Greek classicism in living structure? Some deductive pathways in animal morphology

Classical temples in ancient Greece show two deterministic illusionistic principles of architecture, which govern their functional design: geometric proportionalism and a set of illusion-strengthening rules in the proportionalism's stochastic margin. Animal morphology, in its mechanistic-deductive revival, applies just one architectural principle, which is not always satisfactory. Whether a Greek Classical situation occurs in the architecture of living structure is to be investigated by extreme testing with deductive methods.Three deductive methods for explanation of living structure in animal morphology are proposed: the parts, the compromise, and the transformation deduction. The methods are based upon the systems concept for an organism, the flow chart for a functionalistic picture, and the network chart for a structuralistic picture, whereas the optimal design serves as the architectural principle for living structure. These methods show clearly the high explanatory power of deductive methods in morphology, but they also make one open end most explicit: neutral issues do exist.Full explanation of living structure asks for three entries: functional design within architectural and transformational constraints. The transformational constraint brings necessarily in a stochastic component: an at random variation being a sort of free management space. This variation must be a variation from the deterministic principle of the optimal design, since any transformation requires space for plasticity in structure and action, and flexibility in role fulfilling. Nevertheless, finally the question comes up whether for animal structure a similar situation exists as in Greek Classical temples. This means that the at random variation, that is found when the optimal design is used to explain structure, comprises apart from a stochastic part also real deviations being yet another deterministic part. This deterministic part could be a set of rules that governs actualization in the free management space.     

Changes in metabolism and hormone trafficking during exposure of endocrine cells to elevated ammonium

Endocrine cell cultures have potential in bioprocessing, for the production of biologically active hormones, and in tissue engineering, for the development of implantable artificial tissues for long-term restoration of endocrine function. To optimize such systems, it is necessary to develop a thorough understanding of how inherently present environmental stresses, such as nutrient depletion and metabolite accumulation, affect the cells. This work focuses on the effects of the metabolite ammonium on indicators of endocrine cell metabolism and on the processing, storage and secretion of regulated secretory proteins. Experiments were conducted on recombinant insulin-producing mouse pituitary AtT-20 cells and mouse insulinoma TC3 cells. Exposure for 24–48 hours to 6 mM of exogenous ammonium resulted in higher rates of glucose consumption by both AtT-20 and TC3 cells, while the formation of additional ammonium generally decreased relative to ammonium-free controls. When TC3 cells were discharged of their intracellular insulin stores, the presence of ammonium during a subsequent recharge completely inhibited addition of new insulin-related peptides to the stores, as we had observed previously for both cell lines. There was a correlation between insulin-related peptides stored in TC3 cells during recharging and the amount that could be released upon secretagogue stimulation. Using a combination of radioimmunoassay and high performance liquid chromatography, we found that intracellular insulin and insulin-related peptides changed in the same fashion. Intracellular mechanisms that may be producing the observed results are discussed.Abbreviations IRP insulin-related peptides - HPLC high performance liquid chromatography - DAMP 3-(2,4-dinitroanilino)-3 amino-N-methyldipropylamine     

Interaction of aluminium ions with some amino acids present in human blood

Summary. The interaction of aluminium with some amino acids present in human blood was studied combining ion-chromatography (IC), atomic absorption spectrometry (AAS) and ultrafiltration (UF) techniques. An IC system for simultaneous determination of ornithine, lysine, glutamic acid, aspartic acid and tyrosine was developed. By adding aluminium to standard solutions of the amino acids and keeping the pH at 6 and 7 it was possible to verify that aluminium caused a reduction on the amino acid chromatographic signals. Similar experiment, carried out for copper showed the same behaviour (with different percentage of signal reductions) and validated the results for aluminium, considering that the interaction Cu-amino acid is well-established. The AAS analysis of sample fractions (500l) after the IC separation showed that aluminium (as copper as well) is not present in the fractions in which the amino acid peaks appear in the chromatogram. These approaches carried out with serum samples after UF showed that part of the free fraction of serum aluminium is distributed, besides other ligands, among these amino acids. It was found that in serum the affinity for aluminium followed the sequence Lys>Orn>Tyr>GluAsp.     

