Work Package 5

Tuesday 5 June 2012
by  daubin
popularity : 0%

Coordinator: Céline Brochier-Armanet (LBBE)

Contributions: BMGE, LBBE


An approach to understand life history that is complementary to large-scale reconstructions of ancestral genome content is the qualitative and precise reconstruction of the origin and evolution of cellular structure/processes (i.e. macromolecular complexes, biochemical processes, metabolic pathways, regulation networks, etc.). For this, phylogenomics approaches are revealing very useful (Eisen et Fraser 2003). However, they have been so far limited to either a few genes or a few taxa, due to the hard task of analyzing at once systems with hundreds of components along trees of hundreds of taxa.
The goal of this task is to use the data from WP 1 and WP3 to study at a much more larger scale the ancestral state and evolutionary history of diverse cellular structures/processes at different nodes of the tree of life, from the most ancient to more recent ones. This will provide an unprecedented opportunity to follow the evolutionary dynamics of highly integrated cellular structures/processes, as a complement to whole genome analyses.

More precisely, we will focus on cellular structures linked with the membrane, such as those involved in cell wall and membrane biogenesis, assembly of cellular appendices, DNA and chromosome replication and cell division. The study of these cellular systems is of particular interest for ancient evolution because they constitute important distinctive features among the three domains of life and have certainly played a role during early evolution of present-day lineages. Moreover, cell membrane and cell wall systems are also key to the study of present day communities because they define the boundary between cells and the external environment, and have a crucial role in many biological processes (uptake of molecules, excretion of metabolic wastes, antibiotics, sensing, regulation of horizontal gene transfer, cell motility, etc). Accordingly, their comparative study can help understanding the adaptation of organisms to environment and –reciprocally- to understand how the environment controls the structure and evolution of microbial communities. The biological information obtained in this task will therefore be naturally linked with Task 6 for the reconstruction of ancestral microbial communities.

LCB and BMGE will be in charge of the analyses of the cellular structures. The two partners are particularly qualified for this kind of analyses and have successfully applied such approach to the study of various cellular systems (Bapteste et al. 2005; Desmond, Celine Brochier-Armanet, et Gribaldo 2007b; Desmond et al. 2010b; Eme et al. 2009b; Brochier, Forterre, et Gribaldo 2004; Celine Brochier-Armanet, Talla, et Gribaldo 2009b; Gribaldo, Talla, et Celine Brochier-Armanet 2009). In addition the LCB and BMGE labs are favourable places to initiate wet experiment on bacterial and archaeal models in collaboration with local teams. The LBBE partner will also participate to this task by designing specific tools to query specific cellular systems history.