scholarly journals Genetic analysis of an unequal chromosomal translocation in Aspergillus nidulans

1970 ◽  
Vol 15 (3) ◽  
pp. 317-326 ◽  
Author(s):  
B. W. Bainbridge
Keyword(s):  
Linkage Group ◽  
Genetic Analysis ◽  
Aspergillus Nidulans ◽  
Genetic Markers ◽  
Chromosomal Translocation ◽  
Group Viii ◽  
Linkage Groups ◽  
Group Iii ◽  
Attachment Point ◽  
Breakage Point

SUMMARYTranslocation T(III–VIII) in Aspergillus nidulans has been analysed by the detection of meiotic linkage between markers previously located separately on linkage groups III and VIII. The breakage points have been mapped by the detection of linkage between the crinkled type and genetic markers in the region of the break. A segment from linkage group III, approximately 43 units long and including the markers moC96, sC12, sA1 and cnxH3, has been translocated into linkage group VIII. The breakage point is between su6proA and moC96 and the attachment point is close to cha in linkage group VIII. It seems probable that the segment has been inserted into linkage group VIII.

scholarly journals A variegated position effect in Aspergillus nidulans

1970 ◽  
Vol 16 (3) ◽  
pp. 303-316 ◽  
Author(s):  
A. J. Clutterbuck
Keyword(s):  
Linkage Group ◽  
Aspergillus Nidulans ◽  
Position Effect ◽  
Attachment Site ◽  
Low Ph ◽  
Original Strain ◽  
Salt Medium ◽  
Group Viii ◽  
Distal Half ◽  
Group Iii

SUMMARYIn mutants at the ‘bristle’ locus of Aspergillus nidulans the conidiophore remains as a stiff hypha rather than developing a vesicle, sterigmata and conidia. The brlA 12 allele of this locus has a variegated phenotype, and genetic analysis has shown that this is associated with a translocation which has a breakpoint in the map interval adjacent to the bristle locus.The mutant phenotype is partially repaired on high-salt medium at low pH, and can also be repaired by suppressors, one of which has been mapped at a locus unlinked to brlA 12.The mutant provides proof that variegation is due to instability of gene expression and not to mutability since brlA 12 is genetically stable and can be propagated from either conidia or sterile conidiophores, the structures formed at the two extremes of variegation, and the resulting colonies in both cases are identical to the original strain.It has been shown by mitotic recombination that the translocation associated with the variegated mutant is a ‘simple translocation’ in which the distal half of linkage group VIII is attached to the end of linkage group III. This terminal attachment site does not appear to be damaged in any genetically detectable way.

Genetic analysis of two mutations affecting thymidine metabolism in Dictyostelium discoideum.

Genetics ◽  
1988 ◽  
Vol 120 (4) ◽  
pp. 959-964
Author(s):  
C E Bronner ◽  
D L Welker ◽  
R A Deering
Keyword(s):  
Linkage Group ◽  
Genetic Analysis ◽  
Dictyostelium Discoideum ◽  
Thymidylate Synthase ◽  
Nucleoside Analog ◽  
Linkage Groups ◽  
Group Iii ◽  
Auxotrophic Requirement ◽  
Thymidine Auxotrophy

Abstract The tmpA600 mutation confers thymidylate synthase deficiency and thymidine auxotrophy to Dictyostelium discoideum. The tdrA600 mutation enhances transport of thymidine and thereby reduces the auxotrophic requirement of tmpA600 strains. The tmpA locus maps to linkage group III. The tdrA600 mutation is dominant and cosegregates with both linkage groups IV and VI, possibly because of a translocation between the two. The tdrA600 allele is sufficient to allow efficient incorporation of exogenous [3H]thymidine or [3H]uridine into TCA-precipitable material and to sensitize the cell to the nucleoside-analog inhibitor, 5-fluorodeoxyuridine. These properties make the tdrA mutation useful for studies requiring labelling of DNA or RNA in vivo.

scholarly journals Centromere-Linkage Analysis and Consolidation of the Zebrafish Genetic Map

Genetics ◽  
1996 ◽  
Vol 142 (4) ◽  
pp. 1277-1288
Author(s):  
Stephen L Johnson ◽  
Michael A Gates ◽  
Michele Johnson ◽  
William S Talbot ◽  
Sally Horne ◽  
...  
Keyword(s):  
Linkage Group ◽  
Linkage Analysis ◽  
Genetic Analysis ◽  
Linkage Map ◽  
Rapid Method ◽  
Genetic Map ◽  
Dna Polymorphisms ◽  
Linkage Groups

Abstract The ease of isolating mutations in zebrafish will contribute to an understanding of a variety of processes common to all vertebrates. To facilitate genetic analysis of such mutations, we have identified DNA polymorphisms closely linked to each of the 25 centromeres of zebrafish, placed centromeres on the linkage map, increased the number of mapped PCR-based markers to 652, and consolidated the number of linkage groups to the number of chromosomes. This work makes possible centromere-linkage analysis, a novel, rapid method to assign mutations to a specific linkage group using half-tetrads.

