The nucleotide sequence homologies of unique DNA's of some cultivated and wild mushrooms

Abstract

The unique sequence DNA's of several wild and cultivated fungi including Agaricus brunnescens (=Agaricus bisporus), Agaricus bitorquis, Amanita muscaria, Amanita phalloides, Pleurotus ostreatus, Lentinus edodes, and Schizophyllum commune were compared by DNA–DNA hybridization. In addition, the characterization of a number of fungal DNA's are reported for the first time. Unique sequence DNA from Agaricus brunnescens and P. ostreatus was labeled by nick translation and each was hybridized with an excess of unlabeled driver DNA. Unique sequence DNA from two different isolates of Agaricus brunnescens showed nearly complete homology with one another, while only 56% of the unique sequence DNA from Agaricus bitorquis hybridized with the same Agaricus brunnescens DNA. Furthermore, very little sequence homology existed between Agaricus brunnescens DNA and the DNA's of the other mushrooms studied. Similarly, very little hybridization occurred between P. ostreatus labeled DNA and the DNA's of the other species. The stability of the DNA duplexes was examined by thermal elution. The Tm of Agaricus brunnescens:Agaricus bitorquis duplexes was 7.7 °C lower than Agaricus brunnescens:Agaricus brunnescens duplexes. This indicated a 7.7–11.6% mismatch between the unique DNA's of these two species.