Experimental data on the inheritance of some taxonomic characters inHordeum spontaneum C. Koch emend. Bacht

Summary Hordeum spontaneum C. Koch emend. Bacht. varieties have been both intercrossed and crossed with two cultivated barley varieties ofH. vulgare (L.) emend Vav. et Bacht. with a view of eliciting the nature of inheriting the spikelet-pedicel of the lateral spikelets and the shape of their apex in the said wildgrowing barley. The investigations of F₁ and F₂ showed the inheritance of the spikelet-pedicel to have a dominating nature and to segregate in F₂ in conformity with the Mendelian monohybrid type. In the second case the forms with shorter awn-like formations, or their rudiments, were dominating.As a result ofH. spontaneum x H. vulgare hybridization along with already known forms, new formations were received, they have been conditionally named by the author:sessiliproskowetzii, proskowfertillum, ischnofertillum, and pallipodum.

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Zusammenfassung Im Rahmen größerer Untersuchungen über die Abstammung und Phylogenie der Gerste wurden mehrere Varietäten vonHordeum spontaneum C. Koch emend. Bacht. sowohl untereinander als auch mit zwei Varietäten der Kulturgerste,H. vulgare (L.) emend. Vav. et Bacht., gekreuzt. Es sollte geklärt werden, wie bei den genannten Wildgersten das Stielchen (pedicel) der Seitenährchen sowie die Ausbildung des Apex der Seitenährchen (d. h. ihre Begrannung) vererbt werden. Die Untersuchung der F₁ und F₂ zeigte, daß das Stielchen (gegenüber ungestielten Seitenährchen) dominant und gemäß einer monohybriden Mendelspaltung vererbt wird. Bezüglich der Ausbildung des Apex der Seitenährchen ergab sich im allgemeinen Dominanz der kürzeren oder rudimentären Grannen gegenüber längeren Grannen.Im Ergebnis der Hybridisation zwischenH. spontaneum undH. vulgare wurden, neben bereits bekannten, verschiedene neue Formen gefunden, die vom Autor vorläufig wie folgt benannt werden:sessiliproskowetzii, proskowfertillum, ischnofertillum, pallipodum.Die Ergebnisse werden im Zusammenhang mit Fragen der Abstammung der Kulturgerste diskutiert.

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With 4 figures     

Effect of cerulenin on the production of mannosyl-erythritol lipids as biosurfactants by Candida antarctica

Summary The effect of cerulenin, anti-lipogenic antibiotic, on the production and fatty-acid profiles of biosurfactants (mannosyl-erythritol lipids) of Candida antarctica were investigated by changing the chain-length of fatty acid as the carbon source. On longer-chain acid (C₁₄ to C₁₈), the production and fatty-acid profiles of the biosurfactants were not entirely affected by the antibiotic, indicating that the yeast is able to synthesize the biosurfactants from those substrates without the operation of de novo synthesis system of fatty acid. These results thus confirm our previous presumption that a new type of chain-shortening system (partial -oxidation system) mainly contributes to the formation of the extracellular glycolipids as biosurfactants.     

Production of transgenic rats using cryopreserved pronuclear‐stage zygotes

We investigated the application of cryopreserved pronuclearstage zygotes for the production of transgenic rats. Most of the pronuclearstage zygotes cryopreserved by conventional twostep freezing or vitrification appeared morphologically normal, but the proportion of frozen zygotes that developed into fetuses following transfer (59.7–60.2%) was higher than that of vitrified zygotes (5.5–22.1%). When the frozenthawed zygotes were used for DNA microinjection, 97.5% survived after DNA microinjection and 25.1% of the transferred zygotes developed into fetuses. These proportions were comparable to those of the fresh control zygotes (97.0% and 30.0%, respectively). The integration efficiency of the exogenous DNA into fetuses was similar between the frozen group (3.3% per injected zygote) and the control group (3.5%). These results indicate that pronuclearstage rat zygotes can be successfully cryopreserved by conventional twostep freezing for production of transgenic rats.     

