scholarly journals Genetic Analysis of Isoenzymes in Raspberry

1992 ◽  
Vol 117 (6) ◽  
pp. 996-999 ◽  
Author(s):  
Johanne C. Cousineau ◽  
Danielle J. Donnelly
Keyword(s):  
Linkage Group ◽  
Genetic Analysis ◽  
Isocitrate Dehydrogenase ◽  
Mendelian Inheritance ◽  
Rubus Idaeus ◽  
Lethal Gene ◽  
Expected Number ◽  
Recessive Lethal ◽  
Segregation Ratios ◽  
Aberrant Segregation

The inheritance of five isoenzymes was studied in red and purple raspberry F1 progenies (Rubus idaeus L. and Rubus × neglectus Peck). Isocitrate dehydrogenase (IDH; EC 1.1.1.42) was a dimeric enzyme present in the cytosol and coded for by one locus (Idh-1). Three of the four crosses analyzed at this locus had deviations from expected ratios, possibly caused by its linkage to a recessive lethal gene. Malate dehydrogenase (MDH; EC 1.1.1.37), phosphoglucoisomerase (PGI; EC 5.3.1.9), and triose phosphate isomerase (TPI; EC 5.3.1.1) were dimeric enzymes with two loci. Each of these three enzymes was present in an organelle and in the cytosol for locus 1 and 2, respectively. Phosphoglucomutase (PGM; EC 2.7.5.1) was monomeric with two loci, Pgm-1 and Pgm-2, located in an organelle and the cytosol, respectively. Each allele at Pgm-1 resulted in the formation of two bands. Although most progenies analyzed supported Mendelian inheritance of polymorphic loci (except for Idh-1), there was a higher than expected number of aberrant segregation ratios observed (18.4%). Analysis of 85 pairs of jointly segregating loci revealed a possible linkage group consisting of Mdh-2, Tpi-2, and Pgm-1.

scholarly journals Inheritance and Linkage Relationships of Isozymes in Easter Cactus

1998 ◽  
Vol 123 (1) ◽  
pp. 98-103
Author(s):  
Maureen C. O'Leary ◽  
Thomas H. Boyle
Keyword(s):  
Interspecific Hybrids ◽  
Triosephosphate Isomerase ◽  
Recombination Frequency ◽  
Polyacrylamide Gel Electrophoresis ◽  
Interspecific Crosses ◽  
Germplasm Collections ◽  
Segregation Ratios ◽  
Isozyme Loci ◽  
Linkage Relationships ◽  
Aberrant Segregation

Polyacrylamide gel electrophoresis was used to study inheritance and linkage of isozymes in Easter cactus (Hatiora species and interspecific hybrids). Five isozyme systems were analyzed: aspartate aminotransferase (AAT), glucose-6-phosphate isomerase (GPI), malate dehydrogenase (MDH), phosphoglucomutase (PGM), and triosephosphate isomerase (TPI). F1, F2, BC1, and S1 progeny were used for inheritance studies. Six polymorphic loci (Aat-1, Gpi-1, Mdh-1, Pgm-1, Pgm-2, and Tpi-2) were identified. Aat-1 and Pgm-1 were linked (recombination frequency = 26% ± 7%), but the other isozyme loci assorted independently. Aberrant segregation ratios were observed in at least one segregating family for all six isozyme loci. We hypothesize that segregation distortion was due to linkage between isozyme loci and other genes subject to pre- or postzygotic selection. The existence of five additional isozyme loci (Aat-2, Gpi-2, Mdh-2, Mdh-3, and Tpi-1) was inferred from segregation patterns and by comparison of isozyme profiles from phylloclades and pollen. These isozyme loci may prove useful for confirming hybridity in intra- and interspecific crosses, determining parentage of cultivars, and assessing genetic diversity in germplasm collections.

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.

CAENORHABDITIS ELEGANS DEFICIENCY MAPPING

Genetics ◽  
1984 ◽  
Vol 108 (2) ◽  
pp. 331-345
Author(s):  
D Christine Sigurdson ◽  
Gail J Spanier ◽  
Robert K Herman
Keyword(s):  
Caenorhabditis Elegans ◽  
Linkage Group ◽  
Ethyl Methanesulfonate ◽  
Single Site ◽  
Crossing Over ◽  
Wild Type ◽  
Nematode Caenorhabditis Elegans ◽  
Recessive Lethal ◽  
X Ray ◽  
New Mutations

ABSTRACT Six schemes were used to identify 80 independent recessive lethal deficiencies of linkage group (LG) II following X-ray treatment of the nematode Caenorhabditis elegans. Complementation tests between the deficiencies and ethyl methanesulfonate-induced recessive visible, lethal and sterile mutations and between different deficiencies were used to characterize the extents of the deficiencies. Deficiency endpoints thus helped to order 36 sites within a region representing about half of the loci on LG II and extending over about 5 map units. New mutations occurring in this region can be assigned to particular segments of the map by complementation tests against a small number of deficiencies; this facilitates the assignment of single-site mutations to particular genes, as we illustrate. Five sperm-defective and five oocyte-defective LG II sterile mutants were identified and mapped. Certain deficiency-by-deficiency complementation tests allowed us to suggest that the phenotypes of null mutations at two loci represented by visible alleles are wild type and that null mutations at a third locus confer a visible phenotype. A segment of LG II that is about 12 map units long and largely devoid of identified loci seems to be greatly favored for crossing over.

