Mitotic mapping in linkage group V of Aspergillus niger based on selection of auxotrophic recombinants by Novozym enrichment

1989 ◽  
Vol 35 (11) ◽  
pp. 982-988 ◽  
Author(s):  
Alfons J. M. Debets ◽  
Klaas Swart ◽  
Cees J. Bos
Keyword(s):  
Aspergillus Niger ◽  
Linkage Group ◽  
Genetic Analysis ◽  
Chromosome Mapping ◽  
Crossing Over ◽  
Diploid Strain ◽  
Group V ◽  
Clonal Distribution ◽  
Homozygous Diploid ◽  
Selection Of

This paper describes a procedure which allows the quantitative selection of auxotrophs of the fungus Aspergillus niger by enzymatic killing of immobilized germinating prototrophic conidiospores. We have applied this procedure to linkage analysis on the basis of mitotic crossing-over in this fungus. Starting with a heterozygous diploid strain, we could select auxotrophic homozygous diploid recombinants quantitatively. We estimated the frequency of crossing-over after correction for clonal distribution of recombinants, and localized four auxotrophic markers as well as the centromere on chromosome V of this fungus. The Novozym enrichment procedure proved to be useful in genetic analysis and for the construction of recombinant genotypes in the case of closely linked auxotrophic markers. The detemination of gene order and the estimation of distances on the basis of benomyl-induced recombinant haploid segregants may lead to incorrect conclusions. Genetic analysis on the basis of homozygous recombinants, however, can provide reliable estimates of map distances.Key words: Aspergillus niger, chromosome mapping, mitotic crossing-over, Novozym enrichment, auxotrophic recombinants.

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 USE OF NYSTATIN-RESISTANT MUTATIONS IN PARASEXUAL GENETIC ANALYSIS IN DICTYOSTELIUM DISCOIDEUM

Genetics ◽  
1983 ◽  
Vol 104 (2) ◽  
pp. 271-277
Author(s):  
Durgadas P Kasbekar ◽  
Sanford Madigan ◽  
Eugene R Katz
Keyword(s):  
Linkage Group ◽  
Genetic Analysis ◽  
Dictyostelium Discoideum ◽  
Resistance Genes ◽  
Nutrient Agar ◽  
Group V ◽  
Complementation Groups ◽  
Extreme Sensitivity ◽  
Selection Of ◽  
Nystatin Resistance

ABSTRACT Nystatin-resistant mutations exhibit extreme sensitivity to 1.3 mm coumarin. The mutations fall into three complementation groups so it is possible to select for nonallelic mutations conferring sensitivity to coumarin by selection on nystatin-containing nutrient agar plates. Complementation between such coumarin-sensitive mutations allows the selection of diploids on coumarin-containing nutrient agar. Two of the nystatin resistance genes, nysB and nysC, have been mapped tentatively to the previously unmarked linkage group V.

scholarly journals The two-way selection of mutants and revertants in respect of acetate utilization and resistance to fluoro-acetate in Aspergillus nidulans

1965 ◽  
Vol 6 (3) ◽  
pp. 317-329 ◽  
Author(s):  
David Apirion
Keyword(s):  
Linkage Group ◽  
Aspergillus Nidulans ◽  
Group Vi ◽  
Major Pathway ◽  
Group V ◽  
Mutant Strains ◽  
Other Substances ◽  
Acetate Utilization ◽  
A Minor ◽  
Selection Of

An extension of two-way selection (i.e. selection of mutant from wild-type and vice versa within the same locus and with the same efficiency) to four different mutational or segregational situations was made possible by using acetate, fluoro-acetate and other substances related to their metabolism.Two types of mutants resistant to fluoro-acetate were selected, the first of which (designated fac) cannot grow on acetate as the sole carbon source, while the second (designated fan) can.Commencing with either a fac or a fan strain a double fac fan strain may be isolated, which is much more resistant to fluoro-acetate than either single mutant strain. Such double mutant strains may also be obtained by crossing a fac to a fan strain. Various characteristics of growth response of these strains on various media were observed.fac mutants are recessive and map in three meiotically unlinked loci, one in linkage group V and two in linkage group VIII.fan mutants are recessive and map in five loci, one in each of the linkage groups V, VII and VIII, and two linked in linkage group VI.Most fac mutants isolated did not revert and this failure is considered genuine. Of the revertants tested, most resulted from extra-cistron suppressors, while revertants of two fac mutants resulted from very closely linked or intra-cistron suppressors.It is argued that the findings indicate the existence of two pathways for acetate utilization in Aspergillus nidulans, a major and a minor; fac mutants are blocked in the major pathway, fan mutants in the minor pathway.

scholarly journals Genetic analysis of spontaneous half-sectored colonies ofSaccharomyces cerevisiae

1971 ◽  
Vol 18 (2) ◽  
pp. 179-184 ◽  
Author(s):  
J. R. Johnston
Keyword(s):  
Cell Division ◽  
Genetic Analysis ◽  
Mitotic Recombination ◽  
High Rate ◽  
Crossing Over ◽  
Diploid Strain ◽  
Negative Interference ◽  
Low Incidence

