Email : laurent [dot] chesneau [at] univ-rennes1 [dot] fr
Phone : +33 2 23 23 48 85
Former projet : Dyneine recrutement mechanism at cortex
How a minus-end molecular moto could be enriched at cortex where only plus-end microtubules are present?
Those research unraveled two mechanismes : cortex recrutment via GPR-1/2 (LGN) by diffusion from cytoplasme and in a minority way the concentration at the microtubules plus-end thanks to EBP-2 (EB protein), dynactin and LIS-1.
This study has shown that the asymmetry of pulling forces, which allows posterior positioning of the spindle, depends on the asymmetric enrichment of GPR-1/2 in the cortex, but not on the distribution of dynein in the cytoplasm and at the microtubules plus-end since it's symmetrical as well as the residence time of the dynein to the cortex.
This project was led by Ruddi Rodriguez Garcia, accompanied and finalized by myself.
Current project: Influence of Kinetochore-Microtubule attachment errors on the length of the spindle and vice versa
Do kinetochore-microtubule attachment errors affect spindle length? And conversely can the spindle change its length to avoid or correct kinetochore-microtubule attachment errors?
In the context of the C. elegans embryo, where the distribution of kinetochores on the chromosomes is holocentric (distributed all along the chromosomes and non-centromeric as in mammals), the probability of merotelic attachments (a chromatide connected to both poles of the spindle) is large and yet this type of event is very rarely observed in undisturbed embryos.
Do the global properties of the spindle (dynamic, mechanical, adaptability) help to avoid these errors?
This project was initiated by Xavier Pinson, with the development of an inducible and reversible system of disruption of kinetochore microtubule attachments. I took over the driving of this project. Maxime Léon started during his Master 1 internship to perturbed the spindle and observe the impact on attachment errors.
FIELDS OF INTEREST
Molecular and Cellular Biology with a particular interest for dynamical and polarized process.
Genetic Manipulation : transgenese, directed mutagenese, ARN interferent
Wide field Microscopy for tracking with very high temporal resolution (33Hz) of large and bright structures.
Confocal Microscopy (type spinning disk) for tracking with high temporal resolution (5Hz) of small and low brightness structures.
Confocal Microscopy (type AiryScan) for detail imaging with high temporal resolution (1Hz) in 3D with high spatial resolution (bellow diffraction optical law).