210 likes | 422 Views
Life History Traits and Genome Structure . Aerobiosis and G+C Content in Bacteria. J.R. Lobry Université Claude Bernard - Lyon I CNRS UMR 5558 & INRIA Helix FRANCE. Aerobic versus Anaerobic. You need the presence of O 2 to live, you are aerobic (obligate)
E N D
Life History Traits and Genome Structure Aerobiosis and G+C Content in Bacteria J.R. Lobry Université Claude Bernard - Lyon I CNRS UMR 5558 & INRIA Helix FRANCE
Aerobic versus Anaerobic • You need the presence of O2 to live, you are aerobic (obligate) • You need the absence of O2 to live, you are anaerobic (obligate) • [...snip...]
Anaerobic and Aerobic Species Only Anaerobic Species
Aerobic >> Anaerobic • In aerobic conditions (with O2) the oxydation of one molecule of glucose (respiration) yields 38 ATP (metabolic currency unit). Short generation times. • In anaerobic conditions (without O2) the fermentation of one molecule of glucose yields 2 ATP (metabolic currency unit). Long generation times. The generation time is a life history trait
Life History Traits and Genome Structure Aerobiosis and G+C Content in Bacteria J.R. Lobry Université Claude Bernard - Lyon I CNRS UMR 5558 & INRIA Helix FRANCE
Bacteria in the Universal Tree of Life Oryza Saccharomyces EUCARYA Drosophila Prorocentrum Tetrahymena ARCHAEA Crithidia Homo Physarum Halococcus Halobacterium Methanococcus ? Methanobacterium Desulfurococcus Thermoproteus EUBACTERIA Thermus Streptomyces « BACTERIA » Anacystis Escherichia Bacillus Pseudomonas
Bacteria and Eucarya Only Bacteria
Bacterial Genomes:Circular dsDNA Here G+C = 50% The G+C content is a genome structure
Life History Traits and Genome Structure Aerobiosis and G+C Content in Bacteria J.R. Lobry Université Claude Bernard - Lyon I CNRS UMR 5558 & INRIA Helix FRANCE
Aerobiosis and G+C Content in Bacteria Anaerobic Aerobic Naya et al. (2002) J. Mol. Evol.,55:260
Aerobiosis and G+C Content in Bacteria Anaerobic Aerobic Why? Naya et al. (2002) J. Mol. Evol.,55:260
Metabolic cost of amino-acids in Aerobiosis 38.3 ATP 11.7 ATP 52.0 ATP 11.7 ATP 27.3 ATP 14.7 ATP 15.3 ATP 27.3 ATP Akashi & Gojobori (2002) PNAS,99:3695
From amino-acid cost to Protein cost Protein cost in ATP Protein concentration in cells Akashi & Gojobori (2002) PNAS,99:3695
The growth of genomic data But available fossil DNA is < 0.00013 109 years...
Dataset • ~300 bacterial species • ~1,000,000 proteins • ~100,000,000 amino-acids
Akashi (2002) Naya (2002)
Interpretation Aerobic bacteria have a higher genomic G+C content than anerobic bacteria because this induces an average protein composition which is less expensive in aerobic conditions
Life History Traits and Genome Structure Aerobiosis and G+C Content in Bacteria J.R. Lobry Université Claude Bernard - Lyon I CNRS UMR 5558 & INRIA Helix FRANCE