Phenotypic polymorphism and allele differentiation of isozymes in fodder beet,multigerm sugar beet and monogerm sugar beet

Summary Thirteen enzymes (MDH, SDH, LAP, PGM, PX, IDH, GPI, 6PGD, APH, GOT, GDH, ME and SOD) of 3 cultivated beet (B. vulgaris L.) gene pools, comprising 12 accessions of fodder beet, 11 of old multigerm sugar beet and 10 of modern monogerm sugar beet, were investigated using horizontal starch gel electrophoresis. Eleven accessions of primitive or wild B. vulgaris were also included for the comparison of isozymes. Variation in isozyme phenotypes was investigated to detect diversity in the three cultivated forms of beet. Phenotypic variation was observed in all except ME and SOD, which were monomorphic. A high degree of phenotypic polymorphism (Pj) was found in GDH, PGM, IDH, APH and MDH. Differences in phenotypic polymorphism in MDH, GPI and PX were recognized between fodder beet and both sugar beet groups. Average polymorphism for 13 enzymes in both sugar beets was significantly higher than that in fodder beet. For 13 enzymes, the existence of high isozyme diversity in both sugar beet gene pools was revealed. Allele frequencies in 13 alleles of five enzyme-coding loci, Lap, Px-1, Aph-1, Got-2 and Gdh-2, were investigated. New alleles, Px-1 ¹ and Got-2 ¹, were found in fodder beet accessions. No significant differences of average allele frequencies of five loci between fodder beet and both sugar beets were recognized. Several unique alleles and different isozyme phenotypes were observed in the accessions of B. vulgaris ssp. macrocarpa and ssp. adanensis. Future utilization of cultivated beet gene pools for sugar beet breeding is discussed from the viewpoint of genetic resources.     

Chromosomal location of isozyme and seed storage protein genes in Dasypyrum villosum (L.) Candargy

Summary The zymogram phenotypes of glucose-phosphate isomerase (GPI), alcohol dehydrogenase-1 (ADH-1), glutamate oxaloacetate transaminase (GOT), superoxide dismutase (SOD), lipoxygenase (LPX), esterase (EST) and the banding patterns of gliadin and glutenin seed storage proteins were determined for Triticum aestivum cv. Chinese Spring (CS), Dasypyrum villosum, the octoploid amphiploid T. aestivum cv. Chinese Spring D. villosum (CS × v) (2n=8x=56; AABBDDVV), and for five CS-D. villosum disomic addition lines. The genes Gpi-V1, Adh-V1, Got-V2, and Sod-V2 coding for GPI-1, ADH-1, GOT-2, and SOD-2 isozymes were located in D. villosum on chromosome 1V, 4V, 6V, and 7V, respectively. Genes coding for gliadin- and glutenin-like subunits are located in D. villosum chromosomes 1V. There are no direct evidence for chromosomal location of genes coding for GOT-3, EST-1 and LPX-2 isozymes. The linkage between genes coding for glutenin-like proteins and GPI-1 isozymes in chromosome 1V is evidence of homoeology between chromosome 1V and the chromosomes of homoeologous group 1 in wheat.Research supported by the National Research Council (Italy) and National Science Foundation (USA). International cooperative project, Grant No. 85.01504.06 (CNR)     

Duplicated phosphoglucose isomerase genes in avocado

Summary Avocado (Persea americana) cultivars were assayed for phosphoglucose isomerase (PGI) isozymes using starch gel electrophoresis. Three PGI genes were identified: one monomorphic locus, Pgi-I, coding for the plastid isozyme and two independently assorting loci, Pgi-2 and Pgi-3, coding for the cytosolic isozymes. The genetic analysis was based on comparisons of PGI zymograms from somatic and pollen tissue and on Mendelian analysis of progeny from selfed trees. The isozymic variability for PGI can be used for cultivar identification and for differentiating between hybrid and selfed progeny in avocado breeding.     

