Glucose Phosphate Isomerase Locus Research Articles

Chromosomal localization of the glucose phosphate isomerase (GPI) gene in cattle, sheep and goat by in situ hybridization - chromosomal banding homology versus molecular conservation in Bovidae

A porcine genomic glucose phosphate isomerase (GPI) DNA probe was used for in situ hybridization with metaphase chromosomes in cattle, sheep and goat. The probe gave distinct signals on the q22----proximal part of the q24 segment of chromosome 18, 14 and 18 in cattle, sheep and goat, respectively, indicating the location of GPI gene. The three species belong to the family Bovidae and have high resemblance in chromosome banding patterns. The localization of the GPI locus to the same site on chromosomes with almost similar banding patterns suggests high degree of homology at these sites in the three species. Correlation between banding homologies and possible similarities at the molecular level is discussed.

The spleen is a major site of megakaryopoiesis following transplantation of murine hematopoietic stem cells

The stem cell pool can be fractionated by using the mitochondrial dye, rhodamine-123, into Rho(low) hematopoietic stem cells and Rho(high) progenitors. Rho(low) stem cells permanently engraft all lineages, whereas Rho(high) progenitors transiently produce erythrocytes, without substantial platelet or granulocyte production. We hypothesized that the inability of the Rho(high) cells to produce platelets in vivo was due to the fact that these cells preferentially engraft in the spleen and lack marrow engraftment. Initially, we demonstrated that Rho(high) progenitors produced more megakaryocytes in vitro than Rho(low) stem cells did. To study the activity of the Rho(low) and Rho(high) subsets in vivo, we used mice allelic at the hemoglobin and glucose phosphate isomerase loci to track donor-derived erythropoiesis and thrombopoiesis. Rho(low) stem cells contributed to robust and long-term erythroid and platelet engraftment, whereas Rho(high) progenitors contributed only to transient erythroid engraftment and produced very low numbers of platelets in vivo. Donor-derived megakaryopoiesis occurred at higher densities in the spleen than in the bone marrow in animals receiving Rho(low) stem cells and peaked around day 28. Blockade of splenic engraftment using pertussis toxin did not affect the peak of splenic megakaryopoiesis, supporting the hypothesis that these megakaryocytes were derived from progenitors that originated in the bone marrow. These data emphasize that in vitro behavior of hematopoietic progenitor cell subsets does not always predict their behavior following transplantation. This study supports a major role for the spleen in thrombopoiesis following engraftment of transplanted stem cells in irradiated mice.

Ecological Genetics of Mpi and Gpi Polymorphisms in the Acorn Barnacle and the Spatial Scale of Neutral and Non-neutral Variation

Different allozyme genotypes at the mannose phosphate isomerase (Mpi) locus in the northern acorn barnacle (Semibalanus balanoides) show a strong association with distinct intertidal microhabitats. In estuaries along the Maine Coast, the FF homozygote has higher fitness in exposed, high-tide level microhabitats while the SS homozygote has higher fitness under algal cover or at low-tide microhabitats. These patterns are consistent with a Levene (1953) model of balancing selection. In these same samples, polymorphisms at the glucose phosphate isomerase locus (Gpi) and mitochondrial DNA (mtDNA) show no fitness differences among microhabitats, providing intra-genomic controls supporting selection at or near Mpi. Here we report a similar analysis of genotype-by-microhabitat associations at sites in Narragansett Bay, Rhode Island, close to the southern range limit of S. balanoides. Genotype zonation at Mpi between high- and low-tide microhabitats is significantly different between Maine and Narragansett Bay due to opposite zonation patterns for the SF and FF genotypes. Enzyme activity data are consistent with this "reverse" zonation. At Gpi, there is significant microhabitat zonation in Narragansett Bay, while this locus behaves as a neutral marker in Maine. Mt DNA shows no significant microhabitat zonation in either Rhode Island or Maine. The Mpi data suggest that Levene-type selection for alternative genotypes in alternative habitats may operate at scales of both 10's of meters and 100's of kilometers. The Gpi data show how an apparently neutral locus can exhibit non-neutral variation under different environmental conditions. We argue that both Mpi and Gpi provide important genetic variation for adaptation to environmental heterogeneity that is recruited under distinct conditions of stress and carbohydrate substrate availability.