SUMMARYGenetic analysis of spontaneous half-sectored colonies of a diploid strain homozygous forade2and heterozygous for linked markersaro1A,hom2,ade8 and trp4was undertaken. Some of these were due to an unexpectedly high rate ofade2reversion and others to a low incidence of haploid sectors. About 50% resulted from mitotic recombination. Only a few were due to mitotic crossing over alone, the majority resulted from non-reciprocal ‘conversion’, including recombination extending over two loosely-linked loci, and some colonies featured both mitotic crossing over and mitotic conversion. The latter indicate that negative interference operates for mitotic recombination. The rate of mitotic recombination forade8, calculated from the frequency of half-sectored colonies was 3·1 × 10−4per cell division.

scholarly journals CHROMOSOME REARRANGEMENTS IN CAENORHABDITIS ELEGANS

Genetics ◽  
1976 ◽  
Vol 83 (1) ◽  
pp. 91-105
Author(s):  
Robert K Herman ◽  
Donna G Albertson ◽  
Sydney Brenner
Keyword(s):  
Linkage Group ◽  
Fluorescence Microscopy ◽  
The Other ◽  
Crossing Over ◽  
Group V ◽  
X Chromosomes ◽  
Recessive Lethal ◽  
C Elegans ◽  
Lethal Mutations ◽  
Chromosome Fragments

ABSTRACT A method for selecting unlinked duplications of a part of the X chromosome of C. elegans is described. Five such duplications have been identified. One of them, Dp(X;V)1, is translocated to linkage group V, where it suppresses crossing over along the left half of linkage group V. Dp(X;V)1 homozygotes grow slowly and are sterile. The other four duplications are associated with chromosome fragments, as observed cytologically by fluorescence microscopy, and tend to be lost. Their frequency of loss is higher in strains homozygous for a mutation that promotes nondisjunction of X chromosomes. The recombination frequencies between two of these duplications and the X have been measured: the frequencies are at least 50 times less than for X-X recombination in the same region. The duplications may prove useful as balancers of recessive lethal mutations.

scholarly journals THE SELECTION OF S. CEREVISIAE MUTANTS DEFECTIVE IN THE START EVENT OF CELL DIVISION

Genetics ◽  
1980 ◽  
Vol 95 (3) ◽  
pp. 561-577 ◽  
Author(s):  
Steven I Reed
Keyword(s):  
Cell Division ◽  
Genetic Analysis ◽  
Linkage Map ◽  
Nuclear Genes ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Mating Pheromone ◽  
Preliminary Characterization ◽  
Complementation Groups ◽  
Selection Of

ABSTRACT Thirty-three temperature-sensitive mutations defective in the start event of the cell division cycle of Saccharomyces cereuisiae were isolated and subjected to preliminary characterization. Complementation studies assigned these mutations to four complementation groups, one of which, cdc28, has been described previously. Genetic analysis revealed that these complementation groups define single nuclear genes, unlinked to one another. One of the three newly identified genes, cdc37, has been located in the yeast linkage map on chromosome IV, two meiotic map units distal to hom2.—Each mutation produces stage-specific arrest of cell division at start, the same point where mating pheromone interrupts division. After synchronization at start by incubation at the restrictive temperature, the mutants retain the capacity to enlarge and to conjugate.

SEX AND CROSSING OVER IN LINKAGE GROUP III OF TRIBOLIUM CASTANEUM

1977 ◽  
Vol 19 (2) ◽  
pp. 259-263 ◽  
Author(s):  
Alexander Sokoloff
Keyword(s):  
Sex Differences ◽  
Linkage Group ◽  
Tribolium Castaneum ◽  
Relative Position ◽  
Genetic Background ◽  
Crossing Over ◽  
Group Iii ◽  
The Third ◽  
Main Factors ◽  
Coleoptera Tenebrionidae

The relative position of the genes black (b), light ocular diaphragm (lod) and aureate (au) for the third linkage group of T. castaneum (Herbst) (Coleoptera, Tenebrionidae) has been determined as b – lod – au. The distances between the various genes vary, depending on the cross. The b++/+ lod au ♂ × + lod au/+ lod au ♀ crosses give the following recombination values: au – lod = 18.32 ± 1.21%; b – lod = 21.05 ± 1.51% and b – au = 37.43 ± 1.27%. The reciprocal crosses give au – lod = 27.67 ± 1.62%; b – lod = 13.97 ± 1.26% and b – au = 39.79 ± 1.78%. For the larger distances encompassed in the b – au region the recombination values in the two sexes were not significantly different. For the shorter b – lod region the recombination values were significantly larger in the females than in the males, while for the adjacent lod – au region the opposite was true. On the basis of the current literature it would appear that the main factors contributing to these sex differences in recombination are the modifiers which are different in the genetic background of the two sexes.

Linkage group analysis in Aspergillus niger

1993 ◽  
Vol 38 (6) ◽  
pp. 742-745 ◽  
Author(s):  
C. J. Bos ◽  
S. M. Slakhorst ◽  
A. J. M. Debets ◽  
K. Swart
Keyword(s):  
Aspergillus Niger ◽  
Linkage Group ◽  
Group Analysis
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