Untersuchungen über den PolyploidkomplexVeronica cymbalaria agg. (Scrophulariaceae)

Veronica panormitana Tin. inGuss. (sparsely distributed from Corsica and Sicily to Syria) andV. trichadena Jord. etFourr. var.freyniana M. Fisch. (Mallorca) are diploid (2n = 18), and very probably the ancestors of the allopolyploidV. cymbalaria Bod. The latter consists of tetraploid (2n = 36) and hexaploid (2n = 54) strains (confirmed on new material from Italy, Greece, and Turkey). The diploid taxa are morphologically well separated from each other and fromV. cymbalaria, whereas the tetraploids and hexaploids are not separable morphologically.—Another poorly known diploid strain from Kurdistan is described as new:Veronica cymbalaria Bod. var.baradostensis M. Fischer.—V. panormitana is reported from Greece for the first time.     

Acetylcholinesterase-containing nerve cells in the pineal complex and subcommissural area of the frogs,Rana ridibunda and Rana esculenta

Summary In Rana esculenta and Rana ridibunda the frontal organ and the pineal organ (epiphysis cerebri) form a pineal complex. Approximately 60 nerve cells of the frontal organ and 220–320 nerve cells of the pineal organ display a positive acetylcholinesterase reaction (Karnovsky and Roots, 1964). The dorsal wall of the pineal organ is considerably richer in acetylcholinesterase-positive neurons than the ventral wall (ratio 31); a group of unusually large-sized nerve cells occurs in the rostral portion of the frog pineal. Two different types of nerve cells were observed in the pineal complex: multipolar and pseudounipolar elements. The former are embedded in the pineal parenchyma and their processes penetrate radially into the plexiform layer, whereas the latter are distributed along the roots of the pineal tract near the basal lamina. The ratio of the multipolar to pseudounipolar neurons is 14 for the frontal organ and 35 for the pineal organ. The multipolar elements may be interneurons; the pseudouni-polar cells send one of their processes into the pineal tract. At the caudal end of the pineal organ 30–50 unipolar nerve cells are clustered in juxtaposition with the pineal tract, and other 30–50 unipolar neurons are scattered along the basis of the subcommissural organ. Some of these nerve cells emit their processes toward the mesencephalon and others toward the pineal organ via the pineal tract. The results are discussed with respect to previous physiological and morphological findings on the pineal complex of Anura.Supported by a fellowship from the Alexander von Humboldt Foundation, Federal Republic of Germany, to K. Wake. Completed November 22, 1973.Supported by the Deutsche Forschungsgemeinschaft.     

Kern- und Chloroplastenteilung sowie Photosyntheseleistung synchron kultivierter Bumilleriopsis (Xanthophyceae)

1. Durch Licht-Schwachlicht-Temperatur-Wechsel (LS-T 33:15 h/15000: 3000 Lux/24: 19 C) wird Bumilleriopsis zu 96 bis 98% synchronisiert. 2. Die Kernzahl je Zelle wurde während der Zellentwicklung im LS-T verfolgt. Während des größten Teils des Zyklus sind die Zellen mehrkernig; Zellwandbildungen treten erst nach Abschluß der Kernteilungen auf. Der Anteil der Zellen mit zwei Kernen ist 12 bis 14 Stunden, derjenige mit vier Kernen 20 bis 21, derjenige mit acht Kernen 23 bis 27 Stunden nach Zyklusbeginn maximal. Es wurden keine Zellen mit drei, fünf, sechs oder sieben Kernen gefunden, so daß die Teilungen innerhalb einer Zelle sehr synchron zu sein scheinen. 3. Chloroplasten werden während der gesamten ersten Phase der synchronisierenden Bedingungen gebildet; ein Zusammenhang mit der Zellteilung besteht nicht. 4. Die Photosyntheserate nimmt gegen Ende der ersten Phase des LS-T stark ab und durchläuft etwa 35 bis 36 Stunden nach Zyklusbeginn (also während der Zellwandbildung) ein Minimum. Im anschließenden Bereich, in den die vollständige Zellteilung fällt, steigt die Rate auf den zwei- bis dreifachen Wert rasch an. Gleiche Verhältnisse liegen bei Temperaturwechseln in Dauerlicht (33: 15 h/15 000 Lux/24: 19 C) vor. Herrn Prof. Dr. P. Böger danke ich für sein stetes Interesse an diesen Untersuchungen, Herrn P. Bley für sorgfältige technische Assistenz. Die Arbeit wurde durch den Sonderforschungsbereich 138 unterstützt.     

