Retention of lead within the digestive vacuole inTetrahymena

Summary The ciliateTetrahymena pyriformis was exposed to lead acetate. Cell proliferation in the presence of 0.1% lead salt (with or without EDTA) equaled, after a variable lag period, that of the control cells. The lead (550 ppm) forms a fluffy precipitate with the organic growth medium; this was in part prevented by addition of EDTA. The cells primarily ingested the fluffy precipitate whereby they became exposed to large amounts of lead. Within the digestive vacuole, the fluffy precipitate became converted into refractile structures (3 m in diameter) which were egested and accumulated at the bottom of the culture flask. The lead content of these defecation balls was higher than that of the fluffy precipitate. In addition to the lead-containing vacuoles, the cells contained small, refractile granules. The apparent, high tolerance ofTetrahymena towards lead is believed to be due in part to the low ionic concentration of lead under the present conditions and in part to a detoxication mechanism consisting of retention of lead within the digestive vacuoles and perhaps of accumulation of lead within the small, refractile granules.     

Photosynthese und Photomorphogenese bei Farnvorkeimen vonDryopteris filix-mas

Summary Under conditions of identical rate of photosynthesis (measured by dry weight increase under steady state conditions) growth and differentiation of the gametophytes of ferns (e.g.Dryopteris filix-mas) are completely different in red and blue light. In the blue light normal growth and morphogenesis take place and normal two or three-dimensional prothallia are formed (Fig. 3). In the red, however, the prothallia look very similar to those growing in complete darkness: they grow as one-dimensional filaments (Fig. 1).It has been shown in this paper that photosynthesis, which is important as a source of organic material and free energy, has no influence at all on morphogenesis. Morphogenesis, i.e. the formation of normal prothallia instead of filaments, is controlled by a photoreactive system which depends on blue light of suitable intensity and which is not related to photosynthesis as such. If no blue light is present no morphogenesis occurs in spite of high photosynthetic activity.In our opinion theprimary products of photosynthesis are the same in all wavelengths. But now the photomorphogenic light reaction which depends on blue light apparently directs the flow of metabolites. In this way even the same initial products of CO₂ fixation may lead subsequently to rather different photosynthetic products and consequently to the very great difference between prothallia growing with or without blue light.The addition of sucrose has practically no influence on growth and morphogenesis under our conditions. On the basis of our results we cannot agree with the general conclusions drawn byMiller andMiller (1961) who regard photosynthesis as a photomorphogenetic system in these gametophytes of ferns.Mit 6 Textabbildungen.Herrn Professor Dr.E. G. Pringsheim in Verehrung zum 80. Geburtstag.     

Evolution alpiner Populationen vonEuphrasia (Scrophulariaceae): Die mittel- bis kleinblütigen,drüsenhaarigen Arten

A more precise taxonomic concept ofE. hirtella and its infraspecific synonymy is presented. Its diploid nature (2n = 22) is confirmed. Within the European area ofE. hirtella five different races may be recognised: typical, brandisii, capitulata, Rofan and Bretagne. Taxonomic rank is not yet attributed to these races. The heterogeneous taxonomic assembly E. drosocalyx is disentangled. The type refers to products of hybrid introgression ofE. rostkoviana-characters (long glandular hairs) intoE. minima.

Former contributions of this series areEhrendorfer & Vitek (1984) andGreilhuber & al. (1984).     

