Abstract
A reciprocal chromosomal translocation strain, T (I; II) KH 5-9, was obtained by spontaneous chromosomal rearrangements. In strains heterozygous for KH 5-9, 50-60% of the ascospores are aborted. The ascus frequencies (black: white) were 27% 8:0, 18% 6:2, 27% 4:4, 9% 2:6 and 14% 0:8. In homozygous strains 0 to 10% of the ascospores were aborted. The strain harbored in the left arm of LG I a chromosomal break point between leu-3 and un-3 very close to ser-3. The resulting left arm of LG I has been translocated to the right arm of LG II distal to un-20 at very near position to ace-1. The right arm of LG II has been translocated to the left arm of LG I. The direction of chromosomal attachment of LG IL to LG IIR was from arg- 12, un-20 (LG IIR), break point, leu-3 and un-5 (LG IL). Strain T (I; II) KH 5-9 was inseparable from morphological mutations designated eas-2 (easily wettable-2) and brm (branched mycelia). Strain with brm was derived from T (I; II) KH 5-9 eas-2 and zygotes between them produced 0 to 10% of abortive ascospores. Strains with eas-2 form conidia readily soluble to water and strains with brm form aconidial mycelia with defective cell wall. Forced heterocaryon between them formed wild type hydrophobic conidia. In the zygotes between them, brm and eas-2 behaved closely linked to mating type and un-3. From these results KH 5-9 was assumed to harbor one or closely linked two mutations in the regulator for eas-2 and brm.