Über Konstitution und Erbgang eines neuen Delphinidinglycosids „Floridorin“ aus der Garteniris-Sorte cv. ‘Floridor’ (Cayeux 1929)

Zusammenfassung Bei der diploiden hohen Garten-Iris cv. Floridor (Cayeux 1929) wurde als bisher einziger Sorte ein neues Delphinidinglycosid Floridorin aufgefunden. Seine chemische Konstitution wurde als Delphinidin-3-Glukose-Rhamnose-p-Cumarsäure aufgeklärt. Es fand sich zusammen mit dem schon von uns aufgeklärten Anthozyan Tulipanin (Delphinidin-3-Glucose-Rhamnose). Das Hauptanthozyan der anderen Garten-Iris ist das von uns neuerdings nachuntersuchte Violanin. Die Untersuchungen wurden mit bereits von uns angegebenen neueren Methoden ausgeführt, wie der stufenweisen Hydrolyse und dem oxidativen Abbau. Das neue Floridorin zeigte bei den diploiden Garten-Iris einen monohybriden rezessiven Erbgang gegen Violanin. Die Blüten der Sorten, die Floridorin enthalten, sind schon mit dem Auge an einem charakteristischen taubenblauen Farbton zu erkennen.

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On the constitution and inheritance of a new delphinidine glycoside Floridorin from the cultivated iris variety cv. Floridor (Cayeux 1929)Studies on anthocyanins LI

Summary The diploid tall bearded garden Iris cv. Floridor (Cayeux 1929) proved to be thus far the only variety with a different anthocyanine, called Floridorin. Its chemical structure has been found to be delphinidine-3-glucose-rhamnose-p-coumaric-acid. It occurs together with tulipanine already analyzed by us as delphinidine-3-glucose-rhamnose. The main anthocyanine of thePogoniris garden varieties proved to be violanin the structure of which has been studied by us lately. The investigations were carried out by some newer methods, such as partial hydrolysis and oxidative degradation already published by us. The new Floridorin gives a monohybrid recessive Mendelian ratio with other diploid varieties ofPogoniris colored by violanine. The varieties colored by Floridorin show a characteristic greyish blue coloration which can be recognized with the naked eye.

     

Immature erythroid cells with novel morphology and cytoskeletal organization in adultXenopus

Summary Nucleated erythrocytes of non-mammalian vertebrates are a useful model system for studying the correlation between changes in cell shape and cytoskeletal organization during cellular morphogenesis. They are believed to transform from spheres to flattened discs to ellipsoids. Our previous work on developing erythroblasts suggested that pointed cells containing incomplete, pointed marginal bands (MBs) of microtubules might be intermediate stages in the larval axolotl. To test whether the occurrence of such pointed cells was characteristic of amphibian erythrogenesis, we have utilized phenylhydrazine (PHZ)-induced anemia in adultXenopus. In this system, circulating erythrocytes are destroyed and replaced by erythroblasts that differentiate in the blood, making them experimentally accessible. Thus, we followed the time-course of morphological and cytoskeletal changes in the new erythroid population during recovery. During days 7–9 post-PHZ, pointed cells did indeed begin to appear, as did spherical and discoidal cells. The percentage of pointed cells peaked at days 11–13 in different animals, subsequently declining as the percentage of elliptical cells increased. Since degenerating old erythrocytes were still present when pointed cells appeared, we tested directly whether pointed ones were old or new cells. Blood was removed via the dorsal tarsus vein, and the erythrocytes washed, fluorescently tagged, and re-injected. In different animals, 2–8% of circulating erythrocytes were labeled. Subsequent to induction of anemia in these frogs, time-course sampling showed that no pointed cells were labeled, identifying them as new cells. Use of propidium iodide revealed large nuclei and cytoplasmic staining indicative of immaturity, and video-enhanced phase contrast and anti-tubulin immunofluorescence showed that the pointed cells contained pointed MBs. The results show that pointed cells, containing incomplete, pointed MBs are a consistent feature of amphibian erythrogenesis. These cells may represent intermediate stages in the formation of elliptical erythrocytes.Abbreviations MB marginal band - MS membrane skeleton - PHZ phenylhydrazine     

