Genetic and developmental analyses of chaetae pattern formation in Drosophila tergites

Summary The role of the achaete-scute complex and extramacrochaetae, Notch, Delta, Enhancer of split and Hairless genes in chaeta patterning in Drosophila tergites was studied in genetic mosaics and in mutant combinations. The mutant phenotypes of different alleles of each gene can be ordered in characteristic topographical seriations. These seriations are related to the pattern of proliferation of histoblasts and the time of singularization of sensory organ mother cells from surrounding epidermal cells. Genetic mosaics of lethal alleles show that these genes are fundamentally involved in this singularization and subsequent differentiation. The study of mutant combinations of alleles of these genes reveals specific relationships of epistasis and synergism between them. The results suggest that spatial and temporal variations in achaete-scute complex functional products in cells, modulated by the activity of other genes involved in signal transduction, define the patterned differentiation of sensory organs in tergites. Offprint requests to: A. García-Bellido     

Oenanthe aquatica (L.)Poir.: Seed reproduction,population structure,habitat conditions and distribution in Czechoslovakia

The paper summarizes data concerning the biology and ecology ofOenanthe aquatica. The species is commonly distributed all over Czechoslovakia, from lowlands to the submontane belt, especially in fishpond and river basins.O. aquatica shows no special relationship to the chemical and physical soil properties, and is well adapted to habitats with a changing water level. The reproduction ofO. aquatica depends on emerging of the bottom. The most developed populations are formed by biennial plants and arise in the year following summer or autumn drainage.     

Quercus ilex browse utilization by Caprini in Sierra de Cazorla and Segura (Spain)

The impact of domestic and wild Caprini browsing on Quercus ilex has been examined in an area of the Sierra de Cazorla. Vegetation as a herbivore food supply, herbivore feeding regime and density in the study area during six sampling periods throughout two years, has been quantified. Wild Caprini show diets similar to the available vegetation, whereas domestic Caprini tend more towards the trophic specialities (browsing or grazing) of their genus. Nevertheless, this tendency was more pronounced in domestic goats than in sheep. A hypothetical estimate of Q. ilex intake by each species under the study conditions was carried out. It was found that domestic Caprini have a greater impact on the holm oak than wild Caprini, density and feeding-niche deviations being the main factors responsible for this situation.Abbreviations DM= dry matter     

Members of the alpha-amylase inhibitors family from wheat endosperm are major allergens associated with baker's asthma

We have identified the major antigens or IgE binding components from wheat flour. Thirty-five sera from patients with baker's asthma were used to analyze the reaction with wheat salt-soluble proteins. We found a 15 kDa SDS-PAGE band which reacted with all sera tested. Purified members of the alpha-amylase inhibitor family, which are the main components of the 15 kDa band, were recognized by specific IgE when tested with a pool of reactive sera. Immunodetection after two-dimensional electrophoretic fractionation of crude inhibitor preparations from wheat endosperms also detected several inhibitor subunits as major low-molecular-weight allergens.     

Ouabain-insensitive, Na-ATPase activity in pure suspensions of rat kidney proximal tubules

The present work was undertaken to evaluate the distribution of the Na-ATPase activity in the different components of the rat kidney cortex. Suspensions of glomeruli, proximal and distal tubules were prepared following a collagenase digestion of outermost kidney cortex slices and a separation on a Percoll gradient. It was found that the Na-ATPase activity is higher in the fraction enriched in proximal tubules. The fraction enriched in glomeruli and in distal tubules show also a Na-ATPase activity, but it is lower.     

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.     

The effect of soluble glucan derivates on spleen colony-forming units in sublethally irradiated mice

We examined the effects of 5 soluble derivatives of yeast glucan on the formation of exogenous (CFU-S) and endogenous (E-CFU) colony-forming units in the spleens of sublethally irradiated (⁶⁰Co, 6.5–7.0 Gy) mice of two inbred strains. For the estimation of CFU-S, glucans were administered intravenously either to donors or recipients of spleen cells 24 h prior to irradiation or removal of the spleen. The number of CFU-S was increased when both the donors and recipients were treated with glucan; the highest increase was obtained with glucans S, P and K. All glucan preparations increased significantly also the number of E-CFU even when administered 90 min after irradiation. There exist differences in the response to the stimulatory effect of glucans among individual mouse strains. Thus, for example, the stimulatory effect of glucan KM on the E-CFU number was significantly more pronounced in strain A/Ph than in strain C57B1/6.     

Genetic stability of the antagonistic character ofEnterococcus faecalis ssp.liquefaciens and the detection of a new inhibitory bacteriocin-like substance

The inhibitory capacity of strain S-48 ofEnterococcus faecalis ssp.liquefaciens was studied. The strain produces a broad-spectrum peptide antibiotic (AS-48) that has been characterized elsewhere. The isolation of mutants from S-48 after mutagenic treatment revealed another inhibitory substance which remained masked in the wild strain. The protein nature and restricted spectrum of this substance points to its being a bacteriocin (Bc-48).