Essentialistisches und evolution?res Denken in der systematischen Ornithologie des 19. und 20. Jahrhunderts

Zusammenfassung Die Ablösung des essentialistischen (typologischen) Denkens bei Vertretern der systematischen Ornithologie durch das darwinistische (evolutionäre) Populationsdenken um die letzte Jahrhundertwende bildete eine scharfe historische Diskontinuität. Die essentialistische Denkweise, die in Europa während des 19. Jahrhunderts dominierend war, erreichte ihr Ende im Werk vonOtto Kleinschmidt (1870–1954), dem letzten Vertreter derPallas-Schlegel Schule. In den ersten Jahrzehnten dieses Jahrhunderts wurde die evolutionäre Denkweise der Ornithologen der nordamerikanischenBaird-Coues Schule und der europäischenSeebohm-Harter Schule bestimmend. Die weite taxonomische Begrenzung von Arten durch die Ornithologen der essentialistischenPallas-Schlegel Schule und der evolutionären Mikrotaxonomie täuscht Gemeinsamkeiten dieser Schulen vor; im theoretischen Denken ihrer Vertreter bestanden fundamentale Unterschiede. Gegenwärtig ist eine Entwicklung innerhalb der evolutionären Mikrotaxonomie erkennbar, die möglicherweise in naher Zukunft zu einer Trennung in zwei Schulen mit verschiedenen Artkonzepten und unterschiedlicher Artabgrenzung führen wird: (a) Weite Artabgrenzung (mit relativ wenigen polytypischen Arten) und (b) enge Artabgrenzung (mit relativ vielen monotypischen Arten). Dazwischen vermitteln intermediäre Vorschläge. Der wissenschaftliche Naturschutz bezieht sich heute auf evolutionär signifikante Einheiten und ist unabhängig von den verschiedenen systematischen Konzeptionen über die Art.

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Essentialistic and evolutionary thinking in the field of systematic ornithology during the 19^th and 20^th century

Essentialistic thinking dominated systematic ornithology in North America during the first half of the 19^th century and in Europe until the beginning of this century, when evolutionary thinking superseded it marking a sharp historical discontinuity. Evolutionary thinking of the ornithologists of the North AmericanBaird-Coues school and of the EuropeanSeebohm-Hartert school prevailed increasingly from the late 19^th century and early 20^th century onward, respectively. The representatives of the essentialisticPallas-Schlegel school and of evolutionary microtaxonomy delimited species taxa broadly which common procedure concealed the fundamental differences in their theoretical thinking. Within the near future, evolutionary microtaxonomy may split into two different schools supporting different species concepts and a different delimitation of species taxa: (a) Wide species limits resulting in relatively few polytypic species taxa and (b) narrow species limits resulting in numerous monotypic species taxa; intermediate views connect these extremes. Conservation biology refers to evolutionarily significant units and is independent of the different views of systematists as to what constitutes a species.

     

Myosatellite cells associated with different muscle fibre types in the Atlantic hagfish (Myxine glutinosa,L.)

Summary The incidence of myosatellite cells associated with white and red muscle fibres of the parietal muscle and red fibres of the craniovelar muscle was estimated by quantitative electron microscopy in the Atlantic hagfish (Myxine glutinosa, L.). Myosatellite cell nuclei constitute 3, 11 and 23 % of the total number of nuclei inside the basal lamina of the three types of muscle fibres, respectively. However, the total number of nuclei is highest in white fibres, most of the nuclei belonging to striated muscle cells. Myosatellite cell profiles in transverse sections constitute 23, 41 and 61 % of the number of muscle fibre profiles of the three types, respectively. The intervals between adjacent myosatellite cells are 135 m in white fibres, 55 m in red parietal fibres, and only 25 m in craniovelar fibres. Since craniovelar fibres are also comparatively thin, myosatellite cells constitute a significant fraction of the volume inside the basal lamina in these fibres. The myosatellite cells are 30–50 m long and up to 5 m thick. Some myosatellite cells possess few organelles, whereas others appear to contain many free ribosomes, granular endoplasmic reticulum, prominent Golgi apparatus and lysosome-like bodies.This investigation was supported by the Norwegian Research Council for Science and the Humanities (NAVF grant No. C20.30–37). The authors are indebted to Jorunn Line Vaaland and Berit Branil for technical assistance, and to Dr. Finn Walvig, Biological Station, University of Oslo, Drøbak, for supplying the hagfish     

The ultrastructural ionic fixation technique localizing acetylcholinesterase activity,reveals simultaneously acetylcholine-like cation in the synaptic vesicles of the motor nerve terminals