Use of cluster analysis with monoclonal antibodies for taxonomic differentiation of phytopathogenic fungi and for screening and clustering antibodies

Cluster analysis of ELISA (A405) values resulting from tests using all possible combinations of 43 monoclonal antibodies (raised againstPhytophthora megasperma f.sp.glycinea) and 14 phytopathogenic fungi separated these fungi into taxonomically appropriate clusters. Two distance measurements (Pearson's correlation coefficient and normalized Euclidean distance) and five linkage methods (single, complete, median, centroid, and average) were evaluated. The combination of Pearson's correlation coefficient and complete linkage produced the most natural clusters. A modification of the data matrix allowed clustering of the monoclonal antibodies by specificity. Numerically coded ELISA values clustered identically with the orginal data. The taxonomic and evolutionary implications of using monoclonal antibodies specific to carbohydrates are discussed.     

Les Nématodes Trichostrongylina parasites d'Amphibiens et de Reptiles: problèmes taxonomiques, phylétiques et biogéographiques

Except for four species of the Mertensinematinae (Molineoidea) not considered in this work, the Trichostrongylina parasitic in amphibians and reptiles, comprising 15 genera and 105 species, are reviewed. The morphological characteristics of each species are analysed. The most important characteristics are provided by the disposition of the caudal bursal rays, the morphology of the synlophe (at the oesophago-intestinal junction and mid-body level) and by the anatomy of the spicules. The species are classified into seven groups:Group 1: relict species with six lips and well-developed buccal capsule (six genera and 16 species).Group 2: ancient species with one or two primitive characters (eight genera and 15 species).Seventy-four species, without primitive characters, comprise the genus Oswaldocruzia which is subdivided into five groups.Group 3: Oriento-Ethiopian species with non-idiomorphic spicules with two to three tips (10 species).Group 4: Neo-Ethiopian species with non-idiomorphic spicules with numerous tips (11 species).Group 5: Holarctic species with idiomorphic spicules with the spicular fork divided above the distal third of the spicule length (24 species).Group 6: Continental Neotropical species with idiomorphic spicules and spicular fork divided within the distal third of the spicule length (21 species).Group 7: Caribbean Neotropical species with modified idiomorphic spicules, the three main branches of which are each divided into numerous tips (eight species).The geographical distribution of the species appears to be of greater significance than the host spectrum and suggests the following biogeographical hypotheses: Group 1, entirely Gondwanan, diversified during the Cretaceous era prior to the separation of the southern continents. The expansion of Group 2, which is represented by Gondwanan and Oriental species mainly from India, Malaysia and Indochina, could have occurred throughout South-East Asia at the end of the Cretaceous era when India collided with Eurasia. Group 3 could be interpreted either as a migration from Asia to Africa during the upper Eocene, or more likely during the Miocene, or, by a dispersion due to the migrations of Bufo melanostictus. Group 4 may result from the expansion of the former group in the Ethiopian region. Group 5 could be interpreted as a colonisation of western Europe and the Nearctic from Asia during the Tertiary. Group 6 could have arisen after the migration of the Neartic species to the Neotropical region during the Pliocene period and Group 7 by the expansion of the former group in the Caribbean.Amongst the Trichostrongylina, the relict and ancient genera parasitic in amphibians and reptiles can only be compared with the genera parasitic in birds and mammals, probably dating from the Palaeocene period (mainly marsupials and primitive insectivores). On the other hand, the genus Oswaldocruzia can be compared with other members of the Molineoidea parasitic in fissipeds, Pholidota and Chiroptera dating from a later period (Eocene) (see Durette-Desset, 1971). Thus, the Trichostrongylina of amphibians and reptiles are distinguished by the persistence of very old species, the evolution and the geographical distribution of which was arrested for millions of years, and by the existence (in some regions) of groups undergoing full evolutionary expansion.The new taxa proposed in the paper are: Bakeria (Moravec & Sey, 1986) status emend. (= Bakeria Moravec & Sey sub. g.), Ragenema n. g., Ragenema robustum (Baker, 1982) n. comb. (= Oswaldocruzia robusta), Typhlopsia quentini (Durette-Desset, 1980) n. comb. (= Trichoskrjabinia quentini), T. secundus (Pinnell & Schmidt, 1977) n. comb. (= Trichoskrjabinia secundus), T. gansi (Crusz & Ching, 1975) n. comb. (= Oswaldocruzia gansi), T. limnodynastes (Johnston & Simpson, 1942) n. comb. (= Oswaldocruzia limnodynastes), T. legendrei (Chabaud & Brygoo, 1962) n. comb. (= Oswaldocruzia legendrei).

