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21.
Summary Variation in the arachin polypeptides of groundnut genotypes was observed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Three regions could be observed on the electropherogram. Region 1, corresponding to conarachin, did not show any variation; region 2, consisting of arachin acidic subunits, showed variation; region 3, containing the arachin basic subunits, did not show any variation. There are four varietal classes of arachin polypeptide patterns: class A comprised three acidic subunits of arachin of molecular weights 47.5, 45.1 and 42.6 kd and a basic subunit of 21.4 kd; class B, with three acidic subunits of molecular weights 47.5, 45.1 and 41.2 kd and a basic subunit of 21.4 kd; class C of an additive pattern of class A and class B; class D, of two acidic polypeptides of 47.5, 45.1 kd and the basic 21.4 kd subunit. Of the 90 genotypes studied, 73% belong to class A, 15% to class B and 6% each to class C and D. Analysis of F2 seeds from a cross between class A and class B genotypes showed that the two polypeptides (42.6 kd and 41.2 kd) are coded by nonallelic genes and also revealed that class C and class D patterns arose as a result of hybridisation between class A and class B. A. monticola, the progenitor of A. hypogaea, showed a pattern similar to the additive pattern of class A and class B while some diploid Arachis species had the 41.2 kd polypeptide. Based on arachin polypeptide patterns the probable origin of A. hypogaea has been suggested.  相似文献   
22.
Summary Eight transfer RNA (tRNA) genes which were previously mapped to five regions of the Pisum sativum (pea) chloroplast DNA (ctDNA) have been sequenced. They have been identified as tRNAVal(GAC), tRNAAsn(GUU), tRNAArg(ACG), tRNALeu(CAA), tRNATyr(GUA), tRNAGlu(UUC), tRNAHis(GUG), and tRNAArg(UCU) by their anticodons and by their similarity to other previously identified tRNA genes from the chloroplast DNAs of higher plants or from E. gracilis. In addition,two other tRNA genes, tRNAGly (UCC) and tRNAIle(GAU), have been partially sequenced. The tRNA genes are compared to other known chloroplast tRNA genes from higher plants and are found to be 90–100% homologous. In addition there are similarities in the overall arrangement of the individual genes between different plants. The 5 flanking regions and the internal sequences of tRNA genes have been studied for conserved regions and consensus sequences. Two unusual features have been found: there is an apparent intron in the D-loop of the tRNAGly(UCC), and the tRNAGlu(UUC) contains GATTC in its T-loop.  相似文献   
23.
STIMULATION OF BRAIN SEROTONIN SYNTHESIS BY DIBUTYRYL-CYCLIC AMP IN RATS   总被引:3,自引:1,他引:2  
Cyclic AMP and dibutyryl-cyclic AMP, a derivative of cyclic AMP resistant to phosphodiesterase inactivation, were injected into the lateral ventricles of rats. These nucleotides did not change the level of brain 5-HT but increased the brain level of its principal metabolite, 5-hydroxyindoleacetic acid. Cyclic AMP was less potent than dibutyryl-cyclic AMP. Butyrate and 5′-AMP were inactive. The effect of dibutyryl cyclic AMP on 5-HT metabolism was studied both in vivo and in vitro. The rate of synthesis of 5-HT was measured by the rate of accumulation of 5-hydroxyindoleacetic acid after the transport of this acid out of the brain was blocked with probenecid. The rate of synthesis of brain 5-HT increased from 0-38 μg/g/h in control rats to 0-65 μg/g/h after dibutyryl-cyclic AMP. In addition cyclic AMP and dibutyryl-cyclic AMP markedly increased brain tryptophan, while AMP was inactive. Since brain tryptophan hydroxylase has a Km for its substrate that is much higher than the concentrations of tryptophan normally present in the brain, it is likely that the increase in the rate of synthesis of brain 5-HT is secondary to the cyclic AMP induced increase in the levels of brain tryptophan. In vitro studies revealed that dibutyryl-cyclic AMP increased the uptake of radioactive labelled tryptophan into slices of rat brain stem and the formation of 5-HT and 5-hydroxyindoleacetic acid.  相似文献   
24.
A trispecific hybrid combination ofNicotiana glutinosa-trigonophyllatabacum was successfully colchicine doubled, and multiple polyploids were raised. Chromosome complement was full (96) in most of the plants. Three of the fifteen plants studied showed chromosomal elimination of varying numbers.Six plants showed floral modifications, each of a different type; of these two were associated with chromosome loss, others were attributed to genome-cytoplasm interaction, or to genetic factors.Pollen fertility was good in almost all the plants but no capsule was set on them. On some plants parthenocarpic fruits developed easily and capsules were quickly set when back- or out-crossed.Several quadruple hybrid combinations were obtained and their survival capacity is reported. Difficulties in establishing, and possibilities of successfully utilising the multiple polyploids for breeding work are discussed.An abstract of this paper has been presented at the 3rd Tobacco Research Worker's Conference held at Madras from 13th to 15th September, 1962.  相似文献   
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26.
