Molecular probes for the detection of Kluyveromyces marxianus chromosomal DNA in electrophoretic karyotypes of intergeneric protoplast fusion products.

Random genomic DNA fragments from Kluyveromyces marxianus were cloned in order to identify chromosomal bands in pulsed field electrophoresis patterns of intergneric hybrid strains which were obtained by protoplast fusion. Molecular hybridization data indicated that the K. marxianus parental strain might be triploid, and it showed strong chromosome length polymorphism. We analyzed the karyotype of two Saccharomyces cerevisiae/K. marxianus hybrid strains (St. 1.St.46) with our DNA probes and with a Ty1 specific probe. We found indications for recombinational events which lead to the formation of hybrid chromosomal DNA molecules.