Rapid communication: a PCR amplified product length polymorphism (APLP) marker at the porcine glucosephosphate isomerase locus shows between-population frequency variation.

Rapid communication: a PCR amplified product length polymorphism (APLP) marker at the porcine glucosephosphate isomerase locus shows between-population frequency variation.

Genetic Responses of Isonychia bicolor (Ephemeroptera:Isonychiidae) to Chronic Mercury Pollution

The relationship between allozyme genotype and survival of nymphs of the mayfly Isonychia bicolor (Walker) when exposed to acute mercury concentrations was tested in laboratory experiments. The probability of survival and individual times-to-death were found to be significantly different among genotypes at the glucose phosphate isomerase locus, but not at the phosphoglucomutase locus. This pattern was consistent for both summer and winter temperatures and for populations from 2 separate, unpolluted streams. Subsequent field surveys were conducted to determine if results of these acute laboratory tests could be extrapolated to the more chronic, sublethal conditions present in the South River, Virginia. Genotypes identified as sensitive and tolerant in the laboratory experiments showed no consistent relationship with environmental mercury levels in the South River. In fact, one heterozygote identified as tolerant was found to be more frequent at the reference site than at contaminated sites, and no signific...

Testing neutral theorists: Revisiting heterozygosities at the phosphoglucomutase locus and glucose phosphate isomerase locus

A previous examination (6) of the distribution of frequencies of protein polymorphisms at the phosphoglucomutase and glucose phosphate isomerase loci showed a statistical bias against both loci being simultaneously polymorphic. A rebuttal of these findings based on a neutral theory approach to analysis has been published that argues against such a bias. The neutral theory approach is disputed on the grounds that 1) a fundamentally different data set was used and 2) that the data was skewed by the use of inappropriate transforms. Upgrading the original data with new observations confirms the original observation of a statistical bias against both loci being simultaneously polymorphic. A model based on different chemistries associated with different polymorphism can explain the observed distribution of PGM and GPI heterozygosities.

Effects of metal contamination from mine tailings on allozyme distributions of populations of great plains fishes

This study was conducted to assess the effects of zinc and lead on genetic variability of minnow populations (Gambusia affinis, Pimephales notatus, and Fundulus notatus) sampled from two creeks, one receiving mine drainage (Willow Creek) and one reference (Brush Creek), in the Tri-State Mining district in Kansas. Zinc and lead concentrations were greater in water samples taken from sites in Willow Creek compared to sites sampled in Brush Creek. While total numbers of fish captured from Willow Creek were smaller than numbers taken from Brush Creek, there were no differences in these fish communities for estimates of species diversity, richness and evenness. Genetic differentiation within creeks was rare. However, there was significant differentiation between creeks for allozymes of the enzymes glucose phosphate isomerase (GPI) in F. notatus and P. notatus, malate dehydrogenase (MDH) in G. affinis, and phosphogluconate dehydrogenase (PGDH) in F. notatus. Proportions of heterozygous genotypes of P. notatus and G. affinis were higher in Willow Creek compared to Brush Creek. In vitro experiments were conducted to assess the effects of zinc and lead on sensitivity of enzyme staining during electrophoresis. Results indicated allozyme sensitivity to zinc for GPI and PGDH loci. Other studies suggest that zinc competitively competesmore » with magnesium as a cofactor for these enzymes. Allozymes did not exhibit differential sensitivity to lead. The significant differentiation between creek populations and the results of the in vitro tests indicate a selective effect of zinc on allozymic distributions of these fishes. These results demonstrate the potential use of genetic variability as a bioindicator of heavy metal contamination.« less

Pacific oysters crassostrea gigas (Thunberg) of possible French origin in natural spat in the British Isles

