MOLECULAR ANALYSIS OF A LEU2(-) MUTANT OF CANDIDA-MALTOSA DEMONSTRATES THE PRESENCE OF MULTIPLE ALLELES

Three different alleles of the beta-isopropylmalate dehydrogenase gene were cloned and sequenced from a leucine auxotrophic mutant, G587, of Candida maltosa. The cloning of functionally-intact wild-type genes f rom this mutant strain suggests the presence of silent gene copies. An interallelic-divergence comparison has provided evidence for new regu latory mechanisms. Sequence data and karyotype analysis argue for a hi ghly-aneuploid genome of C. maltosa. An interpretation for the spontan eous auxotrophy - prototrophy - auxotrophy sequence of mutations in C. maltosa is suggested.