scholarly journals GENETIC ANALYSIS OF THE GENE FOR N-ACETYLGLUCOSAMINIDASE IN DICTYOSTELIUM DISCOIDEUM

Genetics ◽  
1978 ◽  
Vol 88 (2) ◽  
pp. 277-284 ◽  
Author(s):  
William F Loomis
Keyword(s):  
Linkage Group ◽  
Genetic Analysis ◽  
Dictyostelium Discoideum ◽  
Structural Gene ◽  
Regulatory Protein ◽  
Group Iv ◽  
Single Locus ◽  
Stages Of Development ◽  
Separate Locus

ABSTRACT Three independent mutations affecting N-acetylglucosaminidase in Dictyostelium discoideum were mapped by the parasexual system and found to lie on linkage group IV. These mutations as well as two others were found to be recessive and noncomplementing in heterozygous diploids. Thus they all appear to affect the nagA locus. Since two of the mutations give rise to thermolabile enzyme, this defines the structural gene for N-acetylglucosaminidase. The enzyme is a homodimer of a 68,000 dalton subunit and thus would be expected to be determined by a single locus. The expression of this gene is regulated by the stages of development; however, it should be mentioned that none of the mutations fell in a separate locus that might determine a specific positive regulatory protein.

Repeated Family of Genes Controlling Maltose Fermentation in Saccharomyces carlsbergensis

1983 ◽  
Vol 3 (5) ◽  
pp. 796-802
Author(s):  
Richard B. Needleman ◽  
Corinne Michels
Keyword(s):  
Genetic Analysis ◽  
Structural Gene ◽  
Regulatory Gene ◽  
Regulatory Protein ◽  
Physical Analysis ◽  
Saccharomyces Carlsbergensis ◽  
Maltose Permease ◽  
Maltose Fermentation ◽  
Complex Locus ◽  
Dna Fragment

Maltose fermentation in Saccharomyces spp. requires the presence of any one of five unlinked genes: MAL1, MAL2, MAL3, MAL4 , or MAL6. Although the genes are functionally equivalent, their natures and relationships to each other are not known. At least three proteins are necessary for maltose fermentation: maltase, maltose permease, and a regulatory protein. The MAL genes may code for one or more of these proteins. Recently a DNA fragment containing a maltase structural gene has been cloned from a MAL6 strain, CB11, to produce plasmid pMAL9-26. We have conducted genetic and physical analyses of strain CB11. The genetic analysis has demonstrated the presence of two cryptic MAL genes in CB11, MAL1g and MAL3g (linked to MAL1 and to MAL3 , respectively), in addition to the MAL6 locus. The physical analysis, which used a subclone of plasmid pMAL9-26 as a probe, detected three Hin dIII genomic fragments with homology to the probe. Each fragment was shown to be linked to one of the MAL loci genetically demonstrated to be present in CB11. Our results indicate that the cloned maltase structural gene in plasmid pMAL9-26 is linked to MAL6. Since the MAL6 locus has previously been shown to contain a regulatory gene, the MAL6 locus must be a complex locus containing at least two of the factors needed for maltose fermentation: the structural gene for maltase and the maltase regulatory protein. The absence of other fragments which hybridize to the MAL6 -derived probe shows that either MAL2 and MAL4 are not related to MAL6 , or the DNA corresponding to these genes is absent from the MAL6 strain CB11.

scholarly journals Repeated Family of Genes Controlling Maltose Fermentation inSaccharomyces carlsbergensis

1983 ◽  
Vol 3 (5) ◽  
pp. 796-802 ◽  
Author(s):  
Richard B. Needleman ◽  
Corinne Michels
Keyword(s):  
Genetic Analysis ◽  
Structural Gene ◽  
Regulatory Gene ◽  
Regulatory Protein ◽  
Physical Analysis ◽  
Maltose Permease ◽  
Maltose Fermentation ◽  
Complex Locus ◽  
Dna Fragment

