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1.
Rapid multiplication of axillary meristems and direct shoot development occurred from nodal explants of mature Eucalyptus tereticornis Sm. with 5.3 M NAA, 1.1 M IAA and 4.4 M BA in Murashige-Skoog medium. Repeated subcultures of the second generation shoot cultures into low cytokinin-auxin containing media (0.44–0.88 M BA+0.1 M NAA) yielded axillary microshoots in large numbers. Half-strength MS liquid medium with 4.9 M IBA, 5.5 M IAA and 5.3 M NAA for four days, half-strength semi-solid hormonefree MS medium with charcoal, and MS liquid medium without charcoal and hormones, in sequence, induced rooting of shoots in the dark. This system is suitable for the mass propagation of this difficult-to-root eucalypt.Abbreviations BA 6-benzyladenine - IAA indole-3-acetic acid - IBA -indole-3-butyric acid - 2-iP isopentyl adenine - Kn kinetin - MS Murashige-Skoog - NAA -naphthalene acetic acid - PVP polyvinylpyrrolidone  相似文献   

2.
Geir Hestmark 《Oecologia》1992,92(3):305-312
The lichen Lasallia pustulata has a mixed strategy of asexual and sexual reproduction. Close-dispersed, asexual, symbiotic isidia are produced early, when the thalli are small. The asexual propagules are subsequently supplemented by far-dispersed, sexually generated ascospores when the thalli grow larger. This observation is consistent with evolutionary stable strategy (ESS) models of dispersal allocations in heterocarpic plants accordin to which the production of far-dispersed propagules should increase as clutch size and sibcompetition in the local habitat increases. The observation is also consistent with the tangled bank or elbow room hypothesis for the maintenance of sexuality, according to which sex, by generating genetic variation, represents an escape from competition in biologically saturated environments. Thus the advantage of sex is density dependent. L. pustulata grows in densely packed populations where intraspecific competition results in self-thining and the development of distinct sizehierarchies.  相似文献   

3.
Four glycosidases were analyzed in 10 mm apical segments prepared from growing roots (15 mm) of Zea mays L. The pH optima were found to be 5.8 for -glucosidase, 4.4 for -galactosidase, 6.4 for -glucosidase and 6.0 for -galactosidase. The -glucosidase showed 4-fold higher activity than the -galactosidase. The distribution of the -glucosidase activity was signifcantly different from that of the -galactosidase, -glucosidase and -galactosidase.Abbreviations -Glu -glucosidase - -Gal -galactosidase - -Glu -glucosidase - -Gal -galactosidase  相似文献   

4.
Summary The histochemical activities of succinic dehydrogenase (SDH), myofibrillar Adenosine triphosphatase (ATPase) and alpha glycerophosphate dehydrogenase were studied in serial sections of rat vastus lateralis (red) (RVL), gastrocnemius and diaphragm muscles. Three main fibre-types were distinguished. The Type I fibres of RVL and gastrocnemius muscles fell into two distinct groups: one category-Type IA showed very low ATPase activity. The second category of Type IB fibres displayed moderate ATPase reaction. The Type IA fibres were divisible into two sub-groups when tested for SDH reaction. Type IA1 fibres possessed a homogenous distribution of diformazan·granules throughout the fibre: Type IA2 fibres displayed characteristic moth-eaten pattern of diformazan localization. The diaphragm muscle did not show either Type IB or Type IA2 varieties. The great majority of Type I fibres were sub-type IA1 in the three fast muscles studied. It is also demonstrated here that an inherent heterogeneity exists between Type I fibres of diaphragm and leg muscles in regard to -GPD localization. This histochemical data emphasizes the fact that subdivision of Type I striated muscle fibres of mammalian animals into two sub-types is only approximate and that a further subcategorization is possible.  相似文献   

