Molecular cloning of a widely distributed microsatellite core sequence from the cultivated mushroom Agaricus bisporus

An Agaricus bisporus microsatellite with the tetranucleotide motif TATG tan demly repeated was isolated from an A. bisporus library enriched in repeate d sequences. The use of the 16-mer oligonucleotide (TATG)(4) indicates that many loci contain nearby copies of the microsatellite in opposite orientat ions, The wide distribution of the microsatellite in the A. bisporus genome was assessed (i) by polyacrylamide gel electrophoresis of the products gen erated by directed amplification of microsatellite-region DNA (DAMD) and (i i) by hybridization of these products with A. bisporus chromosomes separate d by pulsed-field gel electrophoresis, This is, to our knowledge, the first microsatellite reported in the cultivated edible mushrooms. DAMD-PCR produ cts were generated using DNA of three Pleurotus species (P, pulmonarius, P, sajor-caju, and P. florida), indicating that (TATG)(4) repeats are also pr esent in these cultivated species. The variability found within closely rel ated strains indicates that such microsatellites are useful in fingerprinti ng and studying genetic variability in wild and commercial mushrooms. (C) 2 000 Academic Press.