Comparative genomics 917868 212651086 2008-05-15T17:59:02Z 192.207.234.194 /* External links */ '''Comparative genomics''' is the study of relationships between the [[genome]]s of different [[species]] or [[Strain (biology)|strains]]. Comparative genomics is an attempt to take advantage of the information provided by the signatures of selection to understand the function and evolutionary processes that act on genomes. While it is still a young field, it holds great promise to yield insights into many aspects of the evolution of modern species. The sheer amount of information contained in modern genomes (750 [[megabyte]]s in the case of humans) necessitates that the methods of comparative genomics are automated. [[Gene finding]] is an important application of comparative genomics, as is discovery of new, non-coding functional elements of the genome. Comparative genomics exploits both similarities and differences in the [[proteins]], [[RNA]], and [[regulatory regions]] of different organisms to infer how [[selection]] has acted upon these elements. Those elements that are responsible for similarities between different [[species]] should be conserved through time ([[stabilizing selection]]), while those elements responsible for differences among species should be divergent ([[positive selection]]). Finally, those elements that are unimportant to the evolutionary success of the organism will be unconserved (selection is neutral). Identifying the mechanisms of eukaryotic genome evolution by comparative genomics is one of the important goals of the field. It is however often complicated by the multiplicity of events that have taken place throughout the history of individual lineages, leaving only distorted and superimposed traces in the genome of each living organism. For this reason comparative genomics studies of small [[model organisms]] (for example [[yeast]]) are of great importance to advance our understanding of general mechanisms of evolution. Having come a long way from its initial use of finding functional proteins, comparative genomics is now concentrating on finding [[regulatory regions]] and [[siRNA]] molecules. Recently, it has been discovered that distantly related species often share long conserved stretches of [[DNA]] that do not appear to code for any protein. It is unknown at this time what function such [[ultra-conserved regions]] serve. Computational approaches to genome comparison have recently become a common research topic in computer science. The development of computer-assisted mathematics (using products such as [[Mathematica]] or [[Matlab]]) has helped engineers, mathematicians and computer scientists to start operating in this domain, and a public collection of case studies and demonstrations is growing, ranging from whole genome comparisons to gene expression analysis. <ref>Cristianini, N. and Hahn, M. [http://www.computational-genomics.net/ ''Introduction to Computational Genomics''], Cambridge University Press, 2006. (ISBN-13: 9780521671910 | ISBN-10: 0521671914)</ref>. This has increased the introduction of different ideas, including concepts from systems and control, information theory, strings analysis and data mining. It is anticipated that computational approaches will become and remain a standard topic for research and teaching, while students fluent in both topics start being formed in the multiple courses created in the past few years. ==See also== * [[Evolution]] * [[Molecular evolution]] * [[Genetic drift]] * [[Selection]] * [[Molecular clock]] * [[Evolutionary biology]] * [[Comparative anatomy]] * [[Model organism]] == References == <references/> * Kellis M, Patterson N, Endrizzi M, Birren B, Lander E (2003). Sequencing and Comparison of yeast species to identify genes and regulatory elements. ''[[Nature (journal)|Nature]]'', pp. 241-254 (15 May 2003). * Cliften P, Sudarsanam P, Desikan A (2003). Finding functional features in Saccharomyces genomes by phylogenetic footprinting. ''[[Science (journal)|Science]]'', pp. 71-76 (4 July 2003). * Hardison RC. (2003). Comparative genomics. ''[[PLoS]] biology'', '''1(2)''':e58. * Stein LD, ''et al.'' (2003). The genome sequence of Caenorhabditis briggsae: a platform for comparative genomics. ''[[PLoS]] Biology'', '''1(2):E45. doi: [http://dx.doi.org/10.1371/journal.pbio.0000045 10.1371/journal.pbio.0000045] * Boffeli D, McAuliffe J, Ovcharenko D, Lewis KD, Ovcharenko I, Pachter L, Rubin EM (2003). Phylogenetic shadowing of primate sequences to find functional regions of the human genome, ''[[Science (journal)|Science]]'', '''299(5611)''':1391-1394. * Dujon B, ''et al.'' (2004). Genome evolution in yeasts. ''[[Nature (journal)|Nature]]'', '''430''':35-44 (1 July 2004). * Filipski A, Kumar S (2005). Comparative genomics in eukaryotes. In [[The Evolution of the Genome]] (ed. T.R. Gregory), pp. 521-583. Elsevier, San Diego. * Gregory TR, DeSalle R (2005). Comparative genomics in prokaryotes. In [[The Evolution of the Genome]] (ed. T.R. Gregory), pp. 585-675. Elsevier, San Diego. * Xie X, Lu J. Kulbokas EJ, Golub T, Mootha V, Lindblad-Toh K, Lander E, Kellis M (2005). Systematic discovery of regulatory motifs in human promoters and 3' UTRs by comparison of several mammals. ''[[Nature (journal)|Nature]]''. * Champ PC, Binnewies TT, Nielsen N, Zinman G, Kiil K, Wu H, Bohlin J, Ussery DW (2006). Genome update: purine strand bias in 280 bacterial chromosomes. [http://mic.sgmjournals.org/future/152.3.shtml ''Microbiology'', '''152(3)''':579-583]. [http://www.hubmed.org/display.cgi?uids=16514138 HubMed] ==External links== * [http://www.genomesonline.org/ Genomes OnLine Database (GOLD)] * [http://www.genomenewsnetwork.org/ Genome News Network] * [http://cmr.jcvi.org/ JCVI Comprehensive Microbial Resource] * [http://pathema.jcvi.org/ Pathema: A Clade Specific Bioinformatics Resource Center] * [http://www.cbs.dtu.dk/services/GenomeAtlas/ CBS Genome Atlas Database] * [http://genome.ucsc.edu/ The UCSC Genome Browser] * [http://www.genome.gov/ The U.S. National Human Genome Research Institute] * [http://www.ensembl.org/ Ensembl] The [[Ensembl]] Genome Browser * [http://cbi.labri.fr/Genolevures/ Genolevures, comparative genomics of the Hemiascomycetous yeasts] * [http://phigs.jgi-psf.org Phylogenetically Inferred Groups (PhIGs)], a recently developed method incorporates phylogenetic signals in building gene clusters for use in comparative genomics. * [http://www.metazome.net/ Metazome], a resource for the phylogenomic exploration and analysis of Metazoan gene families. * [http://img.jgi.doe.gov/ IMG] The Integrated Microbial Genomes system, for comparative genome analysis by the DOE-JGI. * [http://www.dcode.org/ Dcode.org] Dcode.org Comparative Genomics Center. * [http://supfam.org/SUPERFAMILY/ SUPERFAMILY] Protein annotations for all completely sequenced organisms [[Category:Evolutionary biology]] [[Category:Genomics]] {{evolution-stub}} [[es:Genómica comparativa]] [[ja:比較ゲノミクス]] [[ko:비교유전체학]]