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Raphaël Mercier, INRA award "Scientific challenge" 2016

Raphaël Mercier, young Senior Scientist of his team « Meiosis mechanisms and apomixis », in the group « Meiosis and recombination », the Department « Dynamics and Expression of the Genome »,specialized very early on meiosis (the universal mechanism allowing to shuffle and distribute chromosomes during the formation of sexual cells). His interest in science began in ninth grade, and since 2003 he contributed in the group to the characterization of no less than sixty genes involved in meiosis, these results having heavy impact in the plant’s field. Axel Kahn, President of the « Comité d'éthique » Inra-Cirad-Ifremer, presented the INRA award "Scientific challenge ( « Défi scientifique 2016 ») during the 11th ceremony the 13th december 2016.

Raphaël Mercier explains us: « The genes involved in meiosis are remarkably well conserved among organisms as different as yeasts, plants, mice, and humans. Therefore, identifying such genes in the plant model Arabidopsis thaliana should help us identify their homologs in other species, but working with Arabidopsis is much easier. »
Step by step, to switch off genes in plant and to observe the consequences in offspring allow to understand the role of these genes during meiosis, the heart of heredity and a key issue in biology. To better understand how chromosomes mix up and control their distribution have direct applications in the field of plant breeding. His work and the work of the MeioRec group have greatly contributed to better reach fundamental mechanisms of meiosis being also attached to transfer knowledge to field plants as for example to potatoe plant. His fundamental research leads to discoveries with crucial applications, outskirts of a revolution in plant breeding.

The stimulating context of a cohesive research group of around thirty people with the unique facilities of IJPB to grow and study plants (green houses, culture chambers and platforms of the Plant Observatory) are in favor of a top-level research. Raphaël’s scientific works has been awarded of several scientific prices, the first one as earlier as for is PhD thesis. His research results on apomixis (see IJPB news «A new way to clone plants») were one of the 10 discoveries of the year 2011 of the journal « La Recherche ». A « Starting Grant » of the European Council (ERC) with a financial support of 5 years (2012-16) allowed the development of is work and his team.

In the future, his dream is to understand meiosis mysteries still unraveled. One question continues to haunt Raphaël Mercier: what controls the number of crossing-over events that take place during meiosis? Why this number is highly constrained and with an average of about two per chromosome and per meiotic cycle in most species, considering that a cell is perfectly healthy when 10 crossing occur ?

More informations:
Video at IJPB: Raphaël Mercier—unraveling the mysteries of plant genetics
Portrait of Raphaël Mercier: Delving into the heart of cell division

2016 INRA Awards: speeches of Axel Kahn and Raphaël Mercier following his portrait
Actualities IJPB:
A new way to clone plants
A main scientific progress: MiMe, mitosis instead of meiosis

December 2016

14 décembre 2016


Reproduction: a missing piece of the jigsaw puzzle of meiotic recombination identified in plants


 

Nathalie Vrielynck, Aurélie Chambon, Daniel Vezon, Lucie Pereira, Liudmila Chelysheva, Arnaud De Muyt, Christine Mézard, Claudine Mayer, Mathilde Grelon. A DNA topoisomerase VI-like complex initiates meiotic recombination. Science.351(6276):939-43. doi: 10.1126/science.aad5196 (PubMed Abstract)

Scientific Contacts:
Mathilde Grelon (+33 (0)11 30 83 33 08) Institut Jean-Pierre Bourgin (Inra, AgroParisTech, ERL3559 CNRS)

Press Relations:
Inra Press Office (+33 (0)1 42 75 91 86)
Associated Division :
Plant Biology and Breeding
Associated Centre :
Versailles-Grignon

Details : conmmuniqué de presse INRA

26 février 2016


Seminars
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Monday 18th january 2016
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14:00 PM
Invited Speacker
Dr. Patrick GALLOIS
(Cell Organisation and Dynamics,
The University of Manchester, GB)
What happened to plant caspases ?

