The plasmids of the morels: characterization and prerequisites for vector development

Summary In several Morchella species linear dsDNA plasmids have been discovered and analyzed. Two linear plasmids of the strain Morchella conica 3 analyzed in detail are associated with the mitochondria but not as an integrative part of the high molecular weight mt DNA. In addition, homologies between different plasmids from different species could be detected. These homologies extend to all parts of the plasmids. Differences in size are due to different lengths of nonhomologous inner parts rather than to differences at the termini. Fragments comprising the entire plasmids were cloned into bacterial vectors and a selectable marker gene for eukaryotes was added to the resulting hybrid plasmids. Transformation of yeast led to the identification of autonomously replicating sequences, this being a prerequisite for the development of autonomously replicating vectors for Morchella.Dedicated to Prof. Dr. H.-J. Rehm on the occasion of his 60th birthday