Coevolution of gene families in prokaryotes * Otto X. Cordero^1 , Berend Snel, and Paulien Hogeweg * / Theoretical Biology and Bioinformatics, University of Utrecht, 3584 CH Utrecht, The Netherlands / We study gene family coevolution on a tree of life based on^ a large-scale ancestral gene content reconstruction, which includes^ gene duplication and deletion events. The insights obtained^ from this study are threefold: (1) Global properties, such as^ the distribution of coevolution partners and the formation of^ disconnected clusters of coevolving families, can be an inevitable^ consequence of evolution along a tree. (2) Concerted family^ expansion (gene duplication) and contraction (gene deletion)^ reflect functional constraints and therefore lead to better^ function prediction. (3) "Long-range" coevolutionary relationships,^ caused mostly by large family expansions or contractions, reveal^ high-level evolutionary organization of cellular processes in^ prokaryotes. -- ================================================================== Klaas Vandepoele, PhD Tel. 32 (0)9 33 13822 VIB Department of Plant Systems Biology, Ghent University Technologiepark 927, 9052 Gent, Belgium E-mail: Klaas.Vandepoele@psb.ugent.be Website: http://bioinformatics.psb.ugent.be/ ==================================================================