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 FURTHER EVIDENCE FOR A POLYMORPHISM IN GAMETIC SEGREGATION IN THE TETRAPLOID TREEFROG HYLA VERSICOLOR USING A GLUTAMATE OXALOACETIC TRANSAMINASE LOCUS

Genetics ◽  
1983 ◽  
Vol 103 (4) ◽  
pp. 753-769
Author(s):  
Roy G Danzmann ◽  
James P Bogart
Keyword(s):  
Chromosome Segregation ◽  
Null Allele ◽  
Interspecific Cross ◽  
Staining Intensity ◽  
Interspecific Crosses ◽  
Hyla Versicolor ◽  
Hyla Chrysoscelis ◽  
Segregation Ratios ◽  
Aberrant Segregation ◽  
Glutamate Oxaloacetic Transaminase

ABSTRACT Intra- and interspecific cross combinations between the tetraploid treefrog Hyla versicolor, and between H. versicolor and the diploid treefrog Hyla chrysoscelis were performed. Progeny phenotypes resulting from these crosses were examined electrophoretically using a polymorphic glutamate oxaloacetic transminase (GOT-1) locus, to determine the mechanism of chromosome segregation in H. versicolor, and to test theoretical expectations for isozyme expression in interspecific (2n × 4n or 4n × 2n) hybrids. In some intraspecific tetraploid crosses progeny phenotypes fit a disomic mode of segregation, whereas in other crosses a tetrasomic mode of segregation was the most probable. Additional crosses produced phenotypic ratios that conformed to either a disomic or tetrasomic mode of segregation. These results suggest that a polymorphism, with respect to segregation of gametes, exists in H. versicolor, resulting from differences in chromosome pairings during meiosis I. This polymorphism in gametic segregation occurred in both sexes. Certain crosses, however, produced phenotypic ratios that did not conform to any chromosome segregation model. Progeny phenotypes observed from most interspecific crosses conformed to expected interspecific isozyme staining intensity models. Symmetrical heterozygotes, representing either a single dose for both alternate alleles or double doses for both alternate alleles, were also observed. Such phenotypes are unexpected in triploid progeny. A null allele was postulated to account for the aberrant segregation ratios and phenotypes observed in certain intra- and interspecific crosses.

scholarly journals Inheritance and Linkage Relationships of Melon (Cucumis melo L.) Isozymes

1998 ◽  
Vol 123 (2) ◽  
pp. 264-272 ◽  
Author(s):  
Jack E. Staub ◽  
Vladimir Meglic ◽  
James D. McCreight
Keyword(s):  
Cucumis Melo ◽  
Linkage Studies ◽  
Genomic Information ◽  
Linkage Groups ◽  
Map Construction ◽  
Segregation Ratios ◽  
Isozyme Loci ◽  
Cucumis Melo L ◽  
Linkage Relationships ◽  
Linkage Distance

Nineteen polymorphic and eleven monomorphic isozyme loci were identified in thirteen enzyme systems in a survey of four-hundred melon (Cucumis melo L.) accessions. Segregation of allozymes in F2 and backcross (BC) families for isozyme loci agreed with the expected 1:2:1 and 1:1 segregation ratios (P <0.01). Eleven isozyme loci were linked and were integrated to form a map containing two linkage groups spanning 98 cM with a mean linkage distance of ≈9 cM. Linkage groups (A and B) contain the following loci in the order: A Fdp-2, Pgd, Pgm, Mpi-1, Idh, and Ac, and B Pep-gl, Mdh-2, Mdh-4, Mdh-5, Mdh-6. The remaining eight loci (Acp-1, Acp-4, Ak-4, Fdp-1, Gpi, Mpi-2, Pep-la, and Pep-pap) segregated independently. The isozyme map constructed in this study provides genomic information for future linkage studies with economically important traits and concensus map construction through map merging.

scholarly journals Linkage relationships of markers on chromosome 17 of the house mouse

1975 ◽  
Vol 26 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Graig Hammerberg ◽  
Jan Klein
Keyword(s):  
House Mouse ◽  
Chromosomal Region ◽  
Recombination Frequency ◽  
Genetic Distances ◽  
Chromosome 17 ◽  
Linkage Data ◽  
Crossing Over ◽  
The Right ◽  
Linkage Relationships ◽  
Important Marker

SUMMARYLinkage data for the following markers on chromosome 17 of the house mouse were obtained: centromere (marked by translocation R67), Brachyury (T), tufted (tf), H-2, and thin fur (thf). The markers were found to be arranged in that order in the genetic map and the combined genetic distances between individual markers were found to be as follows: Rb7…T, 4·5 cM; T…tf, 5·8 cM; tf…H-2, 5·0 cM; H-2…thf, 15·1 cM. The localization of the thf locus on the non-centromeric side of the H-2 complex provides an important marker for this arm of chromosome 17. The map distances in the centromeric portion of chromosome 17 changed drastically in the presence of various t factors. These factors strongly reduce the recombination frequency in the T…tf and tf…H-2 intervals and this crossing-over suppression is most likely responsible for the linkage disequilibrium between t and H-2 reported earlier. Recombinants involving a t chromosome but occurring to the right of the H-2 complex do not change the properties of t factors suggesting that all determinants responsible for the t phenotype are located in the chromosomal region between T and tf (H-2).