Summary A new cytochemical technique is proposed for side by side localization of acetylcholine and of acetylcholinesterase activity of motor end-plate at ultrastructural level. The technique is based on the simultaneous ionic fixation of vesicular acetylcholine and of histochemical copper thiocholine precipitate with phosphomolybdic acid: the molybdic heteropolyanion forms insoluble salts with these two quaternary ammonium cations, providing in situ acetylcholine phosphomolybdate and copper thiocholine phosphomolybdate. Both of them are osmium resistant; the electron dense precipitates allow for a fine localization of acetylcholine and acetylcholinesterase activity at electron microscopic level.     

Hexagonally ordered “rosettes” of particles in the plasma membrane ofMicrasterias denticulata Bréb. and their significance for microfibril formation and orientation

Summary Cells ofMicrasterias denticulata Bréb. at the stage of secondary wall formation have been studied by freeze-etching. It was found that the plasma membrane exhibits oval areas in which arrays of membrane particles occur. These particles form rosettes which are arranged in a hexagonally ordered lattice with a center to center spacing of 25 nm. Nearly the same periodicities can be found between microfibrils. It is concluded that the rosettes probably together with the thickened area of the plasma membrane below them represent the apparatus for the production and orientation of microfibrils. The hypothesis suggesting the incorporation of membrane templates functional in microfibril formation, originally advanced byKiermayer andDobberstein (1973) has received further support.     

Units of measurement for fractal extent,applied to the coastal distribution of bald eagle nests in the Aleutian Islands,Alaska

Summary Attempts to measure the nesting density or territory size of bald eagles led to a fundamental difficulty, inherent in all such measurements on organisms which are distributed along an irregular boundary, such as a coastline. The length of such a boundary is not a meaningful measure, and neither can a meaningful area be associated with each nest. Mandelbrot's (1983) fractal geometry applies to the problem, but has not previously supplied practical units of measurement for fractals such as coastlines or rugged surfaces. A practical method is given for measuring the extent of such fractals, introducing a unit of variable dimension, the metron, which includes the existing SI units of length, area and volume as special cases. A linear measure, the spacing allows densities on fractals of different dimensions to be compared directly. The method is applied to the distribution of bald eagle nests along the coastlines of two islands in the Aleutians, and an extension of the method to handle distributions on mountainsides and island surfaces is indicated.     

The demonstration of chloride ions in the “chloride cells” of the gills of eels (Anguilla anguilla L.) adapted to sea water

Summary The ultrastructure of chloride cells in the gills of eels kept in artificial sea water and of a control animal kept in fresh water was studied. In addition to glutaraldehydeosmium tetroxide and simple osmium tetroxide fixation, a special method for the demonstration of chloride ions was used (Komnick, 1962, 1963). Based on the principle of silver chloride precipitation in the presence of chloride ions, the procedure showed positive results in the chloride cells of eels adapted to sea water. Smooth-surfaced tubules of the endoplasmic reticulum contained a material of medium to strong electron density, that was often in communication with the plasma membrane. The same material, always of very high density, was present in the intercellular spaces, thus forming conspicuous lines around cells. The silver precipitate was found very often in large quantities in the pits of chloride cells, having thereby the aspect of a secretory product. However, a direct communication between the system of endoplasmic reticulum tubules containing the silver reaction product with the above-mentioned masses of silver chloride was not demonstrated. Schultz (1958) first published an electron micrograph of these cells. Two features, numerous mitochondria and highly developed agranular endoplasmic reticulum, affirmed by all later investigators, have remained the most important criteria for the identification of chloride cells (Kessel and Beams, 1962; Philpott, 1962; Philpott and Copeland, 1963; Rhodin, 1964; Henrikson and Matoltsy, 1968). Kessel and Beams (1962) and Philpott and Copeland (1963) demonstrated pits, or apical cavities (Oberg, 1967) filled with an amorphous granular substance of medium electron density. (Threadgold and Houston, 1964). These cavities are found in animals adapted to sea water only, and correspond to the excretory vesicles described earlier by Copeland (1948). Philpott and Copeland demonstrated numerous vesicles and tubules in the cytoplasm surrounding the apical cavities and opening into them, possibly contributing to their granular material. Several authors attempted to demonstrate a chloride excretory function of chloride cells with the aid of some histochemical reactions. Copeland (1948), Datta Munshi (1964) and Philpott (1966) used silver techniques     

