. ImageJ and RStudio were used to analyze data through three methods utilizing the Simpsons Diversity Index along with three metrics. The unprotected Mavericks Beach displayed greater biodiversity through two metrics while the third did not find significant difference in biodiversity between sites. 30 unique species were present at each site with 43 species between both. These mixed findings prevent us from drawing definitive conclusions on the effectiveness of Half Moon Bays tide pool MPAs but suggest the MPA is less biodiverse. Potential explanations include the Intermediate Disturbance Hypothesis, lack of sample size, or that the MPA is not effective in maintaining biodiversity.

ecology↗

bioRxiv2021

Whole genome resequencing data enables a targeted SNP panel for conservation and aquaculture of Oreochromis cichlid fishes

Cichlid fish of the genus Oreochromis form the basis of the global tilapia aquaculture and fisheries industry. Non-native farmed tilapia populations are known to be widely distributed across Africa and to hybridize with native Oreochromis species. However, many species are difficult to distinguish morphologically, hampering attempts to maintain good quality farmed strains or to identify pure populations of native species. Here, we describe the development of a single nucleotide polymorphism (SNP) genotyping panel from whole-genome resequencing data that enables targeted species identification in Tanzania. We demonstrate that an optimized panel of 96 genome-wide SNPs based on FST outliers performs comparably to whole genome resequencing in distinguishing species and identifying hybrids. We also show this panel outperforms microsatellite-based and phenotype-based classification methods. Case studies indicate several locations where introduced aquaculture species have become established in the wild, threatening native Oreochromis species. The novel SNP markers identified here represent an important resource for assessing broodstock purity and helping to conserve unique endemic biodiversity, and in addition potentially for assessing broodstock purity in hatcheries.

evolutionary biology↗