DFG/ANR-Project AncesMag

This project is funded in the framework of a joint program of the German Research Foundation (DFG) and the French Agence Nationale de la Recherche (ANR). It is a collaboration between research groups located at universities of Aix-Marseille/Cadarache, Lyon, and Bayreuth.

Summary

Magnetotactic bacteria are capable of biomineralizing intracellular ferrimagnetic nanoparticles in specific membrane-bounded organelles called magnetosomes. Among different bacterial strains, these unusual cellular compartments show a great variety of shapes. Their biosynthesis is a genetically complex process orchestrated by more than 30 proteins which are encoded in large, contiguous gene clusters within a so-called genomic magnetosome island (MAI).

So far, there is no knowledge about the evolution of the magnetosome organelle and its structural diversity. The ancestral functions of extant magnetosome proteins are unknown, as are the mechanisms of selection that caused their evolutionary diversification.

In our Franco-German research project, we will combine paleogenomic and synthetic biology methods in an inter-disciplinary approach to gain fundamentally new insights into the evolution of biomineralization and the development of organelles. As illustrated below, we plan to

(1) extend the so far unknown diversity of magnetosome biosynthesis pathways by genome sequencing of phylogenetically ancient (deep-branching) magnetotactic bacteria

(2) identify the composition of diverse magnetosome biosynthesis gene clusters and unravel the evolution of the magnetosome proteins

(3) reconstruct the ancestral sequences of the magnetosome genes at different taxonomic levels

(4) after in silico reconstruction and chemical synthesis of the principal magnetosome genes, express them functionally in a magnetotactic model organism and characterize the ensuing "resurrected" magnetic paleo-phenotypes.

Overview

Principal investigators:

(1,2): Dr. Christopher Lefèvre und Dr. Caroline Monteil, University Aix-Marseille/CEA, Cadarache, France

(2,3): Prof. Dr. Guy Perrière, Laboratoire de Biométrie et Biologie Evolutive (LBBE), University of Lyon, France

(1,4): Prof. Dr. Dirk Schüler, University of Bayreuth (UBT)