Résumé L'AcridienGesonula punctifrons St?l attaque la Jacinthe d'eau (Eichhornia crassipes) dans plusieurs parties de l'Inde et est adapté à un habitat aquatique ou semi-aquatique. Les œufs, pondus dans les pétioles des feuilles, éclosent en 3 à 4 semaines. Les larves se développent en 4 à 5 semaines et demi, avec 5 mues. Les adultes vivent au maximum 4 à 5 mois en s'alimentant seulement de Jacinthe d'eau. En essais de laboratoire cet Acridien se nourrit activement deCanna orientalis dont les tiges sont percées de trous pour la ponte par les femelles, mais aucun œuf n'est déposé. Quarante trois autres plantes d'intérêt économique ont été expérimentées: plusieurs d'entre elles ont été l'objet d'attaques légères à modérées. L'analyse de la littérature concernant les plantes-h?tes du genreGesonula et la distribution deG. punctifrons montrent que cette espèce s'est adaptée secondairement àE. crassipes. Bien que cet Acridien s'observe en grand nombre dans quelques régions, l'ensemble de ses dégats à la mauvaise herbe n'est pas suffisant pour assurer le contr?le de celle-ci.

This research has been financed in part by a grant made by the United States Department of Agriculture under P. L. 480.  相似文献   
27.
In studying inhibitors and activators of enzymes it has often been found that inhibitors act as activators when in very low concentrations and that certain activators (in suitable concentrations) show inhibition. Similar results were obtained in the present work in studying urease from soya bean in the presence of lead acetate. Lead acetate is normally an inhibitor of urease. It was found, however, that in small concentrations of lead acetate increase in the activity of urease occurs. On prolonging the time of the reaction inhibition develops and still later increased enzymatic activity again occurs. The results were elaborated statistically and are discussed in relation to the use of “adaptation” of urease in unfavourable conditions in reaction mixtures by the action of lead acetate.  相似文献   
28.
Using data for 27 Texas counties from 1978-1987, it is shown that the incidence rates of suicide, homicide, and rape are significantly higher in counties whose drinking water supplies contain little or no lithium than in counties with water lithium levels ranging from 70-170 micrograms/L; the differences remain statistically significant (p less than 0.01) after corrections for population density. The corresponding associations with the incidence rates of robbery, burglary, and theft were statistically significant with p less than 0.05. These results suggest that lithium has moderating effects on suicidal and violent criminal behavior at levels that may be encountered in municipal water supplies. Comparisons of drinking water lithium levels, in the respective Texas counties, with the incidences of arrests for possession of opium, cocaine, and their derivatives (morphine, heroin, and codeine) from 1981-1986 also produced statistically significant inverse associations, whereas no significant or consistent associations were observed with the reported arrest rates for possession of marijuana, driving under the influence of alcohol, and drunkenness. These results suggest that lithium at low dosage levels has a generally beneficial effect on human behavior, which may be associated with the functions of lithium as a nutritionally-essential trace element. Subject to confirmation by controlled experiments with high-risk populations, increasing the human lithium intakes by supplementation, or the lithiation of drinking water is suggested as a possible means of crime, suicide, and drug-dependency reduction at the individual and community level.  相似文献   
29.
Summary Investigations have been carried out on the production of fungal rennet using a thermophilic strain ofMucor miehei under solid state fermentation conditions. A high milk clotting enzyme activity (58000 Soxhlet units/g) was achieved when optimum conditions were used. Further, a high ratio of 6.6:1 between milk clotting and proteolytic activities for this enzyme was obtained. Cheese prepared using this enzyme was also found to be acceptable in organoleptic quality. Large scale production of the enzyme in trays using the optimum conditions gave milk-clotting enzyme activities comparable to those in flask experiments.  相似文献   
30.
Our recent spin trapping studies of free radical generation by ultrasound in aqueous solutions are reviewed. The very high temperatures and pressures induced by acoustic cavitation in collapsing gas bubbles in aqueous solutions exposed to ultrasound lead to the thermal dissociation of water vapor into H atoms and OH radicals. Their formation has been confirmed by spin trapping. Sonochemical reactions occur in the gas phase (pyrolysis reactions), in the gas-liquid interfacial region, and in the bulk of the solution (radiation-chemistry reactions). The high temperature gradients in the interfacial regions lead to pyrolysis products from non-volatile solutes present at sufficiently high concentrations. The sonochemically generated radicals from carboxylic acids, amino acids, dipeptides. sugars, pyrimidine bases. nucleosides and nucleo-tides were identified by spin trapping with the non-volatile spin trap 3.5-dibromo-2.6-dideuterio-4-nitrosobenzenesulfonate. At low concentrations of the non-volatile solutes. the spin-trapped radicals produced by sonolysis are due to H atom and OH radical reactions. At higher concentrations of these non-volatile solutes, sonolysis leads to the formation of additional radicals due to pyrolysis processes (typically methyl radicals). A preferred localization of non-volatile surfactants (compared to analogous non-surfactant solutes) was demonstrated by the detection of pyrolysis radicals at 500-fold lower concentrations. Pyrolysis radicals were also found in the sonolysis of aqueous solutions containing only certain nitrone spin traps. The more hydrophobic the spin trap, the lower the concentration at which the pyrolysis radicals can be observed. The effect of varying the temperature of collapsing transient cavities in aqueous solutions of different rare gases and of N2O on radical yields and on cell lysis of mammalian cells was investigated.  相似文献   
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