Genetic analysis and the construction of master strains for assignment of genes to six linkage groups in Aspergillus niger

1988 ◽  
Vol 14 (5) ◽  
pp. 437-443 ◽  
Author(s):  
C. J. Bos ◽  
A. J. M. Debets ◽  
K. Swart ◽  
A. Huybers ◽  
G. Kobus ◽  
...  
1967 ◽  
Vol 10 (1) ◽  
pp. 45-61 ◽  
Author(s):  
Pol Lhoas

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.


Genetics ◽  
1981 ◽  
Vol 99 (3-4) ◽  
pp. 415-428
Author(s):  
Raja E Rosenbluth ◽  
David L Baillie

ABSTRACT The Caenorhabditis elegans mutation e873, which results in a recessive uncoordinated phenotype (formerly named Unc-72) and which had been isolated after 32P t reatment (BRENNER1 974), has now been found to act as a crossover suppressor and to be associated with a translocation between linkage groups (LG's) IIIand V. The translocation has been named, eTl(ZI1; V); eT1acts as a dominant crossover suppressor for both the right half of LGIIIand the left half of LGV,providing a balancer for a total of 39 map units. The uncoordinated e873phenotype has been shown to be a consequence of Eminactive unr- 36111gene. It was possible to demonstrate that, in translocation heterozygotes, eT1chromosomes marked with either sma-3or dpy-11segregate from normal LGIII,while those marked with bli-5, sm-2or unc-42segregate from normal LGV.Since bli-5and sma-2are normally on LGIII,and dpy-11is normally on LGV,it is concluded that: (a) eT1is a reciprocal translocation; (b) there is a breakpoint between sma-3and sma-2in LGIII(the region containing unc- 36)and one between dpy-11and unc-42in LGV;(c) thera is no dominant centromere between sma-2and bli-5on LGIII,since in eT1these genes are not linked to a LGIIIcentromere. Similarly, it is highly unlikely that there is a centromere to the left of dpy-11on LGV.The new gene order in eT1was determined by measuring recombination rates between markers in eT1homozygotes. It is concluded that the new order is: dpy-1 sma-3 (break) dpy-11 unc-60,and bli-5 sma-2 (break) unc-42 unc-51.——Thisis the first analysis of a C. eleganstranslocation with respect to reciprocity, breakpoints and new gene order.


Genetics ◽  
1996 ◽  
Vol 142 (4) ◽  
pp. 1277-1288
Author(s):  
Stephen L Johnson ◽  
Michael A Gates ◽  
Michele Johnson ◽  
William S Talbot ◽  
Sally Horne ◽  
...  

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.


2016 ◽  
Vol 18 (9) ◽  
pp. 1268-1284 ◽  
Author(s):  
Joohae Park ◽  
Mark Hulsman ◽  
Mark Arentshorst ◽  
Matthijs Breeman ◽  
Ebru Alazi ◽  
...  

1997 ◽  
Vol 122 (6) ◽  
pp. 822-828 ◽  
Author(s):  
Kittipat Ukoskit ◽  
Paul G. Thompson

Low-density randomly amplified polymorphic DNA (RAPD) markers of sweetpotato [Ipomoea batatus (L.) Lam.; 2n = 6x = 90] were constructed from 76 pseudotestcross progenies obtained from `Vardaman' × `Regal'. Of 460 primers, 84 generating 196 well-resolved repeatable markers were selected for genetic analysis. `Vardaman' and `Regal' testcross progenies were analyzed for segregation and linkages of RAPD markers. Type of polyploidy, autopolyploidy, or allopolyploidy is uncertain in sweetpotato and was examined in this study using the ratio of nonsimplex to simplex RAPD markers and the ratio of simplex RAPD marker pairs linked in repulsion to coupling. Both measures indicated autopolyploidy. Low-density RAPD linkage maps of `Vardaman' and `Regal' were constructed from simplex RAPD marker linkage analysis. Duplex and triplex markers were then mapped manually into the simplex marker map. Homologous linkage groups were identified using nonsimplex RAPD markers and three homologous groups were found in each of the parent maps. Use of nonsimplex markers increased mapping efficiency. The `Vardaman' map had a predicted coverage of 10.5% at a 25-cM interval of the genome size of 5024 cM. In `Regal', genome coverage was estimated to be 5.6% at a 25-cM interval of the genome size of 6560 cM. Therefore, average chromosome length was ≈56 to 73 cM.


1965 ◽  
Vol 6 (1) ◽  
pp. 13-26 ◽  
Author(s):  
G. Dorn

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.


1991 ◽  
Vol 19 (4) ◽  
pp. 261-264 ◽  
Author(s):  
J. G. Boschloo ◽  
E. Moonen ◽  
R. F. M. van Gorcom ◽  
H. F. M. Hermes ◽  
C. J. Bos

1979 ◽  
Vol 34 (3) ◽  
pp. 239-252 ◽  
Author(s):  
M. de Bertoldi ◽  
C. E. Caten

SUMMARYThe steps in the parasexual cycle required for genetic analysis by mitotic haploidization were readily accomplished in Aspergillus amstelodami. Balanced heterokaryons were synthesized between strains carrying complementary auxotrophic mutations and heterozygous-diploid colonies were recovered from these heterokaryons at frequencies between 1 × 10−6 and 5 × 10−6 among conidia plated. When grown in the presence of p-fluorophenylalanine or benomyl, heterozygous-diploid strains produced discrete haploid segregants. Examination of the segregation of 12 mutations among haploid segregants from ten diploids indicated that these genes were located in six linkage groups, thereby increasing the number of linkage groups recognized in this species. This haploidization analysis provided a clear distinction between linked and unlinked genes and continuation of this approach should reveal the chromosome number of A. amstelodami. Linkage at meiosis was detected between only one of five pairs of mitotically linked genes tested, emphasising the value of mitotic-haploidization analysis for assigning markers to linkage groups. A. amstelodami is amenable to both mitotic and meiotic genetic analysis and further studies should permit extensive comparisons of the genetic and biochemical organization of this species with that of A. nidulans.


2001 ◽  
Vol 52 (2-3) ◽  
pp. 335-343 ◽  
Author(s):  
K. Swart ◽  
A.J.M. Debets ◽  
M. Slakhorst ◽  
E.F. Holub ◽  
R.F. Hoekstra ◽  
...  

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