Zur Cytotaxonomie vonVeronica chamaedrys L., I.: subsp.vindobonensis M.Fischer,eine neue,diploide Sippe

Zusammenfassung Außer typischerVeronica chamaedrys L. findet sich in Österreich eine Sippe mit deutlich dichterer und kürzerer Behaarung der Sepalen, meist merklich tiefer eingeschnittenen Laubblättern, immer rein zweizeiliger Behaarung der Hauptachse und hellblauen, seltener rosa Blüten. Diese Sippe wurde auf Grund ihrer diploiden Chromosomenzahl (2 n=16) entdeckt und wird alsVeronica chamaedrys L. subsp.vindobonensis M.Fischer neu beschrieben. Sie wächst nur an trocken-warmen Standorten der Ebenen- und Hügelstufe, besonders im östlichen Österreich. Die weiter verbreiteteV. chamaedrys L. subsp.chamaedrys erwies sich dagegen als tetraploid (2 n=32); diese Chromosomenzahl entspricht den bisherigen Angaben für diese Art. Weitere Untersuchungen über den Formenkreis sind im Gange.

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Summary Veronica chamaedrys L. subsp.vindobonensis M.Fischer, a new subspecies, differs from the type of the Linnean species by denser and shorter hairs on the sepals, deeply incised leaves and light blue or pink corolla; there are never hairs between the two rows of hairs on the primary stem. This new subspecies proved to be diploid (2 n=16), whereasV. chamaedrys subsp.chamaedrys is tetraploid (2 n=32) in accordance with all previous counts of the species. Subsp.vindobonensis occurs only in dry and warm habitats in low altitudes, especially in the eastern parts of Austria, while the typical subspecies prefers mesic meadows and woods from the plains up into the mountains.

     

The distributions of some granule-associated enzymes in guinea-pig polymorphonuclear leucocytes

1. Homogenates of guinea-pig polymorphonuclear leucocytes were separated by differential centrifugation into six particulate fractions and a soluble fraction. 2. The distributions in these fractions of protein, DNA, succinate dehydrogenase, beta-glucuronidase, peroxidase, alkaline phosphatase, acid phosphatase (against p-nitrophenyl phosphate and beta-glycerophosphate), cathepsin, and catalase were compared. 3. Almost all of the DNA sedimented in the first two pellets, indicating that the nuclei were relatively intact. 4. The four hydrolases and peroxidase showed different distribution patterns, although these activities were previously reported to be localized mainly in the single ;granule' fraction isolated from leucocytes. 5. The particles containing peroxidase, acid phosphatase and alkaline phosphatase all exhibited latency. Maximum activity for each enzyme was obtained at roughly similar concentrations of Triton X-100. 6. The acid phosphatase of these cells was distributed between two populations of particles that differed in both sedimentation characteristics and density. The acid phosphatase(s) of the two populations showed slightly different substrate specificities. This bimodal distribution was not an artifact of the procedure used to elicit the cells. 7. Catalase was recovered almost entirely in the soluble fraction and showed no latency in freshly prepared homogenates. No urate oxidase was detected. 8. We conclude that the ;granule' fraction of the polymorphonuclear leucocyte, as isolated by previous workers, contains at least three, probably more, populations of particles with different enzyme contents, and that these cells probably do not contain peroxisomes.     

Specificity and Evolutionary Divergence of the Antigenic Structure of the Polypeptide Chain Elongation Factors

Antisera have been prepared against two electrophoretically homogeneous "polypeptide chain elongation factors," T and G, from Escherichia coli. Inactivation and precipitation tests showed that these two fractions were antigenically distinct with no cross-reaction. The immune inactivation curve of G factor from E. coli was distinguishable from that of G factor from Pseudomonas fluorescens. Mammalian factors were not inhibited by antibody directed against the E. coli T and G factors. By Ouchterlony diffusion tests, the antisera also detected significant antigenic variability among different bacterial species. It is concluded that the factors have undergone considerable evolutionary divergence in their antigenic structure.     