5.
Using an immunoblotting technique and goat antihuman C4, we observed five distinct electrophoretic variants of C4 in a panel of 60 random dogs. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of immunoprecipitated C4 showed that dog C4 is composed of three polypeptide subunit chains (, , and ) and that structural variability occurs within the - and -chain regions. Two distinct molecular weight forms of both the C4- ( A and B) and C4-( A and B) chain were detected. The variant forms of C4 and C4 were found in association with particular C4 allotypes.  相似文献   

6.
A Forssman antigen (GalNAc1-3GalNAc1-3Gal1-4Gal1-4Glc1-1Cer)-binding lectin has been purified from velvet bean (Mucuna derringiana) seeds by a combination of affinity chromatography and reversed phase HPLC. This lectin agglutinates both native and trypsin-treated sheep erythrocytes as well as trypsinized rabbit erythrocytes, but neither native rabbit nor human erythrocytes, irrespective of blood group type. SDS-PAGE and gel filtration chromatography reveal the lectin to be a homodimer consisting of two 54 kDa subunits linked by non-covalent bonds. The results obtained by quantitative precipitation, haemagglutination inhibition and TLC overlay assays indicate that theMucuna lectin specifically recognizes Forssman antigen and Forssman disaccharide (GalNAc1-3GalNAc)-related structures. Abbreviations: The abbreviations and the trivial names used are: AH, 6-aminohexyl; BSA, bovine serum albumin; Cer, ceramide; HPLC, high performance liquid chromatography; PAGE, polyacrylamide gel electrophoresis; PBS, 10mm phosphate-buffered saline, pH 7,2, containing 0.15m NaCl; PMSF, phenyl methyl sulfonyl fluoride; SDS, sodium dodecyl sulphate; TFA, trifluoroacetic acid; TBS, 20mm tris-buffered saline, pH 7.2; TLC, thin-layer chromatography; A disaccharide, GalNAc1-3Gal; A trisaccharide, GalNAc1-3[Fuc1-2]Gal; Forssman disaccharide, GalNAc1-3GalNAc; CDH (ceramide dihexoside or lactosyl ceramide) Gal1-4Glc1-1Cer (LacCer); CTH (ceramide trihexoside or globotriosyl ceramide), Gal1-4Gal1-4Glc1-1Cer (GbOse3Cer or Gb3); globoside (globotetraosyl ceramide), GalNAc1-3Gal1-4Gal1-4Glc1-1Cer (GbOse4Cer or Gb4); Forssman antigen (globopentaosyl ceramide), GalNAc1-3GalNAc1-3Gal1-4Gal1-4Glc1-1Cer (GbOse5Cer).  相似文献   

7.
Biology cannot accommodate all aspects of culture. Aspects of culture that a biological approach can take into account can be covered by the biological categories of phenotype and environment. There is no need to treat culture as a separate category. Attempts to elaborate biological explanations of cultural variation will meet with success only if biologists expand theories of development, and integrate them in evolutionary biology. The alternative — elaborating the idea of so-called cultural inheritance — makes little sense from a biological point of view.  相似文献   

8.
Liver homogenate-supernatants from most Japanese exhibit an atypical pH optimum for ethanol oxidation at pH 8.8 instead of 10.5, the typical pH-activity optimum. It has been proposed that atypical livers contain alcohol dehydrogenase isozymes with 2 subunits while typical livers contain isozymes with 1 subunits, both produced by the ADH 2 gene. Because it is difficult to differentiate the atypical ADH2 2-2 phenotype from the ADH2 2-1 phenotype by starch gel electrophoresis, an agarose isoelectric focusing procedure was developed that clearly separated the atypical Japanese livers into two groups, A1 and A2. The isozymes in A1 and A2 livers were purified. Type A1 livers contained a single isozyme with an atypical pH-rate profile; it was designated 22. Three isozymes were isolated from A2 livers, two of which corresponded to 11 and 22. A third, absent from the typical and the atypical A1 livers, had an intermediate mobility; it was designated 21. Type A1 livers are, therefore, the homozygous ADH2 2-2 phenotype, and type A2 livers, the heterozygous ADH2 2-1 phenotype. The ADH2 2-2 phenotype was found in 53% of 194 Japanese livers, and the ADH2 2-1 phenotype, in 31%. Accordingly, the frequency of ADH 2 2 was 0.68.This study was supported by U.S. Public Health Service Grant AA 02342.  相似文献   

