scholarly journals ALLOZYMIC VARIATION AND LINKAGE DISEQUILIBRIUM IN SOME LABORATORY POPULATIONS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1979 ◽  
Vol 92 (4) ◽  
pp. 1295-1314
Author(s):  
C C Laurie-Ahlberg ◽  
B S Weir
Keyword(s):  
Linkage Disequilibrium ◽  
Gel Electrophoresis ◽  
Natural Populations ◽  
Starch Gel Electrophoresis ◽  
Random Drift ◽  
Linkage Disequilibria ◽  
Laboratory Populations ◽  
Rate Of Decay ◽  
Starch Gel ◽  
Selective Effects

ABSTRACT Nine laboratory populations of D. melanogaster were surveyed by starch gel electrophoresis for variation at 17 enzyme loci. A single-fly extract could be assayed for all 17 enzymes, so that the data consist of 17-locus genotypes.— Pairwise linkage disequilibria were estimated from the multilocus genotypic frequencies, using both BURROWS' and HILL'S methods. Large amounts of link-age disequilibrium were found, in contrast to the results reported for natural populations.—Knowledge of the approximate sizes of these populations was used to compare the observed heterozygosities and linkage disequilibria with predictions of the neutral allele hypothesis. The relatively large amount of linkage disequilibrium is consistent with the small sizes of the populations. However, the levels of heterozygosity in at least some populations suggest that some mechanism has been operating to retard the rate of decay by random drift. Several examples of significant deviation from Hardy-Weinberg frequencies and the large amount of linkage disequilibnim present in these populations indicate that a likely mechanism is selective effects associated with neutral alleles because of linkage disequilibrium with selected loci (e.g., "associative overdominance"). The results are therefore consistent with both neutralist, and selectionist hypotheses, but suggest the importance of considering linkage disequilibrium between neutral and selected loci when attempting to explain the dynamics of enzyme polymorphisms.

Genetic variability in natural populations of the gray wolf, Canis lupus

1991 ◽  
Vol 69 (5) ◽  
pp. 1183-1188 ◽  
Author(s):  
Phyllis K. Kennedy ◽  
Michael L. Kennedy ◽  
Peter L. Clarkson ◽  
Ilme S. Liepins
Keyword(s):  
Genetic Variability ◽  
Spatial Heterogeneity ◽  
Canis Lupus ◽  
Gel Electrophoresis ◽  
Human Impacts ◽  
Natural Populations ◽  
Gray Wolf ◽  
Starch Gel Electrophoresis ◽  
Gray Wolves ◽  
Starch Gel

The genetic variability of gray wolves (Canis lupus) from northwestern Canada was assessed through starch-gel electrophoresis. Of 27 protein systems examined, 25, representing 37 presumptive loci, were consistently scorable; 7 proteins (5 were consistently scorable) exhibited polymorphism. The level of heterozygosity (3.0%) was medial relative to values reported for natural populations of Carnivora and high relative to values reported for natural populations of canids. An overall pattern of few deviations from Hardy–Weinberg expectations and some spatial heterogeneity was observed. Wolves associated with different caribou herds exhibited a low level of differentiation (FST = 0.029). The pattern of variability supports the view of a large panmictic population resulting from extensive movements of individuals and packs and from natural and human impacts on pack structure and formation.

Biochemical Genetics of Fundulus heteroclitus (L.): V. Inheritance of 10 Biochemical Loci

1988 ◽  
Vol 79 (5) ◽  
pp. 359-365 ◽  
Author(s):  
D. C. Brown ◽  
I. J. Ropson ◽  
D. A. Powers
Keyword(s):  
Gel Electrophoresis ◽  
Fundulus Heteroclitus ◽  
Tissue Specificity ◽  
Intracellular Localization ◽  
Natural Populations ◽  
Starch Gel Electrophoresis ◽  
Biochemical Genetics ◽  
Linkage Groups ◽  
Electrophoretic Variants ◽  
Starch Gel

Abstract Starch gel electrophoresis has shown that natural populations of Fundulus heteroclitus have electrophoretic variants for at least 21 loci. We provide inheritance data for 10 polymorphic systems: esterases (Est-B, EST-C, and Est-D); aspartate amlnotransferases (Aat-A, and Aat-B); mannosephosphate isomerase (Mpl-A); acid phosphatase (Ap-A); phosphoglucomutase (Pgm-B); hexose-6-phosphate dehydrogenase (H6pdh-A); and fumarase (Fum-A). Variants for nine of these loci segregate as autosomally inherited codominant alleles. The other system, EST-C, does not reflect such inheritance. We have identified two possible linkage groups: H6pdh-A may be loosely linked to Pgm-B, and Fum-A appears to be linked to Pgm-A. Tissue specificity and intracellular localization for all these loci are also presented.

