6-phosphogluconate dehydrogenase activity variants inMusca domestica L.: A further allele at thePgd locus as proved by densitometric assay

A new electrophoretic variant of 6-phosphogluconate dehydrogenase (6PGD) has been detected in flies of a laboratoryMusca domestica strain. This variant is to be added to the two already described, PGD-A and PGD-B, identified by a fast-weak and a slow-thick electrophoretic band, respectively. The new variant, PGD-C, has the same mobility as PGD-A but provides a more intensely stained band; therefore it can be described as a fast-thick phenotype. The staining intensity of PGD-C is slightly lower than that of PGD-B. Genetic and densitometric tests have shown that the different levels of enzymatic activity of the two fast variants A and C are inherited as alternative genetic units, and they have been interpreted as one aspect of the phenotypic expression of twoPgd alleles, namely,Pgd ^A andPgd ^C. These alleles determine both the rates of electrophoretic mobility (fast in both cases) and the levels of activity (low for A, strong for C; shown by weak or thick stained electrophoretic bands). Similarly, the two distinctive features of PGD-B, namely, slow mobility and high activity level, are always jointly inherited and appear as two pleiotropic aspects of the phenotype coded for by thePgd ^B allele. ThePgd ^B/Pgd^C heterozygous flies provide a slightly asymmetrical three-banded zymogram, while thePgd ^A/Pgd^C combination leads to a single-banded pattern, showing the same mobility as the parents and an intermediate staining intensity. The quantitative analysis of enzyme activity of 6PGD zymograms, performed through densitometric methods, has led to the recognition of three different activity levels coded for byPgd alleles, one of which, namely,Pgd ^C, would not have been detected using electrophoretic methods alone.     

Associations between marker genotypes, halothane reaction, creatine kinase activity and meat quality characters in a sample of German Landrace pigs

Routine blood typing of German Landrace pedigree populations and an earlier study revealed very low frequencies of the favourable alleles at the marker loci Phi, Pgd and H. The hypothesis was that in this population the whole linkage group of favourable alleles at the halothane and neighbouring marker loci may have been lost as a consequence of intense selection for leanness and type. The present study of 1050 German Landrace pigs at the Relliehausen experimental station, where some effort has been made to maintain a higher frequency of the favourable alleles PhiA (0.48), H- (0.43) and PgdA (0.70) gave quite different results. The frequency of halothane-positive pigs found by using a severe test was only 30%. Only 5.4%, 8.8%, 13.4% and 13.9% of animals with PhiA/A, H-/-, PgdA/A and PhiA/B genotypes respecitively were halothane-positive. Forty to sixty per cent of pigs with these marker genotypes could therefore be expected to be homozygous halothane-negative (N/N) animals. Creatine kinase activity and three selected meat quality characters showed highly significant differences between the A/A and the B/B genotypes for the marker loci Phi and Pgd, with the heterozygotes being intermediate. These differences are greater than those observed between halothane-negative and halothane-positive phenotypes. The only other consistently superior marker genotype in this population was the H blood group genotype H-/-. In contrast to findings from Sweden and Switzerland, the postalbumin locus Po2 and the suppressor locus S for the A-O blood groups did not exhibit useful marker qualities.(ABSTRACT TRUNCATED AT 250 WORDS)     

6-Phosphogluconate dehydrogenase (PGD) genetics in the mouse: Linkage with metabolically related enzyme loci

An electrophoretic polymorphism of 6-phosphogluconate dehydrogenase (PGD) has been observed in the subspecies Mus musculus musculus from northern Denmark. M. m. musculus is interfertile with inbred strains of mice, and F1 hybrids with C57BL/6J show a three-banded phenotype. This pattern is consistent with a dimeric enzyme structure with codominant expression of alleles. In backcrosses and the F2 generation, PGD segregated as a singly autosomal gene, designated Pgd, closely linked to Gpd-1 on chromosome 4(1.7 +/- 1.1%). Both gene products are dimers, both require NADP, and these enzymes catalyze sequential steps in metabolism.     

