Changes In Isozyme Patterns Research Articles

Isozyme patterns in Rous sarcoma virus-induced tumors in the rat.

Electrophoretic isozyme patterns of 9 enzyme systems were studied in normal tissues of an inbred rat strain, in 11 Rous sarcoma virus-induced tumors in this strain, in cultured cells from one of the primary tumors, and in 22 tumors from reimplanted cells of 5 clonal isolates from the cells in culture. All primary tumors showed largely similar deviations of the isozyme patterns in comparison with the tissue of origin (subcutaneous connective tissue). Changes of the patterns occurred in the cultured primary tumor, but the characteristic patterns of primary tumors returned in the tumors after implantation in vivo of the cultured cells. The experiments indicated that the change in isozyme patterns induced by the virus was the same each time a normal tissue was transformed into a Rous tumor. The changes accompanying the explantation of the tumor cells in vitro were of another character and were reversible on reimplantation of the cells in vivo.

Variation and Morphogenetic Characteristics of Different Stachys Species during Microclonal Propagation

Morphogeneses of Stachys different species introduced in culturing in vitro have been compared. The frequency of altered forms have been demonstrated to be related to the plant genotype. All regenerants of S. sieboldii, which reproduces in vivo only vegetatively, are phenotypically normal, irrespective of the concentrations of plant growth regulators at which they have been obtained. Only changes in isozyme patterns have been observed in the regenerants grown in media containing at least 10 mg/l benzyl aminopurine (BAP); most of these changes are the absence of a particular component of the pattern. The cross-pollinating species Stachys ocymastrum, which typically reproduces by seeds, has yielded morphologically altered forms even in phytohormone-free media; its isozyme patterns often contained a new component. Analysis of the isoperoxidase patterns of regenerants of both Stachys species obtained with the use of high phytohormone concentrations has demonstrated qualitative and quantitative changes suggesting the appearance of somaclonal variants even in the course of plant regeneration directly from nodal segments, bypassing callus formation. Changes have also been found in Stachys plants regenerating from the callus tissue.

Aluminum stress in the roots of naked barley

Phytotoxicity of aluminum (Al) is the major limiting factor for the crops grown in acid soils rapidly inhibiting root elongation. In this study, changes in root growth, total activity and isozyme patterns of antioxidant enzymes such as peroxidase, ascorbate peroxidase, catalase and glutathione reductase by Al stress were investigated in the roots of naked barley (Hordeum vulgare L. cv. Kwangwhalssalbori). As Al concentration increased up to 500 M, the rooting rate and root elongation substantially decreased. Growth results suggested that this cultivar is an Al-sensitive species. Total activities of antioxidant enzymes generally increased at lower Al concentrations and then gradually decreased at higher Al concentrations. They also increased when the exposure time to Al was extended up to 48 hr. Changes in the isozyme patterns of antioxidant enzymes were investigated byin situ enzyme activity staining on a non-denaturing PAGE gel. They generally coincided with the changes in the total activity in parallel. Changes in the total activity of antioxidant enzymes also coincided with the changes of the root growth. Since growth reduction in the roots by Al stress could be related with the changes in the activities of antioxidant enzymes, these results suggested that Al might cause the oxidative stress in the roots of this cultivar of naked barley.

Cadmium-induced changes in antioxidant enzymes from the marine alga Nannochloropsis oculata

Cadmium-induced oxidative stress symptoms such as lipid peroxidation and H2O2 production were examined in the marine alga Nannochloropsis oculata. Changes in antioxidant enzyme levels and isozyme patterns were also examined. Increasing concentrations of Cd produced growth inhibition. Among the responses to added Cd, the H2O2 content and malonyldialdehyde accumulation increased significantly, indicating a state of oxidative stress. In the case of ascorbate peroxidase activity the increase was about 2.5 times and a marked induction of the isozyme APX2 contributed to this increase. Guaiacol peroxidase activity increased about 4-fold, this being due mainly to the isozyme GPX3. Catalase activity increased slightly, whereas superoxide dismutase and glutathione reductase activity decreased markedly. Alterations of antioxidant enzyme levels and isozyme pattern changes in Cd-treated alga suggest that they might be involved in the heavy metal tolerance in this alga.

Changes in Isozyme Patterns During in Vitro Regeneration from Cotyledon Explants of Brassica Species

High frequency shoot regeneration from cotyledons excised from 4-d-old seedlings of Brassica campestris L. cv. M 27 and Brassica juncea (L.) Czern. cv. Pusabold was achieved on Murashige and Skoog's (MS) medium supplemented with 1.0 mg dm-3 N6-benzyladenine (BA) and 3 % (m/v) saccharose. Rooting occurred simultaneously with shoot formation on the medium containing 1.0 mg dm-3 BA and 0.5 mg dm-3 1-naphthaleneacetic acid. Cultures of cotyledon, cotyledon derived non-differentiating calli and differentiated calli with shoots and/or roots were analysed at different intervals for isozyme patterns of esterase and peroxidase. With the BA-induced development of shoot and/or root from non-differentiating callus, some conspicuous isozymes appeared which indicates the involvement of these isozymes in root and shoot development rather than in induction of morphogenesis in callus.

