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Biology subjects

Dupouy, G.

Publications and source records attributed to Dupouy, G..

3 recordsLinked to original sources

The INO80-EEN complex prevents genomic rearrangements at protein coding genes regions

Plants are continuously exposed to a myriad of DNA-damaging agents, including environmental cues such as sunlight. At the cellular level, plants respond to DNA damage by activating DNA damage response (DDR) pathways, in which chromatin remodelers play an important role. Among them, the evolutionary conserved INO80 complex (INO80c) has been shown in Arabidopsis to play a key role in DDR, notably by positively regulating Homologous Recombination (HR). Arabidopsis EIN6 ENHANCER (EEN) is the homolog of Yeast INO EIGHTY SUBUNIT 6 and interacts with the N-terminal region of INO80 in the INO80c. Using plant phenotyping, cellular and molecular biology, and third-generation sequencing technology we investigated how INO80 and EEN regulate plant development and genome integrity. We uncovered new roles for INO80 and EEN in plant growth and for INO80 in fine tuning endoreduplication. In addition, linear genome analysis revealed an important and unexpected function for the INO80-EEN complex in preventing Protein Coding Genes (PCGs) from structural rearrangements in somatic tissue and upon exposure to UV-B. Therefore, our results shed new light on the previously overlooked roles of INO80 and EEN in protecting genome integrity at PCGs.

plant biology↗

Root hair growth phases are coordinated by cytoskeleton, nucleus dynamics and cell mechanics in Arabidopsis

Polar cell growth is a fundamental process across organisms, yet its coordination with nuclear movement and cytoskeleton dynamics remains underexplored. Focusing on Arabidopsis thaliana root hairs, we investigate these processes using high-resolution live imaging within microfluidics-based experiments. By incorporating data on cytoskeletal dynamics, nuclear positioning, and tip growth into a mathematical model, we analyse how their interactions shape the different growth phases that we reveal for the first time in this study. Chemical treatments and mutant analyses further support our model, revealing that timely cytoskeletal changes drive transitions between these growth phases, and correlate with shifts in nuclear movement and morphology. This regulation suggests a microtubule-actin crosstalk in the root hair subapical region. Additionally, we present novel findings on vacuole movement and cell stiffness, further refining our understanding of tip growth dynamics. Collectively, our work provides a comprehensive framework for understanding how transitions between growth phases are orchestrated in plant tip-growing cells.

cell biology↗

Machine learning segmentation tool trained on synthetic data for tracking cytoskeleton polymerisation and depolymerisation

The cytoskeleton is important in controlling the growth and morphology of plant cells, so tracking its morphological changes is essential. Here, we develop a new machine learning based segmentation tool for microtubules (MTs), which can distinguish between polymerised and depolymerised fibres. To circumvent the low abundance of data, we trained on synthetic images of microtubules from a computational micro-tubule model, pre-processed to reproduce microscope effects and partial depolymerisation. We used this tool to investigate how the MT network in an Arabidopsis thaliana root hair cell repolymerises after depolymerisation under Oryzalin (OZ) drug treatments. Specifically, we show the network initially repolymerises from the shank region. This work demonstrates the viability of using synthetic data to train machine learning systems handling cytoskeletal image data.

plant biology↗