Electrophoretic Alleles Research Articles

A New PstI Restriction Fragment Length Polymorphism (RFLP) of Placental Alkaline Phosphatase

A new PstI restriction fragment length polymorphism (RFLP) of placental alkaline phosphatase (PLAP) was discovered in a study of a Finnish population sample and designated PstI(b)1 or Pst(b)2 depending on the presence or absence of the cleavage site. The frequency of the PstI(b)2 allele was 0.24. This allele showed a positive (p = 3 x 10(-6) association with the electrophoretic allele 2(F) and a negative association (2 x 10(-7) with the electrophoretic allele 1(S). The previously described PstI RFLP [PstI(a)] was also found to be associated with electrophoretic types; the PstI(a)1 allele (presence of site) was associated with the electrophoretic type 2 (p = 0.023). Haplotype frequencies and disequilibria were calculated between PstI(a), PstI(b) and RsaI RFLPs. A complete disequilibrium (p = 1 x 10(-6) was found between PstI(a) and RsaI, whereas there was no significant disequilibrium between PstI(b) and RsaI. There was no strict correlation between the distances between the RFLP loci and the degree of linkage disequilibrium. The allele controlling the electrophoretic variant PLAP 18 (D) was found in polymorphic frequency (0.024) in the Finnish population.

Comparison of electrophoretic allele frequencies and genetic variability of common carp stocks from Indonesia and Japan

Allele frequencies and genetic variability of six stocks of common carp collected from Indonesia and three stocks from Japan were evaluated. Twenty-three loci were identified from 11 enzyme and protein systems. Five loci were polymorphic for the Indonesian stocks and eight loci were polymorphic for the Japanese stocks. PGM, EST and GPI were useful for comparison between the Indonesian and Japanese stocks as well as stocks from Europe and China. In general, genetic variability of the stocks from Japan was higher than that of stocks from Indonesia. The genetic distance between pairs of stocks, based on 23 isozyme and protein loci, showed distinct genetic differentiation between Japanese and Indonesian stocks. The sources for the Japanese and Indonesian common carp are discussed in relation to the European and Chinese common carp.

Investigations on the PGM (phosphoglucomutase) polymorphism by isoelectric focusing inDrosophila melanogaster

Pgm allele frequencies of 383 individuals were determined in a sample of Drosophila melanogaster from three laboratory Sardinian populations, using the techniques of standard electrophoresis, heat denaturation, and isoelectric focusing. The analysis of the progeny obtained from informative crosses showed that the isoelectric focusing patterns segregate in a Mendelian way. The Pgm1.00 and Pgm0.70 electrophoretic alleles displayed different isoelectric points, whereas the Pgm1.00,tr and Pgm1.00,ts isoelectrophoretic alleles could not be differentiated when tested by isoelectric focusing. Moreover, the Pgm0.70,ts allele was split into two classes, with isoelectric points of pH 6.4 and pH 6.6.

Molecular evidence on the origin of wheat chromosomes 4A and 4B

The genome allocation of the Triticum aestivum L. chromosomes denoted 4A and 4B was based on an erroneous inference. Since neither chromosome pairs with the chromosomes of putative ancestors of wheat, molecular tools were employed to clarify the origin of the two chromosomes. Disomic substitutions for T. aestivum chromosomes 4A or 4B by chromosomes 4 from T. speltoides (Tausch) Gren., a putative ancestor of the wheat B genome, T. longissimum (Schweinf. et Muschl.) Bowden (a close relative of T. speltoides), or T. monococcum L. ssp. aegilopoides (Link) Thell., a close relative of the ancestor of the wheat A genome, were produced. The ability of the substituted chromosome to compensate in the disomic substitution lines, the C-banding patterns of the chromosomes, electrophoretic alleles at the Adh-1 and Lpx-1 loci, and in situ hybridization with an interspersed repeated sequence all were consistent in showing that the chromosome previously denoted as 4A belongs to the B genome and the chromosome previously denoted as 4B is a rearranged chromosome of the A genome. Chromosome 4A is consequently reallocated to the B genome and chromosome 4B to the A genome in T. turgidum L. em. Morris et Sears and T. aestivum. To reflect the fact that the chromosome previously denoted as 4B has only a homoeologous relationship to chromosome 4A of T. urartu (the ancestor of the A genome in polyploid wheats), the chromosome is designated 4Aa.Key words: repeated nucleotide sequence, alcohol dehydrogenase, lipoxygenase, in situ hybridization, chromosome evolution.