Inheritance of mitochondrial DNA in interspecific crosses of Piceaglauca and Piceaomorika

1996 ◽  
Vol 26 (3) ◽  
pp. 428-432 ◽  
Author(s):  
Andrew J. David ◽  
Daniel E. Keathley
Keyword(s):  
Mitochondrial Dna ◽  
Interspecific Hybrids ◽  
Maternal Inheritance ◽  
White Spruce ◽  
Mitochondrial Genes ◽  
Interspecific Crosses ◽  
Length Polymorphisms ◽  
Dna Restriction ◽  
Total Dna ◽  
Serbian Spruce

Fifteen interspecific hybrids of Serbian spruce (Piceaomorika (Panc) Purkyne) and white spruce (Piceaglauca (Moench) Voss) representing five separate crosses, including reciprocals, were used to demonstrate maternal inheritance of mitochondrial DNA. Total DNA was extracted from foliage samples of Serbian spruce (S), white spruce (W), and both S(♂) × W(♀) and W(♂) × S(♀) hybrids, digested and probed with one of two maize mitochondrial genes, ATPaseα or COXII. ATPaseα generated diagnostic Serbian and white spruce genotypes for all five enzymes tested, while COXII differentiated between the two species for four of five enzymes. Maternal inheritance was indicated in all hybrids for every diagnostic enzyme–probe combination. No paternal or nonparental bands were detected. A dilution experiment indicated that the Serbian and white spruce mitochondrial DNA restriction fragment length polymorphisms could be detected in as little as 60 and 500 ng of total DNA, respectively. It appears that the mechanism that controls the inheritance of mitochondria in Picea is still functional in wide interspecific crosses.

Evidence for the existence of endosperm balance number in the true clovers (Trifolium spp.)

1986 ◽  
Vol 28 (4) ◽  
pp. 581-586 ◽  
Author(s):  
W. A. Parrott ◽  
R. R. Smith
Keyword(s):  
Ploidy Level ◽  
Related Species ◽  
Interspecific Hybrids ◽  
2N Gametes ◽  
Endosperm Development ◽  
Individual Species ◽  
Interspecific Crosses ◽  
Endosperm Balance Number ◽  
Endosperm Tissue ◽  
2N Eggs

The endosperm balance number (EBN) hypothesis was first advanced to explain results from interspecific crosses in Solanum and later in Impatiens. According to the EBN hypothesis, normal endosperm development following intra- or inter-specific crosses depends on having a ratio of two EBNs from the female to one EBN from the male in the endosperm tissue. EBNs may differ among related species. Successful hybrids can be obtained between species with the same EBN. The ploidy level of an individual species can be varied to modify its EBN, making it cross compatible with a species sharing its modified EBN. Interspecific crosses within Trifolium have been limited and difficult. Crosses reported in the literature, including evidence from our own study, suggest that EBN is operating in Trifolium and have been used to assign EBN numbers to some clover species. The use of 2n eggs enabled two species, differing in EBN, to be crossed. An understanding of the EBN mechanism that operates in Trifolium should make successful interspecific hybrids easier to obtain in the future.Key words: endosperm balance number, hybrids (interspecific), 2n gametes, Trifolium.

HYBRID CHLOROSIS IN INTERSPECIFIC CROSSES OF OENOTHERA: POLYGENIC INHERITANCE OF THE NUCLEAR COMPONENT

1974 ◽  
Vol 16 (1) ◽  
pp. 193-201 ◽  
Author(s):  
J. P. van der Meer
Keyword(s):  
Interspecific Hybrids ◽  
The Other ◽  
Interspecific Crosses ◽  
Polygenic Inheritance ◽  
Oenothera Hookeri ◽  
Nuclear Component ◽  
Parallel Series

Interspecific hybrids between Oenothera hookeri or O. elata and O. argillicola are severely chlorotic and die as seedlings because the chloroplasts of either species are unable to function in the presence of the chromosome complex inherited from the other (Stubbe, 1959; Stinson, 1960). In the present investigation the chromosome complex of O. argillicola was genetically partitioned into a number of small sets of chromosomes by means of backcrosses, and the chlorosis-inducing potential of these sets on chloroplasts of O. hookeri and O. elata was determined. The chlorosis-inducing potential of sets of O. hookeri and O. elata chromosomes on the chloroplasts of O. argillicola was determined in a parallel series of crosses.In both series the results indicated that the nuclear component of hybrid chlororis was polygenic. No individual foreign chromosome produced an observable degree of chlorosis while various combinations produced various degrees of chlorosis. In general, the level of the chlorosis paralleled the number of foreign chromosomes in the hybrid, the F-1 hybrid in each case being the most severely affected.

Inheritance and linkage relationships of seed peroxidase loci in hexaploid oat (Avena sativa L.)

Genome ◽  
1995 ◽  
Vol 38 (3) ◽  
pp. 467-471
Author(s):  
N. R. Sharopova ◽  
A. A. Sozinov ◽  
V. A. Portyanko
Keyword(s):  
Avena Sativa ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
The Other ◽  
Linkage Groups ◽  
Peroxidase Isozyme ◽  
Linkage Relationships

Polyacrylamide gel electrophoresis has been used to investigate the inheritance and linkage relationships between anodal (PXA) and cathodal (PXC) seed peroxidases in hexaploid oat (Avena sativa L.). A total of 12 seed peroxidase loci (5 loci of PXA and 7 loci of PXC) were identified in three crosses. Only two Pxc loci (Pxc5 and Pxc7) were not linked to any peroxidase loci; the others were scored in three linkage groups. The order of the three loci assigned to one of the linkage groups was Pxc1–Pxa5–Pxc2. The order of loci in the other two linkages were Pxc4–Pxa1–Pxa3 and Pxc3–Pxa4–Pxa2. Also, the Pxc6 locus was shown to be linked to the Pxc3 locus. Considering that A. sativa is an allohexaploid, it can be proposed that the three peroxidase linkages represent homoeologous chromosomes.Key words: seed peroxidase, isozyme inheritance, linkage, Avena sativa.

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