Studies on the Nucleocapsid Structure of a Group A Arbovirus

When Sindbis virus (273S) was treated with sodium desoxycholate, a nonhemagglutinating 136S particle was liberated from the virion, representing the viral nucleocapsid (core). Electron microscopically it appeared as a spherical particle 35 nm in diameter, showing ringlike morphological units 12 to 14 nm in diameter on its surface. When the one- and two-sided images of core particles were correlated, their structure could be demonstrated to have the T = 3 arrangement of 32 hexamer-pentamer morphological units within a symmetrical surface lattice. The core contained a further spherical structure (12 to 16 nm in diameter) which was designated as the central core component. Two proteins were found associated with the core, a third viral protein belonged to the hemagglutinating surface structures. The significance of these findings for virus classification is discussed.     

Development and replenishment of the P-depletion zone around the primary root of maize during the vegetation period

The dynamics of the development and replenishment of P-depletion zones around the primary root of maize (Zea mays L. cv ‘Garbo’) was studied during a vegetation period (80 days) under greenhouse conditions in a loamy sand of low P-availability. A recently described freeze-cutting technique was used to determine radial diffusion of labelled phosphate to the primary root. The development of the depletion zone was biphasic. In the initial phase after two days of growth of the primary root in a soil layer labelled with³³P a minimum of isotopically exchangeable P (EP) was observed which had decreased to about 30% of its original amount at the root surface. At that time the corresponding P-concentration in the soil solution was calculated to be as low as 5×10⁻⁷ M. The depletion zone had already spread 0.4 mm from the root surface. During the second phase, between the 10th and 20th day of plant growth the concentration of EP at the root surface increased slowly but did not change markedly. However, the depletion zone continued to spread and after the 20th day of growth reached its maximal diameter (1.07 mm from the root surface) but remained completely within the root hair cyclinder; the single root hairs never exceeded 1.14 mm in length. The biphasic growth of the depletion zone was probably caused by proton extrusion of the root tip. Acidification of the soil solution from pH 5.8 to about 3.9 results in an about 3-fold rise of the concentration of desorbed phosphate and might also have activated acidophilic P-translocators of the root during the initial phase. Anion over cation uptake normally prevailing during the later stage of root development might resulted in a rise of the soil pH within the root hair zone. Consequently P-availability, as well as P-uptake capacity declined, but P-uptake by the seminal root still continued until the 20th day. Subsequently, the P-concentration within the depletion zone increased again while simultaneously its extent was reduced until it was almost completely replenished after 60 days indicating a loss of P-uptake capacity of the primary root. Within the root tissue³³P was accumulated to about twice the concentration of that in the undepleted soils. This accumulation corresponded to periods of high uptake due to the development of root laterals. In the root cortex a high P-content was observed during the first 30 days of growth. At the onset of the reproductive stage of the plant the P-content of the shoot and especially in the developing seeds rose considerably at the cost of phosphate stored in the root cortex. The accumulation of³³P in the root tissue indicated that nutrient gain was mainly achieved during the early stages of plant development and that P was temporarily stored to some extent within the root system.     

Further Characterization of Dopamine Release by Permeabilized PC 12 Cells

Rat pheochromocytoma cells (PC12) permeabilized with staphylococcal alpha-toxin release [3H]dopamine after addition of micromolar Ca2+. This does not require additional Mg2+-ATP (in contrast to bovine adrenal medullary chromaffin cells). We also observed Ca2+-dependent [3H]-dopamine release from digitonin-permeabilized PC12 cells. Permeabilization with alpha-toxin or digitonin and stimulation of the cells were done consecutively to wash out endogenous Mg2+-ATP. During permeabilization, ATP was removed effectively from the cytoplasm by both agents but the cells released [3H]dopamine in response to micromolar Ca2+ alone. Replacement by chloride of glutamate, which could sustain mitochondrial ATP production in permeabilized cells, does not significantly alter catecholamine release induced by Ca2+. However, Mg2+ without ATP augments the Ca2+-induced release. The release was unaltered by thiol-, hydroxyl-, or calmodulin-interfering substances. Thus Mg2+-ATP, calmodulin, or proteins containing -SH or -OH groups are not necessary for exocytosis in permeabilized PC12 cells.