Maltose fermentation inSaccharomycesspp. requires the presence of any one of five unlinked genes:MAL1, MAL2, MAL3, MAL4, orMAL6.Although the genes are functionally equivalent, their natures and relationships to each other are not known. At least three proteins are necessary for maltose fermentation: maltase, maltose permease, and a regulatory protein. TheMALgenes may code for one or more of these proteins. Recently a DNA fragment containing a maltase structural gene has been cloned from aMAL6strain, CB11, to produce plasmid pMAL9-26. We have conducted genetic and physical analyses of strain CB11. The genetic analysis has demonstrated the presence of two crypticMALgenes in CB11,MAL1gandMAL3g(linked toMAL1and toMAL3, respectively), in addition to theMAL6locus. The physical analysis, which used a subclone of plasmid pMAL9-26 as a probe, detected threeHindIII genomic fragments with homology to the probe. Each fragment was shown to be linked to one of theMALloci genetically demonstrated to be present in CB11. Our results indicate that the cloned maltase structural gene in plasmid pMAL9-26 is linked toMAL6.Since theMAL6locus has previously been shown to contain a regulatory gene, theMAL6locus must be a complex locus containing at least two of the factors needed for maltose fermentation: the structural gene for maltase and the maltase regulatory protein. The absence of other fragments which hybridize to theMAL6-derived probe shows that eitherMAL2andMAL4are not related toMAL6, or the DNA corresponding to these genes is absent from theMAL6strain CB11.

PARASEXUAL GENETIC ANALYSIS OF CELL PROPORTIONING MUTANTS OF DICTYOSTELIUM DISCOIDEUM

Genetics ◽  
1981 ◽  
Vol 99 (2) ◽  
pp. 183-196
Author(s):  
James H Morrissey ◽  
William F Loomis
Keyword(s):  
Cell Differentiation ◽  
Linkage Group ◽  
Genetic Analysis ◽  
Dictyostelium Discoideum ◽  
Double Mutant ◽  
Complementation Group ◽  
Stalk Cell ◽  
Recessive Mutation ◽  
Group Vi ◽  
Recessive Mutations

ABSTRACT Eight independently isolated mutants of Dictyostelium discoideum that differentiate exclusively into stalk cells make up one complementation group and carry single recessive mutations at the stalky locus, stkA, located on linkage group II. KY19, a previously described strain that differentiates into spores, but not stalk cells, was found to possess a recessive mutation defining the stalkless locus, stlA, located on linkage group VI. An analysis of the properties of these mutants, together with the phenotype of a haploid double mutant carrying stkA and stlA indicates that stlA results in poorly organized stalk tubes and incomplete stalk cell differentiation, while stkA causes all of the cells to differentiate into stalk cells, even when not enclosed in the stalk tube. The significance of these results is discussed in relation to current theories of pattern formation in D. discoideum.

scholarly journals TRANSLOCATIONS IN DICTYOSTELIUM DISCOIDEUM

Genetics ◽  
1985 ◽  
Vol 109 (2) ◽  
pp. 341-364
Author(s):  
D L Welker ◽  
K L Williams
Keyword(s):  
Dna Repair ◽  
Linkage Group ◽  
Chromosome Number ◽  
Dictyostelium Discoideum ◽  
Genetic Characterization ◽  
Group Iv ◽  
Chromosome Rearrangements ◽  
Linkage Groups ◽  
Independent Origin

ABSTRACT Fourteen translocations of independent origin were identified in Dictyostelium discoideum on the basis of segregation anomalies of diploids heterozygous for these chromosome rearrangements, all of which led to the cosegregation of unlinked markers. Many of these translocations were discovered in strains mutagenized with MNNG or in strains carrying mutations affecting DNA repair; however, spontaneous translocations were also obtained. Haploid mitotic recombinants of the rearranged linkage groups were produced from diploids heterozygous for the translocations at frequencies of up to 5% of viable haploid segregants; this is at least a ten-fold higher frequency than that seen with diploids not heterozygous for translocations (∼0.1%). These haploid recombinants included both translocated and nontranslocated strains. The T354(II,VII) translocation and possibly the T357(IV,VII) translocation reduce the chromosome number to n = 6; haploids carrying 11 other translocations all have karyotypes with n = 7. Genetic characterization of the T357(IV,VII) translocation showed that the bwnA and whiC loci normally found on linkage group IV were physically linked to the linkage group VII loci couA, phgA, bsgB and cobA.

