EC Accepts, published online ahead of print on 24 April 2009

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Wang, S. Articles by St. Leger, R. J. Search for Related Content PubMed PubMed Citation Articles by Wang, S. Articles by St. Leger, R. J.

 Previous Article  |  Next Article 

Eukaryotic Cell doi:10.1128/EC.00058-09
Copyright (c) 2009, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Comparative genomics using microarrays reveals divergence and loss of virulence associated genes in host specific strains of the insect pathogen Metarhizium anisopliae

Sibao Wang, Andreas Leclerque, Monica Pava-Ripoll, Weiguo Fang, and Raymond J. St. Leger^*

Department of Entomology, University of Maryland, College Park, MD, 20742, USA

^* To whom correspondence should be addressed. Email: stleger{at}umd.edu.

Many strains of Metarhizium anisopliae have broad host ranges but others are specialists and adapted to particular hosts. Patterns of gene duplication, divergence and deletion in three generalist and three specialist strains were investigated by heterologous hybridization of genomic DNA to genes from the generalist strain Ma2575. As expected, major life processes are highly conserved, presumably due to purifying selection. However, up to 7% of Ma2575 genes were highly divergent or absent in specialist strains. Many of these sequences are conserved in other fungal species suggesting that there has been rapid evolution and loss in specialist Metarhizium genomes. Some poorly hybridizing genes in specialists were functionally coordinated, indicative of reductive evolution. These included several involved in toxin biosyntheses and sugar metabolism in root exudates, suggesting that specialists are loosing genes required to live in alternative hosts or as saprophytes. Several components of mobile genetic elements were also highly divergent or lost in specialists. Exceptionally, the genome of the specialist cricket pathogen Ma443 contained extra insertion elements that might play a role in generating evolutionary novelty. This study throws lights on the abundance of orphans in genomes as 15% of orphan sequences were rapidly evolving in the Ma2575 lineage.