An electrophoretic karyotype comparison of the yeast genera Dipodascopsis Batra et Millner Lipomyces Lodder et Kreger-van Rij, Myxozyma van der Walt et al

Abstract

The chromosomal DNA banding patterns of twenty-nine strains representing the family Lipomycetaceae and the associated anamorph genus Myxozyma, were determined by orthogonal-field-alternation gel electrophoresis (OFAGE). In order to evaluate this genomic character, the results obtained were compared with carbon source utilization and coenzyme Q systems. Species within a genus produced the same number of chromosomal bands but not necessarily the same chromosome sizes, except for members of the anamorph genus Myxozyma, which produced different numbers of DNA bands. On the basis of the chromosomal DNA band number, it was possible to distinguish between the genera Dipodascopsis (one DNA band), Lipomyces and Waltomyces (two DNA bands), Zygozyma (three DNA bands) and Myxozyma (five DNA bands and more). It was however impossible to differentiate between the representative species of Dipodascopsis, Lipomyces or Myxozyma, on this basis. We found that the more complex hyphal species (characterized by the utilization of a large amount of carbon sources and the presence of a CoQ9 system) produced only one heavy DNA band, while the less complex budding forms (characterized by the utilization of a small amount of carbon sources and the presence of a CoQ8 system) produced five or more smaller chromosomal bands. No teleomorph/anamorph relations between the genus Myxozyma and the genera Dipodascopsis, Lipomyces and Waltomyces were found on the basis of OFAGE, CoQ system or physiological characteristics.