Abstract Hatchery‐reared Pacific oysters (Crassostrea gigas) grown in the British Isles and Guernsey originate from an introduction through quarantine of small numbers of oysters from British Columbia, Canada. Previous electrophoretic analysis of samples of these oysters have shown the glucose phosphate isomerase locus to be monomorphic. Recent analysis of oysters from a commercial hatchery in Guernsey revealed a second allele at low frequencies which was unexpected and was thought to indicate the presence of oysters from another stock. Samples of hatchery‐reared oysters from France showed that they were highly polymorphic and carried the unexpected allele and four others. A natural spatfall of oysters from the River Teign (Devon) was sampled and these carried three alleles which were also found in the French C. gigas. This suggests that there has been movement of C. gigas possibly of French origin into this river. This finding and its implications in terms of conservation and management are discussed.

Long-range mapping of the calcium release channel and glucosephosphate isomerase loci using pulsed-field gel electrophoresis.

Long range restriction maps of the calcium release channel (CRC) and glucosephosphate isomerase (GPI) loci have been constructed using pulsed field electrophoresis, Southern blotting and CRC- and GPI-specific probes. The maps, deduced from the restriction fragments detected by the probes, covered 1.1 and 0.3 Mb respectively and no overlap between the maps of these closely linked loci was detected. The minimal distance between the GPI and CRC loci was estimated to be at least 500 kb.

Characterization of a porcine variable number tandem repeat sequence specific for the glucosephosphate isomerase locus.

A variable number of tandem repeat from a porcine glucosephosphate isomerase intron has been isolated and sequenced. The repeat has a unit size of 39 bp, is highly conserved and is present in at least 14 copies. Flanking sequences show a sequence periodicity of 53-54 bp and some sequence homology to the 39 bp repeat. A considerable part of the genomic DNA has been lost during subcloning and is considered to be deletion prone or refractory to propagation in E. coli. The tandem repeat is locus specific and detects at least six alleles in BamHI digested porcine DNA. No homology to other tandem repeat sequences has been found.

Detection of linkage between genetic markers and genes that affect growth and carcass traits in pigs.

Segregation of paternal marker alleles in the progeny of a single boar was used to estimate linkage between the marker genes and associations of these genes with quantitative trait loci (QTL). The sire was heterozygous at four polymorphic marker loci, haptoglobin (HP), glucosephosphate isomerase (GPI), phosphogluconate dehydrogenase (PGD), and esterase D (ESD), and sired 30 litters during an 8-mo period. Glucosephosphate isomerase and PGD were linked (theta = .09; P less than .005). The phase of these two loci in the sire was determined to be GPI A-PGD B, GPI B - PGD A. NO other linkages were detected. Growth (135 less than or equal to n less than or equal to 172) and carcass data (70 less than or equal to n less than or equal to 80) were analyzed assuming a fixed linear model. Least squares means were compared for differences in growth and carcass traits between pigs that inherited alternative paternal marker alleles. Pigs that inherited the GPI A allele from the sire had a 22-g higher daily live weight gain postweaning and reached 103 kg live weight in 2.6 fewer days than did pigs that inherited the GPI B allele (P less than .05), indicative of the presence of gene(s) that affect rate of gain linked to the GPI locus. Pigs that inherited the PGD B allele had a .14 unit higher score for muscle firmness (score ranged from 1 to 3 units) than pigs that inherited the PGD A allele (P less than .05). Pigs that inherited the HP 3 allele had a .06-kg higher weaning weight and a .11 lower ham muscle mass score than did pigs that inherited the HP 2 allele from the sire (P less than .05). No associations with quantitative traits were detected for ESD.