Genetic polymorphism and evolution in parthenogenetic animals. IV. Triploid Otiorrhynchus salicis Ström (Coleoptera: Curculionidae)

1976 ◽  
Vol 7 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Juhani Lokki ◽  
Pekka Lankinen ◽  
Anssi Saura ◽  
Esko Suomalainen
Keyword(s):  
Genetic Polymorphism ◽  
Genetic Variability ◽  
Central Europe ◽  
Gel Electrophoresis ◽  
Genetic Similarity ◽  
Natural Populations ◽  
Starch Gel Electrophoresis ◽  
Carpathian Mountains ◽  
Bisexual Population ◽  
Starch Gel

AbstractThe genetic variability at 20 enzyme loci in natural populations of Otiorrhynchus salicis Ström was studied by starch gel electrophoresis. Altogether 135 weevils were analyzed. The samples originated from a diploid bisexual population in Austria, from four triploid parthenogenetic populations in the Carpathian mountains, and from three triploid parthenogenetic populations in central Sweden. Altogether 16 different genotypes were found in triploid parthenogenetic populations. Two major types, comprising 39 out of the 76 parthenogenetic individuals, occur both in Scandinavia and in central Europe. The less frequent types can be derived from these through mutations. O. salicis is a flightless insect, which has been assumed to have overwintered the Würm glaciation in icefree refugia in Scandinavia. The overall genetic similarity found in the material suggests that the parthenogenetic race spread to its isolated Scandinavian area in postglacial times.

scholarly journals EXPECTED LINKAGE DISEQUILIBRIUM FOR A NEUTRAL LOCUS LINKED TO A CHROMOSOMAL ARRANGEMENT

Genetics ◽  
1983 ◽  
Vol 103 (3) ◽  
pp. 545-555
Author(s):  
Curtis Strobeck
Keyword(s):  
Linkage Disequilibrium ◽  
Balancing Selection ◽  
Natural Populations ◽  
Transient Behavior ◽  
Random Drift ◽  
Strong Linkage ◽  
Linkage Disequilibria ◽  
Chromosomal Arrangement ◽  
Neutral Locus ◽  
Selection For

ABSTRACT The expected value of the squared linkage disequilibrium is derived for a neutral locus associated with a chromosomal arrangement that is maintained in the population by strong balancing selection. For a given value of recombination, the expected squared linkage disequilibrium is shown to decrease as the intensity of selection maintaining the arrangement increases. The transient behavior of the expected square linkage disequilibrium is also derived. This theory applies to loci that are closely linked to inversions in Drosophila species and to loci closely linked to the differential segments of the translocation complexes in ring-forming species of Oenothera. In both cases the strong linkage disequilibria that have been observed in natural populations can be explained by random drift.

scholarly journals Inheritance and linkage relationships of allozyme variants of ilex paraguariensis St. Hil

2009 ◽  
Vol 52 (6) ◽  
pp. 1443-1451
Author(s):  
Simone Neumann Wendt ◽  
Valderês Aparecida de Sousa ◽  
Alexandre Magno Sebbenn ◽  
José Alfredo Sturion ◽  
Felipe Luíz ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Segregation Distortion ◽  
Gel Electrophoresis ◽  
Ilex Paraguariensis ◽  
Starch Gel Electrophoresis ◽  
Polymorphic Loci ◽  
Gene Segregation ◽  
Enzyme Systems ◽  
Starch Gel ◽  
Linkage Relationships

Eighteen enzyme systems were examined in Ilex paraguariensis St. Hil. using starch gel electrophoresis. Seven out of 12 active isozyme systems revealed one or more polymorphic loci (PGI, GOT, MR, G-6PDH, MDH, NDH, and 6-PGDH). However, the segregation and linkage analyses were performed only for PGI, GOT, G-6PDH and 6-PGDH systems. Gene segregation at these loci was regular, except for a few trees that showed segregation distortion. Weak linkage disequilibrium between loci was detected, but it was not enough to influence the multilocus estimate.

