Coaction of three factors controlling chlorophyll and anthocyanin synthesis

In a three-factor analysis the rate of chlorophyll a (Chl) accumulation in excised mustard cotyledons was studied as a function of kinetin, light (operating through phytochrome, P _fr) and an excision factor. It was found that the three factors operate additively provided that the P _fr level is high enough. When the P _fr level is below approximately 1 per cent (<0.01) the effectiveness of the excision factor decreases while the effect of kinetin remains additive. The observed additivity is explained by a model where the three factors operate independently through a common intermediate (presumably 5-aminolevulinate) in the biosynthetic chain leading to Chl. With regard to the coaction of the excision factor and phytochrome it is concluded that the production of the excision factor requires the operation of phytochrome (even though saturated at a low P _fr level) while the action of the excision factor is independent of phytochrome. This conclusion was confirmed by experiments in which the rate of light-mediated anthocyanin synthesis was measured in excised mustard cotyledons. The effect of excision in the case of anthocyanin formation differs kinetically from the effect of excision on Chl formation.Abbreviations Chl chlorophyll(ide) a - P _fr far-red absorbing form of phytochrome - P _fr/P _tot ratio at photoequilibrium - RL red light - FR far-red light - GL green light - RG9 light long wavelength far-red light - WL white light     

Different handling of parathyrin by basal-lateral and brush-border membranes of the bovine kidney cortex.

The two parts of the bovine kidney cortex plasma membrane, the basal-lateral and the brush-border membrane, were simultaneously prepared from the same organ. Both types of membrane bound parathyrin, but only from the basal-lateral fraction was the hormone displaceable by its bioactive N-terminal fragment. In parallel, parathyrin-stimulated adenylate cyclase was predominantly found in basal-lateral membranes. The hormone was fragmented by both membrane types. Basal-lateral membranes generated fragments with a rather uniform size distribution (somewhat smaller than the intact peptide) and apparently preferred the hormone itself as a substrate. In contrast, the fragments produced by brush-border membranes were numberous small peptides.     

The interaction of methemoglobin and modified poly-(hydroxyethylmethacrylates) studied by spectroscopic methods

The interaction between methemoglobin (MetHb) and macroporous matrices on the basis of polymethacrylates was investigated by means of optical and e.p.r. spectroscopy. The spectroscopic data show that the adsorption of MetHb to imidazole-containing matrices occurs by complex formation between matrix-bound imidazole and the iron of the prosthetic group, with all 4 polypeptide chains of the MetHb molecule being included in the interaction. The adsorption to hydrophobic side chains containing matrices leads, via the protein-matrix interaction, to considerable disturbances of iron protoporphyrin IX in equilibrium or formed from protein-contacts, which are of general importance with respect to the functional variablity and control, respectively, of iron porphyrins in hemoproteins. In case of matrix containing n-hexyl groups deoxyHb is oxidized by O2 to MetHb, instead of being oxygenated to HbO2. Not all prosthetic groups are able to bind N-3. With the increase in hydrophobicity of the matrix a conformational change is enforced leading in the beta-chains to the direct interaction between iron and sulfur of cysteine (beta-cys 92), as it is proved in all cytochrome P-450 and other model compounds.     

Opsonizing effect of serum and albumin gland extracts on the elimination of human erythrocytes from the circulation of Helix pomatia

The removal of human erythrocytes of the A₁ and B types from the circulation of the gastropod Helix pomatia follows an exponential curve. The elimination of the nonself particles is apparently dependent on serum opsonins as preincubation of A₁ and B erythrocytes in Helix serum increases the rate of their clearance. This conclusion is supported by our finding that secondary doses of nonsensitized A₁ erythrocytes injected 12–19 hr after a similar primary dose are cleared very slowly; however, the clearance rate returns to normal if erythrocytes comprising the second dose are preincubated with Helix serum. Furthermore, the elimination of second-dose A₁ erythrocytes is strongly enhanced after their pretreatment with agglutinating extracts of the albumin glands from H. pomatia and Cepaea (Helix) nemoralis. On the other hand, no opsonizing effect was obtained by pre-incubating A₁ erythrocytes in the agglutinating extract of the sponge Aaptos papillata.     