Invited by Céline Masclaux-Daubresse
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Friday 15th April 2016
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11:00 AM
Invited Speaker IJPB
Dr. Wim SOPPE
(Control of seed germination, Department of Plant Breeding and Genetics,
Max Planck Institute for Plant Breeding Research, Cologne, Allemagne)

How do seeds wake up at the right time?

Viable seeds are not always able to germinate and can cycle between a dormant and a non-dormant state. Dormancy prevents germination during unfavourable seasons and has been selected against during domestication of many crop species. In the model plant Arabidopsis, dormancy is induced during seed maturation and released by dry storage (after-ripening) or imbibition at low temperatures (stratification). The plant hormone abscisic acid has an essential role in the induction of dormancy, whereas gibberellins are required for germination. However, the molecular mechanisms that regulate dormancy downstream and in parallel with these hormones are poorly understood.
DELAY OF GERMINATION 1 (DOG1) and REDUCED DORMANCY 5 (RDO5) have been identified as major regulators of seed dormancy in Arabidopsis. The function of DOG1 is conserved throughout the plant kingdom. The DOG1 gene encodes a protein with unknown function and RDO5 encodes a pseudophosphatase. The amount of DOG1 protein in freshly harvested seeds highly correlates with their dormancy level and the protein loses its function during dry storage of seeds. I will present our latest results about the functions of DOG1 and RDO5 in seed dormancy and their possible regulation by after-ripening.

Wim Soppe team Webpage
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Invited by José Jiménez-Gómez
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Monday 30th may 2016
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14:00 PM
Intited Speaker IJPB/SPS
Dr. Richard S. SMITH
(Computational modelling of morphogenesis and biomechanics,
Max Planck Institute for Plant Breeding Research, Kholn, Germany)

Towards an integrated framework for computational MorphoDynamX

Morphogenesis emerges from complex interactions between genetic and mechanical processes. Computer simulation models are becoming increasingly important to aid our understanding of the complexity involved, in an emerging field that is now being called Computational Morphodynamics. Key to this methodology is the combination of experimental work with dynamic, spatial simulation modeling. Time-lapse microscopy to quantify changes in cell geometry and gene expression is a tool of choice, and the data are used to inform the models and verify predictions. Full 3D imaging is desirable, however this is often technically challenging in opaque plant tissue. Equally challenging is the modeling of growth and cell division in full 3D. Fortunately, many biological processes occur on surface layers of cells, and 2D models can be used. However on highly curved surfaces, flat projections can introduce too much distortion to accurately record the dynamics of growth experimentally. To address this problem we have developed MorphoGraphX, a software that enables image processing on curved surface meshes. Many image processing algorithms designed for 2D and 3D images can be adapted to work with these “2.5D” images, such as cell segmentation and lineage tracking. Several examples of the use of the software on different plant organs will be presented, followed by our inroads towards developing an integrated simulation and imaging environment for computational morphodynamics.

Richard S. Smith team Webpage

Invited by Magalie Uyttewaal
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Monday 20th june 2016
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14:00 PM
Seminar
Dr. Ariel ORELLANA-LOPEZ
(Andrés Bello University, Santiago, Chili)
The role of nucleotide sugar transporters during the biosynthesis of the plant cell wall Rhamnogalacturonane

Invited by Helen North
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Tuesday 21th june 2016
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14:00 PM
salle de réunion, RdC, Bât.2
Seminar
Dr. Bruce VEIT
(Massey University, Palmerston North, New Zealand)
A genetic analysis of RAPTOR in plants: Novel facets of an ancient form of growth control

Invited by Christian Meyer

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Seminars location except other indications
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Amphithéâtre de Versailles, Bât. 10
INRA Centre de Versailles-Grignon
Route de St Cyr (RD10)
F-78026 Versailles Cedex
France

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Page Intranet séminaires

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