Starch-gel electrophoretic variants of erythrocyte 6-phosphogluconate dehydrogenase in asian macaques

Five alleles with eight electrophoretic phenotypes of 6-phosphogluconate dehydrogenase were found in 1,195 blood samples from fourteen populations of nine macaque species.Macaca fascicularis from Malaya showed the most polymorphism, with three Pgd alleles resulting in five phenotypes.Macaca mulatta, M. speciosa, M. nemestrina, andM. cyclopis had two alleles each (although the last two species showed a high percentage of homozygosity). The remaining four species (M. fuscata, M. radiata, M. maura, andM. nigra) were homozygous for the Pgd^a allele. The predominance of Pgd^a was observed in all macaque species, exceptM. speciosa which showed a high (57%) frequency of Pgd^d. The distinctive position ofM. speciosa with regard to 6PGD variants parallels observations that indicate that this species carries transferrin and carbonic anhydrase I alleles in different frequencies from those of the other macaque species. Other similarities between the patterns of transferrin and 6PGD variations include a tendency toward homozygosity at the Pgd locus in the insular macaque forms. However, in this case only the Pgd^a allele is involved, while some variation was found in the transferrin alleles fixed by the founder effect in the insular macaques.This research was supported by NSF grants GF 253, GB 7426, and GB 15060 of the U.S.-Japan Cooperative Science and Systematic Biology Programs.     

Cytidine deaminase: a new genetic polymorphism demonstrated in human granulocytes.

Cytidine deaminase in human white blood cells has three electrophoretic phenotypes representing the homozygous and heterozygous expression of two common alleles, CDA1 and CDA2, at an autosomal locus. To explain the multibanded pattern of the heterozygote, the enzyme is assumed to have a tetrameric structure.     

Genetic variation at a pig serum protein locus, Po-2 and its assignment to the Phi, Hal, S, H, Pgd linkage group

Two-dimensional agarose gel (pH 5.4)-polyacrylamide gel (pH 9.0) electropho-resis of pig serum samples revealed a new serum protein (postalbumin-2, PO-2) polymorphism. Family data supported the hypothesis that the three PO-2 phenotypes observed were controlled by two codominant, autosomal alleles ( Po-2^F and Po-2^S ) at a single locus. The frequency of Po-2^F in Swedish Landrace and in Swedish Yorkshire breeds was estimated at 0.74 and 0.65, respectively. Evidence was presented for close genetic linkage between Po-2 and the red cell phospho-hexose isomerase locus ( Phi ). A recombination frequency of 3.2 % was obtained from double backcross material. Data obtained in a Danish Landrace material showing linkage between the Po-2 locus and the H blood group locus, the Pgd locus and Hal (locus for halothane sensitivity) are also given. A total of seven re-combinants were observed. They show that Po-2 is a new locus in a previously established linkage group. The likely sequence of the loci is: Phi, Hal, S, H, Po-2, Pgd .     

Xylose dehydrogenase-1, a new gene on mouse chromosome 7

We report a new enzyme xylose dehydrogenase, the structural locus for which is on chromosome 7 of the mouse, closely linked to Tam-1. Three alleles have been detected in both laboratory strains and wild populations. Two of these determine proteins differing in electrophoretic mobility and the third is a null. This easily scored variation may prove useful both for gene mapping and in population genetics.This work was supported by the Medical Research Council.     

