Table of Contents
International Journal of Evolutionary Biology
Volume 2011 (2011), Article ID 423821, 7 pages
http://dx.doi.org/10.4061/2011/423821
Research Article

Evolutionary Origins of the Fumonisin Secondary Metabolite Gene Cluster in Fusarium verticillioides and Aspergillus niger

1UCD Conway Institute of Biomolecular and Biomedical Research, UCD School of Medicine and Medical Sciences, and UCD Complex and Adaptive Systems Laboratory, University College Dublin, Dublin 4, Ireland
2Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland

Received 15 October 2010; Revised 10 January 2011; Accepted 15 March 2011

Academic Editor: Hiromi Nishida

Copyright © 2011 Nora Khaldi and Kenneth H. Wolfe. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The secondary metabolite gene clusters of euascomycete fungi are among the largest known clusters of functionally related genes in eukaryotes. Most of these clusters are species specific or genus specific, and little is known about how they are formed during evolution. We used a comparative genomics approach to study the evolutionary origins of a secondary metabolite cluster that synthesizes a polyketide derivative, namely, the fumonisin (FUM) cluster of Fusarium verticillioides, and that of Aspergillus niger another fumonisin (fumonisin B) producing species. We identified homologs in other euascomycetes of the Fusarium verticillioides FUM genes and their flanking genes. We discuss four models for the origin of the FUM cluster in Fusarium verticillioides and argue that two of these are plausible: (i) assembly by relocation of initially scattered genes in a recent Fusarium verticillioides; or (ii) horizontal transfer of the FUM cluster from a distantly related Sordariomycete species. We also propose that the FUM cluster was horizontally transferred into Aspergillus niger, most probably from a Sordariomycete species.