Better evolution through gene clustering

The recent availability of a large number of fungal genomes has facilitated systematic investigations of metabolic pathway evolution across the kingdom. Through combining phylogenetic and genomic techniques, we have recently examined the evolution of metabolic pathways across a well-sampled fungal phylogeny, and gained new insight into the role of metabolic gene clusters in fungal evolution. The occasional occurrence of horizontal gene transfer of entire pathways between distantly related fungi via gene clusters suggests that fungal species have access to larger pan-genomes than previously thought. Furthermore, analysis of gene cluster decay suggests these transfers are underestimated by analyses of single strains, and that evolution within clustered pathways is constrained by natural selection. Increased evolvability in fungi is also implied by the discovery of chromosomal loci that maintain large alternative secondary metabolite gene clusters within recombining lineages. Together, these phylogenomic analyses in fungi illustrate a multi-faceted role of gene clustering in fungal evolution.