scholarly journals Genetic analysis of the phosphatases in Aspergillus nidulans

1965 ◽  
Vol 6 (1) ◽  
pp. 13-26 ◽  
Author(s):  
G. Dorn
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Genetic Analysis ◽  
Aspergillus Nidulans ◽  
Alkaline Ph ◽  
Wild Type ◽  
Linkage Groups ◽  
Partial Restoration ◽  
Suppressor Mutations ◽  
Alkaline And Acid Phosphatase

Summary1. A histochemical method has been applied to the detection of alkaline and acid phosphatase mutants in single colonies of Aspergillus nidulans.2. With the above method it has been possible to isolate mutants in which the alkaline and acid phosphatase activities are affected either separately or simultaneously.3. Crude extracts of wild-type A. nidulans contain four electrophoretically distinct phosphatase components, two with activity at alkaline pH and two with activity at acid pH. Genes affecting three of the four components have been identified.4. Two suppressor mutants of an alkaline phosphataseless mutant (palB7) have been isolated. In a strain carrying palB7 and one of these suppressors, the restoration of an alkaline phosphatase component is accompanied by loss of the faster acid phosphatase component. In a similar strain carrying the other suppressor, the partial restoration of the alkaline phosphatase component goes with an electrophoretic alteration of the slower acid phosphatase component.5. Genetic analysis of twenty-seven mutants has resulted in the identification of fifteen loci affecting the phosphatases. All these loci have been assigned to linkage groups, and twelve of them were also mapped meiotically in relation to other loci.6. One possible model (based on heteropolymeric proteins) has been proposed to account for the electrophoretic and genetic data on the various phosphatase and suppressor mutations.

A CROSSOVER SUPPRESSOR-ENHANCER SYSTEM IN THE MOSQUITO AEDES AEGYPTI

1971 ◽  
Vol 13 (3) ◽  
pp. 561-577 ◽  
Author(s):  
Satish C. Bhalla
Keyword(s):  
Linkage Group ◽  
Reciprocal Translocation ◽  
Paracentric Inversion ◽  
Chromosome 1 ◽  
Crossing Over ◽  
Linkage Groups ◽  
Group Iii ◽  
Partial Sterility ◽  
The Right ◽  
And Inversion

A small reciprocal translocation T(1;2)1 involving chromosomes 1 and 2 and a paracentric inversion In(1)3 on m chromosome (1) of A. aegypti interact to give peculiar but consistent crossover values. The system is termed COSES and is associated with partial sterility. In females it suppresses crossing over tremendously to the right of bz and enhances crossing over to its left. In the males it enhances crossing over to the right of m (only 3 crossover units away from bz) hut the region to its left remains unaffected. COSES also displays interchromosomal effects by enhancing crossing over in linkage group III. Cytological and genetic evidence for the presence of translocation and inversion are presented. All three pairs of chromosomes are correlated to the three linkage groups.

Genetics of Glossina palpalis palpalis: designation of linkage groups and the mapping of eight biochemical and visible marker genes

Genome ◽  
1995 ◽  
Vol 38 (5) ◽  
pp. 833-837 ◽  
Author(s):  
R. H. Gooding ◽  
B. M. Rolseth
Keyword(s):  
Linkage Group ◽  
Recombination Frequency ◽  
Marker Genes ◽  
Glossina Palpalis Palpalis ◽  
Linkage Groups ◽  
Group Iii ◽  
Eye Color ◽  
Eye Color Mutants ◽  
Octanol Dehydrogenase ◽  
Glossina Palpalis

The loci for three enzymes (hexokinase, phosphoglucomutase, and testicular esterase) and two eye-color mutants (brick and tan) are mapped on the X chromosome of Glossina palpalis palpalis. The loci occur in the order brick Hex (tan/Pgm) Est-t, with a recombination frequency of approximately 78% between the outer two loci. The locus for octanol dehydrogenase is located in linkage group II and the loci for malate dehydrogenase and phosphoglucose isomerase are separated by a recombination frequency of about 42.5% in linkage group III. Intrachromosomal recombination occurs at a much lower frequency in males than in females. The distribution of five biochemical marker genes in the linkage groups of G. p. palpalis is markedly different from that found in other higher flies.Key words: tsetse, Glossina palpalis palpalis, linkage map.