Associations between marker genotypes, halothane reaction, CC activity and meat quality characters in a sample of German Landrace pigs

Routine blood typing of German Landrace pedigree populations and an earlier study revealed very low frequencies of the favourable alleles at the marker loci Phi, Pgd and H . The hypothesis was that in this population the whole linkage group of favourable alleles at the halothane and neighbouring marker loci may have been lost as a consequence of intense selection for leanness and type. The present study of 1050 German Landrace pigs at the Relliehausen experimental station, where some effort has been made to maintain a higher frequency of the favourable alleles Phi^A (0.48), H- (0.43) and Pgd^A (0.70) gave quite different results.
The frequency of halothane-positive pigs found by using a severe test was only 30 %. Only 5.4 %, 8.8 %, 13.4 % and 13.9 7% of animals with Phi^AIA, H^-I-, Pgd^A/A and Phi^A/B genotypes respectively were halothane-positive. Forty to sixty per cent of pigs with these marker genotypes could therefore be expected to be homozygous halothane-negative ( N/N ) animals. Creatine kinase activity and three selected meat quality characters showed highly significant differences between the A/A and the B/B genotypes for the marker loci Phi and Pgd , with the heterozygotes being intermediate. These differences are greater than those observed between halothane-negative and halothane-positive phenotypes. The only other consistently superior marker genotype in this population was the H blood group genotype H -^I- . In contrast to findings from Sweden and Switzerland, the postalbumin locus Po2 and the suppressor locus S for the A-O blood groups did not exhibit useful marker qualities.
It is concluded that in the German Landrace the marker loci Phi, Pgd and H could also be helpful in breeding homozygous halothane-negative pigs with distinctly better meat quality characteristics.     

Isozyme Analysis in a Genetic Collection of Amaranths (<Emphasis Type="Italic">Amaranthus</Emphasis> L.)

In various populations of the cultivated and weedy amaranth species, the electrophoretic patterns of alcohol dehydrogenase (ADH), glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), isocitrate dehydrogenase (IDH) and malic enzyme (Me) were studied. In total, 52 populations and two varieties (Cherginskii and Valentina) have been examined. Allozyme variation of this material was low. Irrespective of species affiliation, 26 populations and two varieties were monomorphic for five enzymes; a slight polymorphism of three, two, and one enzymes was revealed in three, nine, and fourteen populations, respectively. A single amaranth locus, Adh, with two alleles, Adh F and Adh S, controls amaranth ADH. Two alleles, common Gdh S and rare Gdh F, control GDH; no heterozygotes at this locus were found. The MDH pattern has two, the fast- and slow-migrating, zones of activity (I and II, respectively). Under the given electrophoresis conditions, the fast zone is diffuse, whereas slow zone is controlled by two nonallelic genes, monomorphic Mdh 1 and polymorphic Mdh 2 that includes three alleles: Mdh 2-F, Mdh 2-N, and Mdh 2-S. Low polymorphism of IDH and Me was also found, though their genetic control remains unknown.     

Isozyme analysis in a genetic collection of amaranths (Amaranthus L)

In various populations of the cultivated and weedy amaranth species, the electrophoretic patterns of alcohol dehydrogenase (ADH), glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), isocitrate dehydrogenase (IDH) and malic enzyme (Me) were studied. In total, 52 populations and two varieties (Cherginskii and Valentina) have been examined. Allozyme variation of this material was low. Irrespective of species affiliation, 26 populations and two varieties were monomorphic for five enzymes; a slight polymorphism of three, two, and one enzymes was revealed in three, nine, and fourteen populations, respectively. A single amaranth locus, Adh, with two alleles, Adh F and Adh S, controls amaranth ADH. Two alleles, common Gdh S and rare Gdh F, control GDH; no heterozygotes at this locus were found. The MDH pattern has two, the fast- and slow-migrating, zones of activity (I and II, respectively). Under the given electrophoresis conditions, the fast zone is diffuse, whereas slow zone is controlled by two nonallelic genes, monomorphic Mdh 1 and polymorphic Mdh 2 that includes three alleles: Mdh 2-F, Mdh 2-N, and Mdh 2-S. Low polymorphism of IDH and Me was also found, though their genetic control remains unknown.     