Changes in Isozyme patterns of Peroxidase and Polyphenol Oxidase by VAM fungi in Roots of Ziziphus species

Summary Changes in isozyme patterns of peroxidase and polyphenol oxidase by VA mycorrhizal fungi was investigated under glass-house conditions in three Ziziphus species. The VA mycorrhizal plants had two extra peroxidase isozyme bands and one extra polyphenol oxidase band as compared with the uninoculated plants of all three Ziziphus species. The activities of peroxidase and polyphenol oxidase were higher in roots of VA mycorrhizal plants of all three Ziziphus species than non-mycorrhizal plants. Details about the isozyme patterns are also discussed.

Ontogenic change of digestive enzymes in Penaeus monodon

1. Ontogenic changes of both proteases and carbohydrases of Penaeus monodon from different larva stages to adult were investigated. 2. Total protease activity was low during nauplius and zoea but peaked up in mysis. This was due to the activity increase of both trypsin and chymotrypsin. 3. The change of isozyme pattern of these two enzymes from different life stages of the shrimp was further determined by functional staining on an electrophoregram. 4. Activity of α-amylase increased after the post-larva stage, while that of chitinase and maltase showed a peak in zoea then gradually decreased to adult. 5. The ratio of α-amylase activity to protease coincided with the dietary change of the shrimp in different life stage.

Chemically induced murine erythroleukemia cell differentiation is severely impaired when cAMP-dependent protein kinase activity is repressed by transfected genes.

During chemically induced differentiation of murine erythroleukemia (MEL) cells, cAMP-dependent protein kinase activity increases, and the enzyme's isozyme pattern changes. To examine the enzyme's role during MEL cell differentiation, we stably transfected MEL cells with recombinant plasmids in which the mouse metallothionein I promoter controlled expression of either a mutant form of the type I regulatory subunit of cAMP-dependent protein kinase (RI) or the enzyme's specific peptide inhibitor (PKI); expressing either sequence rendered cells cAMP-dependent protein kinase-deficient. Chemically induced differentiation of MEL cells as assessed by beta-globin mRNA and hemoglobin accumulation was inhibited in RI mutant and PKI transfectants; adding zinc further inhibited differentiation in the transfectants but had no effect on parental MEL cells. The inhibition of differentiation correlated with the amount of RI mutant mRNA and protein in the RI mutant transfectants and with the cells' degree of cAMP-dependent protein kinase deficiency in both the RI mutant and PKI transfectants. Overexpression of wild type RI did not interfere with differentiation or enzyme activity. We conclude that cAMP-dependent protein kinase activity is important for chemically induced differentiation of MEL cells and that the down-regulation of RI protein which occurs during MEL cell differentiation is not essential for differentiation to proceed.

Changes in Isozyme Patterns Associated with the Development of Calli Derived from Mature Embryo Culture of Barley(Hordeum vulgare L.).

Changes in Isozyme Patterns Associated with the Development of Calli Derived from Mature Embryo Culture of Barley(Hordeum vulgare L.).

Selection of higher regenerative callus and change in isozyme pattern in rice (Oryza sativa L.)

Calli were initiated from seedling roots in rice (Oryza sativa L. var. Tadukan) and subcultured at 45-day intervals on MS medium supplemented with 2 mg/l 2,4-D. Sectors of callus which differentiated shoot meristems (green spots) under the same 2,4-D concentration were selected from the calli subcultured 90 days after initiation. The selection was continued for about 2 years. Responses to 2,4-D between original and selected lines differed considerably, although differentiation was not generally seen in rice callus in the presence of 2 mg/l 2,4-D. After 180 days, calli of the selected line differentiated into numerous shoot-bud primordia and grew out new callus tissues under 2 mg/l 2,4-D concentration; the frequency of the differentiation exceeded 90%. On the other hand, no calli of non-selected line differentiated into shootbuds under 2 mg/l 2,4-D, and the frequency of the shootbud was only about 50% under lower 2,4-D concentration (0.1 mg/l). The pattern and activity of peroxidase isozyme varied markedly between calli of the selected and non-selected lines. First, two strong peroxidase bands which show fast mobility and one intermediate peroxidase band with slow mobility were detected only in the calli of selected line. Secondly, changes in band pattern of proteins separated by SDS-PAGE were observed. In the calli of selected line, there was a loss of the polypeptide bands with molecular weight of 24 and 42 K in the selected calli, but they were clearly present in the unselected line. The appearance of new peroxidase isozyme bands and loss of polypeptide bands, change in response to auxin and increased ability for shoot bud differentiation are closely correlated to each other.