Grazing by a dominant rotifer Conochilus unicornis Rousselet in a mountain lake: in situ measurements with synthetic microspheres

Grazing rates of zooplankton were analysed in the summer of 1999 in Yellow Belly Lake, an oligotrophic system in the Sawtooth Mountains of Idaho (U.S.A.). The colonial rotifer Conochilus unicornis was a dominant species in the epilimnion, with densities reaching 20 colonies l^–1 (ca. 400 ind. l^–1). Clearance rates were measured with an in situ Haney Grazing chamber and synthetic microspheres 5, 9 and 23m in diameter. At epilimnetic temperatures of around 14 °C, mean clearance rates for 5m particles ranged from 30 to 65 l ind.^–1 h ^–1. Clearance rates were 2–9 times higher on the 5m spheres than on the 9 m spheres, and C. unicornis almost never fed on the 23 m spheres. Grazing rates did not change over the diel cycle. Clearance rates declined more than 10-fold as temperatures declined from 14 °C in the epilimnion to 7 °C in the metalimnion. In the epilimnion, grazing by C. unicornis was more important than grazing by crustaceans in the community, at least on particles 9m. The results show the importance of grazing by rotifers in lakes, and the significance of spatial variations that influence grazing rates.     

Polymerization of β-amino Acids in Aqueous Solution

We have compared carbonyl diimidazole (CDI) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as activating agents for the oligomerization of negatively-charged - and -amino acids in homogeneous aqueous solution. -Amino acids can be oligomerized efficiently using CDI, but not by EDAC. -Amino acids can be oligomerized efficiently using EDAC, but not by CDI. Aspartic acid, an - and -dicarboxylic acid is oligomerized efficiently by both reagents. These results are explained in terms of the mechanisms of the reactions, and their relevance to prebiotic chemistry is discussed.     

Experimentally elevated testosterone increases status signalling in male Greylag geese (<Emphasis Type="Italic">Anser anser</Emphasis>)

Testosterone modulates male vertebrates sexual and social behaviour. We experimentally investigated the testosterone-sensitive behaviours in male greylag geese (Anser anser) by implanting silastic tubes containing crystalline testosterone during the mating season (February; 5 implanted and 5 control males) and in the early winter (November; 7 and 7). Focal animals were part of a semi-tame, unrestrained flock with fully intact social relationships. Excreted testosterone and corticosterone immunoreactive metabolites (TM, BM) were determined by enzyme immunoassay. Individual faecal samples and behavioural protocols were collected daily over a period of 5 weeks, including 1 control week before implantation. In February, no significant behavioural effects of the supplemental testosterone were observed, which may be due to the naturally occurring high systemic androgen levels in spring. In November, however, implanted males had higher TM excretion rates and performed status signalling behaviour (beak up) more frequently than control males. No differences between implanted and control males were found with respect to BM, agonistic interactions or vigilance behaviour. Furthermore, during the second week after implantation, TM positively correlated with the frequency of beak up of implanted males, whilst their female partners were attacked with lower latency by other members of the flock than the females of control males. Hence, status signalling in greylag ganders seems to be testosterone-sensitive year-long and inappropriate status signalling of males may draw attacks towards their females.     

The “small but healthy” hypothesis: Historical,political, and ecological influences on nutritional standards

How accurate international nutritional standards are for recommending and assessing adequate nutrient intake and nutritional status of different national populations has been debated by nutritionists, economists, and others. This paper reviews the assumptions and possible motivations behind the design and interpretation of standards in particular countries, with a special emphasis on India and Mexico. The analysis suggests that comparative studies of the ethnonutrition concepts of policy-makers are useful for understanding how standards are set, and their nutritional implications.Substantially revised paper originally presented in the symposium Standards and Reference Values: Problems and Pitfalls for Nutritional Anthropologists at the Annual Meeting of the American Anthropological Association, Chicago, Illinois, November 17, 1983.     