9.
Baroreflex sensitivity was measured in baboons operantly conditioned to increase their diastolic blood pressure in daily, 12-hr sessions, by using the extent of increases in interpulse interval per unit of increase in systolic pressure after intravenous phenylephrine injection as an index of baroreflex sensitivity. Following training, baroreflex sensitivity increases averaging 32% were observed before and after the 12-hr conditioning sessions. During the conditioning sessions, however, consistent diastolic blood pressure elevations averaging 17% (14 mmHg) were accompanied by significant decreases in baroreflex sensitivity averaging 44% relative to the increased before and after sensitivity levels. The results suggest that changes in baroreflex sensitivity participate in operantly conditioned blood pressure changes.  相似文献   

10.
Summary The enzymatic transformation of desacetyl-lanatoside A (DLA) to its secondary glycoside, digitoxin, in solutions of -and -cyclodextrins is effected using of -glucosidase from barley. Due to the interaction of cyclodextrins (CyDs) with desacetyl-lanatoside A, an increase in solubility of the latter of 24.5 and 230 times was observed for -cyclodextrin and -cyclodextrin, respectively. Kinetic studies of the enzymatic transformation gave for -glucosidase the values KM=3.3×10–4 mol. dm–3 and Vmax=0.557 mol mg–1 min–1 when the substrate was the deacetyl-lanatoside A complex with -cyclodextrin, while in the case of the complex with -cyclodextrin these values were KM=5.45×10–4 mol dm–3 and Vmax=0.896 mol mg–1 min–1.  相似文献   

11.
Zusammenfassung In den Jahren 1961 und 1962 wurden Untersuchungen mit Hilfe der Exosmose-Methode durchgeführt, um sich über die Frostresistenz von nahezu 100 Apfelsorten zu orientieren. Die Versuchsergebnisse (ausgedrückt in RLF-Werten, d. h. als Proportion des elektrolytischen Widerstandes zwischen den Kontrollen und den kältebehandelten Pflanzenteilen) zeigen gute Übereinstimmung mit den Resultaten anderer Härtebeurteilungsmethoden, z. B. mit den Gefrierversuchen in Gefrierkammern und mit den amerikanischen, deutschen und schweidischen Freilandbeobachtungen. Die berechneten Korrelationskoeffizienten gaben Werte von r=>+0,750 mit einer statistischen Sicherheit von P=<0,001. Es gibt jedoch Sorten, welche sich unter den verschiedenen Versuchsbedingungen nicht gleichartig verhielten. In diese Gruppe gehören die Sorten Goldparmäne, James Grieve, Lanes Prince Albert, Schöner aus Nordhausen, Slava Petersburga und Transparente de Croncels. Der Zusammenhang zwischen der geographischen Herkunft und der Frostresistenz ist augenfällig. Die durchschnittlichen RLF-Werte der frostempfindlichen oder sehr frostempfindlichen französischen Sorten liegen bei ungefähr 150, die der finnischen und baltischen frostharten Sorten dagegen unter 110. Die Rangordnung der verschiedenen Klimagebiete erfolgte entsprechend der geographischen Lage. Es gab Sorten, die der allgemeinen Tendenz nicht folgten und sich abweichend verhielten. Hierzu gehören: Transparente de Croncels, (Frankreich), Wealthy (USA), Cox Pomona und Ribston (Großbritannien). Über eine wesentlich schlechtere Resistenz, als auf Grund des Ursprungsgebietes zu erwarten war, verfügt Ontario (Kanada).  相似文献   