Biosystematic studies in the Stylidium crassifolium species complex (Stylidiaceae)

1979 ◽  
Vol 27 (1) ◽  
pp. 27 ◽  
Author(s):  
BJ Banyard ◽  
SH James
Keyword(s):  
Species Complex ◽  
Genetic System ◽  
Lethal Gene ◽  
Great Efficiency ◽  
Intermediate Species ◽  
Gene Arrays ◽  
Recessive Lethal ◽  
Tetraploid Form ◽  
Diploid Populations ◽  
Lethal Genes

Stylidium elongatum Benth. (n = 13, 26) and Stylidium crassifolium R. Br. (n = 14, 28) have been restored to specific status and a morphologically intermediate species, Stylidium confluens sp. nov. (n = 14), is described. Polyploid entities in the complex have not been given taxonomic ranks although the tetraploid form of elongatum may be considered worthy of subspecific rank, as it is ecologically distinct and contiguously allopatric to its progenitor and to confluens, forming a buffer between these two diploid entities. Tetraploid populations in crassifolium occur within the distributional range of the diploid. All three species carry recessive lethal gene arrays which eliminate the products of self-pollination with great efficiency and result in crosses between close populations yielding seed more effectively than crosses within populations. There is evidence that interpopulational coadaptation may break down with increasing distance between populations. Polyploidy in crassifolium is probably a conservative response in the genetic system of a species where concentrations of lethal genes in small diploid populations became disadvantageous.

ISOLATION AND GENETIC ANALYSIS OF MMS-SENSITIVE MUS MUTANTS OF NEUROSPORA

1980 ◽  
Vol 22 (4) ◽  
pp. 535-552 ◽  
Author(s):  
E. Käfer ◽  
E. Perlmutter
Keyword(s):  
Dna Repair ◽  
Linkage Group ◽  
Genetic Analysis ◽  
Double Mutant ◽  
Excision Repair ◽  
Methylmethane Sulfonate ◽  
New Genes ◽  
Mutant Strains ◽  
Error Prone Repair ◽  
Isogenic Strains

With the aim of obtaining mutants that affect DNA repair or recombination, mutants sensitive to methylmethane sulfonate (MMS) have been isolated in the ascomycete Neurospora crassa. Seven of these mutants were backcrossed repeatedly to produce isogenic strains for measurements of relative mutagen sensitivities and for analysis of recombination frequencies. The new mus (mutagen sensitives) were compared to four previously known radiation-sensitive mutants which were shown to be cross-sensitive to MMS. Tests for allelism assigned the mus mutants to five new genes, mus-7 to mus-11, each mapping in a different linkage group. In homozygous crosses all mutants were sterile, except the two alleles of gene mus-10 which occasionally produced some viable ascospores. Complementation tests on MMS-media identified double mutant strains from many intercrosses. Such strains can be used for analysis of interactions between mutant alleles from different genes and of possible epistatic groupings for repair-deficient mutants in Neurospora. Four of these double mutant strains, all containing mus-8 and previously known mutants, were checked for survival on MMS media and their sensitivities were compared to those of their parental single mutant strains. Results indicate that mus-8 may be epistatic to uvs-2 which is deficient in excision repair, but not to mutants like uvs-3 that appear to be deficient in error-prone repair.

LINKAGE STUDIES IN TRIBOLIUM CASTANEUM. XI. THE MAP POSITION OF CHARCOAL, A PSEUDOALLELE OF BLACK

1978 ◽  
Vol 20 (1) ◽  
pp. 139-145 ◽  
Author(s):  
Eric Brown ◽  
Alexander Sokoloff
Keyword(s):  
Linkage Group ◽  
Tribolium Castaneum ◽  
Reciprocal Cross ◽  
Autosomal Dominant ◽  
Linkage Studies ◽  
Lethal Effects ◽  
Recessive Lethal ◽  
Reciprocal Crosses ◽  
Group Iii ◽  
Significant Difference

Charcoal, (Chr), an autosomal dominant with recessive lethal effects is located in linkage group III in Tribolium castaneum (Herbst). Its map position has been determined in respect to aureate (au), light ocular diaphragm (lod) and black (b). The distances between the various genes vary, depending on the sex of the cross. The Chr ++/+ lod au ♂ × +lod au/+lod au ♀ crosses give the following recombination values: au-lod = 22.19 ±.42%, Chr-lod = 20.03 ±.40% and Chr-au = 41.28 ±.49%. The reciprocal crosses give au-lod 28.08 ±.45%, Chr-lod = 17.67 ±.38% and Chr-au = 44.11 ±.50%. For the larger distances encompassed by the Chr-au region the recombination values in the two sexes were not significantly different. For the shorter distances the recombination values were significantly higher in the males than in the females in the au-lod region. They were not found to be significantly different in the Chr-lod region probably because of difficulty in identifying lod and non-lod beetles in the presence of Chr. Tests of allelism indicate that Chr and black b are pseudoalleles which recombine at a different rate in the two sexes. Chr +/+b ♂ × +b/+b ♀ gave 0.07% recombinants, while the reciprocal cross gave 0.014% recombinants, a significant difference. The data suggest that the order of the genes in this linkage group is Chr - b - lod - au.

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