Characterization of aLycopersicon esculentum xSolanum lycopersicoides somatic hybrid lacking a glutamate oxaloacetate transaminase isozyme

Morphological, cytological, isozyme and chloroplast DNA analyses were used to determine possible mechanism(s) for the loss of glutamate oxaloacetate transaminase-4 (GOT-4) isozyme activity in a somatic hybrid. Plant 204-1, derived by cell fusion between tomato (Lycopersicon esculentum) andSolanum lycopersicoides, was characterized for bothGot-4 and acid phosphatase-2 (Aps-2), two isozyme loci which are closely linked (recombination 2.5 cM). This hybrid was determined to be chimeric for bothGot-4 andAps-2. TheS. lycopersicoides plant used to provide cells for the fusion was determined to be heterozygous for bothGot-4 andAps-2. Only oneS. lycopersicoides allelic form ofAps-2 andGot-4 was found in plant 204-1. This observation indicated that either the alternative copy of theS. lycopersicoides chromosome region encodingGot-4 andAps-2 is deleted or the entire chromosome is absent. Plant 204-1 was cytologically determined to be aneuploid with approximately 62 chromosomes. Sixty-two somatic hybrids of separate callus origin were analysed for GOT-4 and a high proportion (27%) lacked theS. lycopersicoides form ofGot-4. The loss of this allele and the linkedAps allele most likely occurred in the suspension culture ofS. lycopersicoides used to provide cells for fusion.     

Glutamate oxaloacetate transaminase (got) genetics in the mouse: polymorphism of got-1

We have examined a polymorphism for the soluble glutamate oxaloacetate (GOT-1) isozyme system which was found in the Asian mouse Mus castaneus. Variants of GOT-1 segregate as though they are controlled by codominant alleles for a single autosomal locus which we have designated Got-1. No close linkage of genes for soluble and mitochondrial forms of the enzyme, GOT-1 and GOT-2 respectively, was observed. Furthermore, no close linkage of Got-1 and the loci c, Gpi-1, Mod-2, Mod-1, Ld-1, Gpd-1, Pgm-1 or Gpo-1 was observed. Our results demonstrate the utility of sampling Mus from diverse populations to extend the repertoire of polymorphic loci and the genetic linkage map.     

Allozyme Variation of Nonspecific Esterases in Russian Sturgeon Acipenser güldenstädti Brandt

Electrophoresis in 7% polyacrylamide gel was used to analyze nonspecific esterases from different organs and tissues of Russian sturgeon. The basic enzymatic activity was observed in four zymogram zones. In sixteen cases the patterns of isozyme distribution in these zones allowed to consider them as allele systems (14 polymorphic and 2 monomorphic) corresponding to the four structural genes. The observed genotype frequencies of the nine of these systems (EST-1* of brain and intestine; EST-2* of serum and intestine; EST-3* of spleen and kidney; and EST-4* of spleen, brain, and heart) were largely concordant with Hardy–Weinberg proportions for codominant disomic inheritance. Genetic control of other polymorphic systems is unknown, but, high enzymatic activity of these esterases, sufficient for qualitative electrophretic detection, permits utilization of these polymorphisms for phenotypic monitoring of Russian sturgeon populations.     

Linkage relationships of 19 protein coding genes in watermelon

Summary Segregation of seed proteins and isozymes was analysed in two Citrullus crosses. In the first cross an F1 hybrid between C. lanatus and the wild species C. colocynthis was used as a female parent in a backcross to C. lanatus. In this interspecific cross the segregation of 17 markers was analysed. Four linkage groups were identified: linkage group 1 includes the genes Est-2, Skdh-2, Tpi-1, Fdp-1, Sod-1 and Prx-1; linkage group 2 — Got-1, Got-2 and Sp-4; linkage group 3 — Pgm-1 and Gdh-2; linkage group 4 with Pgi-1 and Pgi-2. In the second cross an F1 hybrid between two C. colocynthis accessions was backcrossed to one of its parents. Seven loci were scored and no new linkages were found.     

