GENETIC AND COMPLEMENTATION STUDIES OF A NEW CAROTENOID MUTANT OF NEUROSPORA CRASSA

1968 ◽  
Vol 10 (2) ◽  
pp. 351-356 ◽  
Author(s):  
R. E. Subden ◽  
S. F. H. Threlkeld
Keyword(s):  
Linkage Group ◽  
Neurospora Crassa ◽  
Biosynthetic Pathway ◽  
Group I ◽  
The Right

A spontaneously occurring mutant called "yellow b" has been isolated and mapped on the right arm of linkage group I in Neurospora crassa 0.15 c.o.u. distal to aur and 2 c.o.u. distal to al-2. These three markers complement each other and are involved in the same biosynthetic pathway.

scholarly journals Determination of the inactivating alterations in two mutant alleles of the Neurospora crassa cross-pathway control gene cpc-1.

Genetics ◽  
1990 ◽  
Vol 124 (3) ◽  
pp. 599-606
Author(s):  
J L Paluh ◽  
M Plamann ◽  
D Krüger ◽  
I B Barthelmess ◽  
C Yanofsky ◽  
...  
Keyword(s):  
Amino Acid ◽  
Linkage Group ◽  
Neurospora Crassa ◽  
Group Vi ◽  
Group I ◽  
Base Pair Deletion ◽  
Single Base Pair ◽  
Activating Transcription Factor ◽  
Global Increase ◽  
The Right

Abstract cpc-1 is the locus specifying what is believed to be the major trans-activating transcription factor that regulates expression of amino acid biosynthetic genes subject to cross-pathway control in Neurospora crassa. Mutants altered at this locus are incapable of the global increase in gene expression normally seen in response to amino acid starvation. Using polymerase chain reaction methodology we have cloned and sequenced the inactive mutant allele, cpc-1 (CD15). The cpc-1 (CD15) mutation was found to be a single base pair deletion in codon 93 of the cpc-1 structural gene. A second, presumed lethal, allele, cpc-1 (j-5), also was investigated. Northern analyses with strains carrying the cpc-1 (j-5) allele revealed that no cpc-1 mRNA is produced. Southern and genetic analyses established that the cpc-1 (j-5) mutation involved a chromosomal rearrangement in which a break occurred within the cpc-1 locus, normally resident on linkage group VI; a small fragment from the left arm of linkage group VI, containing the cpc-1 promoter region and ylo-1, was translocated to the right arm of linkage group I. Other studies indicate that the cpc-1 locus itself is not essential for viability. Lethality previously attributed to the cpc-1 (j-5) mutation is due instead to the production of progeny that are deficient for essential genes in an adjoining segment of linkage group VI. Molecular characterization of cpc-1 (j-5) x ylo-1 pan-2 duplication progeny indicated that cpc-1 is normally transcribed towards the linkage group VI centromere.

scholarly journals COMPLEMENTATION ANALYSIS OF LINKED CIRCADIAN CLOCK MUTANTS OF NEUROSPORA CRASSA

Genetics ◽  
1976 ◽  
Vol 82 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Jerry F Feldman ◽  
Marian N Hoyle
Keyword(s):  
Linkage Group ◽  
Circadian Clock ◽  
Neurospora Crassa ◽  
Period Length ◽  
Complementation Analysis ◽  
Wild Type ◽  
The Right

ABSTRACT A fourth mutant of Neurospora crassa, designated frq-4, has been isolated in which the period length of the circadian conidiation rhythm is shortened to 19.3 ± 0.3 hours. This mutant is tightly linked to the three previously isolated frq mutants, and all four map to the right arm of linkage group VII about 10 map units from the centromere. Complementation tests suggest, but do not prove, that all four mutations are allelic, since each of the four mutants is co-dominant with the frq  + allele—i.e., heterokaryons have period lengths intermediate between the mutant and wild-type—and since heterokaryons between pairs of mutants also have period lengths intermediate between those of the two mutants.