Localization of the malignant hyperthermia susceptibility locus to human chromosome 19ql2–13.2

Malignant hyperthermia (MH) is an inherited human skeletal muscle disorder and is one of the main causes of death due to anaesthesia. The reported incidence of MH varies from 1 in 12,000 in children to 1 in 40,000 in adults. MH is triggered in susceptible people by all commonly used inhalational anaesthetics; it is characterized by a profoundly accelerated muscle metabolism, contractures, hyperthermia and tachycardia. Susceptibility to MH (MHS) is predicted by contracture tests on muscle tissue obtained by biopsy. An almost identical disorder known as porcine MH exists in pigs. The genetics of the porcine syndrome have been extensively studied; the locus controlling expression of porcine MH is genetically linked to the glucose phosphate isomerase locus (GPI). In man, GPI has been mapped to the q12-13.2 region of chromosome 19 (refs 10-12). We have now investigated genetic linkage in several extended Irish pedigrees in which MHS is segregating as an autosomal dominant trait. Here we show linkage between MHS and DNA markers from the GPI region of human chromosome 19 with a maximum log likelihood ratio (lod score) of 5.65 at the CYP2A locus. These results indicate that human and porcine MH are most probably due to mutations in homologous genes, and also provide a potentially accurate and noninvasive method of diagnosis for MHS.

Evidence for tandem duplication of a glucosephosphate isomerase locus in Sciaenops ocellatus

Abstract Starch gel electrophoresis of the enzyme glucosephosphate isomerase from samples of tissue of the red drum ( Sciaenops ocellatus ) revealed more isozyme bands than would be expected for a dimeric protein that is coded by two loci, the common condition among teleostean fishes. We conclude that this is the result of a recent tandem duplication of the Gpi-B locus.

Discrimination among and variation within species of Pseudocalanus based on the GPI locus

Patterns of allozyme variation at the GPI (glucose phosphate isomerase) locus showed that the recently described or clarified Pseudocalanus newmani, P. acuspes, P. moultoni and P. minutus are genetically isolated from each other even though morphologically they are very similar, and in places sympatric. This genetic isolation was inferred from the presence of private alleles in some species, and from differences in their degrees of observed heterozygosity and in the observed frequencies of shared alleles in all the species examined. Temporal variations were not detected in P. newmani, P. acuspes and P. minutus. Populations of P. newmani and P. moultoni from the Atlantic and Pacific coasts of North America have apparently diverged. No such divergence was detected among samples of P. acuspes from Nova Scotia, the Canadian Arctic and the Baltic sea, and of P. minutus from Nova Scotia and Hudson Bay. P. elongatus collected in the English Channel differed from P. acuspes from the Baltic Sea.

Allelic expression at the sorbitol dehydrogenase and glucosephosphate isomerase loci in an interspecific hybrid ricefish

1. 1. The expression of alleles encoding the enzymes sorbitol dehydrogenase (SDH; EC 1.1.1.14) and glucosephosphate isomerase (GPI; EC 5.3.1.9) was investigated in Oryzias melastigma, O. javanicus and in O. melastigma ♀ × O. javanicus ♂ hybrids by acrylamide gel electrophoresis. 2. 2. It was not possible to investigate the expression of SDH or GPI in reciprocal hybrids as these fry failed to develop past the stage of embryonic body formation. 3. 3. The delay in appearance of isozymes of paternal SDH subunit composition, and paternal and maternal GPI-B subunit composition is in keeping with observed effects of gene regulatory divergence where alleles of maternal origin interact more effectively with maternal cytoplasmic regulatory factors than do alleles of paternal origin.

Porcine malignant hyperthermia carrier detection and chromosomal assignment using a linked probe.

In pigs, the gene for glucosephosphate isomerase (GPI) is linked to the halothane (HAL) gene which is responsible for malignant hyperthermia (MH). A single copy DNA probe, designated GPI8R, has been isolated from a pig genomic library using a porcine GPI cDNA probe. This probe detects, as was the case for the cDNA probe, a five allele polymorphism in SacI and PvuII digested pig DNA. Family studies show that this polymorphism is linked to the HAL locus and hence can be used in carrier detection. In situ hybridization with GPI8R assigned the GPI locus to bands p12-q22 of chromosome 6. We conclude that the HAL linkage group resides on chromosome 6.