The “biological ego”. From Garrod's “chemical individuality” to Burnet's “self”

Starting from the conceptual premises of Garrod, who as long ago as 1902 spoke of chemical individuality, and of Burnet (1949), who recognized as self one's own molecular antigenic structures (as opposed to the antigenic alien: the non- self), the discovery and understanding of HLA antigens and of their extraordinarily individual and differentiated polymorphisms have gained universal recognition. Transplant medicine has now dramatically stressed, within man's knowledge of himself, the characteristic of his biological uniqueness. Today man, having become aware of being a biological antigenic-molecular individuality which is unique and different from that of all of his fellow men (except for monozygotic twins), can therefore easily consider himself a true biological Ego.Abbreviations BMT bone marrow transplantation - GVHD graft versus host disease - HLA human leukocyte antigens - MHC major histocompatibility complex - MLC mixed lymphocyte culture - MLR mixed lymphocyte reaction     

Die Hypokotylfarbe als Markierungsfaktor von Genomstufen der Zuckerrübe

Zusammenfassung In zunehmendem Maße werden anisoploideBeta-Rübensorten angebaut, deren zytologische Kontrolle zwecks Feststellung der Genomstufenprozentanteile recht arbeitszeitaufwendig ist. Übereinstimmend mit polnischen Autoren wurde festgestellt, daß die Hypokotylfarbe ein geeigneter Markierungsfaktor für die einzelnen Genomstufen darstellt. Kreuzt man tetraploide Pflanzen, die ein grünes Hypokotyl besitzen, mit diploiden Pflanzen, die ein rosa Hypokotyl aufweisen, so erhält man von dem tetraploiden Partner tetraploide grüne und triploide hellbraune, von dem diploiden Partner diploide rosa und triploide hellbraune Nachkommenschaften. Die in bezug auf die Hypokotylfarbe heterozygoten Pflanzen kann man demnach von den homozygot grünen und homozygot rosa Individuen unterscheiden. Die Kreuzung diploid grünxtetraploid rosa ist für diese Zwecke nicht brauchbar, da sich die triploiden Heterozygoten mit einem grünen und zwei rosa Allelen in der Hypokotylfarbe nicht deutlich von den homozygoten rosa Pflanzen abheben. Auf die Bedeutung dieser Markierungsmöglichkeit für bestimmte Forschungsprobleme, die Züchtung und die Saatgutkontrolle wird hingewiesen.     

Computational constraints that may have favoured the lamination of sensory cortex

At the transition from early reptilian ancestors to primordial mammals, the areas of sensory cortex that process topographic modalities acquire the laminar structure of isocortex. A prominent step in lamination is granulation, whereby the formerly unique principal layer of pyramidal cells is split by the insertion of a new layer of excitatory, but intrinsic, granule cells, layer IV. I consider the hypothesis that granulation, and the differentiation between supra- and infra-granular pyramidal layers, may be advantageous to support fine topography in their sensory maps. Fine topography implies a generic distinction between where information, explicitly mapped on the cortical sheet, and what information, represented in a distributed fashion as a distinct firing pattern across neurons. These patterns can be stored on recurrent collaterals in the cortex, and such memory can help substantially in the analysis of current sensory input. The simulation of a simplified network model demonstrates that a non-laminated patch of cortex must compromise between transmitting where information or retrieving what information. The simulation of a modified model including differentiation of a granular layer shows a modest but significant quantitative advantage, expressed as a less severe trade-off between what and where. The further connectivity differentiation between infra-granular and supra-granular pyramidal layers is shown to match the mix of what and where information optimal for their respective target structures.     