Recombinational landscape across a 650-kb contig on the right arm of linkage group V in Neurospora crassa

1999 ◽  
Vol 36 (5) ◽  
pp. 270-274 ◽  
Author(s):  
Frederick J. Bowring ◽  
David E. A. Catcheside
Keyword(s):  
Linkage Group ◽  
Neurospora Crassa ◽  
Group V ◽  
The Right

scholarly journals Correlation of the physical and genetic maps of the centromeric region of the right arm of linkage group III of Neurospora crassa.

Genetics ◽  
1994 ◽  
Vol 136 (4) ◽  
pp. 1297-1306
Author(s):  
C R Davis ◽  
R R Kempainen ◽  
M S Srodes ◽  
C R McClung
Keyword(s):  
Linkage Group ◽  
Neurospora Crassa ◽  
Fragment Length Polymorphism ◽  
Centromeric Region ◽  
Recombination Frequency ◽  
Genetic Maps ◽  
Polymorphism Analysis ◽  
Group Iii ◽  
Sib Selection ◽  
The Right

Abstract We have cloned three linked genes serine-1 (ser-1), proline-1 (pro-1) and acetate-2 (ace-2) that lie near the centromere on the right arm of linkage group III (LGIIIR) of Neurospora crassa. The ser-1 gene was cloned by sib selection. A chromosomal walk that spans 205 kilobases (kb) was initiated from ser-1. Complementation analysis with clones isolated during the walk allowed identification of the pro-1 and ace-2 genes. Restriction fragment length polymorphism analysis has confirmed the localization of ser-1, pro-1 and ace-2 to the centromeric region of LGIIIR. Genetically, we measured 1% recombination between ser-1 and pro-1 and 2% recombination between pro-1 and ace-2. Physical distances for these intervals were 114 kb from ser-1 to pro-1 and 36 kb from pro-1 to ace-2. Thus, for the pro-1 to ace-2 interval we calculate a physical/genetic correlation of 18 kb/map unit (mu) whereas, in the immediately adjacent, centromere-proximal interval from ser-1 to pro-1, we calculate 114 kb/mu. This provides evidence for a centromere effect, a decrease in recombination frequency as one approaches the centromere.

Cloning, sequence, and photoregulation of al-1, a carotenoid biosynthetic gene of Neurospora crassa

1990 ◽  
Vol 10 (10) ◽  
pp. 5064-5070
Author(s):  
T J Schmidhauser ◽  
F R Lauter ◽  
V E Russo ◽  
C Yanofsky
Keyword(s):  
Linkage Group ◽  
Neurospora Crassa ◽  
Carotenoid Biosynthesis ◽  
Mrna Levels ◽  
Biosynthetic Gene ◽  
Biosynthetic Enzyme ◽  
Group I ◽  
Phytoene Dehydrogenase ◽  
Initiation Of Transcription ◽  
Residue Polypeptide

Carotenoid biosynthesis is regulated by blue light during growth of Neurospora crassa mycelia. We have cloned the al-1 gene of N. crassa encoding the carotenoid-biosynthetic enzyme phytoene dehydrogenase and present an analysis of its structure and regulation. The gene encodes a 595-residue polypeptide that shows homology to two procaryotic carotenoid dehydrogenases. RNA measurements showed that the level of al-1 mRNA increased over 70-fold in photoinduced mycelia. Transcription run-on studies indicated that the al-1 gene was regulated at the level of initiation of transcription in response to photoinduction. The photoinduced increase of al-1 mRNA levels was not observed in two Neurospora mutants defective in all physiological photoresponses. Analysis of cosmid containing al-1 and of a translocation strain with a breakpoint within al-1 indicated that al-1 transcription proceeds towards the centromere of linkage group I of N. crassa.

scholarly journals Location of factors enhancing crossing over on linkage group I of Neurospora

1973 ◽  
Vol 21 (2) ◽  
pp. 195-204
Author(s):  
Jenny Hargrave ◽  
S. F. H. Threlkeld
Keyword(s):  
Linkage Group ◽  
Distal Region ◽  
Proximal Region ◽  
Crossing Over ◽  
Group I ◽  
The Right

SUMMARYAn enhancement of cross-over frequencies previously reported by Newcombe & Threlkeld (1972) is shown to be due to two regions located on linkage group I, a few cross-over units to the right of the centromere. The distal region appears to be shorter than the proximal region, but equally effective in enhancing cross-over frequencies. The longer proximal region is readily divisable by cross-overs and probably spans several crossover units.

