Primers are designed for amplification and direct sequencing of ITS region of rDNA from Myxomycetes

Abstract

Four new primers were designed, based on comparison of Physarum polycephalum sequences retrieved from Genbank (primers PHYS-5 and PHYS-4) and our own sequences (primers PHYS-3 and PHYS-2), to amplify the ITS regions of rDNA, including the 5.8S gene segment from Lamproderma species. Sequencing analysis shows that Lamproderma contains ITS1-5.8S-ITS2 regions of approximately 900 bp, which is similar in size to most eukaryotes. However, the corresponding region in another common myxomycete, Fuligo septica, is more than 2000 bp due to the presence of large direct-repeat motifs in ITS1. Myxomycete rDNA ITS regions are interesting both as phylogenetic markers in taxonomic studies and as model sequences for molecular evolution.

• DNA amplification
• Lamproderma
• ribosomal DNA
• sequencing

We thank M. Schnittler for helpful advice during the elaboration of this work and K. Haugli for technical assistance in sequencing F. septica rDNA. This work has been financially supported by DGES, under the research project Flora Micológica Ibérica PB98-0538-C04-01 and the postdoctoral grant from the Comunidad de Madrid to MPM. Thanks to A. A. Diaz, G. Porras and S. Carbajo (Automatic Sequencing Service, CIB-CSIC, Madrid).