Australasian Microarray & Associated Technologies Association, AMATA

Heathcott, RW*#, Maass, DR*#, Truman, P* and Atkinson, PH#
*Environmental Science and Research, Porirua, New Zealand; *Chemical Genetics Laboratory, School of Biological Sciences, Victoria University of Wellington.

Toxic blooms of the algal species Karenia brevisulcata kill marine life and can cause respiratory symptoms and skin irritation in humans. Chemical genomics is the study of the interaction of small molecules and gene products on a genome-wide scale. Here we describe a chemical genetic approach in yeast to study the biological activity and mode of action of the marine algal toxin KBT.

The Yeast Genome Deletion Set (YGDS) was constructed by an international consortium as a collection of 5000 mutants, each with one open reading frame of the Saccharomyces cerevisiae genome deleted and replaced with an antibiotic resistance marker. Each deletion is flanked by unique 20mer barcode tags allowing identification of the mutant. The YGDS is available as haploids, homozygous and heterozygous diploids. Growth of the deletion pool in the presence of the toxin and in parallel with an untreated control, followed by PCR of the pool’s genomic DNA using universal primers and microarray hybridisation, allows identification of the barcodes present and thus strains sensitive or resistant to the toxin. The pooled heterozygous deletion set can provide direct information on drug targets.

Preliminary results of this research show genes involved in sterol modification, endosomal sorting and protein catabolism via the multivesicular body pathway are important in the cellular response to KBT.