Genes for serum amyloid A proteins map to Chromosome 7 in the mouse.

Several restriction fragment length variants have been detected among inbred strains using a mouse serum amyloid A cDNA clone. Five variants were shown to segregate as a single genetic unit and were mapped to Chromosome 7 between the glucose phosphate isomerase locus (Gpi-1) and the pink eye dilution locus (p) using recombinant inbred and congenic strains. The finding that no major MspI or BclI restriction fragments were shared between digests of DNAs from a Chromosome 7 congenic strain and its inbred partner, indicate that most, and probably all, sequences detected with the probe are clustered on Chromosome 7. Aneuploid mapping was used to show that the serum amyloid A gene complex (Saa) is proximal to the Chromosome 7 breakpoint in T(7;X)1Ct, a translocation in which the middle third of Chromosome 7 is inserted into the X-chromosome. A survey of inbred strains revealed a single common Saa haplotype and eight rare haplotypes. The complex distribution of 14 different variants suggests that recombination may have played a role in haplotype evolution.

A reciprocal relationship between heterozygosities of the phosphogiucomutase and glucose phosphate isomerase loci

Examination of the published literature shows that generally there is an association between heterozygosities of the phosphoglucomutase and glucose phosphate isomerase loci such that either heterozygosity of one locus is low when heterozygosity of the other is high; or both loci have low heterozygosities. There appears to be a general constraint that prevents both loci from being highly heterozygous together. An exception to this general rule is reported and the significance of this discovery is discussed.

Genetics of glucose phosphate isomerase and phosphoglucomutase in Aedes albopictus (diptera: culicidae)

Glucose phosphate isomerase (E.C. 5.3.1.9) and phosphoglucomutase (E.C. 2.7.5.1) were found to be polymorphic in a laboratory colony of Aedes albopictus. The glucose phosphate isomerase locus is represented by two alleles resulting in three genotypes, while the phosphoglucomutase locus is represented by at least five alleles giving rise to a total of 15 genotypes. The inheritance of these two enzymes is of the Mendelian type with codominant alleles. Present data indicate that these genes are not linked.Of 105 mosquitoes analysed for these two gene-enzyme systems, the frequencies for glucose phosphate isomerase alleles are Gpi (S)=0.68 and Gpi (F)=0.32, while the frequencies for phosphoglucomutase alleles are Pgm (A)=0.16, Pgm (B)=0.11, Pgm (C)=0.19, Pgm (D)=0.30 and Pgm (F)= 0.24. The frequencies of the three glucose phosphate isomerase genotypes are in accord with Hardy-Weinberg expectations (X 1 (2) =2.74). Similarly, the frequencies of the 15 phosphoglucomutase genotypes probably do not differ significantly from Hardy-Weinberg expectations (X 10 (2) = 18.45).

The geographical distribution of phosphoglucomutase and glucose phosphate isomerase alleles of some New Zealand fishes

1.1. Six species of New Zealand marine fishes were examined electrophoretically for enzyme polymorphisms at the phosphoglucomutase and glucose phosphate isomerase loci, the tarakihi (Cheilodactylus macropterus: Cheilodactylidae), the trevally (Caranyx georgianus: Carangidae), the barracouta (Thyrisites atun: Gempylidae), the red cod (Pseudophycis bacchus: Pseudophycidae), the jack mackerel (Trachurus declivis: Carangidae) and the gurnard (Trigla kumu: Triglidae).2.2. When the allele frequencies of five of these species are analysed statistically on the assumption of selective neutrality of observed electromorphs a number of apparent stock boundaries are observed.3.3. A number of these stock boundaries are shared by more than one species.4.4. When the same data is analysed statistically on the assumption that differences in allele frequency are due to differences in fitness of alleles, then the previously observed stock boundaries are replaced in two species by a North South cline apparently related to temperature. There is insufficient data available for the remaining four species to make a similar comparison.5.5. Further evidence indicates that these are genuine clines and not mosaic effects.