Associations of genes encoding allozymes peroxidase and superoxide dismutase in poplar and spruce species

Summary Isozymes of peroxidase (PER) and superoxide dismutase (SOD) were analyzed in vegetative buds or very young leaves of seven species and two interspecific hybrids of Populus, in progenies of seven controlled crosses of three Populus species, and in needles of five Picea species and one putative hybrid. One to three PER, and one or two SOD zones of activity were observed. Electrophoretic mobility (EM) and banding phenotypes of isozymes of one PER locus were identical to those of one SOD locus in vegetative buds of five Populus species and hybrid. In leaves of the four Populus species and hybrid and progenies of controlled crosses, EM and phenotypes of isozymes of two PER loci were identical to those of two SOD loci. In Picea species, EM of isozymes of the only SOD locus was somewhat similar but not identical to that of one PER locus, and isozyme phenotypes of all individuals at the SOD locus were not identical to those at a PER locus. Chi-square tests verified the single-gene Mendelian control of the segregating allozyme variants at each of Per-L1 and Sod-1 in the three Populus species. The results of joint two-locus segregation tests indicated a very tight linkage and no recombination between Per-L1 and Sod-1 in three Populus species. Genes coding for isozymes of one or two PER loci are either presumably the same as, or very tightly linked to, the genes coding for isozymes of one or two SOD loci in the Populus species.     

Inheritance and linkage relationships of glutamate oxaloacetate transaminase isoenzymes in apple

Summary Independent dimeric genes GOT-2 and GOT-4 determining activity for glutamate oxaloacetate transaminase (E.C.2.6.1.1; GOT) in zones GOT-II and GOT-IV respectively were identified. Three alleles were found for GOT-2 and two for GOT-4, including a null allele for GOT-2 which produced detectable heterodimeric bands but not homodimeric bands. Linkage studies with leucine aminopeptidase (E.C.3.4.11.1; LAP) genes suggested linkage of GOT-2 with LAP-2 (r=0.13±0.23) and GOT-4 with LAP-1 (r=0.10±0.40).The results reported in this paper are part of a London University PhD thesis by the first author     

Genetics of esterase isoenzymes in Malus

Summary Three main zones of esterase activity (EST-I, EST-III, EST-IV) identified in leaf extracts of cultivated apple and Malus species were determined by the genes EST-1, EST-3 and EST-4, respectively. In addition to earlier reported alleles of EST-1 (a, b) three further bands c, d and f were identified in the EST-I zone of which c was found to be determined by an allele, c. Two alleles, a, b, and a null allele were found for both the genes EST-3 and EST-4. Differences in allelic frequency were observed between cultivars, rootstocks and Malus species. Allele EST-1a was rare amongst the rootstocks. The examination of Malus species and derivatives showed a geographical relationship. Allele EST-1c was confined to species of Asian origin, and EST-1d was confined to American species.     

Genetic divergence between two forms of a tongue sole <Emphasis Type="Italic">Cynoglossus interruptus</Emphasis>

Genetic differences between trilinear and dilinear forms of a tongue sole, Cynoglossus interruptus, were examined by use of isozymes. Unequivocal differences were detected between the two forms, including complete replacement of alleles at the FBALD-2*, MDH-3*, PROT-1*, and SOD-1* loci, almost complete replacement at the AAT-3*, AH-1*, AH-2*, EST-3*, G3PDH-3*, GPI-2*, IDHP-1*, and MDH-1* loci, and extreme differences in allelic frequencies at the GPI-1* and PGDH* loci. The genetic distances (D values) between the two forms were 0.4207–0.4353, figures predicatively significant at the specific level. The considerable genetic differences strongly suggested that the two forms represent distinct species. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Inheritance and linkage relationships of ten isozyme genes in hazelnut

Summary The inheritance of 6-phosphogluconate dehydrogenase (6PGD), malate dehydrogenase (MHD), aconitase (ACO), phosphoglucomutase (PGM), phosphoglucoisomerase (PGI), and glutamate-oxalacetate transaminase (GOT) polymorphic isozymes was studied in leaf extracts of nine hazelnut progenies using horizontal starch gel electrophoresis. Evidence of Mendelian inheritance was obtained for ten loci: 6-Pgd-2, Mdh-1, Aco-1, Aco-2, Pgm-1, Pgm-2, Pgm-3, Pgi-2, Pgi-3, and Got-2, which permitted the analysis of 28 alleles (2.8 per locus). The presence of null alleles was detected in Pgm-1 and Pgm-3. Joint segregation analysis of pairs of isozymes revealed four linkages: Mdh-1-Pgi-2, Aco-2-Pgm-2, Pgm-1-Pgm-3, and 6Pdg-2-Pgm-2.     