Continuous Synthesis of (R)-(+)-Benzaldehydecyanohydrin Using (R)-Oxynitrilase in Lyotropic Liquid Crystals

The possibility of using the enzyme (R)-Oxynitrilase in a biphasic lyotropic liquid crystal/dibutylether system has been demonstrated. This reaction system is applicable for the continuous production of (R)-benzaldehydecyanohydrin in a fixed bed reactor. The optical purity was between 94 and 96% ee and independent of the flow rate. The space time yield was maximal (2650 g/(1*d)) at a flow rate of 1.6 ml/min.     

Digital roentgen analysis as a tool for kinematic studies of the shoulder--a study of radiation dosage

The radiation exposure during biomechanical investigation of the shoulder joint done with a digital radiography system (Polytron 1000 VR - Siemens) was measured experimentally. Total radiation dose and surface dose were determined by phantom measurements. The radiation exposure per image is about 1/6 to 1/7 of that of a conventional study. The digital radiography system used is thus suitable for kinesiologic studies of large joints in healthy volunteers.     

Steuerung und potentielle Evolutionsgeschwindigkeit des obligaten Teilzieherverhaltens: Ergebnisse eines Zweiweg-Selektionsexperiments mit der M?nchsgrasmücke (Sylvia atricapilla)

Zusammenfassung 1. In Südfrankreich lebt eine obligat teilziehende Population der Mönchsgrasmücke (Sylvia atricapilla) mit rund drei Vierteln Zugvögeln und einem Viertel Standvögeln. Das Teilzugverhalten dieser Population wird in beträchtlichem Umfang von genetischen Faktoren gesteuert (Berthold &Querner 1982). Der starke Selektionserfolg eines Zweiweg-Selektionsexperiments bis zur F₁-Generation ließ eine hohe potentielle Evolutionsgeschwindigkeit des obligaten Teilzieherverhaltens vermuten (2). Wir haben das Evolutionspotential in einem Langzeit-Selektionsversuch experimentell untersucht.2. Wir zogen insgesamt 267 Individuen der freilebenden Mönchsgrasmückenpopulation in fünf Gruppen von Hand auf, und alle fünf Stichproben zeigten entsprechende Verhältnisse von Ziehern und Nichtziehern. Wir konnten das Langzeit-Zweiweg-Selektionsexperiment bis zu einer F₆-Generation durchführen und konnten dabei insgesamt 455 Mönchsgrasmücken in Volieren züchten.3. Das Zweiweg-Selektionsexperiment zeigt, daß die untersuchte teilziehende Mönchsgrasmückenpopulation bereits nach drei Generationen eine ausschließlich ziehende und nach vier bis sechs Generationen eine fast nicht mehr ziehende Population werden kann.4. Das Zweiweg-Selektionsexperiment zeigt starken Selektionserfolg und hohe Heritabilitätswerte (ca. 0,6–1), die deutlich höher liegen als bisher für das Verhalten von (meist domestizierten) Wirbeltieren angegeben. Demnach sind genetische Faktoren für die Steuerung dieses obligaten Teilzugs sehr bedeutsam und wahrscheinlich dominant über Umwelteinflüsse.5. Die Versuchsergebnisse lassen im Falle von schnellen Umweltveränderungen und der Wirkung von starken Selektionsfaktoren ein enorm großes Evolutionspotential des obligaten Teilzieherverhaltens annehmen und damit allgemein eine schnelle Mikroevolution der Ortsbewegung von Vögeln. Sollten die von Meteorologen prophezeiten Klimaänderungen in Bälde eintreten (Erwärmung aufgrund von Verunreinigungen der Atmosphäre durch den Menschen, Treibhauseffekt), dann könnten viele obligate Teilzieher auf genetischer Basis rasch zu Standvögeln werden und wenig ausgeprägte Zieher rasch zu Teilziehern. Unter diesem allgemeinen Anwachsen von Standvögeln könnten ausgeprägte Zugvögel mehr und mehr zu leiden haben.6. Eine genetische Kontrolle obligaten Teilzugs scheint weit verbreitet zu sein, und sie stellt wohl auch für alle Individuen den zuverlässigsten Steuerungsmechanismus dar. Beim fakultativen Teilzug hingegen dürften Umweltfaktoren mehr unmittelbar steuernd wirken.

