Distribution among the COG categories for all the E

Copyright information:Taken from "The impact of horizontal gene transfer in shaping operons and protein interaction networks – direct evidence of preferential attachment"http://www.biomedcentral.com/1471-2148/8/23BMC Evolutionary Biology 2008;8():23-23.Published online 24 Jan 2008PMCID:PMC2259305. coli genes. Counts were estimated for each evolutionary gene category, and expressed as percentages per total number of genes per COG category. The , and gene sets differ in their distribution of COG functional categories (P-value < 0.001).