Prof. Denis LJ LAFONTAINE, ULB-FRS/FNRS
Denis.Lafontaine@ulb.ac.be
Denis L.J. LAFONTAINE obtained a BSc (1991) and a PhD (1995) in Molecular Biology & Genetics from the University of Namur (Belgium). He performed a post-doctoral training with Prof David Tollervey in the Gene Expression programme (EMBL, Heidelberg) and The Welcome Trust Center for Cell Biology (University of Edinburgh). Denis is Maître de Recherche of the Belgian FNRS and leads a group studying RNA metabolism at the Institute of Molecular Biology & Medecine at the University of Brussels since 2001. Denis is working on several aspects of RNA metabolism (including, surveillance and quality controls, pre-rRNA synthesis, processing & modification, pre-ribosome assembly & trafficking) and organelle morphogenesis (nucleolus and cytoplamsic P-bodies) with a particular focus on their relationships to human diseases (cancer). Denis published >30 manuscripts in international peer-reviewed journals and contributed chapters to several books destined to specific and general audiences. Denis is acting as a referee for top journals in the field of Molecular and Cellular Biology, as well as for international funding agencies.
Jaunius URBONAVICIUS, Ph. D.
jurbonav@ulb.ac.be
Jaunius Urbonavičius was born in 1969, and studied at Vilnius University, Lithuania, from which he received a Diploma in Chemistry in 1992. He obtained his PhD in Microbiology with Glenn Björk at the Umeå University, Sweden, in 2002. He did post-doctoral studies in Henri Grosjean’s group at the CNRS in Gif-sur-Yvette, France in 2003-2006 and in Louis Droogmans’ group at the Laboratoire de Microbiologie, Université Libre de Bruxelles, in 2007-2008. He has joined Denis Lafontaine’s group at the CMMI at the end of 2008. His research interests are RNA processing, trafficking, and modification. At present, he is developing the working protocols for automated image acquisition and analysis (high-content analysis). He has received a Federation of European Biochemical Societies Distinguished Young Investigator Award in 2007 as recognition of the work performed under a FEBS long-term fellowship in Gif-sur-Yvette, France.
Automation and quantitative morphometry
Equipment
- The BD Pathway ‘high content analysis system’ 435 (BD, U.S.A.)
- Plate-forme multimodale à haute résolution pour morphométrie quantitative
Bibliographical references
- Thiry M, Lamaye F, Lafontaine DLJ (2011) The nucleolus: When two became three. Nucleus 2: 289-293.
- Leporé L, Lafontaine DLJ (2011) A functional interface at the rDNA connects rRNA synthesis, pre-rRNA processing and nucleolar surveillance in budding yeast. PLoS ONE 6: e24962.
- Lamaye F, Galliot S, Alibardi L, Lafontaine DLJ, Thiry M (2011) Nucleolar structure across evolution: the transition between bi- and tricompartmentalized nucleoli lies within the class Reptilia. J Struct Biol 174: 352-359.
- Leporé N, Lafontaine DLJ (2010) {'Catch me if you can': how the structural and functional integrity of eukaryotic RNA molecules is monitored by surveillance mechanisms}. Médecine/Sciences 26: 259-266.
- Lafontaine DLJ (2010) A ‘garbage can’ for ribosomes: how eukaryotes degrade their ribosomes? Trends Biochem Sci 35: 267-277.
- Hernandez-Verdun D, Roussel P, Thiry M, Sirri V, Lafontaine DLJ (2010) The nucleolus: structure/function in RNA metabolism. Wiley Interdisciplinary Reviews: RNA 1: 415-431.
Description and applications
In Cell Biology, it is quite common that within a population many cells show different phenotype, a phenomenon known as “penetrance” that has to be quantified by statistical approaches. By numerical characterization, quantitative morphometry statistically validates various objects such as the different cell types or particular sub-cellular structures (for example the organelles).
It includes counting objects, calculating their diameter, surface, volume, level of the co-localization of different antigens, etc. The recognition of the cellular and sub-cellular structures can either be done on the basis of their particular morphology (histochemistry) or their fluorescence signal (using protein or RNA reporters). As the segmentation of the images is highly dependent on the parameters chosen, a key aspect of our work is the exact determination of the parameters used by the imaging software for the autonomous recognition and discrimination of the objects of interest (see the illustration).
These automated analysis techniques (high-content analysis) allow to (i) determine the number of bacteria in the cytoplasm of macrophages, (ii) test the effects of dozens of synthetic molecules (“drug design”) on stem cell differentiation or (iii) on the sub-cellular localization pattern of antigens of interest (for ex. the dynamic re-localization of a membrane receptor in the cytoplasm).
Macroscopic applications such as lytic plaque analysis or the calculation of the relative distribution of several species of pathogenic organisms are possible. The development of working protocols is done in collaboration with the RNA metabolism laboratory of the Université Libre de Bruxelles.
See the poster: POSTER_CMMI_-_A.__Q._Morphometry.pdf
