MBE Advance Access published online on October 13, 2004
Molecular Biology and Evolution, doi:10.1093/molbev/msi018
Molecular Biology and Evolution © Society for Molecular Biology and Evolution 2004; all rights reserved
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Center for the Application of Molecular Biology to International Agriculture (CAMBIA), GPO Box 3200, Canberra ACT 2601, Australia
* To whom correspondence should be addressed. E-mail: peter{at}cambia.org.
Lateral gene transfer (LGT) from prokaryotes to microbial eukaryotes is usually detected by chance through genome-sequencing projects. Here we explore a different, hypothesis-driven approach. We show that the fitness advantage associated with the transferred gene, typically invoked only in retrospect, can be used to design a functional screen capable of identifying postulated LGT cases. We hypothesized that
Research Article
A Functional Screen Identifies Lateral Transfer of
-glucuronidase (gus) from Bacteria to Fungi
2 Cell GeneSys, 500 Forbes Boulevard, South San Francisco, CA 94080, USA
3 Department of Biochemistry, Faculty of Biology, Kim Il Sung University, Kumsong St., Pyongyang, DPR Korea
Abstract 
-glucuronidase (gus) genes may be prone to LGT from bacteria to fungi (thought to lack gus) because this would enable fungi to utilize glucuronides in vertebrate urine as a carbon source. Using an enrichment procedure based on a glucose-releasing glucuronide analogue (cellobiouronic acid), we isolated two gus+ ascomycete fungi from soils (Penicillium canescens, Scopulariopsis sp.). A phylogenetic analysis suggested that their gus genes, as well as the gus genes identified in genomic sequences of the ascomycetes Aspergillus nidulans and Gibberella zeae, had been introgressed laterally from high-GC Gram+ bacteria. Two such bacteria (Arthrobacter spp.), isolated together with the gus+ fungi, appeared to be the descendants of a bacterial donor organisms from which gus had been transferred to fungi. This scenario was independently supported by similar substrate affinities of the encoded -glucuronidases, the absence of introns from fungal gus genes, and the similarity between the signal peptide-encoding 5'-exentensions of some fungal gus genes and the Arthrobacter sequences upstream of gus. Differences in the sequences of the fungal 5'-extensions suggested at least two separate introgression events after the divergence of the two main Euascomycete classes. We suggest that deposition of glucuronides on soils as a result of the colonization of land by vertebrates may have favored LGT of gus from bacteria to fungi in soils.-glucuronidase; bacteria; fungi.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  A. Eudes, G. Mouille, J. Thevenin, A. Goyallon, Z. Minic, and L. Jouanin Purification, Cloning and Functional Characterization of an Endogenous beta-Glucuronidase in Arabidopsis thaliana Plant Cell Physiol., September 1, 2008; 49(9): 1331 - 1341. [Abstract] [Full Text] [PDF]
|
|