Genetic control of allozymes from the juniper tall (<Emphasis Type="Italic">Juniperus excelsa</Emphasis> Bieb.) of Crimea

The genetic control of nine enzyme systems has been analyzed in the preserved juniper species (Juniperus excelsa Bieb.) from a natural population of the Mountain Crimea. Isozymes were extracted from endosperms of the haploid seeds to be studied by electrophoresis. As a result 16 loci have been identified, of which 14 loci were polymorphic (Gdh, Got-1, Mdh-1, Mdh-2, Mdh-3, Acp-1, Acp-2, Acp-3, Lap-1, Dia-1, Fdh, Sod-1, Sod-2, and Sod-3). Analysis of allele segregation in heterozygous trees confirmed monogenic inheritance of these alleles.     

Genetics of superoxide dismutase in apple

 Four zones of superoxide dismutase (SOD), activity were detected in apple. Genetic studies confirmed the presence of three genes Sod-1, Sod-3 and Sod-4 with three, two and two alleles respectively, including one null allele. One of these genes, Sod-1, was found to be loosely linked to Prx-2 and Prx-3. The Sod-1a allele predominated in all the three groups studied, cultivars, rootstocks and Malus species. The distinct achromatic bands produced by SOD after electrophoresis facilitate its important role with peroxidase (PRX), glutamate oxalacetate transaminase (GOT) and phosphogluconate dehydrogenase (PGD) in the discrimination of apple cultivars. Received: 22 November 1996/Accepted: 29 November 1996     

Allozyme variation of nonspecific esterases in Russian sturgeon (Acipenser güldenstädti Brandt

Electrophoresis in 7% polyacrylamide gel was used to analyze nonspecific esterases from different organs and tissues of Russian sturgeon. The basic enzymatic activity was observed the four zymogram zones. In sixteen cases the patterns of isozyme distribution in these zones allowed to consider them as allele systems (14 polymorphic and 2 monomorphic) corresponding to the four structural genes. The observed genotype frequencies of the nine of these systems (EST-1* of brain and intestine; EST-2* of serum and intestine; EST-3* of spleen and kidney; and EST-4* of spleen, brain, and heart) were largely concordant with Hardy-Weinberg proportions for codominant disomic inheritance. Genetic control of other polymorphic systems is unknown, but, high enzymatic activity of these esterases, sufficient for qualitative electrophretic detection, permits utilization of these polymorphisms for phenotypic monitoring of Russian sturgeon populations.     

Dissociation-recombination of intergenic sunflower alcohol dehydrogenase isozymes and relative isozyme activities

Two unlinked genes, Adh ₁ and Adh ₂, control the production of alcohol dehydrogenase (ADH) in seeds of the annual sunflower (Helianthus annuus). Each gene is polymorphic, having F and S alleles. Starch gel electrophoretic zymograms of the four possible double homozygotes have three bands, representing two homodimers and an intermediately migrating intergenic isozyme. Zymograms of double heterozygotes consist of nine bands produced by ten isozymes: six intragenics and four intergenics, two of which are coincident. Results of dissociation-recombination (D-R) experiments are reported which demonstrate the subunit composition of the intergenic isozymes, thus supporting the relationships suggested by genetic studies. Densitometric tracings of the zymogram of a cleared gel and measurements of activities of homodimer isozymes eluted from gels following D-R of an intergenic isozyme showed that the Adh ₂ isozymes were more than twice as active as those of Adh ₁. Measurements of activities of crude extracts from the four possible double homozygous genotypes indicated that the seeds of the genotype Adh ₁ ^F /Adh ₁ ^F , Adh ₂ ^S /Adh ₂ ^S produced more activity than the other three. This genotype is the most common one found in wild and cultivated stocks. Isozymes eluted following electrophoresis of the same extracts had averages of 19%, 70%, and 11% of total activity contributed by the Adh ₁, Adh₂, and intergenic isozymes, respectively. A simple but efficient method of isozyme elution from starch gels is described which resulted in nearly full expected recovery (approximately 46%) of the ADH activity in the applied sample.Supported by Graduate School and BioMed grants and by NSF Grant GB35853.     