scholarly journals LINKAGE ANALYSIS OF NYSTATIN RESISTANCE MUTATIONS IN DICTYOSTELIUM DISCOIDEUM

Genetics ◽  
1986 ◽  
Vol 113 (1) ◽  
pp. 53-62
Author(s):  
Dennis L Welker
Keyword(s):  
Linkage Group ◽  
Linkage Analysis ◽  
Dictyostelium Discoideum ◽  
Group Iv ◽  
Resistance Locus ◽  
Resistance Mutations ◽  
Group Vi ◽  
Group V ◽  
The Third ◽  
Nystatin Resistance

ABSTRACT Earlier linkage analyses of nystatin resistance loci in Dictyostelium discoideum tentatively mapped the nysB and nysC loci to the previously unmarked linkage group V. The data presented here establishes that nysB maps to linkage group VI and that nysC maps to linkage group IV. The third nystatin resistance locus, nysA, maps to linkage group II.

scholarly journals THE STRUCTURAL GENE FOR α-MANNOSIDASE-1 IN DICTYOSTELIUM DISCOIDEUM

Genetics ◽  
1976 ◽  
Vol 84 (2) ◽  
pp. 159-174
Author(s):  
S J Free ◽  
R T Schimke ◽  
W F Loomis
Keyword(s):  
Linkage Group ◽  
Dictyostelium Discoideum ◽  
Structural Gene ◽  
Gene Dosage ◽  
Dosage Effect ◽  
Substrate Affinity ◽  
Developmentally Regulated ◽  
Group Vi ◽  
Gene Dosage Effect

ABSTRACT We have isolated 4 independent mutations affecting α-mannosidase-1, a a developmentally regulated activity in Dictyostelium discoideum. Three of these result in a thermolabile α-mannosidase-1 activity. One mutation also affects the substrate affinity (Km) of the activity. In diploids these mutations show a gene dosage effect and are all alleles. The structural gene for α-mannosidase-1, as defined by these mutations, defines a new linkage group, linkage group VI. α-Mannosidase-1 is probably a homopolymer with subunits of 54,000 daltons.

scholarly journals CHROMOSOME FRAGMENTS IN DICTYOSTELIUM DISCOIDEUM OBTAINED FROM PARASEXUAL CROSSES BETWEEN STRAINS OF DIFFERENT GENETIC BACKGROUND

Genetics ◽  
1980 ◽  
Vol 95 (2) ◽  
pp. 289-304
Author(s):  
Keith L Williams ◽  
Gillian E Robson ◽  
Dennis L Welker
Keyword(s):  
Linkage Group ◽  
Genetic Analysis ◽  
Dictyostelium Discoideum ◽  
Genetic Background ◽  
Deleterious Effect ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Chromosome Fragments ◽  
Group Ii ◽  
Different Genetic Background

ABSTRACT The first aneuploid strains of Dictyostelium discoideum have been unambiguously characterized, using cytological and genetic analysis. Three independently isolated, but genetically similar, fragment chromosomes have been observed in segregants from diploids formed between haploid strains derived from the NC4 and VI2 isolates of D. discoideum. Once generated, the fragment chromosomes, all of which have Vl2-derived centromeres, can be maintained in a NC4 genetic background. Genetic evidence is consistent with the view that all three fragment chromosomes studied encompass the region from the centromere to the whiA locus of linkage group II and terminate in the interval between whiA and acrA. From cytological studies, one of the fragment chromosomes consists of approximately half of linkage group II.——We observed no deleterious effect on viability or asexual fruiting-body formation in either haploid or diploid strains carrying an additional incomplete chromosome and hence are disomic or trisomic, respectively, for part of linkage group II. The incomplete chromosome is lost at a frequency of 2 to 3% from disomic and trisomic strains, but surprisingly this loss is not increased in the presence of the haploidizing agent, benlate. A new locus (clyA), whose phenotype is altered colony morphology, is assigned to the region of linkage group II encompassed by the fragment chromosome.

Sign in / Sign up

Export Citation Format

Share Document