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Les Nématodes Trichostrongylina parasites d'Amphibiens et de Reptiles: problèmes taxonomiques, phylétiques et biogéographiques

     

Glycosylphosphatidylinositol (GPI) hydrolysis by Transforming Growth Factor-β1 (TGF-β1) as a potential early step in the inhibition of epithelial cell proliferation

Glycosylphosphatidylinositol (GPI) was previously identified in rabbit articular chondrocytes as being a precursor of inositolphosphate glycan (IPG), released upon (Transforming Growth Factor-) (TGF-) exposure, and capable of mimicking the proliferative effects of the growth factor. Here, using mink lung epithelial cells (CCL 64), which are known to be growth-inhibited by TGF-, we studied the potential role of GPI-derived molecules in the antiproliferative effect of TGF-1. We first identified an endogenous pool of GPI material and three different anionic forms of IPG in epithelial cells pre-labeled with [3H] glucosamine. Shortly (8 min) after TGF-1 addition, the cells responded by a rapid and transient hydrolysis of GPI, accompanied by the release of the most anionic form of IPG. This TGF--released IPG, after partial purification, was shown to decrease the proliferation of CCL 64 cells. Moreover, anti-IPG antibodies reduced the effects of TGF- and blocked the effects of partially purified IPG. These data strongly suggest that GPI hydrolysis may be an early step of the TGF- signalling pathway involved in growth inhibition of epithelial cells.     

NMR confirmation of an alkali-insoluble glucan from Kluyveromyces marxianus cultivated on a lactose-based medium

Yeast cells of Kluyveromyces marxianus grown in a sterile lactose-based medium, were extracted with sodium hydroxide to give a fraction of alkali-insoluble yeast (AIY) glucan. From ¹H- and ¹³C-NMR characterization it was concluded that the glucan consisted mostly of (1 3) linkages and was similar to that obtained from Saccharomyces cerevisiae used in the preparations for skin revitalization and repair. The molecular weight of the glucan was determined to be approximately 3 × 10⁵ Da. Therefore, K. marxianus grown on a lactose-based medium similar to whey, a waste stream of the dairy industry, could be a commercial source of (1 3) glucans for use in the food and pharmaceutical industries.     

An immunohistochemical study of adenohypophyseal cells containing follicle-stimulating hormone and luteinizing hormone during the phase of selective follicle-stimulating hormone release in postnatal female rats

Summary Serum concentration of follicle-stimulating hormone (FSH) in the juvenile female rat increases independently from that of luteinizing hormone (LH). The objective of this study was to determine whether this increase in serum FSH is accompanied by a proliferation of FSH-cells greater than the proliferation of LH-cells. Thus, we measured circulating FSH and LH in female rats on days 3, 10, 13, 17, and 20, calculated the percentages of adenohypophyseal cells that contained FSH or LH on days 3, 10, and 20, and determined whether cells containing only FSH existed on day 10. Serum FSH concentrations on days 10 and 13 were significantly greater than those on days 3, 17, or 20. No differences existed in serum LH concentrations. Cells containing FSH or LH were distributed throughout the entire adenohypophyses of 3, 10, and 20-day-old females. Clusters of these cells were observed in the ventral regions of adenohypophyses of 3-day-old females. The percentages of adenohypophyseal cells containing FSH increased significantly from 9% in 3-day-old rats to 17% in 10-day-old rats and then decreased to 14% in 20-day-old animals. At all ages the percentages of adenohypophyseal cells containing FSH were similar to the percentages of cells containing LH. At 10 days of age, all cells containing FSH also contained LH and all cells containing LH also contained FSH. These data suggest that the increase in serum FSH in the juvenile female rat is associated with an increase in the percentage of adenohypophyseal cells containing FSH and that at this time all cells containing FSH also contain LH.     

