Enzyme Polymorphism and Metabolism

Johnson, George B.

doi:10.1126/science.184.4132.28

Cited by 259 publications

(98 citation statements)

References 156 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Generally the number as well as the composition of enzyme systems and serum proteins studied seem to have an important influence on estimates of genetic variation and genetic divergence (see e.g. Johnson, 1974;Ward, 1977;Sarich, 1977;Gorman and Renzi, 1979;Lewontin, 1985;Hartl and Csaikl, 1987, for further discussion of this problem). While our results support Nevo's (1984) conclusion that generalist species are genetically more variable than specialist species they provide further evidence against the argument that comparatively large mammals should be genetically less variable than small mammals.…”

Section: Discussionmentioning

confidence: 99%

Biochemical variation in roe deer (Capreolus capreolus L.): are r-strategists among deer genetically less variable than K-strategists?

Hartl

Reimoser

1988

Heredity

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Biochemical variation in roe deer (Capreolus capreolus L.): are r-strategists among deer genetically less variable than K-strategists?

Hartl

Reimoser

1988

Heredity

View full text Add to dashboard Cite

“…An example of such results is given in table 3; more extensive data will be published later (Tomekpe and Lumaret, in preparation). According to Johnson (1974), the biochemical interpretation of this result would be that, in the event of changed reaction conditions associated with varying environments, the possession of several allelic forms of the same enzyme may permit the tetraploid to maintain a sufficient flux through metabolic pathways. Finally, it appears to the present author that the most important conclusions supported by this study are (a) the high probability of adaptive significance of polymorphism at the GOT 1 locus in the Dactylis complex and (b) a wider range of genetic diversity with, consequently, a wider range of ability to adjust to environmental conditions, in tetraploids compared with diploids.…”

Section: Discussionmentioning

confidence: 99%

The role of polyploidy in the adaptive significance of polymorphism at the GOT 1 locus in the Dactylis glomerata complex

Lumaret

1984

Heredity

View full text Add to dashboard Cite

SUMMARYClinal variation along both altitudinal and latitudinal gradients was clearly observed in glutamate oxaloacetate transaminase gene frequencies (GOT 1 locus) from 21 diploid and 90 tetraploid populations of Dactylis glomerata L. collected over the entire area of the primary and secondary geographic distribution of the species. This was the starting point for experiments designed to detect selective effects and determine the significance of polymorphism at this locus. Progressive investigations were made combining different approaches to determine correlations between allelic frequencies and environmental variables. Consistency of these correlations was tested by small scale studies in sites that exhibited gradients in particular environmental variables and comparisons of the in vitro activiti of the allozymes were also made.The results show that alleles, specifically three among the eight investigated, are not randomly distributed. Two of the alleles are correlated with humidity and the other allele with temperature.From these experimental results and the data from natural populations, there appears to be an advantage to those individuals of this perennial species that possess maximal allelic diversity at this locus, especially in transitional climatic areas where variations in temperature and water availability are particularly high and unpredictable.As only tetraploid plants with the highest allelic diversity are found in such fluctuating conditions, it is suggested that tetraploid genetic structure may be directly responsible for the wider niches of tetraploids than of diploids. Consequently, tetraploids may occupy a wider range of habitats and possess a stronger colonisation potential and wider spatial distribution than diploids.

show abstract

“…This type of diversity is typical of polyploids. It has been suggested that polyploids may gain biochemical diversity as a consequence of gene duplication (Barber, 1970;Johnson, 1974) which allows them to be more flexible and tolerant in their ecological requirements. Zangerl and Bazzaz (1984) reported that different PGI genotypes of Amaranthus retroflexus differed in their ecological distribution.…”

Section: Differences Between Speciesmentioning

confidence: 99%

Phosphoglucose isomerase (EC 5.3.1.9) isozymes in diploid and tetraploid Polygala species: evidence for gene duplication and diversification

Lack

Kay

1986

Heredity

View full text Add to dashboard Cite

Phosphoglucose isomerase (PGI, EC 5.3.1.9) isozymes were examined by electrophoresis in the three common British species of Polygala, the diploids P. serpyllifolia and P. calcarea and the tetraploid P. vulgaris. All three species share the most anodal band which is probably the form of the enzyme occurring in the plastids (PGI-1). Individuals of the two diploid species each have one further band, probably the cytosolic form of the enzyme (PGI-2), with two phenotypes in each species, one of which is common to both. Individuals of P. vulgaris have one, three or six PGI-2 bands and 10 different homozygous phenotypes were observed. The commonest phenotypes in most populations show three bands with a central heterodimeric band staining more intensely than the outer two bands. Although P. vulgaris is a predominantly seif-fertilising species with no vegetative spread, many populations or sub-populations consist almost entirely of three-banded phenotypes. This indicates that the three-banded phenotypes are "fixed heterozygotes" resulting from the duplication of the Pgi-2 locus in the tetraploid. Heterozygotes between different three-banded forms show six bands in which the staining intensities are consistent with random pairing of the subunits. Plants showing silencing of one of the duplicate alleles were found in two small isolated areas in West Glamorgan. The biochemical diversity produced by the multiplicity of enzyme morphs in the tetraploid P. vulgaris may have contributed to its success. It is the most common, widespread and ecologically wide-ranging species in the genus in Europe.

show abstract

Enzyme Polymorphism and Metabolism

Cited by 259 publications

References 156 publications

Biochemical variation in roe deer (Capreolus capreolus L.): are r-strategists among deer genetically less variable than K-strategists?

Biochemical variation in roe deer (Capreolus capreolus L.): are r-strategists among deer genetically less variable than K-strategists?

The role of polyploidy in the adaptive significance of polymorphism at the GOT 1 locus in the Dactylis glomerata complex

Phosphoglucose isomerase (EC 5.3.1.9) isozymes in diploid and tetraploid Polygala species: evidence for gene duplication and diversification

Contact Info

Product

Resources

About