Sexuality in Neurospora crassa II. Genes affecting the sexual development cycle

Abstract
Eighteen male sterile mutants of N. crassa which block various stages of the sexual development cycle have been functionally categorized on the basis of complementation tests. Nine of these (those which block early stages of the sexual cycle) have also been analysed through recombination studies. On the basis of these data, a minimum of four genes appear to be involved in early stages of sexual development (i.e. probably prior to karyogamy) and several genes are indicated which control later stages of the cycle. Complementation phases with respect to sexual development in heterothallic Ascomycetes are discussed as well as a comparison of results obtained with expectations and with those obtained in related Ascomycetes.