Collection of reports on medical research published in medical journals Wertheim gives you knowledge of medical subjects: Cross-species comparison of genome-wide expression patterns . | Minireview Cross-species comparison of genome-wide expression patterns Xianghong Jasmine Zhou and Greg Gibson Addresses Department of Biological Sciences University of Southern California Los Angeles CA 90089-0371 USA. Department of Genetics North Carolina State University Raleigh NC 27695-7614 USA. Correspondence Greg Gibson. E-mail ggibson@ Published 21 June 2004 Genome Biology 2004 5 232 The electronic version of this article is the complete one and can be found online at http 2004 5 7 232 2004 BioMed Central Ltd Abstract The rapid accumulation of microarray data from multiple species provides unprecedented opportunities to study the evolution of biological systems. Recent studies have used cross-species comparisons of expression profiles to annotate gene functions to draw evolutionary inferences concerning specific biological processes and to study the global properties of expression networks. Combining sequence and expression information for functional annotation The power of comparative genomic analysis relies on the assumption that important biological properties are often conserved across species. Cross-species sequence comparison has been widely used to infer gene function but it is becoming apparent that sequence similarity is not always proportional to functional similarity 1 2 . In fact Gene Ontology GO terms 3 distinguish between molecular and biological functions and although the amino-acid sequence may imply that a gene possesses a particular molecular function spatiotemporal expression data is required to infer biological function - which cellular or biological process the gene product participates in. To determine the function of a gene precisely therefore we need to investigate not only its sequence characteristics but also its expression characteristics. An increasing number of genetic studies indicate that the divergent functions of many duplicate genes are reflected in the divergence of expression patterns rather