NULL MUTANTS OF THE A AND a MATING TYPE ALLELES OF NEUROSPORA CRASSA

1982 ◽  
Vol 24 (2) ◽  
pp. 167-176 ◽  
Author(s):  
A. J. F. Griffiths
Keyword(s):  
Linkage Group ◽  
Neurospora Crassa ◽  
Uv Irradiation ◽  
Mating Type ◽  
Opposite Mating Type ◽  
Extended Study ◽  
Fundamental Properties ◽  
Group I ◽  
Sexual Compatibility ◽  
Null Mutants

Thirty-five null mutants have now been obtained of the A mating type allele, which have simultaneously lost both known functions-heterokaryon incompatibility and sexual compatibility with strains of the opposite mating type, a. The mutants, designated Am, were obtained by selecting for heterokaryon compatibility following UV-irradiation of the normal A. Twenty-five of the mutations were viable as homokaryons. Both functions reverted together when two of these were irradiated. In most respects, Am mutations resemble the previously reported am mutations in their behavior. The Am mutations differ, however, in failing to produce illegitimate empty perithecia in crosses with testers of the same mating type from which they originated. — The previously obtained am mutants were characterized further. It was confirmed that these am mutants show abortive mating reactions, legitimate and illegitimate, with several tester strains, thus showing that such reactions are fundamental properties of the mutants themselves. In support of this, it was shown that the A-like behavior of am strains in the illegitimate reaction is not due to acquisition of determining elements through cytoplasmic contact with A in heterokaryons. It is possible that the sterile am mutants can be carried through a cross by a fertile heterokaryotic partner, but an extended study of meiotic products presumed to stem from this process confirmed that if such a process occurs it can involve no recombination on linkage group I. The single fertile am mutant was shown to have normal recombination on L.G.I. Escape from (A + a) incompatibility was shown to be possible in the identical heterokaryon used for am induction. Escape cannot be ruled out as a source of nonrecoverable am mutations.

scholarly journals Interspecific crosses and crossing-over in Neurospora

1972 ◽  
Vol 19 (2) ◽  
pp. 115-119 ◽  
Author(s):  
K. D. Newcombe ◽  
S. F. H. Threlkeld
Keyword(s):  
Linkage Group ◽  
Neurospora Crassa ◽  
Interspecific Crosses ◽  
Crossing Over ◽  
Centromere Region ◽  
Group I

SUMMARYThrough a series of backcrosses the centromere region of linkage group I of Neurospora crassa was transferred to the N. sitophila genome, and through another series of backcrosses the centromere region of linkage group I of N. sitophila was transferred to N. crassa. Strains thus synthesized showed, in further crosses, that the N. sitophila centromere region acts as a dominant enhancer of cross-over frequencies across linkage group I of the two species.

AN INTERSTITIAL PERICENTRIC INVERSION IN NEUROSPORA

1982 ◽  
Vol 24 (6) ◽  
pp. 693-703 ◽  
Author(s):  
Edward G. Barry ◽  
John F. Leslie
Keyword(s):  
Linkage Group ◽  
Neurospora Crassa ◽  
Gene Order ◽  
Pericentric Inversion ◽  
Inverted Segment ◽  
Chromosome Inversions ◽  
Central Segment ◽  
Group I ◽  
Higher Eukaryotes ◽  
Inversion Loop

In ln(IL; IR)OY323 of Neurospora crassa, a long central segment of linkage group I is inverted that includes the centromere. This is the first interstitial pericentric inversion to be identified in a fungus. In genetic and cytological behavior, it resembles chromosome inversions in higher eukaryotes. In crosses heterozygous for the OY323 inversion, normally distant markers are closely linked, while in homozygous inversion crosses the gene order is reversed, but recombination is approximately normal within the inverted segment. A characteristic inversion loop may form at pachytene in heterozygous crosses; frequently, segments distal to the breakpoints do not pair, however. Rearrangement breakpoints were mapped precisely by duplication coverage using appropriate recessive markers in crosses of OY323 with a partially overlapping inversion, In(IL→IR)NM176.

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