GENETICALLY MIXED PERITHECIA AND SOMATIC RECOMBINATION IN A PSEUDO-WILD TYPE STRAIN OF NEUROSPORA CRASSA

1970 ◽  
Vol 12 (3) ◽  
pp. 547-552 ◽  
Author(s):  
A. Radford ◽  
S. F. H. Threlkeld
Keyword(s):  
Linkage Group ◽  
Neurospora Crassa ◽  
Recombination Event ◽  
Type Strain ◽  
Wild Type Strain ◽  
Group Iv ◽  
Wild Type ◽  
Somatic Recombination

In a pseudo-wild heterokaryon of Neurospora, mixed perithecia in a cross in which the heterokaryon is used as the protoperithecial parent may be common. In the present work, 4 out of 22 perithecia contained more than one female nuclear type.A somatic recombinant nucleus, resulting from nondisjunction at anaphase II followed by recombination prior to breakdown of the disomic nucleus has been identified. The recombination event occurred between pyr-1 and tryp-4 on linkage group IV.

Isolation of telomere DNA from Neurospora crassa

1987 ◽  
Vol 7 (9) ◽  
pp. 3168-3177
Author(s):  
M G Schechtman
Keyword(s):  
Linkage Group ◽  
Neurospora Crassa ◽  
Genetic Background ◽  
Type Strain ◽  
Wild Type Strain ◽  
The Other ◽  
Wild Type ◽  
Oak Ridge ◽  
Entire Chromosome ◽  
Different Genetic Background

The most distal known gene on Neurospora crassa linkage group VR, his-6, was cloned. A genomic walk resulted in isolation of the telomere at VR. It was obtained from a library in which the endmost nucleotides of the chromosome had not been removed by nuclease treatment before being cloned, and mapping indicates that the entire chromosome end has probably been cloned. Sequences homologous to the terminal 2.5 kilobases of DNA from VR from these Oak Ridge N. crassa strains are found at other sites in the genome. To characterize these sites, I crossed an Oak Ridge-derived his-6 strain with a wild-type strain of different genetic background (Mauriceville) and characterized the hybridization patterns seen in the progeny. It appears that the sequences homologous to the VR terminus are found at genetically different sites in the two parental strains, and no hybridization to the VR telomere from Mauriceville was detected. The other genomic copies identified in the Oak Ridge parent were not telomeres. I suggest that any repeating sequence blocks found immediately adjacent to the VR terminus in Oak Ridge strains must be small and that the repeating element identified in that background may be an N. crassa transposable element integrated near the the chromosome end at VR.

scholarly journals Isolation of telomere DNA from Neurospora crassa.

1987 ◽  
Vol 7 (9) ◽  
pp. 3168-3177 ◽  
Author(s):  
M G Schechtman
Keyword(s):  
Linkage Group ◽  
Neurospora Crassa ◽  
Genetic Background ◽  
Type Strain ◽  
Wild Type Strain ◽  
The Other ◽  
Wild Type ◽  
Oak Ridge ◽  
Entire Chromosome ◽  
Different Genetic Background

The most distal known gene on Neurospora crassa linkage group VR, his-6, was cloned. A genomic walk resulted in isolation of the telomere at VR. It was obtained from a library in which the endmost nucleotides of the chromosome had not been removed by nuclease treatment before being cloned, and mapping indicates that the entire chromosome end has probably been cloned. Sequences homologous to the terminal 2.5 kilobases of DNA from VR from these Oak Ridge N. crassa strains are found at other sites in the genome. To characterize these sites, I crossed an Oak Ridge-derived his-6 strain with a wild-type strain of different genetic background (Mauriceville) and characterized the hybridization patterns seen in the progeny. It appears that the sequences homologous to the VR terminus are found at genetically different sites in the two parental strains, and no hybridization to the VR telomere from Mauriceville was detected. The other genomic copies identified in the Oak Ridge parent were not telomeres. I suggest that any repeating sequence blocks found immediately adjacent to the VR terminus in Oak Ridge strains must be small and that the repeating element identified in that background may be an N. crassa transposable element integrated near the the chromosome end at VR.

scholarly journals Mutation of the cys-9 Gene, Which Encodes Thioredoxin Reductase, Affects the Circadian Conidiation Rhythm in Neurospora crassa

Genetics ◽  
1997 ◽  
Vol 146 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Kiyoshi Onai ◽  
Hideaki Nakashima
Keyword(s):  
Neurospora Crassa ◽  
Type Strain ◽  
Temperature Compensation ◽  
Wild Type Strain ◽  
Thioredoxin Reductase ◽  
Period Length ◽  
Phase Shifting ◽  
Wild Type ◽  
Partial Loss ◽  
Continuous Darkness

Ten cysteine auxotrophs of Neurospora crassa were examined with regard to the period lengths of their circadian conidiation rhythms. One of the these cysteine auxotrophs, cys-9, showed dramatic changes in the circadian conidiation rhythm. At 10 μm methionine, the cys-9 mutant had a period length that was 5 hr shorter than that of the wild-type strain during the first 3 days after transfer to continuous darkness. At this concentration of methionine, the period length was unstable after the fourth day and varied widely from 11 to 31 hr. In contrast, other cysteine auxotrophs did not show such instability of the period length at any of the concentrations of methionine tested. Furthermore, only the cys-9 mutant exhibited partial loss of the capacity for temperature compensation of the period length. With regard to cold-induced phase-shifting of the circadian conidiation rhythm, the cys-9 mutant was more sensitive than the wild-type strain to low temperature. The cys-9  + gene was cloned and was found to encode NADPH-dependent thioredoxin reductase. These results indicate that mutation of the gene for thioredoxin reductase results in abnormal expression of the circadian conidiation rhythm in N. crassa.

