Cover photograph (Copyright © 2000, American Society for Microbiology. All rights reserved.): (Top to bottom [plates] and left to right [test tubes]) cr-1, gna-3, and wild-type Neurospora crassa strains. Mutation of gna-3 (encoding a G protein  subunit) or cr-1 (adenylyl cyclase) results in unrestricted asexual spore production on plates and reduced aerial hypha height in standing cultures. The cr-1 phenotypes are more severe than those of gna-3, producing a gradient effect when all strains are compared. Exogenous cyclic AMP (cAMP) suppresses these defects in gna-3 and cr-1 strains, suggesting that these are cAMP-dependent processes. Decreased adenylyl cyclase activity and protein amounts indicate that GNA-3 regulates adenylyl cyclase enzyme levels in N. crassa. (See related article in October 2000, issue 20, vol. 20, page 7693.)