Effects of thetolmutation on allelic interactions athetloci inNeurospora crassa

Genome ◽  
1997 ◽  
Vol 40 (6) ◽  
pp. 834-840 ◽  
Author(s):  
John F. Leslie ◽  
Carl T. Yamashiro
Keyword(s):  
Neurospora Crassa ◽  
Mating Type ◽  
Vegetative Compatibility ◽  
Vegetative Incompatibility ◽  
Type Locus ◽  
Mating Type Locus ◽  
Inneurospora Crassa ◽  
Incompatibility Reactions

A mutant at the tol locus of Neurospora crassa can suppress heterokaryon (vegetative) incompatibility associated with differences at the mating-type locus. We tested the ability of this allele to suppress the vegetative incompatibility reactions that can occur when strains differ at one of nine het loci (het-C, -D, -E, -5, -6, -7, -8, -9, and -10). We found no cases in which the tol mutant suppresses a heteroallelic het locus interaction. Thus, the interaction(s) that leads to vegetative incompatibility because of differences at the mating-type locus is distinct from the interaction(s) that leads to vegetative incompatibility because of differences at any of these nine het loci.Key words: heterokaryon, mating type, vegetative compatibility.

New mutations that suppress mating-type vegetative incompatibility in Neurospora crassa

Genome ◽  
1994 ◽  
Vol 37 (2) ◽  
pp. 249-255 ◽  
Author(s):  
Tia S. Vellani ◽  
Anthony J. F. Griffiths ◽  
N. Louise Glass
Keyword(s):  
Neurospora Crassa ◽  
Mating Type ◽  
Vegetative Incompatibility ◽  
Type Locus ◽  
Regulatory Locus ◽  
Mating Type Locus ◽  
Recessive Mutations ◽  
Incompatibility Locus ◽  
New Alleles ◽  
New Mutations

The mating-type locus in the ascomycete Neurospora crassa functions as a vegetative-incompatibility locus during asexual growth such that A + a heterokaryons and A/a partial diploids are inhibited in their growth. In this study, we sought mutations that suppress mating-type associated vegetative incompatibility by using A/a partial diploids. Mutants were selected as spontaneous escapes from inhibited growth. Suppressors were identified by selecting escapes that retained the capacity to mate with both A and a strains. The escaped partial diploids were then outcrossed to remove the duplication. Seven suppressors were identified that segregated as single, recessive mutations. All seven of the suppressors were shown to be allelic to a previously obtained suppressor, tol, by segregation analyses and heterokaryon tests. This result indicates that all seven mutations are new alleles of tol and suggests that tol is a key regulatory locus in the expression of mating-type associated vegetative incompatibility in N. crassa.Key words: vegetative incompatibility, mating type, suppressors, Neurospora.

A SEARCH FOR COMPLEXITY AT THE MATING-TYPE LOCUS OF NEUROSPORA CRASSA

1973 ◽  
Vol 15 (3) ◽  
pp. 577-585 ◽  
Author(s):  
Dorothy Newmeyer ◽  
H. Branch Howe Jr. ◽  
Donna R. Galeazzi
Keyword(s):  
Neurospora Crassa ◽  
Mating Type ◽  
Adjacent Gene ◽  
Opposite Mating Type ◽  
Type Locus ◽  
Linked Gene ◽  
Heterokaryon Incompatibility ◽  
Mating Type Locus ◽  
Incompatibility Reaction ◽  
The Right