Restriction-map variation associated with the G6PD polymorphism in natural populations of Drosophila melanogaster.

Restriction-map variation was studied in 126 copies of the G6pd region in X chromosome lines of Drosophila melanogaster from North America, Europe, and Africa. Special attention was focused on the distribution of variation relative to the geographically variable polymorphism for two electrophoretic variants. Nucleotide heterozygosity as determined by eight six-cutter restriction enzymes for the 13-kb region is estimated, on the basis of the worldwide sample, to be 0.065%, which is the lowest value reported for any comparable region in the D. melanogaster genome. Significant linkage disequilibrium between electrophoretic alleles and restriction-site variation is observed for several sites. In contrast to published studies of other genetic regions, there are large insertions that reach significant frequencies and are found across considerable geographic distances. There is a clustering of this variation inside the first large intervening sequence of the G6PD gene.

Isolation and biochemical analysis of ethyl methanesulfonate-induced alcohol dehydrogenase null mutants of arabidopsis thaliana (L.) Heynh.

Several mutants have been isolated at the Arabidopsis thaliana (L.) Heynh. alcohol dehydrogenase (ADH) gene locus using allyl alcohol selection on ethyl methanesulfonate (EMS)-mutagenized seeds. Eleven mutants were isolated in the ADH1-A electrophoretic allele, and 21 in the ADH1-S allele. These null mutants are characterized by the absence of measurable ADH activity and genetic data showed that the mutations were confined to the ADH1 gene locus of Arabidopsis. Eleven mutants in the ADH1-A background were further characterized at the protein and mRNA level. These experiments revealed striking differences in the ADH protein and mRNA content. Some of the mutants did not synthesize any mRNA or ADH-like protein, whereas some of them had a nearly normal level of ADH protein and mRNA. Others had a very low level of both protein and mRNA. ADH null mutants differed physiologically from the wild type by their higher sensitivity to anaerobic treatment in plants and significantly reduced resistance to acetaldehyde in suspension cultures.

Gene Flow and Genetic Differentiation among California Coastal Rainbow Trout Populations

Present levels of genetic variability and estimates of historical rates of gene flow were obtained by analyses of allele frequency data from 31 California coastal rainbow trout populations. Genetic variability was higher than seen in most salmonid species. Seventy-one electrophoretic alleles were segregating at 24 loci. Seven loci were monomorphic. Between-population genetic indentities were high and there was only a weak relationship between geographic proximity of populations and genetic identity. Average within-population heterozygosity and percent polymorphic loci were 0.092 and 35.1, respectively. Estimated total heterozygosity was 0.106; therefore, 86.8% of the total gene diversity could be ascribed to within-population genetic variation. The remaining 13.2% of the total gene diversity represented genetic differences between rainbow trout populations. Both qualitative and quantitative methods of analyses suggested that historical rates of gene flow were high; realized gene flow was estimated to be at least 1.7 migrants per population per generation. It is argued that each population's allele frequencies may simply be expression of temporal fluctuations around the panmictic allele frequencies of the greater global population.

Genetics of growth in blue mussels: family and enzyme-heterozygosity effects

Shell length and electrophoretic heterozygosity at six enzyme loci were scored in juveniles of 30 hatchery-grown families and in adults of 10 field-grown families of the blue mussel Mytilus edulis. A total of 4 809 offspring were scored. We found no consistent pattern in the correlations between shell length and enzyme heterozygosity among sibs within families. However, a significant family effect on shell length was observed, suggesting an influence of background genotype on this character. A family effect on viability was also observed. When the environment and family effects were accounted for, a small positive correlation between heterozygosity and shell length at the juvenile stage remained. This correlation was significant in one of the three experiments. No such correlation was evident at the adult stage. Our interpretation of these results is that electrophoretic alleles appear to have no direct of independent effect of their own on growth. We suggest that the negative correlation of homozygosity with these characters, seen in natural populations, results from homozygosity for hidden recessive deleterious genes with which the electromorphs are in a steady state of quasilinkage disequilibrium.