Studies on the neurosecretory system of Iphita limbata Stal.

Summary The present paper gives an account of some experiments upon the insect Iphita limbata Stal. (Hemiptera: Pyrrhocoridae). The experiments were carried out in order to find out whether in the adult animal there is a relationship between the activity of the neurosecretory cells and the water balance. Under varying conditions one group of the neurosecretory cells of the pars intercerebralis of the brain, the so called A-cells, show histological differences. It has been seen that under conditions stimulating hydration there is a marked retention of the stainable colloids in the cytoplasm of A cells. This retention probably indicates a relationship between the secretions of A cells and the water balance of the insect.The author is indebted to Mr. N. R. Prabhoo and Miss Maya Menon of this Department for a critical discussion of the paper.     

Über das Verhalten von Champignonstämmen in Mischkultur

Zusammenfassung Mischungen aus dem Mycel sweier weißer oder zweier brauner Stämme des Kulturchampignons hatten keinen Einfluß auf den Fruchtkörperetrag.Bei Mischungen aus einem weißen und einem braunen Stamm was dagegen der Ertrag immer niedriger als erwartet und das Mycel verschwand verhältnismäßig schnell. Der Ertragsausfall beruht in der Regel auf einer Unterdrückung des braunen Stammes.Herrn Prof. von Sengbusch zum 65. Geburtstag in Dankbarkeit und Verehrung gewidment.     

The cytology of phytophthora infestans

Summary Phytophthora infestans has three kinds of somatic nuclei: an oval shaped nucleus (approx. 3.1×2.7 ) which stains diffusely except for a crescent shaped Feulgen positive cap which stains intensely; a granular nucleus whose contents are organized into a fairly constant number of stained bodies, and, a deeply staining condensed nucleus. The capped nucleus is thought to be metabolic or resting and the granular nucleus is thought to be dividing as it is most commonly found in hyphal tips. Attenuated forms of all three kinds of nuclei are found.Nuclear division is mitotic and intranuclear. Eight—ten chromosomes are seen at metaphase.Sporangia have a mean of 6.3 nuclei which is constant for age and strain of culture. Sporangia become multinucleate as a result of nuclear migration and not by division in the developing sporangium. Zoospores are usually uninucleate.The nuclear cap is persistent throughout nuclear division when it also divides. It is associated with flagella production and nuclear migration and has some of the properties of a blepharoplast.     

Variant forms ofα-2-l-fucosyltransferase in human submaxillary glands from blood group ABH “secretor” and “non-secretor” individuals

The properties of the -2-l-fucosyltransferases in submaxillary gland preparations from blood group ABH secrefors and non-secretors were compared. The level of activity in the non-secretor gland homogenates amounted to about 5% only of that found in the secretor gland preparations. The enzymes from the two sources differed in solubility properties, charge and affinities for donor and acceptor substrates. The enzyme from secretor glands showed a preference for acceptors with Type 1 [d-galactosyl(1–3)-N-acetyl-d-glucosamine] structures whereas the enzyme from non-secretor glands had a preference for Type 2 [d-galactosyl(1–4)-N-acetyl-d-glucosamine] structures.These results demonstrate that expression of the secretor gene (Se) is associated with a molecular form of the -2-l-fucosyltransferase that is different from the species present in the same tissue when theSe gene is not expressed.     