Interferon-γ-induced increased sensitivity ofHER2/neu-overexpressing tumor cells to lymphokine-activated killer cell lysis: importance of ICAM-1 in binding and post-binding events

Treatment ofHER2/neu-overexpressing target cells with interferon (IFN) (200–2000 U/ml for 3 days) markedly enhances their sensitivity to lymphokine-activated killer (LAK) cell lysis. Increased sensitivity is associated with an up-regulation of intercellular adhesion molecule ICAM-1 determinants and a down-regulation ofHER2/neu expression. In the present study, we show that exposure to another cytokine, tumor necrosis factor (200 U/ml for 3 days), also decreasedHER2/neu expression but had no effect on LAK cell lysis and ICAM-1 expression. This suggests that down-regulation of oncogene expression is not sufficient by itself to induce an enhanced sensitivity to LAK cell lysis. IFN-induced enhanced lysis was associated with an increased binding between effectors and targets, and antibodies to ICAM-1 as well as its counter-receptor LFA-1, blocked the increased binding and lysis. Treatment with IFN still significantly enhanced lysis even when concanavalin A was added to the assay to induce maximal binding, indicating that a post-binding effect also participated in enhanced cytotoxicity. These post-binding alterations, were also sensitive to blocking with anti-ICAM-1 and anti-LFA-1 antibodies. Treatment with IFN also sensitized targets to lysis by T cells in the presence of lectin but had no effect on the relative resistance of HER2⁺ cells to lysis mediated by perforin or TNF. Together these data demonstrate the importance of ICAM-1 determinants in binding and post-binding events in the IFN-induced increased lysis ofHER2/neu ⁺ targets.Supported by research funds of the Veteran's Administration, the California Institute for Cancer Research and Jonsson Cancer Center core grant CA 16042 funded by NIH     

Cell multiplication and ultrastructure ofMicrasterias denticulata (Desmidiaceae) grown under salt stress

Cells ofMicrasterias denticulata Bréb. were kept in nutrient solution of high osmolality (salt stress) for four weeks. In a special cell multiplication test it was established that cell division is gradually inhibited at increasing salt concentrations and totally arrested at the highest concentration (26 mosm/kg). Recovery studies proved that even cells from the highest concentration range start dividing immediately after being placed in aqua bidest. thus indicating the full reversibility of the inhibiting effect. — Cells of the highest concentration range show marked ultrastructural changes. Besides an enormous accumulation of starch and oil bodies and a condensed appearance of the ground plasma, a reduction of mitochondria, ER and the Golgi-system is found. The most striking effect occurs on the vacuolar system which appears extremely reduced and condensed. The cell wall is thickened by the formation of an additional cell wall layer with a spongy electron microscopical appearance. Through the cell wall many droplets of a probably fat-like substance are excreted. — In summary, salt stress induces growth-inhibited akinete cells in the sense ofFritsch; these can be reactivated by decreasing the salt concentration. The salt-induced akinete state seems to be an ecological adaption to unfavourable conditions rather than a degeneration of the cells.Dedicated to Prof. DrLothar Geitler on the occasion of his 90th birthday.23. 12. 1988     

Charles Darwin's theory of evolution: A review of our present understanding

The paper characterizes Darwin's theory, providing a synthesis of recent historical investigations in this area. Darwin's reading of Malthus led him to appreciate the importance of population pressures, and subsequently of natural selection, with the help of the wedge metaphor. But, in itself, natural selection did not furnish an adequate account of the origin of species, for which a principle of divergence was needed. Initially, Darwin attributed this to geographical isolation, but later, following his work on barnacles which underscored the significance of variation, and arising from his work on botanical arithmetic, he supposed that diversity allowed more places to be occupied in a given region. So isolation was not regarded as essential. Large regions with intense competition, and with ample variation spread by blending, would facilitate speciation. The notion of place was different from niche, and it is questioned whether Darwin's views on ecology were as modern as is commonly supposed. Two notions of struggle are found in Darwin's theory; and three notions of variation. Criticisms of his theory led him to emphasize the importance of variation over a range of forms. Hence the theory was populational rather than typological. The theory required a Lamarckian notion of inheritable changes initiated by the environment as a source of variation. Also, Darwin deployed a use/habit theory; and the notion of sexual selection. Selection normally acted at the level of the individual, though kin selection was possible. Group selection was hinted at for man. Darwin's thinking (and also the exposition of his theory) was generally guided by the domestic-organism analogy, which satisfied his methodological requirement of a vera causa principle.     

