Kin groups in closely spaced capercaillie leks

We quantified the genetic structure among 58 capercaillie (Tetrao urogallus) from three closely spaced leks in boreal Russia using ten microsatellite loci. We did not find significant structuring with respect to lek membership in an overall analysis. However, all but one individual could be strongly assigned to one of two genetic clusters, which we interpret as reflecting different local lineages or extended family groups. There was evidence for structuring among some clusters within leks, and one smaller lek consisted of nine out of ten males from one cluster, which could reflect kin biasing of lek membership. One cluster was apparently outperforming the other, since nine out of ten juveniles sampled belonged to it.     

Induction of accessory cell function of human alveolar macrophages by inhalation of human natural interleukin-2

 Accessory function allows antigen-presenting cells to produce sufficient secondary signals for optimum T cell proliferation and interleukin-2 (IL-2) production. Alveolar macrophages are inferior accessory cells compared to monocytes (PBM). We report here that the accessory index (AI) of alveolar macrophages and PBM of patients with lung metastases of solid tumors treated with inhalations of human natural IL-2 (hnIL-2) increased following its administration (P<0.005). The accessory index was significantly elevated from baseline values after 2 weeks of inhalation of 300 000 IU hnIL-2/day (8.2±10.2 compared to 1.1±1; P<0.001). The inhalation of 150 000 IU also induced increases in the index (AI = 2.3±1.9), however, without reaching statistical significance. In addition at 300 000 IU IL-2/day a significant increase in the accessory index was observed for PBM (4±2.5; P<0.05). The indices of PBM and alveolar macrophages prior to inhalation showed a significant negative correlation with the age of the patients (r _s =  – 0.5; r _s =  – 0.8, respectively; P<0.03 for all comparisons). Our data demonstrate that the inhalational application of hnIL-2 enhances the accessory function of alveolar macrophages and, to lesser extent, the accessory index of PBM, indicating the occurrence of pharmacological immunostimulation. Received: 16 August 1995 / Accepted: 4 January 1996     

Ferritin enhances production of DNA strand breaks by 6-hydroxydopamine,ascorbic acid and H2O2 in CCC PM2 bacteriophage DNA

Damage of CCC PM2 DNA by 6-hydroxydopamine (6-OHDA) and ascorbic acid (AA), compounds that are both able to release iron from ferritin, was significantly enhanced in the presence of ferritin. H₂O₂, a product of 6-OHDA autoxidation, did not induce DNA strand breaks in the absence of ferritin and only to a minor extent in the presence of ferritin. DNA damage by 6-OHDA and AA could be reduced by the hydroxyl radical scavenger mannitol, the iron chelator desferrioxamine, and, partly, by a combination of superoxide dismutase and catalase. These inhibitory effects were clearly less pronounced in the presence of ferritin. Ferritin obviously played an important role as a source of iron in the pro-oxidative processes of 6-OHDA and AA. These features might be of importance in cancer therapy since many tumor cells contain elevated ferritin levels.     

Cytokeratin expression in simple epithelia

To study the regulation of the expression of cytokeratins characteristic of simple epithelia, i.e., human cytokeratins nos. 7, 8, 18, and 19, we prepared several cDNA clones coding for these proteins and their bovine counterparts. In the present study, we describe a cDNA clone of the mRNA coding for human cytokeratin no. 18, which was isolated from an expression library using the monoclonal antibody, KG 8.13. This clone (756 nucleotides, excluding the polyA portion), encodes approximately one-half of the mRNA (approximately 1.4 kb), identifies one mRNA band in Northern-hybridization blots, and specifically selects one mRNA species coding for cytokeratin no. 18, as demonstrated by translation in vitro. Comparison of the deduced amino acid sequence--confirmed by direct amino-acid-sequence analyses of some polypeptide fragments produced by cleavage with cyanogen bromide--indicated that cytokeratin no. 18 is a member of the acidic (type I) subfamily of cytokeratins. It has only limited sequence homologies in common with other intermediate-sized filament proteins, and these are essentially restricted to certain domains of the alpha-helical rod portion. The carboxyterminal tail sequence does not contain glycine-rich elements, thus distinguishing this cytokeratin from those acidic (type I) cytokeratins that are characterized by this feature. The similarities and differences between cytokeratin no. 18 and previously described epidermal cytokeratins are discussed in relation to the differences in the stability of the complexes which this cytokeratin forms with basic (type II) cytokeratins, as well as in relation to possible functional differences of cytokeratins in simple and stratified epithelia.     