TWO ALLELES OF MAIZE ALCOHOL DEHYDROGENASE 1 HAVE 3' STRUCTURAL AND POLY(A) ADDITION POLYMORPHISMS

Two standard electrophoretic alleles of the maize alcohol dehydrogenase 1 locus (Adh1-1S and Adh1-1F) have been isolated and characterized. Restriction endonuclease mapping shows that a region of less than 5 kb is conserved in both alleles and is flanked both 5' and 3' by regions highly polymorphic for restriction sites. Nucleotide sequence comparison of these two alleles reveals that polymorphism in the 3' flanking region is due to rearrangements including tandem duplications, a transposable element-like insertion and a deletion. S1 nuclease analysis shows that both the Adh1-1S and the Adh1-1F alleles contain multiple poly(A) addition sites; four sites are observed for the Adh1-1S alleles and seven sites for the Adh1-1F allele. Only two of these poly(A) addition sites appear to be identical in the two alleles. No consensus signal for poly(A) addition is observed near any of these sites.

A mannose phosphate isomerase polymorphism in the Isopod Asellus aquaticus

A mannose phosphate isomerase locus in Asellus aquaticus is highly polymorphic in two populations examined in Britain. Breeding studies indicate four classes of electrophoretic alleles based on mobility differences, a further null allele, and probable genetically determined variation in enzyme activity between individuals with the same electrophoretic alleles. No linkage with the polymorphic glucose phosphate isomerase and phosphoglucomutase loci was detectable.

Electrophoretic and heat-stability polymorphism at the phosphoglucomutase (Pgm) locus in natural populations of Drosophila melanogaster.

Genetic polymorphism for electrophoretic and heart-sensitive alleles is known at the phosphoglucomutase (Pgm) locus in Drosophila melanogaster. Analysis of the distribution of electrophoretic and thermosensitive (ts) alleles was carried out in natural populations from Canada and West Africa and compared with already known data on Italian populations [Trippa, G., Loverre, A., and Catamo, A. (1976). Nature 260:42]. The data show the existence of five common alleles, Pgm1.00,tr, Pmg1.00,ts, Pgm0.70,ts, Pgm1.20,ts, and Pgm1.50,tr, and two rare alleles, Pgm0.55,ts and Pgm1.20,tr. The most frequent allele is always Pgm1.00,tr; the second most common allele is always of the ts type. The cumulated frequencies of ts alleles in the populations varies between 11 and 32%. The heat stability polymorphism is present in all populations examined and shows again the uniform geographic pattern that has been found for electrophoretic variation at this locus.

Genetic determination of sn-glycerol-3-phosphate dehydrogenase synthesis in Drosophila melanogaster. A cis-acting controlling element.

A variant that uniformly reduces the activity of larval and adult isozymes of sn-glycerol-3-phosphate dehydrogenase (EC 1.1.1.8) throughout development has been isolated and analyzed. This low activity line (BI 114), which bears the fast electrophoretic structural allele, has been analyzed in comparison with two high activity control lines, WGM 74 (fast electrophoretic variant) and RI09 (slow electrophoretic variant). The enzyme has been purified from each line and all three variants have similar kinetic, immunological, and physicochemical parameters, except for pI differences associated with the electrophoretic differences observed. Enzyme-specific cross-reacting material analysis corroborates the activity data indicating differential rates of enzyme accumulation between lines throughout development. Protein turnover studies indicate that the rate of intracellular degradation between lines is the same, and that the activity and enzyme-specific cross-reacting material differences observed are due to differential rates of synthesis of the enzyme. Genetic analysis indicates that the variation in the rate of glycerol phosphate dehydrogenase synthesis segregates as a single gene with additive inheritance and is closely linked to the structural gene. Zymogram analysis of F1 heterozygotes has indicated that the variant acts as a cis-regulator and affects both isozymes equally throughout development. We have therefore designated this variant as a systemic regulator controlling the rate of glycerol phosphate dehydrogenase synthesis.

Opportunities for natural selection on DNA and protein at the Adh locus in Drosophila melanogaster