GENETIC AND ACCUMULATION STUDIES IN SULFITE-REQUIRING MUTANTS OFASPERGILLUS NIDULANS

1970 ◽  
Vol 12 (4) ◽  
pp. 831-840 ◽  
Author(s):  
R. A. Gravel ◽  
E. Käfer ◽  
A. Niklewicz-Borkenhagen ◽  
P. Zambryski
Keyword(s):  
Linkage Group ◽  
Genetic Mapping ◽  
Aspergillus Nidulans ◽  
Sulfur Metabolism ◽  
The Other ◽  
Group Viii ◽  
Sulfate Transport ◽  
New Genes ◽  
Ofaspergillus Nidulans ◽  
Induced Mutants

Using complementation tests and genetic mapping, mutants of two new genes, sE (sulfite less) and sF (thiosulfateless) were identified among 145 nitroso-guanidine-induced mutants of the sulfur metabolism in Aspergillus nidulans. Most of the other mutants (134) turned out to be alleles of the four established 'sulfite' genes, sA - sD. The new genes were found to be unlinked to any other s-gene; sE was mapped in linkage group VIII distal to cha and sF in VII. Mapping of several mutants allelic to one or the other of the closely linked sA or sC genes showed that these loci are two cistrons 1.1 cMo units apart.Results from studies using radioactive sulfate as a substrate for the different mutants showed35S-accumulation profiles by electrophoresis consistent with the assignment of the five sulfite genes to the following steps: sB(3), sulfate transport; sC(12), sulfurylation of ATP to produce APS; sD(50 or 205), phosphorylation of APS to PAPS; and sA(6) and sE(15), PAPS reduction to sulfite. Although the last two genes appear to control the same step, their35S-accumulation profiles are distinct. In addition, it was found that mutants of all previously established genes, including sA, are epistatic to sE(15) when single and double mutants are tested for resistance on selenate medium.

scholarly journals Genetic analysis by means of the parasexual cycle in Aspergillus niger

1967 ◽  
Vol 10 (1) ◽  
pp. 45-61 ◽  
Author(s):  
Pol Lhoas
Keyword(s):  
Aspergillus Niger ◽  
Linkage Group ◽  
Genetic Analysis ◽  
Sexual Cycle ◽  
Crossing Over ◽  
Linkage Groups ◽  
Parasexual Cycle ◽  
Sexual Species ◽  
Data Support ◽  
Almost All

An investigation of mitotic segregation and recombination in A. niger gave the following results:1. Thirty-one non-allelic markers have been assigned to six linkage groups (containing 11, 9, 6, 3, 1 and 1 markers respectively) by the analysis of haploid mitotic segregants from synthesized diploids.2. The sequence of nine markers in one linkage group was determined and some of the map intervals were estimated by the analysis of haploids, recombinants for linked markers.3. Almost all the haploid segregants were obtained on medium supplemented with the aminoacid analogue, p-fluoro-phenylalanine, the action of which is interpreted as an induction of chromosome losses.4. The rates of mitotic crossing-over and haploidization are much higher than in the sexual species A. nidulans and the data support Pontecorvo's (1958) suggestion that the parasexual cycle can be a substantial alternative to the sexual cycle.

scholarly journals The regulation of NADL-glutamate dehydrogenase inAspergillus nidulans

1974 ◽  
Vol 23 (1) ◽  
pp. 119-124 ◽  
Author(s):  
J. R. Kinghorn ◽  
J. A. Pateman
Keyword(s):  
Amino Acids ◽  
Linkage Group ◽  
Carbon Source ◽  
Glutamate Dehydrogenase ◽  
Aspergillus Nidulans ◽  
Dehydrogenase Activity ◽  
Carbon Sources ◽  
Wild Type ◽  
Group Iii ◽  
Glutamate Dehydrogenase Activity

SummaryWild-type cells ofAspergillus nidulanshave undetectable NADL-glutamate dehydrogenase activity when utilizing glucose and high levels of NADL-glutamate dehydrogenase when utilizing certain amino acids as sole carbon sources.A mutant, designatedgdhCl, has appreciable NAD-GDH activity when utilizing glucose as a carbon source. ThegdhC1mutation is semi-dominant and is located in linkage group III.

scholarly journals Altered instability due to genetic changes in a duplication strain of Aspergillus nidulans

1975 ◽  
Vol 26 (1) ◽  
pp. 55-61 ◽  
Author(s):  
J. L. Azevedo
Keyword(s):  
Aspergillus Nidulans ◽  
Original Strain ◽  
Group Viii ◽  
Linkage Groups ◽  
Diploid Strain ◽  
Duplicate Segment ◽  
Recessive Factor ◽  
Genetic Changes ◽  
Genetic Mechanisms ◽  
Ultraviolet Treatment

SUMMARYStrains of Aspergillus nidulans with a duplicate segment are mitotically unstable; they produce phenotypically improved variants following deletions in either duplicate segment, and morphologically deteriorated types. The number of variants produced is characteristic of each duplication strain under the same conditions. After ultraviolet treatment two variants, one more stable and the other less stable than the original strain, were selected. Genetic analysis showed that the increased instability in the less stable variant was due to a translocation involving linkage groups V and VIII. The increased stability of the more stable variant was due to a recessive factor (stf–1) located in linkage group VIII. In the homozygous condition this factor also reduces the number of sectors in a diploid strain. The possible genetic mechanisms explaining the instability alterations are discussed.

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