Specific status of Aquarius cinereus (Puton) and A. najas (De Geer) (Hemiptera: Gerridae) and the extent of hybridization in the Mediterranean region

1993 ◽  
Vol 24 (2) ◽  
pp. 197-210 ◽  
Author(s):  
Manfred Zimmermann ◽  
Adolf Scholl
Keyword(s):  
Body Length ◽  
Gel Electrophoresis ◽  
Natural Populations ◽  
Starch Gel Electrophoresis ◽  
Field Observations ◽  
Polymorphic Loci ◽  
Cross Breeding ◽  
Gene Differentiation ◽  
Starch Gel ◽  
Intermediate Size

AbstractResults of field observations, cross-breeding experiments, morphometry, and starch gel electrophoresis suggest that A. cinereus and A. najas are specifically distinct. Cross-breeding experiments between the two taxa in the laboratory were only successful when using males of A. cinereus and females of A. najas. Field observations on mixed populations in spring did not reveal any pre- or postcopulae involving partners of the two taxa (assigned by body length). Instead all pairs observed consisted of conspecific males and females. Morphometry of field caught adults of A. najas and A. cinereus yielded a clearly bimodal distribution of body length with only very few individuals of intermediate size. Therefore, body length alone allows reasonable separation of the two taxa in natural populations. Although F1-hybrids from laboratory rearings (photoperiod 18L:6D, temperature ∼ 23°C) differed only marginally in body length from A. najas reared under the same conditions, backcrosses and also F2-hybrids were of intermediate size. In the field individuals of both taxa are predominantly wingless, but both hybrids and backcrosses from the laboratory showed a net shift in morph ratio with many longwinged specimens. Vertical starch gel electrophoresis of three monomorphic (Apk, Got-2, Mdh-2), six polymorphic loci with low levels of polymorphism (Idh-1, Fum, Got-1, Mdh-1, Me, 6-Pgd) and three highly polymorphic loci (Es-4, Idh-2, Pgm) suggests that the two taxa do not share a common gene pool. Gene differentiation among all A. cinereus populations as measured by Nei's GST values is very low. Between Tyrrhenian and continental A. najas populations, however, gene differentiation is very high, and in the same order of magnitude as gene differentiation between the two taxa A. cinereus and A. najas in sympatric populations. Our field observations, together with morphometric data, laboratory rearings, and information on wing polymorphism, suggest that hybridization in natural populations is rare.

Fractionation of Plasminogen by Starch Gel Electrophoresis

1964 ◽  
Vol 12 (01) ◽  
pp. 126-136 ◽  
Author(s):  
Karl H. Slotta ◽  
J. D Gonzalez
Keyword(s):  
Gel Electrophoresis ◽  
Room Temperature ◽  
Broad Band ◽  
Caproic Acid ◽  
Starch Gel Electrophoresis ◽  
Full Activity ◽  
Veronal Buffer ◽  
Starch Gel ◽  
Alkaline Range

SummaryWhen urea or ε-amino caproic acid were used as solublizing agents for plasminogen in electrophoretic experiments, only one broad band of the proenzyme was obtained on acetate cellulose, in starch block, and in acrylamide gel. In starch gel electrophoresis, however, both forms of plasminogen – the native or euglobulin and Kline’s or Pseudoglobulin plasminogen – separated into six bands. These migrated toward the cathode at room temperature in borate or veronal buffer in the alkaline range and showed full activity in fibrinagar-streptokinase plates.

scholarly journals THE INHERITANCE OF ENZYME VARIANTS FOR TYROSINE AMINOTRANSFERASE, NADP-DEPENDENT MALATE DEHYDROGENASE, NADP-DEPENDENT ISOCITRATE DEHYDROGENASE, AND TETRAZOLIUM OXIDASE IN TETRAHYMENA PYRIFORMIS, SYNGEN 1

Genetics ◽  
1973 ◽  
Vol 74 (4) ◽  
pp. 595-603
Author(s):  
D Borden ◽  
E T Miller ◽  
D L Nanney ◽  
G S Whitt
Keyword(s):  
Detailed Analysis ◽  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Gel Electrophoresis ◽  
Tetrahymena Pyriformis ◽  
Tyrosine Aminotransferase ◽  
Breeding Program ◽  
Starch Gel Electrophoresis ◽  
Enzyme Locus ◽  
Starch Gel

ABSTRACT The isozymic patterns of tyrosine aminotransferase, NADP malate dehydrogenase, NADP isocitrate dehydrogenase, and tetrazolium oxidase were examined by starch-gel electrophoresis in Tetrahymena pyriformis, syngen 1. The genetics of the alleles controlling these enzymes was studied through a breeding program. Each enzyme locus was shown to assort vegetatively, as do other loci in this organism. A detailed analysis of the assortment process for the tyrosine aminotransferase locus indicated that the rate of stabilization of heterozygotes into pure types was essentially identical to previously-reported rates for other loci.

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