ISSN:
1617-4623
Keywords:
Key words Neurospora
;
Mating type
;
Mutations
;
Heterokaryon incompatibility
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The 293-amino acid mt A-1 ORF of the A mating-type idiomorph of Neurospora crassa is multifunctional. It confers A mating identity and is responsible for heterokaryon incompatibility. The goal of this study was to dissect the functional regions of mt A-1. New mutants of mt A-1 selected for loss of the incompatibility function were obtained. One new mutant, A m99 , was partially fertile as a maternal parent. This is the first time that fertility and incompatibility functions have been separated for the A idiomorph. In this mutant, the mt A-1 ORF is truncated after the first 85 amino acids, indicating that this N-terminal region is minimally sufficient for female fertility. A series of deletion constructs and frameshift alleles of mt A-1 was obtained and tested for male-mating activity and vegetative incompatibility in transformation experiments. These experiments showed that a region from position 1 to 111 is sufficient to confer incompatibility, while amino acids from position 1 to 227 are required for mating activity. A transcriptional analysis of mt A-1 showed that the mRNA is expressed both before and after fertilization. This, together with the phenotype of the A m99 mutant, suggests a post-fertilization function for mt A-1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02191831
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