The effect of aluminum on cytokinins in the mycelia of Amanita muscaria

High performance liquid chromatography analysis of immunoaffinity-purified extracts of mycelia of Amanita muscaria, and the Amaranthus bioassay of the eluted fractions, revealed the following seven cytokinins: zeatin, zeatin riboside, zeatin N-9-glucoside, dihydrozeatin, dihydrozeatin riboside, isopentenyl adenine, and isopentenyl adenosine. The decreased growth of aluminum-treated mycelia correlated with a 35% decrease in the total amount of the cytokinins. Among individual cytokinins, zeatin was the most affected, exhibiting a reduction of about 90%. The results are compared with previous investigations of aluminum effects on cytokinins in the mycelia of Lactarius piperatus, whose growth is stimulated by aluminum.Abbreviations ZR zeatin riboside - iPA isopentenyl adenosine - Z zeatin - DHZ dihydrozeatin - iP isopentenyl adenine - DHZR dihydrozeatin riboside - Z-9G zeatin N-9-glucoside - iP-9G isopentenyl N-9-glucoside - HPLC high performance liquid chromatography - DHZRMP dihydrozeatin riboside monophosphate - ZRMP zeatin riboside monophosphate     

Monoacylcadaverines in the blood of schizophrenic patients

Concentrations of cadaverine, monoacetylcadaverine and monopropionylcadaverine in the blood of schizophrenic and nonschizophrenic subjects were measured. Two groups, one from the U.S.A. the other from Japan, were tested. Monoacetylcadaverine and monopropionylcadaverine were found elevated in the blood of some schizophrenic patients in comparison with those in controls in each group. Their increase could be caused by a reduced monoamine oxidase activity or by an increased acylation in schizophrenic patients.     

The fluctuations in the level of endogenous growth regulators in seeds ofAcer pseudoplatanus L. in the course of stratification

In the course of cold stratification ofAcer pseudoplatanus L. fruits a statistically significant alternation occurs in their seeds of a rise and fall in the level of endogenous growth regulators. In the initial weeks the inhibitory effect slightly declines, or, on the contrary, the stimulatory effect slightly increases; in the middle phase of stratification a marked increase in inhibitions and reduction of stimulations appears, and towards the end of stratification the stimulatory effect of isolated substances in the individual biotests rises again, or their inhibition effect is decreased. No direct dependence was found between the decrease of the degree of dormancy and the drop of inhibitor, or increase of promotor levels. However, a certain analogy was observed between the time course of fluctuations in the level of growth regulators and the germination energy of the seeds investigated. An enhancement of the growth activity of the substances isolated (e.g. those of a gibberellin-like nature) in the last weeks of stratification can already be considered as the result of the release of fruits from dormancy.     

UV-induced mutability in repair-deficientrad6-1 strains ofSaccharomyces cerevisiae is caused by a suppressor gene

TheRAD6 gene is a multifunctional gene required for DNA repair, induced mutagenesis and sporulation. The survival and revertibility of two loci in fourrad6-1 mutant strains of different origin after UV irradiation were followed. As expected, all therad6-1 strains tested were more sensitive to UV radiation in comparison withRAD6 strains. The reversion frequency per survivor intrpl-289 andarg4–17 alleles was significantly higher in all fourrad6-1 mutant strains than in wild-type strains after equal doses of UV radiation. On the basis of genetic analysis we suggest that the phenomenon of increased frequency of induced mutagenesis is caused by a suppressor gene.     

Production of fertile tobacco pollen from microspores in suspension culture and its storage for in situ pollination

Summary A simple procedure is described for the in vitro production of tobacco (Nicotiana tabacum L.) pollen from microspores isolated just before entering mitosis. During a 3-day culture period in a liquid medium containing pyrimidine nucleosides these microspores develop into young pollen grains to the stage of starch deposition. Pollen maturation and transition to dormancy is achieved during a further 2- to 3-day culture period in the same medium stepwise supplemented by a concentrated solution of sucrose and l-proline. Upon transfer of the pollen to a simple germination medium containing sucrose and boric acid, up to 40% of the grains were observed to produce relatively long tubes. The in vitro-matured pollen grains can be stored at-20° C either suspended in 1.17 M sucrose and 100 mM l-proline or separated from the medium on filter paper discs. The stored pollen germinated both in vitro and on the stigma, the pollen tubes grew through the style into the ovary and pollination produced up to 300 viable seeds per pod. The procedure is of interest for pollen developmental studies and various fields of pollen manipulation, such as in vitro pollen selection.     

Local and systemic antibody response in infants after oral administration of inactivated enteropathogenicE. coli serotype O111 and O55

In ten infants divided into two groups (up to one month of age and at 2–7 months of age) the dynamics and formation of different antibody isotypes produced locally in the intenstine and in serum after orally administered inactivated enteropathogenicE. coli strains O111 and O55 was followed during 30 d after the first and booster dose by using an indirect immunofluorescence method. Infants up to one month of age produced antibodies of IgM isotype in stool together with the IgA isotype after the first and booster dose of the vaccine against both antigens. Serum IgG antibody increased after 2 d following the first and second dose of antigens and remained higher during 5 d. The infants aged 2–7 months expressed predominantly the IgA isotype response in stool after the first and booster dose of antigens. The serum immunoglobulin levels did not change after oral antigen administration.     

Quantifying the damage of red deer (Cervus elaphus) grazing on grassland production in southeastern Slovenia

The influence of red deer (Cervus elaphus) grazing on grassland production for forage conservation at the forest border during the vegetation period was studied on three locations (Mala gora, Cvišlerji, and Mačkovec) in the Kočevje region (SE Slovenia). The experiment lasted from the 25th of March until the 8th of October 2002. Portable cages were used to exclude red deer from grazing the herbage. At four sampling dates in the season, herbage air dry matter (DM) yield was measured at three different observations (cage-protected plot, cage-protected plot only two to three weeks before sampling date, otherwise freely grazed (removed), and unprotected plot). The results from the experiment showed that red deer grazed on grassland through the entire season and that the regeneration capability of sward was the highest in summer, middle in spring and smallest in autumn. On unprotected plots, an average reduction of 50% of herbage DM yield was found with the most damaged sites also up to 80% reduction.     

Transmembrane adaptor protein WBP1L regulates CXCR4 signalling and murine haematopoiesis

WW domain binding protein 1‐like (WBP1L), also known as outcome predictor of acute leukaemia 1 (OPAL1), is a transmembrane adaptor protein, expression of which correlates with ETV6‐RUNX1 (t(12;21)(p13;q22)) translocation and favourable prognosis in childhood leukaemia. It has a broad expression pattern in haematopoietic and in non‐haematopoietic cells. However, its physiological function has been unknown. Here, we show that WBP1L negatively regulates signalling through a critical chemokine receptor CXCR4 in multiple leucocyte subsets and cell lines. We also show that WBP1L interacts with NEDD4‐family ubiquitin ligases and regulates CXCR4 ubiquitination and expression. Moreover, analysis of Wbp1l‐deficient mice revealed alterations in B cell development and enhanced efficiency of bone marrow cell transplantation. Collectively, our data show that WBP1L is a novel regulator of CXCR4 signalling and haematopoiesis.