The filamentous fungus @entity14940 is an obligate aerobe, which is capable of anaerobic survival, but not anaerobic growth. Since cytochrome c forms an essential part of the oxidative respiratory pathway it was expected that mutants lacking this component would be non-viable. Gene replacement of one homologue of the cycA (cytochrome c) gene was carried out in a diploid strain. Benomyl-induced haploidisation of this diploid yielded all cycA+ haploid colonies, initially suggesting that loss of cycA was indeed lethal. However, use of an alternative unbiased method to recover haploids yielded viable, but slow-growing, cycA- mutants. Replacement of the cycA locus in the cycA- mutants was verified by Southern blotting. Spectral analysis confirmed the absence of detectable levels of cytochrome c, and respiratory insensitivity to @entity3789 suggested the absence of cytochrome c-dependent respiration. Growth parameters were consistent with those expected of a CycA- mutant. Compared to the wild type, the mutants grew slowly on fermentable @entity505 sources, did not grow on non-fermentable @entity505 sources, and produced higher levels of @entity1068 . To our knowledge, this is the first report of a filamentous fungus that remains viable after complete elimination of a functional cytochrome c gene. We propose that the mutants are viable due to their ability to ferment and to use alternative respiratory pathways.

Cytochrome c is not essential for viability of the fungus XXXX .

@entity505 :: ('MESH:D002244', 'Chemical') :: ['carbon'] @entity1068 :: ('MESH:D000431', 'Chemical') :: ['ethanol'] @entity3789 :: ('CHEBI:17514', 'Chemical') :: ['cyanide'] @entity14940 :: ('162425', 'Species') :: ['Aspergillus nidulans']
@entity14940 :: (162425,Species) :: ['Aspergillus nidulans']