AZT toxicity and AIDS prophylaxis: Is AZT beneficial for HIV+ asymptomatic persons with 500 or more T4 cells per cubic millimeter?

Analyses of the effects of prophylactic use of zidovudine (AZT) on progression to acquired immune deficiency syndrome (AIDS) in human immunodeficiency virus seropositive (HIV+) asymptomatic persons with T4 lymphocyte (CD4+) cell counts 500 mm³ is reported for data obtained from two studies, the Australian European Group Collaborative Study, a multi-centered double-blind placebo-controlled clinical trial of the effects of AZT on progression to AIDS and other clinical endpoints, and the San Francisco Men's Health Study, an observational cohort. The analyses of the data of both studies demonstrate no benefit from AZT treatment in terms of progression to AIDS for those who are asymptomatic with CD4+ cell counts 500 mm³. The analysis of the San Francisco study, performed with Kaplan-Meier survivorship estimates, indicates a heterogeneity in the efficacy of AZT between baseline CD4+ cell count strata, 200–499 mm³ and 500–800 mm³. Within the 200–499 stratum, 47% of those receiving AZT therapy and 62% of those not receiving AZT therapy progressed to AIDS during the study period. By contrast, within the 500–800 stratum 41% of those receiving AZT therapy and 27% of those not receiving AZT therapy progressed to AIDS during the same period. Application of the Cox proportional hazards survivorship regression model for the relative risk of progression to AIDS to these same data accounts for this heterogeneity. The model includes an interaction between AZT treatment and baseline CD4+ cell counts. The hematological toxicity of AZT, demonstrated in clinical studies and laboratory investigations, indicates a biological correlate for this interaction: the toxic effects of AZT on the more intact immune system of those with CD4+ cell counts in the 500–800 mm³ range.Abbreviations ACTG AIDS Clinical Trials Group - AIDS Acquired immune deficiency syndrome - AMT 3-amino-3-deoxythymidine - ARC AIDS-related-complex - AZT 3-azido-3-deoxythymidine, zidovudine - BFU-E Erythrocyte burst-forming units - CD4+ T4 lymphocyte - CFU-GM Granulocyte macrophage colony-forming units - EAGCS European-Australian Group Collaborative Study - HIV Human immunodeficiency virus - SFMHS San Francisco Men's Health Study     

Multiple calmodulin genes in fish

In mammals, identical calmodulin (CaM) proteins are encoded by three nonallelic genes that differ in their promoter regions and untranslated regions (UTRs). The UTRs of each of these three genes are specific for each gene and are highly conserved. In this study, sequences obtained from the GenBank and EST databases and sequencing were examined for several species of fish to ascertain whether this multi-gene one protein system exhibited in mammals extends to other vertebrates. Three genes in zebrafish (Danio rerio) designated , , and were identified. As in mammals, these genes differ in the 3-UTR region but encode completely identical CaMs. PCR primers spanning the coding and the 3-UTR regions were designed based on the assembled sequences and used to confirm the presence of each gene in the cDNA library. Other species of fish were also found to contain homologous genes that were closely related as indicated by phylogenetic analysis. The 3-UTR of the , and particularly the CaM gene of fish were not found to be as conserved as the corresponding genes of mammalian species possibly due to the span of evolutionary time. Only a few short elements in the 3-UTR were observed to be similar in fish and mammals. These short regions of identity are shared primarily between the mammalian CaM II and CaM I and the gene and gene of fish, respectively. Thus, the multi-gene one protein system occurs among fish as well as among mammals.     