Evidence for complexity at the mating-type locus of Neurospora crassa was sought by selecting recombinants between closely linked markers on either side. All recombinants were tested for crossing ability, to test the hypothesis that the two mating-type alleles are actually closely linked self-sterile mutants; such tests should also detect subunits analogous to the α and β subunits of the A factor of Schizophyllum or Coprinus. No change in crossing ability was found among the 5,019 recombinants tested, representing 235,000 viable ascospores. The results indicate that if subunits exist, they are not more than 0.002 units apart. Twelve hundred and forty of the recombinants were tested in a way that should also have detected subunits analogous to the A and B factors of Schizophyllum and Coprinus, except that A and B would be closely linked. No such subunits were detected.N. crassa strains of opposite mating type are heterokaryon-incompatible during vegetative growth, and observations of various investigators have suggested that the heterokaryon incompatibility might be controlled by a separate closely-linked gene rather than by mating type itself. A sample of the recombinants was therefore tested for separation of the heterokaryon-incompatibility and crossing-compatibility functions. (Heterokaryon-incompatibility was scored by the presence of an incompatibility reaction in duplications heterozygous for mating type; this technique is simple and eliminates complications due to unlinked heterokaryon-incompatibility loci, several of which are known in N. crassa.) No separation was found. The results indicate that if an adjacent gene is responsible for the heterokaryon-incompatibility, it is not more than 0.0078 units from mating type, if on the left, and not more than 0.018 units from mating type, if on the right.

scholarly journals A Second Gene Controlling Allelic Recombination in Neurospora Crassa

1966 ◽  
Vol 19 (6) ◽  
pp. 1039 ◽  
Author(s):  
DG Catoheside
Keyword(s):  
Neurospora Crassa ◽  
Mating Type ◽  
Type Locus ◽  
Mating Type Locus

Experiments to determine whether rec-l, which increases allelic recombinationat the his-l locus in Neurospora crassa, also affects the am locus disclosed anothergene, rec-3. It appears that ree-l is specific to his-l and that ree-3 is specific to am, inthe sense that his-l is insensitive to rec-3 and am is insensitive to ree-l. The locus of rec-l is 18�9 units from the am his-l region; rec-3 is linked either to the am his-l region or to the mating type locus and 12�1 units from the relevant region.

scholarly journals VEGETATIVE INCOMPATIBILITY AND THE MATING-TYPE LOCUS IN THE CELLULAR SLIME MOLD DICTYOSTELIUM DISCOIDEUM

Genetics ◽  
1979 ◽  
Vol 93 (4) ◽  
pp. 861-875
Author(s):  
Gillian E Robson ◽  
Keith L Williams
Keyword(s):  
Dictyostelium Discoideum ◽  
Mating Type ◽  
Genetic Basis ◽  
Slime Mold ◽  
Cellular Slime Mold ◽  
Vegetative Incompatibility ◽  
Type Locus ◽  
Mating Type Locus ◽  
Slime Mold Dictyostelium Discoideum ◽  
Cellular Slime

ABSTRACT The genetic basis of vegetative incompatibility in the cellular slime mold, Dictyostelium discoideum, is elucidated. Vegetatively compatible haploid strains form parasexual diploids at a frequency of between 10-6 and 10-5, whereas "escaped" diploids are formed between vegetatively incompatible strains at a frequency of ~10-8. There is probably only a single vegetative incompatibility site, which appears to be located at, or closely linked to, the mating-type locus. The nature of the vegetative incompatibility is deduced from parasexual diploid formation between wild isolates and tester strains of each mating type, examination of the frequency of formation of "escaped" diploids formed between vegetatively incompatible strains, and examination of the mating type and vegetative incompatibility of haploid segregants obtained from "escaped" diploids.

scholarly journals The Neurospora crassa pheromone precursor genes are regulated by the mating type locus and the circadian clock

2002 ◽  
Vol 45 (3) ◽  
pp. 795-804 ◽  
Author(s):  
Piotr Bobrowicz ◽  
Rebecca Pawlak ◽  
Alejandro Correa ◽  
Deborah Bell-Pedersen ◽  
Daniel J. Ebbole
Keyword(s):  
Circadian Clock ◽  
Neurospora Crassa ◽  
Mating Type ◽  
Type Locus ◽  
Mating Type Locus
Sign in / Sign up

Export Citation Format

Share Document