Interferometeric sensing of β-galactosidase released by recombinant E. coli responding to an endocrine disruptor, tributyltin

A recombinant E. coli ACV1003 releasing -galactosidase by a SOS regulon system when it is exposed to a DNA-damaging compound, has been used to detect endocrine disruptors such as tributyltin (TBT) and triphenyltin (TPT). Maximum response ratio by E. coli ACV 1003 (recA::lacZ) – indicating the maximum ratio of enzyme produced against an environmental toxicant to that produced in the absence of a toxicant – was estimated as 6.3 with 1.0 g TBT ml^–1 at 37 °C, which was considerably higher than those with other strains. Extracellular -galactosidase activity was 51 unit ml^–1, which was 5% of that obtained by the conventional Miller's enzyme assay using solvents. Such a low enzyme activity can be rapidly determined, not by the usual time-consuming and tedious enzyme assay, but by an alternative interferometric biosensor. Heavily-doped porous silicon to apply to an interferometer was fabricated by etching to produce a Fabry–Pérot fringe pattern, which caused the change in the refractive index of the medium including -galactosidase. The change in the effective optical thickness versus -galactosidase activity showed a sigmoid increase up to the concentration of 250 unit -galactosidase ml^–1.     

Effects of mine drainage on the river hayle,cornwall a) factors affecting concentrations of copper,zinc and iron in water,sediments and dominant invertebrate fauna

Concentrations of copper, zinc and iron were measured in waters, sediments and invertebrates collected from the River Hayle. In river water at least 70% of copper and iron was associated with the particulate fraction whereas 80% of zinc was in the soluble form. Although total concentrations of zinc in water exceeded those of copper approximately ten fold, copper predominated over zinc in the sediments by a factor of approximately three. Iron was the most abundant metal recorded in both water and sediments.Seasonal differences in total metal content of waters suggested that concentrations of copper, zinc and iron increased during. periods of high flow and decreased during lower flows. Copper concentrations in the sediment, unlike zinc and iron, showed markedly higher values during the summer sampling period when flows were minimal.In the free-living Trichoptera larvae, concentrations of copper and zinc in the tissue appeared to follow copper and zinc levels in the water. Similar relationships in Odonata and Plecoptera larvae were not obtained. Factors affecting animal/metal relationships are discussed with particular reference to adaptation shown by organisms exposed to high concentrations of heavy metals in their environment.Department of Applied Biology, Cambridge     

Food uptake and the fine structure of the dinophytePaulsenella sp. an ectoparasite of marine diatoms

Summary Motile dinospores ofPaulsenella attach to a host diatom frustule, form a feeding tube, drive it between epi- and hypocingulum, pierce the host plasmalemma and suck up host cytoplasm gradually. This mode of endocytosis (myzocytosis) implies that the host plasmalemma is not ingested and that the host cytoplasm within the food vacuole is bounded only by the vacuolar membrane. The feeding tube is formed by the emergence of a preformed microtubular basket consisting of plates of microtubules. At its entrance into the cell body the feeding tube channel is surrounded by an electron-dense ring. Similar sphincters enclose the two exits through which the two flagella emerge. These sphincters are composed of microfibrils which reveal a cross striation when the fixative does not contain calcium ions. The flagellar bases as well as the internal part of the feeding tube are surrounded by a common cavity which is in open connection also with the ampullae of the pusule. The light and electron microscopical observations do not support the assumption that food uptake is driven by a flow of the membrane of the feeding tube channel caused by an interaction with the microtubular basket (as postulated for food uptake inSuctoria) but rather by an hydrostatic gradient which might be caused by rhythmical ion pumping and be based on the existence of the common cavity and the sphincters. Myzocytosis is inhibited by cytochalasin B.—The fine structure of dinospores and trophonts, especially with respect to the cell covering, the amphiesma, and the en- and excystment, is described.     

Schwermetallaffine Strukturen des peripheren Nerven

Zusammenfassung Konvertiertes Kupfer wurde an axonalen und Schwannschen Zellmembranen, vor allem im nodalen und paranodalen Bereich beobachtet. Kupfer wird offenbar in inner und outer leaflet der unit membrane ein- und an diese angelagert. Denn bei wenig Präzipitat oder geringer Elektronendichte des Niederschlags stellten sich die Membranen als dreischichtiger Komplex dar, der in den Dimensionen der unit membrane entsprach. Bei großen Präzipitatmengen oder bei hoher Elektronendichte des Niederschlags blieb nur die helle Mittelschicht von ca. 30 Å frei. Diese Metallaffinität wird im Zusammenhang mit den cytochemischen AChE-Nachweisverfahren diskutiert, weil bei diesen Methoden Schwermetallionen im Inkubationsmedium verwendet werden, und die Kupferbindungsstellen zum Teil mit den Lokalisationen der AChE identisch sind. Möglicherweise gibt beim cytochemischen AChE-Nachweis schon die Darstellung von unit membranes in unkontrastierten Präparaten Aufschluß auf erfolgte unspezifische Schwermetallbindung. Als weitere Kontrolle wird Inkubation in der verwendeten Schwermetallösung mit nachfolgender Konversion vorgeschlagen.