Cytological investigations of the effect of colchicine on meiosis in Lilium hybrid cv. “Black Beauty” microsporocytes

Using colchicine, two methods have been successfully applied for the induction of tetraploid meiocytes at premeiotic mitosis in the near achiasmate diploid hybrid cultivar Black Beauty of Lilium. The experiments were aimed at understanding whether the achiasmate condition is attributable to insufficient homology for effective pairing or to some genie defect in order to interpret the data obtained from molecular studies. Cytological observations demonstrate a strong correlation between the induction of tetraploidy and subsequent chiasma formation. The chiasma frequency per cell in untreated diploid control meiocytes ranged from 0 to 8 (mean 2.25), while in colchicine treated undoubled cells sampled 14±2 days after the start of treatment it ranged from 0 to 2 (mean 0.148). By comparison, the chiasma frequency per cell in colchicine-doubled tetraploid cells ranged from 29 to 51 (mean 42.24), such cells showing complete or near complete bivalent pairing. These results, similar to those reported previously for other higher plant species, demonstrate that the achiasmatic condition in Black Beauty is not due to a genie defect. The methods developed have made possible hitherto inaccessible biochemical analyses of meiocytes that had been treated with colchicine or other chemicals at premeiotic stages.     

Nuclear behavior in multinucleate Schizophyllum commune germlings

Summary The ultrastructure of a fir morphological mutant containing multinucleate cells is described in Schizophyllum commune. The germlings of basidiospores which arose from mating fir with wild-type mycelium were studied in culture by phase contrast microscopy to elucidate behavior of multinucleate cells. Nuclear division appeared synchronous from two nuclei yielding four progeny through six nuclei producing twelve products, beyond which loss of synchrony was indicated. Compensatory nuclear migration into an anucleate cell was presumed during synchronous division of nuclear aggregates in the adjacent cell of an individual germling. The migrant nucleus eventually returned to the cell of origin. However, the return route was not via the central pore of the septum but rather occurred at the juncture of the cross-wall with the germling-periphery. Ultrastructure of a partial septum in fir which could accommodate nuclear passage of this sort is described.     

Soil seed bank composition and diversity in a managed temperate deciduous forest

Little is known about the influence of forest management on the interaction between seed bank and aboveground vegetation. We surveyed seed banks and vegetation in 10 forest stands under similar abiotic conditions but submitted either to a coppice-with-standards treatment (n=5) or to a selective-cutting system (n=5). We analyzed species composition and diversity, community ecological profile, and distribution of taxa among different life forms, strategy, morphology and functional type categories. A total of 2085 seedlings (8296 seedsm^–2) germinated-corresponding to 28 species, among which Juncus effusus was the most abundant. Fifty-seven percent of the species were also recorded in the aboveground vegetation, the dominant species being Rubus fruticosus agg., but only 28% of the aboveground species were present in the seed bank. Our results suggest that (1) vernal geophytes and shade-tolerant perennials, which group most true forest species, are not incorporated in the seed bank, (2) parent plants of most seeds were present either in the stand in an earlier dynamic stage or apart from the stand and long-distance dispersed, (3) as expected, early-successional species are well represented in the seed bank, (4) forestry vehicles seem to be a major means of dispersion for stress-tolerant species normally found in forest lanes and wheel tracks. We conclude that seed banks contain species that have a potentially negative impact on the true forest flora and, thus, forest management should minimize soil disturbance and retain remnants of old-coppice woods to conserve disturbance-sensitive true forest species.     

Identification of amino acids involved in the binding of hMIP-1α to CC-CKR1, a MIP-lα receptor found on neutrophils

Human macrophage inflammatory protein-1 (hMIP-1) and human macrophage inflammatory protein-1 (hMIP-1) are chemokines involved in a diverse range of immunological effects. Both hMIP-1 and hMIP-1 are involved in the activation of monocytes and THP-1 cells probably through a common receptor(s). However, only hMIP-1 can bind to neutrophils with high affinity, presumably through CC-CKR1 (CKR1). Since the structure of these two proteins is highly conserved, non-conserved amino acids must define the disparate binding patterns that these two proteins exhibit. Measurements of binding, chemotaxis and calcium influx conducted with hMIP-1 and hMIP-1 chimeric proteins and mutants show that two amino acids (37K and 43L) are important in the binding and signaling of hMIP-1 through CKR1. Furthermore, we also show that mutations of the three charged amino acids at the C-terminus of hMIP-1 and hMIP-1 (amino acids 61, 65 and 67), do not adversely affect the binding to THP-1 cells.