Localization of acid phosphatase in rice calli

Acid phosphatase is an important hydrolytic enzyme and widely distributed in plants. The role of acid phosphatase in plant tissues has been suggested involving in mobilization of nutrient reserves, sugar transport, differentiation of plastid, cell autolysis and senescence. In culture, the differentiating calli show the changes in isozyme patterns and activities, and anatomical localization. In this study, subcellular localization of acid phosphatase in regenerating callis is emphasized.Sterized rice seeds(Oryza sativaTainong 67) were grown on modified MS medium containing 2 ppm 2,4-D. After 2 weeks, calli 2 to 3 mm in size were transfered on differentiation medium containing 1 ppm NAA and 2 ppm kinetin. Different stages of calli were collected and cut into thin slice with razor blade. Slices were fixed in 2.5% glutaraldehyde in 0.1M phosphate buffer(pH 7.0) for 2h and then washed, overnight . Specimens were incubated in Gomori solution containing 3mM p- nitrophenyl phosphate as substrate at 37°C for 90 min, postfixed with 1% OsO4for lh, dehydrated in ethanol series and embedded in Spurr's resin. Control experiments were done as follows: l), incubation medium without substrate; 2),incubation medium without lead nitrate; 3), incubation medium containing 0.01% NaF. Sections were doubly stained with uranyl acetate and lead citrate, and finally observed under Hitachi H-600 at 75 KV.

Glycerol-3-phosphate dehydrogenase (G-3-PDH; EC 1.1.1.8) variation in adult Plebeia droryana bees (Apidae, Hymenoptera).

The study of glycerol-3-phosphate dehydrogenase (G-3-PDH) is important for the elucidation of the physiological meaning of the existence of multiple forms of an enzyme. Because of their relatively short life cycle with welldefined and distinct stages, insects are ideal for this type of investigation. There is evidence suggesting that changes in isozyme pattern may be linked to the acquisition of particular capacities (Kikkawa and Abe, 1960; Eposito and Ulrich, 1966; Murray and Ball, 1967; Doane, 1969; Pasteur and Kastritsis, 1971; Wagner and Selander, 1974; Mukiama, 1980). The order Hymenoptera, and social bees in particular, is interesting with respect to enzyme alterations during ontogenetic development, since, in addition to morphological and physiological variations, social bees undergo a process of caste differentiation which requires extensive physiological changes in the development of traits that define each caste (Rosch, 1925, 1927, 1930; cited by Free, 1965). These physiological changes permit adults to carry out different functions inside their nests or colonies. Marked differences have been observed in the electrophoretic patterns of several isozymes in stingless bees (Contel and Mestriner, 1974; Contel et al., 1977; Martins et al., 1977; Nunamaker and Wilson, 1982; Bitondi and Mestriner, 1983; Del Lama and Mestriner, 1984), and these are related to

Ontogenic changes in isozyme patterns of Penaeus species

1. 1. The electropherograms of four developmental stages, early protozoea, early mysis, early postlarva, and adult are compared. 2. 2. Eight enzyme stains and a Coomassie Blue stain were employed in the comparisons. 3. 3. The electropherograms exhibit differences among developmental stages and among species. Some stage-specific protein bands are present. 4. 4. Complexity of electropherogram pattern tends to increase with age in most of the staining systems.

Ontogenetic changes in isozyme patterns during seed germination of self-pollinatedSecale species

Six isozymatic systems have been studied comparatively during the first week of germination of seeds of self-pollinatedSecale species (S. silvestre Host. andS. vavilovii Gross.). Isozymatic systems do not change at all, or reach their definitive adult plant pattern early during germination.

The Relationship Between Peroxidase Activity and Resistance to Sphaerotheca fuliginea in Melons

AbstractThe levels of peroxidase activity in leaves of non‐infected melon plants resistant to Sphaerotheca fuliginea (Schl. ex. Fr.) Poll. were considerably higher than those in the leaves of susceptible plants. After infection the ratio of peroxidase activity to that in non‐infected plants reached a value of up to 47.5 in susceptible plants whereas in resistant plants it remained between 1 and 2. Changes in isozyme pattern were investigated by polyacrylamide gel electrophoresis. In non‐infected resistant leaves slowly migrating isozymes were found. Their intensities increased with time following infection. These isozymes were absent in the susceptible leaves but appeared after the leaves had been infected with S. fuliginea. The role of these isozymes in the resistance mechanism is discussed.