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Heavy metal affinity of peripheral nerve structuresI. Possibility of interference with cytochemical localisation of AChE

Summary The ultrastructural localisations of copper in ventral and dorsal roots of the rat were studied by varying fixation and converting medium. Precipitated copper was deposited in axonal membranes (axolemma, membranes of axonal organelles) and Schwann cell membranes (inner and outer plasmalemma, major and minor dense lines in the region of the splitting myelin sheath, terminal loops and Schwann cell interdigitations). Copper obviously was bound within and attached to inner and outer leaflet of these membranes. If there was little or less electron-dense precipitate membranes appeared three-layered, dimensions corresponding to those of the unit membrane. If there was electron-dense or plenty of precipitate only the middle electron-lucent layer of approximately 30 Å was revealed. The predominant deposition on nodal and paranodal membranes may be explained either by facilitated access to this region or by specific metal ion binding sites at those specialised membranes. Metal ion binding is discussed in relation to cytochemical demonstration of AChE activity, because these methods use incubation media containing heavy metal cations and copper binding sites partly correspond with the localisation of AChE activity. The appearance of unit membranes in unstained sections probably could be a hint at unspecific heavy metal ion binding ocouring in demonstration of specific AChE. Therefore control-incubation in the heavy-metal solution with subsequent conversion is suggested.

     

Copper but not iron limitation increases astaxanthin production by Phaffia rhodozyma in a chemically defined medium

The influence of copper (0–32 M) and iron (0–108 M) on growth and astaxanthin production by Phaffia rhodozyma was studied. Copper below 3.2 M increased the astaxanthin content of the cells (from 220 to 287 g g^–1) but at the expense of a slightly decreased growth (from 11.3 to 10.2 mg ml^–1). In contrast, iron below 1 M decreased both the growth and astaxanthin content of the cells. Using copper limitation instead of toxic respiratory inhibitors to improve astaxanthin production has obvious advantages from the product quality, environmental and process operation points of view.     

Alzheimer''s Amyloid-β as a Preventive Antioxidant for Brain Lipoproteins

1. Increased production of A in a form of lipoprotein antioxidant under the action of increased oxidative stress in aging with subsequent chelation of transition metal ions by A, accumulation of toxic A–metal lipoprotein complexes, production of reactive oxygen species, and neurotoxicity are reviewed and postulated to form the temporal sequence of events in the development of Alzheimer's disease (AD).2. Since (i) A binds copper stronger than iron and other transition metals, and (ii) copper is a more efficient catalyst of oxidation than other transition metals, chelation of copper by A is proposed to be a most important part of this pathway.3. Whereas this amyloid-binds-copper (ABC) model does not remove A peptide from its central place in our current thinking of AD, it places additional factors in the center of discussion.4. Most importantly, they embrace pathological mechanisms known to develop in aging (which is the most important risk factor for AD), such as increased production of reactive oxygen species by mitochondria, that can be positioned upstream relative to the generation of A.     

Genotype-independent leaf disc transformation of potato (Solanum tuberosum) using Agrobacterium tumefaciens

Summary Leaves of the in vitro grown potato cultivars Bintje, Berolina, Desiree, and Russet Burbank were wounded and co-cultivated with Agrobacterium strains having chimeric bar and nptII genes on a disarmed T-DNA. Each leaf from these cultivars formed numerous calli on kanamycin-containing medium, and almost all calli regenerated shoots. For Russet Burbank, it was necessary to include AgNO₃ in the medium to obtain efficient shoot regeneration. The transformed plants have one to a few copies of the T-DNA, show NPT-II and PAT activities, and are resistant to high doses of the commercial preparation of phospinotricin (glufosinate). Almost no somaclonal variation was detected in trans-genic plants.     