D genome doners for Aegilops cylindrica (CCDD) and Triticum aestivum (AABBDD) deduced from esterase isozyme analysis

Summary Putative D genome donors for Aegilops cylindrica (2n = 28, CCDD) and Triticum aestivum (2n = 42, AABBDD) were studied with the isoelectric focusing patterns of esterase isozymes. 103 strains of Ae. cylindrica were uniform in their isozyme pattern. 30 strains of the putative parent, Ae. caudata, showed no zymogram variation, whereas the other parent, Ae. squarrosa, comprised 3 phenotypes. Natural Ae. cylindrica had an isozyme pattern which corresponded to a mixture of esterases from Ae. caudata and type 3 Ae. squarrosa. Therefore, it is concluded that the D genome donor of Ae. cylindrica is derived from type 3 Ae. squarrosa. These results suggest that Ae. cylindrica originated with a single amphiploidy event, and the C and D genomes have remained remarkably constant regarding esterase isozyme composition.On the other hand, T. aestivum comprised three zymogram phenotypes. These phenotypes contain bands which can be ascribed to the D genome of type 2 Ae. squarrosa. These results suggest that the D genome of Ae. cylindrica differs from that of T. aestivum. Evolution of the AB and D genomes of T. aestivum is indicated by the zymogram polymorphism. The origin of Ae. cylindrica is possibly more recent than that of T. aestivum.Contribution No. 433 of the Laboratory of Genetics, Faculty of Agriculture, Kyoto University     

Malate Dehydrogenase Isozymes (MDH; EC 1.1.1.37) in Long-Term Callus Culture of Cereus peruvianus (Cactaceae) Exposed to Sugar and Temperature Stress

Malate dehydrogenase (MDH; EC 1.1.1.37) isozymes in long-term callus tissue culture of Cereus peruvianus were studied in starch gel electrophoresis to investigate the control of differential Mdh gene expression under sugar and temperature stress. While two cytosol MDH isozymes showed an unchanged phenotype when the callus tissues were transferred to medium maintained at 22 or 37°C and containing different concentrations of sucrose, glucose, and fructose, the different combinations of five mitochondrial MDH (mtMDH) and two microbody MDH (mbMDH) showed different MDH isozyme patterns in the callus populations. Differential expression of mtMDH isozymes seems to be modulated at the posttranslational level in callus tissues exposed to different concentrations and types of sugar and to high-temperature and low-temperature stress. An inductor effect on the expression of mbMDH isozymes was observed under stress conditions and in long-term callus tissue, and they may also present different responses.     

A Study on Glutamate Oxaloacetate Transaminase Isozymes of Citrus Germplasm Resources

The glutamate oxaloacetate transaminase isozymes (GOT) extracted from 125 biotypes of Citrus and its relatives, Fortunella, Poncirus and Microcitrus were analyzed using polyacrylamide gel electrophoresis to investigate the taxonomic relationships among citrus plants. Besides all the isozymes reported before, two new bands were detected and designated their putative alleles B and C in GOT-l. Among pummelo cultivars wide variations were found. Most of the mandarins were identical, having SS for GOI-1 and MM for GOT-2 except for Zou-Pi-Gan and Yao-Gan, which both had FS at GOT-1 and might be hybrids. This finding suggests that all of the mandarins may have originated from a common ancestor. Sour orange biotypes showed a considerable variation in GOT isozymes. Most of the sour oranges in China were assumed to be hybrids between pummelo and mandarin based on GOT isozyme patterns, but two biotypes, Xiao-Hong-Cheng and Zhu-lan, had FS at GOT-1 and MB at GOT-2, which strongly suggests that they be hybrids of pummelo and Ichang papeda because B allele of GOT-2 occurs only in Ichang papeda and its close relatives Yuzu and Ichang lemon. From this study Yuzu is assumed to be derived from hybridizationof Ichan, papeda and mandarin.     

Genetic control of lactate dehydrogenase isozymes in Paramecium caudatum

The LDH isozymes were surveyed in bacterized cultures of syngens 1, 3, 12, and 13 of Paramecium caudatum by polyacrylamide gel electrophoresis. All the examined stocks of different syngens except one stock in syngen 3 had a single common LDH isozyme, and intra- and intersyngenic variation was not observed except for the one stock in syngen 3. Breeding data using the exceptional stock indicated that the LDH isozymes of P. caudatum are controlled by two codominant alleles at a single locus whose products aggregate randomly, forming a dimer.