High-resolution 2-dimensional protein mapping of “diploid” and “aneuploid” mammary adenocarcinomas

Summary Two-dimensional-electrophoretic analysis has been applied to non-neoplastic mammary epithelium from eight healthy women, tumor tissue from eight diploid mammary adenocarcinomas, and tumor tissue from eight aneuploid mammary adenocarcinomas. Compared with non-neoplastic mammary epithelium, a slight numerical net increase of the protein spots was detected in diploid tumors and a marked increase in aneuploid tumors. Two prominent spots were present in all 16 malignant tissues examined and absent in all eight non-neoplastic tissues (silver staining method).The results suggest that a difference in the composition of cellular proteins exists both between non-neoplastic mammary cells and malignant tumor cells, and between diploid and aneuploid tumors.In honour of Prof. P. von Duijn     

Vanadium and molybdenum requirement for the fixation of molecular nitrogen by two Methanosarcina strains

Nitrogen fixation of the Methanosarcina barkeri strains Fusaro (DSM 804) and 227 (DSM 1538) was found to be dependent on the presence of vanadium or molybdenum whereby molybdenum (added as Na₂-molybdate) was preferred to vanadium (added as VCl₃). Strain 227 showed less pronounced effects on diazotrophic growth with respect to vanadium and molybdenum. Rhenium (ReCl₃) or tungsten (Na₂-tungstate) could not replace vanadium or molybdenum. The optimum concentrations were found to be 2M for vanadium and 5M for molybdenum (strain Fusaro). This Mo optimum of methanogenesis was 10-fold higher with N₂ than with NH₄Cl as nitrogen source. A vanadium requirement with NH₄Cl could not be detected. No interferences were observed if molybdenum and vanadium were added simultaneously under diazotrophic conditions. Growth yields were smallest for strain 227 grown diazotrophically ( =0.6g dw/mol in the presence of vanadium and =0.9g dw/mol in the presence of molybdenum), obviously higher for strain Fusaro grown diazotrophically ( =1.15g dw/mol in the presence of V and =1.4g dw/mol with Mo) and highest if M. barkeri was grown on NH₄Cl as N-source ( =3.4g dw/mol with Mo, strain Fusaro).     

Electrophoretic variation between class II molecules expressed on HLA-DRw8 homozygous typing cells reveals multiple distinct haplotypes

Two-dimensional (2D) gel electrophoresis of immunoprecipitated HLA-DR antigens from eight homozygous typing cells (HTC) expressing the HLA-DRw8 specificity revealed a clustering of polymorphic chain patterns into distinct electrophoretic variants. The variant patterns correlate with three discrete HLA-D clusters that are defined in the mixed leukocyte culture reaction (MLR) using DRw8-positive HTC. These HLA-D clusters have been provisionally designated Dw8.1, detected primarily in Caucasoids, Dw8.2, detected primarily in American Indians, and Dw8.3, detected predominantly in Orientals. All three HLA-Dw8.1 cell lines express a single DR-locus product as defined by immunoprecipitation with a DR-specific monoclonal antibody, P4.1. This DR chain is identical among the Dw8.1 cell lines and different from the DR chains of the Dw8.2 and Dw8.3 cell lines. Two separate Dw8.2 HTC express a shared DR chain that is slightly more basic than the 8.1 DR molecule; interestingly, one of these lines also expresses an additional DR-like chain not found in the other cells. Thus, the two lines defining the Dw8.2 cluster share one distinct class 11 molecule, but differ in another and therefore are not biochemically HLA-identical. Cells from the Dw8.3 cluster are likewise distinct from all other Dw8 clusters. One additional DRw8-positive HTC has been analyzed and found to be distinct from the Dw8.1, 8.2 and 8.3 clusters by both MLR and 2D gels. lmmunoprecipitates using monoclonal antibody 1B5 [anti-DR and anti-DQ(DS)] identify additional polymorphic class II variants among the cell lines tested. These data indicate that HLA-DRw8 is a public serologic specificity present on class II molecules expressed on multiple distinct haplotypes. These haplotypes differ from each other in expression of polymorphic class II molecules encoded by at least two HLA loci. They also differ in HLA-D, even though they all type as HLA-DRw8 homozygous. In Dw8.2, variation in expressed chains is not reflected in variation in HLA-D, indicating that MLR, as well as serologic typing, does not detect the full degree of allelic polymorphism within HLA.