The uptake of copper ions by cell suspension cultures of Agave amaniensis,and its effect on the growth,amino acids and hecogenin content

Cell suspension cultures of Agave amaniensiswere able to grow in media containing 10 – 240 M copper ions, and could remove more than 67% copper ions from the media. The cells accumulated up to 106 mg g^–1 copper ions in the biomass. Copper ions at 240 M caused a decrease in growth index and packed cell volume of the cultures of 61.5 and 53.3%, respectively. The presence of copper ions caused the cell walls to thicken and to be more wrinkled. Certain amino acids were released in high concentration into the media. The hecogenin content in the biomass increased up to 157.9% at 20 M copper ions.     

Determination of copper, manganese and zinc in human liver

Autopsied liver tissue samples collected from 42 males and 31 females were analyzed for copper, manganese and zinc using atomic absorption spectrometry (AAS). With the exception of two liver samples for which the copper levels were determined to be 74.8 and 104.0 g/g (dry weight), hepatic copper concentrations were found to range from 1.7 to 32.4 g/g with a mean concentration of 14.2 g/g and standard deviation of 7.0 g/g. Manganese concentrations (with the exception of one sample having 12.9 g/g) ranged from 0.22 to 4.6 g/g with a mean of 2.26 ± 1.00 g/g. Hepatic zinc levels averaged 118.3 ± 44.4 g/g and ranged from 38.5 to 231.3 g/g. There were no apparent trends for the levels of any metals versus age nor were there any differences in average hepatic metal concentrations for males and females. © Rapid Science 1998.     

Untersuchungen zur Kompartimentierung der freien Aminosäure Alanin in den Farnvorkeimen von Dryopteris filix-mas (L.) Schott im Rotlicht und im Blaulicht

Summary In fern gametophytes (= sporelings) there is a strong correlation between the degree of blue light mediated photomorphogenesis and the protein content of the organism (cf. Mohr, 1963). In a previous paper (Payer et al., 1969) we have shown that blue light specifically increases the rate of protein synthesis in the fern sporelings over the rate which is maintained under red light. — In the present paper blue light mediated protein synthesis has been dealt with further using one representative amino acid, alanine, which was labelled with ¹⁴C from ¹⁴CO₂ under steady state conditions of photosynthetic ¹⁴C incorporation under blue or red light.Synthesis of free alanine is proportional to the rate of photosynthesis (Table 1). For a number of reasons we conclude that alanine is derived directly from primary photosynthetic products. Since the pool size of the thoroughly ¹⁴C-labelled pool of free alanine is much less than the actual, pool size of this amino acid, (Table 1), and since the specific activity of the isolated ¹⁴C-alanine is much below the value we can expect on the basis of the specific activity of the ¹⁴CO₂ applied we conclude that there are separate pools of free alanine; active (with respect to protein synthesis) and inactive pools which do not mingle. Taking into account this possibility of compartmentation of pools of free amino acids we have calculated in the case of ¹⁴C-alanine the rate of protein synthesis for two extreme instances (Table 2). A comparison of the theoretical values with the actual data indicates that indeed protein synthesis is fed from active pools of amino acids while the inactive pools are possibly located in the vacuoles. The total pool of alanine is much larger in red grown than in blue grown sporelings while the active pools seem to have the same size under both conditions. The cells of the red grown sporelings have much larger vacuoles than the cells of the blue grown sporelings.The rate of protein synthesis is under our conditions 1.8 times higher in blue light than in red light. The rate of turnover of the total protein is 0.29% per hour in the blue and 0.23% in the red light. The absolute turnover of protein is 1.5 times higher in blue light than in red light. It is concluded that the blue light mediated increase of protein synthesis is very real. Blue light must act specifically at the level of polypeptide synthesis.     

Role of p53 and reactive oxygen species in apoptotic response to copper and zinc in epithelial breast cancer cells