Genetic variation at a pig serum protein locus, Po-2 and its assignment to the Phi, Hal, S, H, Pgd linkage group

Two-dimensional agarose gel (pH 5.4)-polyacrylamide gel (pH 9.0) electrophoresis of pig serum samples revealed a new serum protein (postalbumin-2, PO-2) polymorphism. Family data supported the hypothesis that the three PO-2 phenotypes observed were controlled by two codominant, autosomal alleles (Po-2F and Po-2s) at a single locus. The frequency of Po-2F in Swedish Landrace and in Swedish Yorkshire breeds was estimated at 0.74 and 0.65, respectively. Evidence was presented for close genetic linkage between Po-2 and the red cell phosphohexose isomerase locus (Phi). A recombination frequency of 3.2% was obtained from double backcross material. Data obtained in a Danish Landrace material showing linkage between the Po-2 locus and the H blood group locus, the Pgd locus and Hal (locus for halothane sensitivity) are also given. A total of seven recombinants were observed. They show that Po-2 is a new locus in a previously established linkage group. The likely sequence of the loci is: Phi, Hal, S, H, Po-2, Pgd.     

A phosphoglucomutase polymorphism in the mosquito, Anopheles culicifacies

A survey of phosphoglucomutase (Pgm) among laboratory strains of Anopheles culicifacies has uncovered two electrophoretic variants. Detailed genetic analysis revealed that these variants are inherited as codominant alleles at a single locus. The Pgm locus has been assigned to linkage group III approximately 39 map units from Acph (acid phosphatase) and 8.5 map units from Dl (dieldrin resistance). The data indicate that the probable gene sequence is Acph-Dl-Pgm.     

The genetics of glutamic-pyruvic transaminase in mice: Inheritance,electrophoretic phenotypes,and postnatal changes

Glutamic-pyruvic transaminase (GPT, E.C. 2.6.1.2) from 18 inbred strains of mice was subjected to starch gel electrophoresis. Two electrophoretic phenotypes were observed: a fast-migrating pattern in 16 strains and a slower-migrating pattern in two strains. A comparison of electrophoretic patterns of F₁ and backcross progeny of two strains of mice showed that the inheritance of GPT is autosomal with two codominant alleles. The genetic locus for GPT is designated Gpt-1, and its two alleles are designated Gpt-1 ^a and Gpt-1 ^b to represent the fast-migrating (A) and slow-migrating (B) patterns. The GPT was expressed in 11 tissues with different amounts of enzyme activity. Developmental studies of GPT activity in liver showed that between 5 and 12 days after birth the mean activity was 10 units/g protein. Between 12 and 19 days, a dramatic rise in activity occurred and adult values of 300 units/g protein were reached by 26 days.This research was supported by The National Foundation (CRBS-258) and the National Institutes of Health (GM15253).Preliminary results were reported at the Annual Meeting of the American Society of Human Genetics, October 11–14, 1972, in Philadelphia.R. P. D. is an investigator of the Howard Hughes Medical Institute.     

Polymorphism of red cell glyoxalase I (EI: 4.4.1.5); a new genetic marker in man. Investigation of 169 mother-child combinations.

The polymorphism of glyoxalase I was investigated in 169 mother-child combinations from southwestern Germany. Glyoxalase I (GLO) has 3 common phenotypes: GLO 1, GLO 2-1, and GLO 2. The results are in good agreement with the formal hypothesis: Two alleles GLO1 and GLO2 at an autosomal locus. The GLO1 gene frequency was estimated to be 0.39. From the electrophoretic pattern the GLO-molecule appears to consist of two subunits.     

Mannose-6-phosphate isomerase polymorphism in baboon erythrocytes

Although erythrocytic mannose-6-phosphate isomerase (MPI) has been reported to be undetectable in mammals, we have demonstrated that sufficient activity is present in some species to enable its electrophoretic analysis. A survey of MPI from 2656 baboons revealed four allelic isozymes which segregated codominantly in pedigreed families. The gene frequencies differed significantly among five subspecies of baboons. However, the MPI*C allele had the highest frequency in all subspecies, ranging from 0.830 to 1.000. MPI phenotypes from erythrocytes and liver of the same individual were identical, indicating that the erythrocytic enzyme is specified by the same gene locus as the liver enzyme.     

