Biology subjects

Goswami, S.

Publications and source records attributed to Goswami, S..

3 recordsLinked to original sources

bioRxiv2026

Dynamic microtubules drive yolk-cytoplasm segregation in the syncytial Drosophila embryo

Yolk-cytoplasm segregation is among the earliest spatial organization events in the developing embryo of many oviparous animals. The segregation process is intimately linked to early embryonic cleavage and pattern formation, and exhibits a wide range of spatial and temporal diversity. However, the underlying cytoskeletal mechanism remains largely unknown, except for a small number of species. Using quantitative live imaging, we investigated yolk segregation in the Drosophila embryo during the syncytial nuclear cycles 11-14. We find that the yolk vesicles move progressively inward in spatial and temporal coordination with the inward expanding microtubule networks that are nucleated from centrosomes positioned at the cortex, whereas cortical actin meshwork remains spatially restricted. Using the gnu RNAi embryo to decouple nuclear migration and division from cytoskeletal dynamics, we establish causality with targeted pharmacological disruption and find that microtubule dynamics is required for yolk segregation, while depolymerization of actin has no discernible effect. In support of a mechanism of growth-propelled passive displacement, microtubule plus end comets come in apparent contact with yolk vesicles, and injected, inert microbeads are displaced towards the embryo center presumably by the same pushing force. These findings identify microtubule polymerization as a predominant driver of yolk-cytoplasm segregation in Drosophila and suggest that diverse cytoskeletal mechanisms evolved to accomplish this crucial reorganization process

developmental biology↗

bioRxiv2018

An optimized toolkit for precision base editing

CRISPR base editing is a potentially powerful technology that enables the creation of genetic mutations with single base pair resolution. By re-engineering both DNA and protein sequences, we developed a collection of constitutive and inducible base editing vector systems that dramatically improve the ease and efficiency by which single nucleotide variants can be created. This new toolkit is effective in a wide range of model systems, and provides a means for efficient in vivo somatic base editing.

bioengineering↗

bioRxiv2017

Five years of land surface phenology in a large-scale flooding and draining manipulation in a coastal Arctic ecosystem

This study was motivated by the knowledge gap for observing the complex interplay between surface hydrology and plant phenology in arctic landscapes and was conducted as part of a large scale, multi investigator flooding and draining experiment near Barrow, Alaska (71{degrees}1701\" N, 156{degrees}3548\" W) during 2005 - 2009. Hyperspectral reflectance data were collected in the visible to near IR region of the spectrum using a robotic tram system that operated along a 300m transects during the snow free growing period between June and August, 2005-09. Interannual patterns of land-surface phenology (NDVI) unexpectedly lacked marked differences under experimental conditions. Measurement of NDVI was, however, compromised for presence of surface water. Land-surface phenology and surface water was negatively correlated, which held when scaled to a 2km by 2km MODIS subset of the study area. This result suggested that published findings of greening of the Arctic may relate to a drying of the Arctic i.e. reduced surface water in vegetated high-latitude landscapes where surface water is close to ground level.

ecology↗