Streamlining and Simplification of Microbial Genome Architecture. Export

@article{citeulike:752913, abstract = {The genomes of unicellular species, particularly prokaryotes, are greatly reduced in size and simplified in terms of gene structure relative to those of multicellular eukaryotes. Arguments proposed to explain this disparity include selection for metabolic efficiency and elevated rates of deletion in microbes, but the evidence in support of these hypotheses is at best equivocal. An alternative explanation based on fundamental population-genetic principles is proposed here. By increasing the mutational target sizes of associated genes, most forms of nonfunctional DNA are opposed by weak selection. Free-living microbial species have elevated effective population sizes, and the consequent reduction in the power of random genetic drift appears to be sufficient to enable natural selection to inhibit the accumulation of excess DNA. This hypothesis provides a potentially unifying explanation for the continuity in genomic scaling from prokaryotes to multicellular eukaryotes, the divergent patterns of mitochondrial evolution in animals and land plants, and various aspects of genomic modification in microbial endosymbionts. Expected online publication date for the Annual Review of Microbiology Volume 60 is September 8, 2006. Please see http://www.annualreviews.org/catalog/pub\_dates.asp for revised estimates.}, address = {Department of Biology, University of Indiana, Bloomington, IN 47405 milynch@indiana.edu.}, author = {Lynch, Michael}, citeulike-article-id = {752913}, citeulike-linkout-0 = {http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.micro.60.080805.142300}, citeulike-linkout-1 = {http://dx.doi.org/10.1146/annurev.micro.60.080805.142300}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/16824010}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=16824010}, day = {23}, doi = {10.1146/annurev.micro.60.080805.142300}, issn = {0066-4227}, journal = {Annu Rev Microbiol}, keywords = {prokaryote}, month = {August}, posted-at = {2006-07-18 16:39:38}, priority = {2}, title = {Streamlining and Simplification of Microbial Genome Architecture.}, url = {http://dx.doi.org/10.1146/annurev.micro.60.080805.142300}, year = {2005} }

TY - JOUR ID - citeulike:752913 L3 - citeulike-article-id:752913 N2 - The genomes of unicellular species, particularly prokaryotes, are greatly reduced in size and simplified in terms of gene structure relative to those of multicellular eukaryotes. Arguments proposed to explain this disparity include selection for metabolic efficiency and elevated rates of deletion in microbes, but the evidence in support of these hypotheses is at best equivocal. An alternative explanation based on fundamental population-genetic principles is proposed here. By increasing the mutational target sizes of associated genes, most forms of nonfunctional DNA are opposed by weak selection. Free-living microbial species have elevated effective population sizes, and the consequent reduction in the power of random genetic drift appears to be sufficient to enable natural selection to inhibit the accumulation of excess DNA. This hypothesis provides a potentially unifying explanation for the continuity in genomic scaling from prokaryotes to multicellular eukaryotes, the divergent patterns of mitochondrial evolution in animals and land plants, and various aspects of genomic modification in microbial endosymbionts. Expected online publication date for the Annual Review of Microbiology Volume 60 is September 8, 2006. Please see http://www.annualreviews.org/catalog/pub_dates.asp for revised estimates. JF - Annu Rev Microbiol SN - 0066-4227 AD - Department of Biology, University of Indiana, Bloomington, IN 47405 milynch@indiana.edu. TI - Streamlining and Simplification of Microbial Genome Architecture. KW - prokaryote AU - Lynch, Michael PY - 2005/08/23/ UR - http://dx.doi.org/10.1146/annurev.micro.60.080805.142300 ER -