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Symposium IJPB 2018

March 19-20th 2018, INRA, Versailles, France

The First Symposium IJPB will offer a chance to listen to some of the best research developed at IJPB (but only a fraction of it!) with talks from David Bouchez, Nicolas Arnaud, Hervé Vaucheret, José Jiménez-Gómez, Raphaël Mercier, Enrico Magnani, Helen North, Stéphanie Baumberger, Bertrand Hirel. Contacts

As well as talks from prestigious external invited speakers:
Thomas Greb (Heidelberg University, Germany)
Claudia Köhler (Swedish University of Agricultural Sciences, Uppsala, Sweden)
Gwyneth Ingram (ENS Lyon, France)
Yves Van de Peer (Ghent University, Belgium)
Jonathan Jones (Sainsbury Laboratory, Norwich, United Kingdom)

Anne Krapp et Olivier Loudet

Programme and flyer

Scientific Committee : Nicolas Bouché, Jasmine Burguet, Sylvie Dinant, Jean-Denis Faure, Martine Gonneau, Herman Höfte, Anne Krapp, Patrick Laufs, Loïc Lepiniec, Olivier Loudet, Céline Masclaux-Daubresse, Raphaël Mercier, Christian Meyer, Helen North et Jean-Christophe Palauqui

Organizing Committee : Corine Enard (Institut Jean-Pierre Bourgin (IJPB), Versailles), Maria-Jesus Lacruz (IJPB, Versailles), Philippe Poré (INRA, Versailles) et Stéphane Raude (IJPB, Versailles)

Contact and more information: Symposium IJPB 2018 website



Monday 29th January 2018

2:00 pm

Invited Speaker
(Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Israel)

Plant mitochondria group II introns splicing: A window into the evolution of the nuclear spliceosomal machineries

Mitochondria serve as principal sites for cellular energy metabolism and play pivotal roles in the biosynthesis of many essential metabolites for the (plant) cell. As dependences of a free-living organism, mitochondria contain their own genome, the mtDNA. The mtDNAs in plants are notably larger and more complex in structure than their corresponding ones in Animalia. Plant mitochondria are also remarkable with respect to the presence of numerous group II introns that reside in many organellar genes. The removal of the introns from the coding sequences they interrupt is essential for respiratory functions and is mediated by enzymes that belong to a diverse set of protein-families. These include intron-encoded related proteins (i.e. maturases) that function in the splicing of group II introns in bacteria and mitochondria in fungi and plants, usually with high specificity towards the intron in which they are encoded. While the splicing of group II introns in vivo is facilitated by maturase factors, canonical group II introns are catalytic RNAs that are able to excise themselves from their pre-RNA hosts in vitro, in the absence of the protein cofactors, using a mechanism identical to that utilized by the spliceosome. Structural analyses and phylogenetic data may indicate that the spliceosomal RNAs have evolved from group II intron-related ancestors. Yet, it remains unclear how could such general players in spliceosomal splicing evolve from the monospecific bacterial systems (i.e. a group II intron RNAs and their highly specific intron-encoded maturase factors). Analysis of the organellar splicing machinery in plants may provide us with important clues into the evolution of the nuclear splicing machineries. Genetic and biochemical studies led to the identification of different protein factors that facilitate the splicing of many of the mitochondrial introns in plants. We established the native RNA targets of different maturase factors in plants and analyzed the organellar and developmental defects associated with their mutant lines in vivo. Interestingly, while model maturases in bacteria and fungi mitochondria act specifically on their cognate intron RNAs, the plant maturases are acting on multiple mtRNA targets, thus seem to be acting as organellar proto-spliceosomal factors. The ability of the mitochondrial maturases in plants to act on different intron targets further support the notion that the early organellar self-splicing and mobile group II RNAs spread in the eukaryotic genomes and later ‘degenerated’ into the universal splicing system, known as the spliceosome. The similarities between maturases and the core spliceosomal factor, Prp8, may support this intriguing hypothesis.

Oren Ostersetzer-Biran webpage

Invited by: Hakim Mireau 


Monday 14 May 2018

Invited speaker
Pr. Henrik JÖNSSON
The Sainsbury Laboratory, CAmbridge, GB
How many cells can you fit in a stem cell niche?

Plant shoots harbor stem cells throughout the life of the plant maintained via a gene regulatory feedback network. Perturbations to these regulatory genes lead to changes in the size and shape of the stem cell niche. Similar effects can be achieved by perturbing the cell walls and heterogeneous and anisotropic mechanical wall properties need to be regulated to generate correct form. We use a Computational Morphodynamics approach, combining live imaging and models of cell wall mechanics and gene networks, to understand how growth and differentiation is coordinated. In this talk I will discuss how mechanical patterning can overlap with gene expression patterns, and how cell size and tissue size can influence the maintenance of the stem cell niche.

Hendrik Jönsson webpage

Invited by: and

Registration compulsory up to 10/05/18
Except for INRA Versailles members


Seminars location except other indications

Amphitheatre, Building 10
INRA Centre de Versailles-Grignon
Route de St Cyr (RD10)
F-78026 Versailles Cedex


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