Developmental mutants with defects in fruiting body formation are excellent resources for the identification of genetic components that control cellular differentiation processes in filamentous fungi. The mutant pro4 of the ascomycete @entity23111 is characterized by a @entity1167 during the sexual life cycle. This mutant generates only pre-fruiting bodies (protoperithecia), and is unable to form ascospores. Besides being sterile, pro4 is auxotrophic for @entity368 . Ascospore analysis revealed that the two phenotypes are genetically linked. After isolation of the wild-type leu1 gene from @entity23111 , complementation experiments demonstrated that the gene was able to restore both prototrophy and fertility in pro4. To investigate the control of leu1 expression, other genes involved in @entity368 biosynthesis specifically and in the general control of @entity535 biosynthesis ("cross-pathway control") have been analysed using Northern hybridization and quantitative RT-PCR. These analyses demonstrated that genes of @entity368 biosynthesis are transcribed at higher levels under conditions of @entity535 starvation. In addition, the expression data for the cpc1 and cpc2 genes indicate that cross-pathway control is superimposed on @entity368 -specific regulation of fruiting body development in the leu1 mutant. This was further substantiated by growth experiments in which the wild-type strain was found to show a sterile phenotype when grown on a medium containing the @entity535 analogue @entity37540 . Taken together, these data show that pro4 represents a novel mutant type in @entity23111 , in which @entity535 starvation acts as a signal that interrupts the development of the fruiting body.

A @entity23111 mutant lacking the leu1 gene shows a XXXX during fruiting body formation.

@entity37540 :: ('CHEBI:52446', 'Chemical') :: ['5-methyl-tryptophan'] @entity368 :: ('CHEBI:25017', 'Chemical') :: ['leucine'] @entity535 :: ('CHEBI:33704', 'Chemical') :: ['amino acid'] @entity23111 :: ('5147', 'Species') :: ['S. macrospora', 'Sordaria macrospora'] @entity1167 :: ('MESH:D006323', 'Disease') :: ['developmental arrest']
@entity1167 :: (MESH:D006323,Disease) :: ['developmental arrest']
