ISSN:
1617-4623
Keywords:
Neurospora crassa
;
Geranylgeranyl pyrophosphate synthase
;
Prenyltransferase
;
Repeat-Induced Point mutation
;
Carotenoid biosynthesis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We have used a biological phenomenon that occurs inNeurospora crassa, termed Repeat-Induced Point mutation (RIP), to create partially functional mutant alleles of thealbino-3 (al-3) gene encoding geranylgeranyl pyrophosphate synthase, an enzyme involved in the biosynthesis of carotenoids and diverse prenylated compounds. A total of 70 RIP-inducedal- 3 mutants were identified by their pale albino phenotype, resulting from inactivation of carotenoid biosynthesis. Nucleotide sequence analysis of theal-3 gene in five of the RIP-induced mutants revealed that in each case RIP had introduced no more than six point mutations. The low frequency of RIP mutants (0.42%) and the isolation of only leaky mutants with very few mutations suggest that ascospores containing a heavily mutatedal-3 gene do not survive. These results are evidence that the RIP phenomenon, used to inactivate and silence duplicated genes inN. crassa, may be exploited in its mild version as a method of sequence-specific in vivo mutagenesis to obtain functional mutant alleles ofNeurospora genes. This mild form of mutagenesis may be particularly advantageous in selecting for leaky mutations in essentialNeurospora genes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02172999
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