Enzymes, isozymes, and enzyme variants in the diagnosis of cancer. A short review.

Changes of enzyme activity in tissues, body fluids, and serum as well as changes of isozymes and enzyme variants in patients with malignancy suggest that these parameters may be used in the diagnosis of some types of cancer. A review of available information indicates that: changes of serum enzymes in patients with malignancies relate to the presence of a heavy tumor burden or of metastases, and cannot be utilized for the early diagnosis of malignancies; changes in isozyme patterns and newly developed enzyme variants may be of greater diagnostic value, although possibly not in the early diagnosis of cancer; study of enzymatic activity in body fluid may offer valuable help in specific situations; and occasionally, determination of enzymes may be of help in establishing susceptibility to malignancies.

Regulation of alcohol dehydrogenase in Drosophila melanogaster by dietary alcohol and carbohydrate

When fed to Drosphila melanogaster Canton-S wild-type larvae cultured axenically on Sang's modified medium C with 0.5% (w/v) sucrose, 2.5% (v/v) ethanol induced an alcohol dehydrogenase (ADH) activity at least 2.5-fold higher than the activity in larvae fed an unsupplemented 0.5% sucrose diet. Ethanol induced only a 2-fold change in ADH cross reacting material (CRM), suggesting that there was also a post-translational modification of ADH. The addition of dietary sucrose to the diet (at 5%, w/v) exerted similar, but lesser effects on ADH activity and CRM. Increasing dietary sucrose to 5% in the presence of 2.5% ethanol decreased ADH activity and CRM to levels below those attained in the 0.5% sucrose-2.5% ethanol diet. Upon examination, dietary ethanol was found to decrease the relative concentration of ADH-1 and increase the concentrations of ADH-3 and ADH-5 in larvae; sucrose had a similar but lesser effect on the isozyme pattern. Because dietary ethanol increased both the total NAD content and the NADH NAD + ratio, the diet-induced changes in isozyme pattern were proposed to be linked to the relative amounts of NADH, NAD + and ADH enzyme in larval tissues. Larval ADH activity is modulated by both dietary alcohol and carbohydrate.

Isozyme variation in Silene pratensis: a response to different environments

The isozymes of nine enzyme systems were screened and the frequencies of the flavone glycosylating genes were determined in an outdoor experiment with 70 populations of European S. pratensis and an indoor experiment with 30 populations of the same species. Cluster analysis (using Ward's cluster criterion) were performed on all data sets. In the outdoor experiment, cluster analysis of the flavonoid data gave the same pattern that we obtained in an ealier survey of a larger set of populations and showed clearly that there are eight chemical races in European S. pratensis. No comparable geographic distributiion could be found in the isozyme data set, although the dendrogram showed two very clearly separated groups. The two groups represented the two years in which the populations were grown. This result indicates that isozyme variation in European S. pratensis is largely determined by environmental factors. Observations on changes in isozyme patterns during ontogeny and on differences between indoor and outdoor grown plants of the same F2 crosses confirm this. Differences in isozyme patterns can be caused by very small differencs in environment as is shown by the results of the indoor experiment, in which a slight gradient in environmental conditions was present in the greenhouses. The cluster analysis of the isozyme data from the indoor experiment revealed three distinct groups of populations that could be related to location within the greenhouses. As in the outdoor experiment, the dendrogram for the flavonoids gave the same geographic pattern as found with the earlier survey.

Time serial changes of isozyme patterns of primary leaves on sugi (Cryptomeria japonica D. DON) seedlings

Time serial changes of isozyme patterns of primary leaves on sugi (<i>Cryptomeria japonica</i> D. DON) seedlings

Mechanisms of G6PD isozyme pattern changes at fertilization.

The electrophoretic pattern of G6PD changes in sea urchin egg supernatants, gels, and pellets (homogenized in 0.01 M MgCl2, 0.01 M Tris, pH8, and centrifuged at 4 X 10(4)g) within the first minute following sperm penetration. Therefore, the changes in pattern are an early event of egg activation and are not changes in gene activity. Calcium ionophore activation causes similar changes in G6PD in unfertilized eggs, so calcium is probably involved directly or indirectly. Treatment with 1 mg/ml of G6P and/or NADP, DTT, or papain also causes changes in the isozyme patterns, but the resulting patterns are different from patterns obtained from the fertilized fractions, and each treatment produces a unique pattern. The results lead to the conclusion that the different patterns of unfertilized and fertilized eggs are due to enzyme posttranslational modification. Different patterns may result from intrinsic differences in 1) -SH reduction or levels of glutathione, 2) substrate and cofactor levels, or 3) proteolytic enzymes released naturally or as a result of homogenization.