scholarly journals Interrelationships in trace-element metabolism in metal toxicities in nickel-resistant strains of Neurospora crassa

1983 ◽  
Vol 212 (1) ◽  
pp. 205-210 ◽  
Author(s):  
P Maruthi Mohan ◽  
K Sivarama Sastry
Keyword(s):  
Neurospora Crassa ◽  
Metal Ion ◽  
Type Strain ◽  
Heavy Metal Ions ◽  
Wild Type Strain ◽  
The Other ◽  
Wild Type ◽  
Resistant Strains ◽  
Trace Element Metabolism ◽  
Very High

Three different Ni2+-resistant strains of Neurospora crassa (NiR1, NiR2 and NiR3) have been isolated. All are stable mutants and are fourfold more resistant to Ni2+ than the parent wild-type strain. NiR1 and NiR2 are also sixfold more resistant to Co2+, whereas NiR3 is only twice as resistant to Co2+; the former two are also twofold more resistant to Zn2+, but NiR3 is not. These three strains also differ in sensitivity to Cu2+. Toxicities and concomitant accumulation patterns of Ni2+, Co2+ and Cu2+ have been examined in these strains. NiR1 and NiR2, despite quantitative individual differences, generally accumulate very high amounts of Ni2+ and Co2+, and Mg2+ reverses the toxicities of these two ions by different mechanisms; Ni2+ uptake is suppressed, but not that of Co2+. In NiR3, Mg2+ controls uptake of both Ni2+ and Co2+. Studies indicate that two kinds of Ni2+-resistant strains of N. crassa exist; one kind is resistant because it can tolerate high intracellular concentrations of heavy-metal ions, whereas the other is resistant because it can control metal-ion accumulation.

scholarly journals The effect of thiourea on ureide metabolism in Neurospora crassa

1973 ◽  
Vol 136 (3) ◽  
pp. 749-755 ◽  
Author(s):  
Jasti Nirmala ◽  
Killampalli Sivarama Sastry
Keyword(s):  
Neurospora Crassa ◽  
Nitrogen Source ◽  
Type Strain ◽  
Wild Type Strain ◽  
Inorganic Nitrogen ◽  
Wild Strain ◽  
Sole Nitrogen Source ◽  
Wild Type ◽  
Selective Toxicity ◽  
In The Wild

The wild-type strain of Neurospora crassa Em 5297a can utilize allantoin as a sole nitrogen source. The pathway of allantoin utilization is via its conversion into allantoic acid and urea, followed by the breakdown of urea to ammonia. This is shown by the inability of the urease-less mutant, N. crassa 1229, to grow on allantoin as a sole nitrogen source and by the formation of allantoate and urea by pre-formed mycelia of this mutant. In the wild strain (Em 5297a) thiourea is tenfold more toxic on an allantoin medium than on an inorganic nitrogen medium; allantoin as well as urea counteract thiourea toxicity in the allantoin nitrogen medium. This selective toxicity of thiourea for the mould utilizing allantoin nitrogen does not, however, result in an impairment of allantoin uptake, allantoinase activity or the formation of urea from allantoin. The only process affected by thiourea is the synthesis of urease; urea antagonizes this effect of thiourea in N. crassa.

scholarly journals Preparation of a cell-free translation system from a wild-type strain of Neurospora crassa

1988 ◽  
Vol 13 (4) ◽  
pp. 323-326 ◽  
Author(s):  
M. Devchand ◽  
F. P. Buxton ◽  
D. I. Gwynne ◽  
R. W. Davies
Keyword(s):  
Neurospora Crassa ◽  
Type Strain ◽  
Wild Type Strain ◽  
Translation System ◽  
Wild Type ◽  
Free Translation ◽  
A Cell

EVIDENCE OF A MICROSOMAL FACTOR REQUIRED FOR IN VITRO DEVELOPMENT OF PSEUDO-TRYPTOPHAN SYNTHASE ACTIVITY BY EXTRACTS OF NEUROSPORA CRASSA

1966 ◽  
Vol 44 (1) ◽  
pp. 77-83 ◽  
Author(s):  
S. D. Wainwright
Keyword(s):  
Neurospora Crassa ◽  
Type Strain ◽  
Wild Type Strain ◽  
Enzymic Activity ◽  
Tryptophan Synthase ◽  
Wild Type ◽  
In Vitro Development ◽  
Microsome Fraction ◽  
Vitro Development

Extracts of conidia of the td3 mutant strain of Neurospora crassa did not develop pseudo-tryptophan synthase enzyme activity under conditions leading to formation of the activity by equivalent extracts of the wild type strain. The defect in extracts of the td3 mutant appears to be located in the microsome fraction. The latter is unable to interact effectively with a component of the td3 mutant "post-microsome" fraction which will support in vitro development of the enzymic activity when supplemented with microsomes from other strains of N. crassa.

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