Previous studies revealed that cells may differ in their response to metal stress depending on their p53 status; however, the sequence of events leading to copper-induced apoptosis is still unclear. Exposure of copper (10 and 25 M) and zinc (10 and 25 M) caused activation of p53 in ER+/p53+ human epithelial breast cancer MCF7 cells and resulted in up-regulation of p21. Transactivation of p53 in MCF7 cells also led to increase in expression of Bax, proapototic Bcl-2 family member, triggering mitochondrial pore opening, and PIG3 (p53-induced gene 3 product), and also generation of intracellular reactive oxygen species (ROS). The treatment of MCF7 cells with either copper or zinc for 4 h also caused decrease in mitochondrial membrane potential ( _m), accompanied by an elevation in the ROS production and redistribution of p53 into mitochondria. The loss of _m was correlated with accumulation of Annexin V positive apoptotic cells. However, the release of apoptosis inducing factor (AIF) and its translocation into nucleus was observed only in MCF7 cells treated with copper. In MDA-MB-231 (ER–/p53–) and MCF7-E6 (ER+/p53–) cells, both p53 and p21 protein levels were not altered in the presence of metals. These cells were resistant to metals, and there was no alteration in _m. Copper treatment did not result in accumulation of ROS in these cell lines with an inactive p53 even after exposure to 50 M of copper for 6 h, indicating a key role for p53 in the ROS generation. Pretreatment of MCF7 cells with p53 inhibitor, pifithrin-, resulted in decrease of copper and zinc induced ROS production to the control level, suppression of both Bax expression and AIF release.Therefore, the activation of p53 seems to play a crucial role in copper and zinc induced generation of ROS in epithelial breast cancer cells, and expression of downstream targets of p53, such as PIG3 and Bax, responsible for increased generation of the intracellular ROS, as well as disruption of mitochondrial integrity. Our data suggest that copper induces apoptosis in MCF-7 cells with no caspases through the depolarization of mitochondrial membrane with release of AIF and its translocation into the nucleus. The results demonstrate that a functional p53 is required for the execution of apoptosis in epithelial cells.     

Beobachtungen zum Antagonismus zwischen Asparagin und β-Alanin

Zusammenfassung Hefezellen können aus dem Nährmedium soviel -Alanin aufnehmen, daß sie damit auch nach Übertragung in ein davon freies Substrat beträchtlich wachsen können. Diese Aufnahme von -Alanin ist auch in Abwesenheit einer Stickstoffquelle und nach Verarmung an Stickstoff möglich. Asparagin hemmt als Antagonist des -Alanins dessen Verwertung nur dann, wenn beide Verbindungen gleichzeitig geboten werden. Es kann, wenn es vor der Inkubation mit -Alanin geboten wird, dessen spätere Aufnahme nicht behindern, und es kann, nachträglich geboten, die Exosmose nicht steigern. Aus diesen Beobachtungen wird geschlossen, daß -Alanin nicht nur bis zum Konzentrationsausgleich in die Zelle eindringt, sondern teilweise in höhermolekulare Verbindungen (Pantothensäure, Coenzym A) eingebaut und damit festgelegt wird. Der Vermutung anderer Autoren, wonach antagonistisch wirkende Aminosäuren lediglich den Aufnahmevorgang behindern sollen, wird entgegengehalten, daß im Falle des Antagonismus zwischen -Alanin und Asparagin viel eher mit einer Behinderung der Weiterverarbeitung zu rechnen ist.     

Trace metal contamination initiates the apparent auto-aggregation,amyloidosis, and oligomerization of Alzheimer’s Aβ peptides

Nucleation-dependent protein aggregation (seeding) and amyloid fibril-free formation of soluble SDS-resistant oligomers (oligomerization) by hydrophobic interaction is an in vitro model thought to propagate -amyloid (A) deposition, accumulation, and incur neurotoxicity and synaptotoxicity in Alzheimers disease (AD), and other amyloid-associated neurodegenerative diseases. However, A is a high-affinity metalloprotein that aggregates in the presence of biometals (zinc, copper, and iron), and neocortical A deposition is abolished by genetic ablation of synaptic zinc in transgenic mice. We now present in vitro evidence that trace (0.8 µM) levels of zinc, copper, and iron, present as common contaminants of laboratory buffers and culture media, are the actual initiators of the classic A1–42-mediated seeding process and A oligomerization. Replicating the experimental conditions of earlier workers, we found that the in vitro precipitation and amyloidosis of A1–40 (20 µM) initiated by A1–42 (2 µM) were abolished by chelation of trace metal contaminants. Further, metal chelation attenuated formation of soluble A oligomers from a cell-free culture medium. These data suggest that protein self-assembly and oligomerization are not spontaneous in this system as previously thought, and that there may be an obligatory role for metal ions in initiating A amyloidosis and oligomerization.