Biology subjects

Eglinger, J.

Publications and source records attributed to Eglinger, J..

4 recordsLinked to original sources

bioRxiv2025

Quantitative comparison of methodologies for translation site imaging in living cells

Single-molecule imaging of translation sites in living cells has enabled the dynamics of protein synthesis to be investigated with high spatial and temporal resolution. These methodologies utilize the interaction between a multimerized epitope tag and its cognate fluorescent nanobody to detect nascent polypeptides as they emerge from the ribosome. Here, we present a systematic comparison of current methodologies and determine that the ALFA-tag reduces perturbations of mRNA expression and increases the fluorescent signal of translation sites.

biophysics↗

bioRxiv2022

Live-cell imaging and physical modeling reveal control of chromosome folding dynamics by cohesin and CTCF

Physical proximity between genomic sequences in mammalian chromosomes controls key biological processes such as transcriptional regulation and DNA repair. Yet it is currently unknown if chromosomal contacts are rare and stable or instead frequent and dynamic, and how they depend on the loop extrusion activity of cohesin or barriers such as CTCF. By imaging chromosomal locations at high spatial and temporal resolution over several hours in living cells, we show that sequences within topological associating domains (TADs) frequently come into physical proximity during the course of a cell cycle and remain close to each other only for a few minutes. Such contacts become nonetheless substantially longer and more frequent in the presence of convergent CTCF sites, resulting in a suppression of variability in chromosome folding in single cells across time. Supported by physical models of chromosome dynamics, our data additionally suggests that individual CTCF-anchored loops last around 10 minutes. The estimates of chromosomal contact dynamics in our study provide a novel quantitative framework to link chromosome structure to function and show that cohesin and CTCF stabilize otherwise highly dynamic chromosome structures to facilitate selected subsets of chromosomal interactions.

molecular biology↗

bioRxiv2020

Single-molecule imaging reveals translation of mRNAs localized to stress granules

Cellular stress leads to reprogramming of mRNA translation and formation of stress granules (SGs), membraneless organelles consisting of mRNA and RNA-binding proteins. Although the function of SGs remains largely unknown, it is widely assumed they contain exclusively nontranslating mRNA. Here we re-examine this hypothesis using single-molecule imaging of mRNA translation in living cells. While our data confirms that non-translating mRNAs are preferentially recruited to SGs, we find unequivocal evidence for translation of mRNA localized to SGs. Our data indicate that SG-associated translation is not rare and that the entire translation cycle (initiation, elongation and termination) can occur for these transcripts. Furthermore, translating mRNAs can be observed transitioning between the cytosol and SGs without changing their translational status. Together, these results argue against a direct role for SGs in inhibition of mRNA translation.

cell biology↗

bioRxiv2019

State transitions of a developmental oscillator

Gene expression oscillators can structure biological events temporally and spatially. Different biological functions benefit from distinct oscillator properties. Thus, finite developmental processes rely on oscillators that start and stop at specific times; a poorly understood behavior. Here, we have characterized a massive gene expression oscillator comprising >3,700 genes in C. elegans larvae. We report that oscillations initiate in embryos, arrest transiently after hatching and in response to perturbation, and cease in adults. Experimental observation of the transitions between oscillatory and non-oscillatory states at a resolution where we can identify bifurcation points reveals an oscillator operating near a Saddle Node on Invariant Cycle (SNIC) bifurcation. These findings constrain the architecture and mathematical models that can represent this oscillator. They also reveal that oscillator arrests occur reproducibly in a specific phase. Since we find oscillations to be coupled to developmental processes, including molting, this characteristic of SNIC bifurcations thus endows the oscillator with the potential to halt larval development at defined intervals, and thereby execute a developmental checkpoint function.

systems biology↗