AbstractA study was made of environmental and genetic factors affecting the quantity and disposition of the alcohol dehydrogenase (ADH) protein in Drosophila melanogaster. It was found that the amount of enzyme per fly is greatly influenced by the environmental conditions in which it develops. A critical factor is the concentration of yeast in the medium. A high concentration of yeast can double the quantity of ADH. The yeast appears to act through the provision of protein, and the protein to act through the provision of threonine, which is already known to induce ADH in fungi.Various genetic factors affect the quantity of enzyme. Males have more ADH than females. Files homozygous for the Fast allele have more ADH than those homozygous for the slow allele, and the difference is greater in females than in males. One particular line (ve), homozygous for Slow, has approximately half the normal quantity of enzyme, and the quantity segregates with the electrophoretic allele. Lines differ in the relative amounts of ADH in the gut (including Malpighian tubules) and the fat body. In general it seems that slow lines have relatively more enzyme in the fat body. In a cross between ve and a line homozygous to Fast, the difference in tissue distribution segregated with the electrophoretic allele. It is argued, but not demonstrated, that the differences in quantity and tissue distribution are due to nucleotide substitutions in noncoding regions close to, or within, the structural gene.It seems likely that the observed environmental and genetic differences in the quantity and disposition of ADH will influence the relative selective values of the electrophoretic genotypes.

Protein polymorphisms, segregation in genetic crosses and genetic distances among fishes of the genus Xiphophorus (Poeciliidae).

The products of 49 protein-coding loci were examined by starch gel electrophoresis for populational variation in six species of Xiphophorus fishes and/or segregation in intra-and interspecific backcross and intercross hybrids. Electrophoretic variation was observed for 29 of the 35 locus products in a survey of 42 population samples. The highest frequency of polymorphic loci observed in noninbred populations was 0.143. After ten or more generations of inbreeding, all loci studied were monomorphic. Inbred strains generally exhibited the commonest electrophoretic alleles of the population from which they were derived. An assessment of genetic distances among Xiphophorus populations reflected classical systematic relationships and suggested incipient subspeciation between X. maculatus from different drainages as well as several species groups. Thirty-three loci were analyzed with respect to segregation in hybrids. The goodness of fit of segregations to Mendelian expectations at all loci analyzed (except loci in linkage group I) is interpreted as evidence for high genetic compatibility of the genomes of Xiphophorus species. It is anticipated that these data will result in a rapid expansion of the assignment of protein-coding loci to linkage groups in these lower vertebrate species.

A phylogeny for the principal alleles of the human phosphoglucomutase-1 locus.

The results of phosphoglucomutase-1 (PGM1) typings by starch gel electrophoresis and subtypings by isoelectric focusing are presented for a sample of Japanese. A distinction made on the basis of isoelectric focusing (termed "+" and "-") is nonrandomly associated with each of the products of the four most common electrophoretic alleles (PGM1(1), PGM1(2), PGM1(3), and PGM1(7). The isoelectric trait cosegregates with the allele; the degree of nonrandomness of the association varies from allele to allele. Thus, the four alleles become eight. On the basis of these facts plus the additive nature of the pI differences between allele products and the geographical distribution of the alleles, an allele phylogeny can be constructed. This postulates that the eight alleles may be explained by three nucleotide substitutions involving the stem allele plus four intragenic recombinations between these substitutions. The potential of intragenic recombination as a cause of mutation has been insufficiently appreciated.

Location of structural genes for glucose phosphate isomerase and for leucyl aminopeptidase on chromosome VII of Petunia

A gene termed gpiB, coding for one of the two isoenzyme zones of glucose phosphate isomerase in Petunia, has been mapped to a locus on chromosome VII by means of linkage to the marker An4, and by an allelic dosage effect on enzyme activity in trisomics. The high degree of linkage of electrophoretic alleles of gpiB to the pollen colour allele pair An4/an4, as demonstrated in the ancestral species, P. axillaris s.l. and P. integrifolia s.l., has been conserved in all cultivars of P. hybrida investigated. Another gene, coding for the enzyme leucyl-aminopeptidase could also be mapped to chromosome VII and the gene order An4 - lapB - gpiB determined. Apparently, distribution of lapB alleles is not related to the hybrid descent of P. hybrida.

Vocal Dialect Recognition and Population Genetic Consequences

SYNOPSIS. On the basis of male territorial song, a system of discrete dialects is described in a population of White-crowned Sparrows in central, coastal California. Four of these dialects are genetically differentiated from one another. Inbreeding coefficients calculated from electrophoretic alleles indicate that individuals in a dialect are inbred due to isolation of the dialect not because of inbreeding with close relatives. Males react more aggressively to male song from an adjacent dialect than to song from another member of their own dialect but react only weakly to song from a distant dialect. This indicates that male-male interactions may have a role in maintaining dialect populations. Females of the Mountain White-crowned Sparrow have been tested in dialect experiments in the laboratory and found to respond with precopulatory sexual posturing almost exclusively to song from the home dialect in comparison to song from an alien dialect. This indicates that female choice of mate may also play a role in maintaining dialect populations.

