dates de séjour
projet de recherche
Does regeneration reset the age clock ? Assessing senescence in regenerated organs.
Cells in an ageing organism gradually lose the ability to perform important cellular functions and to respond to stress. Certain privileged populations of cells, such as germ cells, are able to escape ageing. It is uncertain if other types of cells that contribute to tissue renewal, such as stem cells, are similarly protected from ageing.
Many animals have the ability to regenerate body parts that are lost through injury. Regeneration restores both the number of cells and the diversity of cell types of the lost tissue, by mobilizing specific populations of progenitor cells. It also restores pattern, giving rise to well-proportioned and functional organs that are virtually indistinguishable from those of unharmed animals. This project explores whether regeneration can restore the consequences of ageing and how one could assess that experimentally.
We are establishing genetic tools to study limb regeneration in a small crustacean, named Parhyale hawaiensis. Adult Parhyale can completely regenerate their limbs within a week. We recently identified a number of genes that are differentially expressed in young versus aged Parhyale limbs. These genes will serve as markers to assess whether regenerated limbs exhibit the same degree of senescence as their non-regenerated counterparts.
Cette résidence a bénéficié d'une aide de l'État gérée par l'Agence nationale de la recherche dans le cadre des programmes d'Investissements d'avenir au titre du Laboratoire d'excellence RFIEA+.
Since 1999 Michalis Averof has been a researcher and group leader at the Institute of Molecular Biology and Biotechnology (IMBB) in Crete. He was recently appointed group leader at the Institut de Génomique Fonctionnelle de Lyon (IGFL) and will establish his research team in Lyon. He obtained a Biology degree at Trinity College, Dublin, a PhD at the University of Cambridge, and carried our post-doctoral research at the European Molecular Biology Laboratory (EMBL) in Heidelberg. His research lies at the interface of developmental and evolutionary biology: it compares developmental mechanisms among different animals to explore how their bodies are built and how morphological diversity arises during evolution.
Sarrazin A, Peel A and Averof M (2012) A segmentation clock with two-segment periodicity in insects. Science 336: 338-341
Pavlopoulos A, Kontarakis Z and Averof M (2010) Evolution of new appendage types by gradual changes in Hox gene expression: the case of crustacean maxillipeds. Paleodiversity 3 suppl: 141-146
Douris V, Telford MJ and Averof M (2010) Evidence for multiple independent origins of trans-splicing in Metazoa. Mol Biol Evol 27: 684-693
Pavlopoulos A, Kontarakis Z, Liubicich D, Serano J, Akam M, Patel NH and Averof M
(2009) Probing the evolution of appendage specialization by Hox gene mis-expression in an emerging model crustacean. Proc Natl Acad Sci USA 106: 13897-13902
Copf T, Schroeder R and Averof M (2004) Ancestral role of caudal genes in axis elongation and segmentation. Proc Natl Acad Sci USA 101: 17711-17715
Averof M and Patel NH (1997) Crustacean appendage evolution associated with changes in Hox gene expression. Nature 388: 682-686
Averof M and Cohen SM (1997) Evolutionary origin of insect wings from ancestral gills. Nature 385: 627-630