12.
In the present report, we used serological, cellular, and restriction fragment length polymorphism (RFLP) to investigate the DR1 haplotype in the Israeli population. We describe an Israeli homozygous typing cell (HTC), HLA-DwLVA, which defines a new lymphocyte-activating determinant associated with Bw65, DR1 and distinct from Dwl. The parents of this donor, non-Ashkenazi Algerian Jews, are first cousins and share HLA-Cw8, Bw65, BfS, DR1, DQw1, DPw4. No specificity could be assigned to HLA-DwLVA using the 91 Ninth Workshop HTCs. Two families and forty unrelated DR1 individuals were studied with DwLVA and a panel of DR1/Dw1 HTCs. HLA-DwLVA showed segregation as a single determinant within families. This new specificity was present in 24 out of 40 (60%) unrelated DR1 individuals, indicating that in the Israeli population DwLVA is the main lymphocyte-defined determinant associated with the serologically defined DRI specificity, in contrast to non-Jewish Caucasoids where DR1 is significantly associated with Dw1. The vast majority of DwLVA-positive carriers were also Bw65 carriers, indicating that Bw65, DR1, DwLVA may represent a typical allele combination in the Israeli population. The RFLP analysis established the correlation of certain RFLPs with Dw1 and DwLVA. In addition, we describe a cluster of RFLPs that may correspond to a new Dw subtype associated with DR1, for which no serological and cellular reagents have been described so far.  相似文献   

13.
We have developed a new method for the large scale preparation of pyridylaminated (PA-) oligosaccharides from glycoproteins. Phenol/chloroform extration was adapted for the removal of protein and excess 2-aminopyridine, improving the efficiency of preparation. From a 2.5 g sample of human apo-transferrin, 25–30 mol of agalacto biantennary PA-oligosaccharide could be obtained. By increasing the concentration of PA-oligosaccharide substrate, we were able to detect a very low level ofN-acetylglucosaminlytransferase IV activity in CHO cell extracts.Abbreviations PA 2-aminopyridine - SDS sodium dodecyl sulfate - GlcNAc N-acetylglucosamine - GnT N-acetylglucosaminyltransferase - Gn,Gn-bi-PA GlcNAc1-2Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine - Gn,Gn,Gn-tri-PA GlcNAc1-2(GlcNAc1-4)Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine - Gn,Gn,Gn-trí-PA GlcNAc1-2Man1-3({GlcNAc1-2(GlcNAc1-6)Man1-6})Man1-4GlcNac1-4GlcNAc-2-aminopyridine - Gn,(Gn),Gn-bi-PA GlcNAc1-2Man1-3(GlcNAc1-4)(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine  相似文献   

14.
Summary Suspensions of endocrine pancreas cells were prepared by shaking collagenase-isolated rat islets of Langerhans in calcium-free buffer. When incubated with 1.0 mM substrate at pH 7.4, the cells split,P i from 5-AMP at a rate of 87 nmol/h per g DNA, and from-glycerophosphate at a rate of 25 nmol/h per g DNAK m for 5 AMP was about 54 M. Adenosine or theophylline inhibited the 5-AMP hydrolysis. Homogenization of the cells increased the activity toward 5-AMP by 23% and that toward-glycerophosphate by 115%. Injecting rats with cortisone had no effect on the 5-AMP hydrolysis by whole cells but significantly increased the activity in cell homogenates; the intracellular activity toward 5-AMP was more than doubled by the cortisone treatment. Staining whole islet cells for 5-AMP-splitting activity resulted in a demarcation of the cell periphery in control rats. Cells from cortisone-treated rats showed heavier deposits of reaction product, and their cell periphery did not stand out as clearly. It is suggested that 5-nucleotidase is largely an ectoenzyme in normal rat islet cells. The cells also contain an as yet unidentified intracellular phosphatase that seems to be solely responsible for the increased hydrolysis of 5-AMP in cortisone-treated rats.  相似文献   