The α-Glycerophosphate in DROSOPHILA MELANOGASTER II. Genetic Aspects

Seven alleles of the alpha-Glycerophosphate dehydrogenase-1 (alphaGpdh-1) locus of Drosophila melanogaster have been described. These include two naturally occurring electrophoretic variants, one EMS-induced electrophoretic variant, and four EMS-induced "null" or "zero" mutants. With the electrophoretic variants, the locus was mapped to II-20.5 +/- 2.5. A complementation matrix was prepared utilizing the null mutants. Three of the four mutants and a deletion of the locus (Grell 1967) exhibit dosage dependency. The dosage independent mutant exhibits complementation with two of the other null alleles. Flies genetically deficient in alpha-glycerophosphate dehydrogenase are fertile, but their relative viability is severely diminished. Such flies also lose the ability to sustain flight, an observation consistent with the enzyme's function in energy production. The levels of mitochondrial alpha-glycerophosphate oxidase, measured in flies genetically deficient in the cytoplasmic enzyme, were normal.     

Soluble blood proteins and hemoglobin from red-backed and large- toothed voles

Electrophoretic pattern of serum proteins of northern red-backed and large-toothed voles was examined. Seven main protein zones were distinguished. In four of them variability was observed, possibly genetically determined. Polymorphism of transferrins was thoroughly studied. 6 alleles and only 7 phenotypes of this protein were found in the northern red-backed vole, while 3 alleles and 4 phenotypes were revealed in the large-toothed red-backed vole, two alleles being common. Distribution of phenotype frequencies observed in both species differs significantly from the expected value. The portion of heterozygous phenotypes is quite high in both species, being 0.304 and 0.400 in the northern red-backed and large-toothed red-backed voles, respectively. Hemoglobins of the species studied were identical in electrophoretic mobility and monomorphic.     

Mitochondrial iso-citrate dehydrogenase variation in the Australian bush-rat, Rattus fuscipes greyii

Four reproductively isolated populations of the Australian bush-rat, Rattus fuscipes greyii , are polymorphic for electrophoretic variants of the mitochondrial enzyme, NADP-dependent iso-citrate dehydrogenase (M-Idh). The electrophoretic patterns of M-Idh and a small amount of breeding data are in agreement with the hypothesis that the variation is controlled by two alleles at an autosomal locus, Idh-2. In three relatively large populations, the proportion of heterozygotes at the Idh-2 locus ranges from 0.07 to 0.23, while on a small off-shore island it is 0.60. In this latter population there is an excess of heterozygotes which is on the borderline of statistical significance, suggesting that heterotic selection may be maintaining the polymorphism. Populations on eight other small islands are monomorphic for the allele which is the most frequent in the large populations. In most species M-Idh is less variable than most other enzymic proteins and the results presented here constitute one of the few published examples of an extensive M-Idh polymorphism.     

The Study of Genic Variation by Electrophoretic and Heat Denaturation Techniques at the Octanol Dehydrogenase Locus in Members of the DROSOPHILA VIRILIS Group

Heat denaturation studies of three different electrophoretic allozymes of octanol dehydrogenase were performed from 10 species of the Drosophila virilis group. A total of 18 alleles were discovered, and in 3 species in which electrophoretic studies indicated that the locus was monomorphic, heat denaturation showed that the locus was polymorphic. We show that electrophoretic studies underestimate the number of alleles at this locus by a factor of 2.6 in these species. The results are discussed in the light of the continuing controversy over selection and neutral theories of genetic variation.     

Genetic differences in milk proteins among laboratory rats (Rattus norvegicus)

Genetic differences in the electrophoretic pattern of milk proteins were observed among different inbred rat strains. The results of segregation analysis made on a limited number of females is consistent with the hypothesis of two codominant autosomal alleles system.