N-166. A Phylogenetic Microarray for the Study of Eukaryotic Microbial Communities

J. K. Magnuson, J. R. Collett, J. E. McDermott, D. E. Culley, R. Tan, K. S. Bruno, S. E. Baker;
Pacific Northwest Natl. Lab., Richland, WA.

A custom high density microarray for the analysis of eukaryotic microbes has been constructed using the ITS1/5.8S/ITS2 region of ribosomal RNA genes as the source of oligonucleotide probes. The taxa included on the microarray include the fungal kingdom, phylum chlorophyta (green algae) and phylum bacillariophyta (diatoms). The fungi are broadly represented due to the efforts of the scientific community involved in the Assembling the Fungal Tree of Life (AFTOL) project. The green algae and diatoms are less well represented, which emphasizes the need for a concerted effort similar to AFTOL to develop a molecular phylogeny for these environmentally critical taxa. The microarray is intended to be broadly useful for the assessment of complex eukaryotic microbial communities present in terrestrial ecosystems from soils to aquatic sediments. Periphyton collected from the Columbia River in southern Washington State has been grown in the laboratory and used as a system for testing the effects of uranium exposure on microbial communities. The phylogenetic microarray is one tool being used to assess changes in this periphyton microbial community. The first generation of our phylogenetic microarray is a valuable tool for characterizing the diversity of the eukaryotic members of microbial communities. We anticipate that the microarray will evolve as the breadth and depth of representation of rRNA gene sequences for different taxa of eukaryotic microbes grows.