15.
We have observed a TC mutation at position +96 of the untranslated region 3 to the terminating codon of the -globin gene in members of two Czech families and one black family. Data from initial studies suggested that this change was the cause of a -thalassemia, but continued analyses have provided convincing evidence that this mutation is a simple polymorphism.  相似文献   

16.
Sphingomonas paucimobilis degrades aerobically , , and -hexachlorocyclohexane. With -HCH, complete degradation occurred after 3 days but with and , and with -HCH, 98 and 56 % degradation occurred after 12 and 8 days of incubation, respectively. Pentachlorocyclohexene was formed as the primary metabolite during the degradation of all the HCH isomers. © Rapid Science Ltd. 1998  相似文献   

17.
This paper presents a mathematical model of interactions between two herbivorous invertebrates (ciliate Paramecium caudatum and rotifer Brachionus plicatilis) and two planktonic algae (Chlorella vulgaris and Scenedesmus quadricauda) spatially segregated in two compartments of a chemostat–type experimental microcosm system. The model mimics a producer–consumer aquatic biotic cycle, describing the dynamics of the mixed culture of ciliates and rotifers, as consumer compartment, feeding on the mixed algal culture, as producer compartment, under N-limiting conditions. We experimentally found that metabolites of the alga Scenedesmus produce an adverse effect on the reproduction of ciliate Paramecium. Taking this effect into account improved the behavior of the model, the results of which came into qualitative agreement with the experimental results. Both our experimental and modeling approaches demonstrated that, even in conditions of a spatially–segregated producer-consumer biotic cycle, species coexistence is impossible either in the mixed algal culture or in the mixed invertebrate culture. Scenedesmus excluded Chlorella, whereas Brachionus excluded Paramecium.  相似文献   

18.
Isolated embryos ofKarwinskia humboldtiana were cultured in vitro. The growth of embryos and development to plantlets on woody plant medium supplemented with indole-3-acetic acid 6.10-2 mol l–1, gibberellic acid (GA3) 3.10-2 mol l–1, and 6-benzylaminopurine (BA) 2 mol l–1 was obtained. Multiplication of shoots and rooting of excised shoots has been achieved. Callus formation on modified Murashige-Skoog medium supplemented with 1-naphthaleneacetic acid 10 mol l–1, GA3 14 mol l–1, and kinetin 5 mol l–1 on hypocotyls, or on root cultures on medium supplemented with 2.4-dichlorophenoxyacetic acid 10 mol l–1 and BA 10 mol l–1 was induced.Abbreviations BA 6-benzylaminopurine - 2,4-d 2,4-dichlorophenoxyacetic acid - GA3 gibberellic acid - IAA indole-3-acetic acid - NAA 1-naphthaleneacetic acid - TEM transmission electron microscopy  相似文献   

19.
On age morphological changes of males of Chydoridae (Cladocera)   总被引:2,自引:2,他引:0  
N. N. Smirnov 《Hydrobiologia》1967,30(3-4):555-571
Summary Young and adult males of 11 species of Chydoridae are studied, their figures being published here (fig. 1–15). The necessity is stressed to distinguish young forms of males and gynandromorphic individuals.Pleuroxus balatonicus is considered to be described from the population ofPleuroxus unicatus having under Balaton Lake conditions retarded transformation of young males into adult form, and accordingly having unusually numerous young males. \qO\qs\qn\qo\qv\qn\qy\ye \qr\ye\qz\qu\ql\Qj\qt\qa\qt\qy 11 (. 1–15). . , Pleuroxus uncinatus , Pleuroxus balatonicus.  相似文献   

20.
A novel syrup containing neofructo-oligosaccharides was produced from sucrose (Brix 70) by whole cells of Penicillium citrinum. The efficiency of fructo-oligosaccharides production was more than 55% and those of the main carbohydrate components, 1-kestose (Fruf 21Fruf 21 Glc), nystose (Fruf 21Fruf 21 Fruf 21 Glc) and neokestose (Fruf 26 Glc12 Fruf), were 22, 14 and 11%, respectively.  相似文献   

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