Life History, Morphology, and Electrophoretic Characteristics of Five Allopatric Stocks of Lake Whitefish (Coregonus clupeaformis) in the Great Lakes Region

Ecological, morphological, and electrophoretic variation among five allopatric Ontario lake whitefish (Coregonus clupeaformis) stocks was studied. The stocks differ in terms of diet, growth rate, movement patterns, fecundity, and egg and larval size. Morphologically, the five stocks were also different for characters such as number of gill rakers, number of pyloric ceca, and in size, adjusted for fork length, of the tail, dorsal fin, and the eye. Discriminant functions, derived from body measurements and meristic counts, classified specimens accurately into their lakes of origin. Highly significant allele frequency differences were found at 6 of the 32 electrophoretic loci examined. Standard genetic distances, derived from electrophoretic allele frequency differences, corresponded roughly to the order in which these stocks became isolated following retreat of the last continental glaciation. The genetic distance of the Opeongo stock from the other stocks is about one order of magnitude larger than the genetic distances among the other stocks. The Opeongo stock is also somewhat unusual ecologically, having different egg size and fecundity characteristics compared with the other stocks and being a member of a sympatric dwarf/normal pair. Dendrograms, derived from the Mahanalobis distances for the meristic variation and the Nei genetic distances for the electrophoretic variation, showed similar branching patterns, but the branching patterns for the morphometric versus the biochemical variation were different. A significant part of the morphometric variation among the stocks was related to differences in growth rates of the stocks, most body measurements being negatively correlated with growth rate. The Mahanalobis distances for the meristic variation (including pyloric ceca counts) were correlated with the standard genetic distances from the electrophoretic data. The ecological, morphological, and biochemical variation among the stocks, in relation to local adaptation, is discussed.Key words: lake whitefish, stock concept, genotype, phenotype, ecology, morphology, meristics, multivariate analysis, electrophoresis, growth, diet, fecundity

Further genetic heterogeneity of human red cell phosphoglucomutase-1: a mon-electrophoretic polymorphism.

The electrophoretic patterns of human red cell phosphoglucomutase (PGM) were determined by standard starch-gel electrophoresis on two aliquots of haemolysate, one of which was previously heat-treated. Samples from 67 families and 417 unrelated healthy subjects were examined. Heat denaturation studies combined with electrophoresis showed a greater heterogeneity of phosphoglucomutase-1 (PGM1) isozymes than that revealed by electrophoresis alone. Both PGM11 and the PGM21 isozymes turned out to be either heat-resistant (tr) or heat-sensitive (ts) and this new phenotypic property segregated along with the electrophoretic allele with which it was originally associated. Comparison of red cell PGM1 patterns of 217 PGM21-1 heterozygous individuals, analysed both as described in this paper and by acid starch-gel electrophoresis, which also distinguishes two common PGM11 (PGM1S1 and PGM1f1) and two common PGM12 (PGM2S1 and PGM2F1) allelic products, has shown that the two sets of four alleles do not coincide. Thus eight different PGM1 alleles were identified. The PGM1Str1, PGM1Sts1, PGM1Ftr1, PGM1FTSts1, PGM2Str1, PGM2Sts1, PGM2Ftr1 and PGM2Fts1 gene frequencies were estimated as 0 . 523, 0 . 066, 0 . 099, 0 . 029, 0 . 224, 0 . 012, 0 . 043, 0 . 004, respectively. Three polymorphic sites are hypothesized within the PGM1 structural gene and the observed frequencies of the eight alleles discussed in terms of 'disequilibrium' among these sites. This is the second example of a human enzyme isoelectrophoretic polymorphism revealed by research specifically aimed at detecting electrophoretically cryptic genetic variations. The technique used in this study appears to offer a reliable means of detecting isoelectrophoretic variants for proteins already known to be electrophoretically polymorphic.

Temporal and spatial distribution of phosphoglucomutase (PGM) polymorphism in natural populations ofDrosophila melanogaster

Drosophila melanogaster adults were collected for several years in various localities of Italy. The frequencies of thePgm electrophoretic alleles were determined and the similarity of the configuration of allelic frequencies observed. It was concluded that the PGM electrophoretic polymorphism could be maintained by random genetic drift in the natural populations studied only if the effective breeding size (Ne) during the bottle-neck period is about 5000.