Isozyme polymorphism of beta-glucosidase in Aspergillus nidulans.

Electrophoretic analysis of the distribution of various electromorphs at different beta-glucosidase zones was carried out in natural populations of A. nidulans, the A. nidulans group, and various species belonging to the genus Aspergillus from diverse geographical areas of India. The data show the existence of three segregating zones for beta-glucosidase, designated beta-GluI, beta-GluII, and beta-GluIII. All three zones are present in wild isolates of A. nidulans, and only two, i.e., beta-GluI and beta-GluIII, in the A. nidulans group and beta-GluII and beta-GluIII in different species of Aspergillus except A. terreus, A. flavus, and A. brevipes, where only beta-GluIII is present. Overall nine electromorphs are observed at beta-GluI, three at beta-GluII, and six at beta-GluIII zones, respectively. It can be concluded that there may be three structural genes for beta-glucosidase coding the three polymorphic zones in A. nidulans.