Development of a yeast-based assay system for monitoring microsatellite instability

Simple sequence repeats (microsatellites) are found in all eukaryotic genom es. Instabilities within these sequences have been associated with several human disorders including Huntington's chorea and myotonic dystrophy. Furth er studies have identified links between microsatellite instability, faulty mismatch repair and certain human cancers, in particular a form of heredit ary colorectal cancer. The assay system described here consists of a congen ic set of yeast strains mutated in DNA replication and mismatch repair gene s and assay plasmids with which it is possible to measure differences in mi crosatellite stability in the range of 5-850-fold. The development of this technology will allow monitoring of environmental and dietary influences on the genomic stability in the context of human disease. (C) 1999 Published by Elsevier Science B.V. All rights reserved.