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Control and evolutionary potential of obligate partial migration: results of a two-way selective breeding experiment with the Blackcap (Sylvia atricapilla)

Summary 1. In southern France breeds an obligate partially migratory population of the Blackcap with about three quarters of migrants and one quarter of residents. Partial migration of this population is considerably controlled by genetic factors (Berthold &Querner 1982). The large selection response of a two-way selective breeding experiment up to F₁-generations suggested a high evolutionary potential of obligate partial migration (2). We have this evolutionary potential experimentally investigated in a long-term selective breeding study.2. We raised by hand a total of 267 individuals of the free-living Blackcap population in five groups, and all five samples showed corresponding ratios of migrants and nonmigrants. We were able to conduct the long-term selective breeding experiment up to a F₆-generation, and thereby a total of 455 Blackcaps could be bred in aviaries.3. The two-way selective breeding experiment shows, that the investigated partially migratory Blackcap population can become completely migratory in just three generations and almost exclusively sedentary in just four to six generations.4. The two-way selective breeding experiment yielded large selection responses and high heritability values (about 0.6–1) which are distinctly higher than those previously reported for behavioural traits of (mostly domesticated) vertebrates. Hence, genetic factors are very important for the control of this obligate partial migration and are presumedly dominant over environmental influences.5. In case of rapid environmental changes and the effect of strong selection factors the experimental results suggest a strikingly high evolutionary potential of obligate partial migration and thus in general a rapid microevolution of bird movements. If climatic changes would occur in the near future as they are predicted by meteorologists (rise in temperature due to man-made pollution of the atmosphere, greenhouse-effect) then many obligate partial migrants could rapidly become sedentary on a genetic basis and many less typical migrants could then considerably suffer from the general increase of residents.6. A genetic control of obligate partial migration appears to be widespread and it also appears to be the most reliable control mechanism for all individuals of such a partially migratory population. Facultative partial migration, however, appears to be controlled more directly by environmental factors.

     

An analysis of the action of light on betalain synthesis in the seedling of Amaranthus caudatus,var. viridis

Accumulation of betalain (amaranthin) in the seedling of Amaranthus caudatus, var. viridis, is inducible by light. Since the apparent lag-phase of amaranthin accumulation after the onset of light is of the order of 3 h, light induction experiments could be performed up to 3 h after the onset of light without interference with actual synthesis. The intricate induction phenomena can be explained as follows: The inductive light operates through phytochrome and through a blue/UV photoreceptor (cryptochrome). A phytochrome-dependent High Irradiance Reaction is of minor importance. However, there is a strong, specific interaction between the light effects mediated through phytochrome and cryptochrome in the sense that the extent of the reversible response — (response obtained with a particular light treatment terminated with a saturating red light pulse) minus (response obtained with the same light treatment when terminated with a saturating 756 nm light pulse) —increases with increasing P_fr level and total fluence rate during the induction period. It is concluded that light induced amaranthin synthesis is, in fact, a convenient biochemical model system of photomorphogenesis in the case when phytochrome and cryptochrome operate simultaneously in mediating photomorphogenesis. Abbreviations: see Table 1 and 2 Materials and Medthods