IDENTIFICATION OF A COMPLEX CHROMOSOME REARRANGEMENT IN NEUROSPORA CRASSA

Abstract

A complex chromosome rearrangement has been identified using predominantly genetic, but some cytological criteria, in crosses heterozyous for the rearrangement. The rearrangement involves the insertion of a segment of LG I into LG IV in an inverted position with respect to centromere, and a segment of LG IV reciprocally inserted into LG I, possibly in inverted sequence, T (I → IV, I ← IV). Some of the properties of such a rearrangement are considered, including absence of single exchanges in inverted segments, high incidence of even-numbered exchanges, inter-linkage group linkages, and ascospore abortion and genotype patterns; a good fit of the model to the data is demonstrated.