Transport and metabolism of exogenously applied gibberellins to Malus domestica Borkh. cv. Jonagold

The radio-labeled gibberellins GA₁, GA₃,GA₄, and GA₇ were applied to intact developing applefruits (Malus domestica Borkh. cv. Jonagold) during theperiod when GAs are suggested to inhibit flower bud induction for the followingyear. Radioactivity from these compounds was found to be transported intoadjacent tissues as there are pedicels and bourses (4%). Application topedicels, after removal of the fruits, enhanced the transport into adjacentbourses up to 11%. The bud-carrying lateral bourse shoots contained onlyminor amounts of radioactivity on average 0.4% in both cases. Theseexport rates were identical, 1 or 5 days after application.After application of the corresponding deuterium-labeled GAs and analyses bymass spectrometry the specific metabolization of GA₁ toGA₁ 13-O-glucoside and of GA₃ to GA₃13-O-glucoside was demonstrated. Additional metabolites of GA₁ andGA₃ were not detected. After fruit application of GA₃ theratio of GA₃ to GA₃ 13-O-glucoside was found to be 1:2 inthe fruit. Pedicel application led to ratios of 1:4 and 1:5, respectively, inthe pedicel and in the adjacent bourse. After the application of GA₄and GA₇, neither glucosylation products nor other GA-like metabolitescould be identified.This is the first report of the metabolism of GAs to GA 13-O-glucosides indeveloping apple fruits. The possible function of the GAs as a signal in flowerbud formation for the following year is discussed.     

Studies on the protolytic reactions coupled with water cleavage in photosystem II membrane fragments from spinach

The protolytic reactions of PSII membrane fragments were analyzed by measurements of absorption changes of the water soluble indicator dye bromocresol purple induced by a train of 10 s flashes in dark-adapted samples. It was found that: a) in the first flash a rapid H⁺-release takes place followed by a slower H⁺-uptake. The deprotonation is insensitive to DCMU but is completely eliminated by linolenic acid treatment of the samples; b) the extent of the H⁺-uptake in the first flash depends on the redox potential of the suspension. In this time domain no H⁺-uptake is observed in the subsequent flashes; c) the extent of the H⁺-release as a function of the flash number in the sequence exhibits a characteristic oscillation pattern. Multiphasic release kinetics are observed. The oscillation pattern can be satisfactorily described by a 1, 0, 1, 2 stoichiometry for the redox transitions S_i S_i+1 (i=0, 1, 2, 3) in the water oxidizing enzyme system Y. The H⁺-uptake after the first flash is assumed to be a consequence of the very fast reduction of oxidized Q₄₀₀(Fe³⁺) formed due to dark incubation with K₃[Fe(CN)₆]. The possible participation of component Z in the deprotonation reactions at the PSII donor side is discussed.Abbreviations A protonizable group at the PSII acceptor side - BCP Bromocresol Purple - DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea - FWHM Full Width at Half Maximum - Q_A, Q_B primary and secondary plastoquinone at PSII acceptor side - Q₄₀₀ redox group at PSII-acceptor side (high spin Fe²⁺) - P680 Photoactive chlorophyll of PSII reaction center - S_i redox states of the catalytic site of water oxidation - Z redox component connecting the catalytic site of water oxidation with the reaction center     

Vertical transmission and overwintering of microsporidia in the gypsy moth, Lymantria dispar

Vertical transmission and the overwintering success of three different microsporidia infecting Lymantria dispar (Lepidoptera: Lymantriidae) larvae were investigated. Endoreticulatus schubergi, a midgut pathogen, was transmitted to offspring via female and male via the egg chorion (transovum transmission). Between 8% and 29% of the emerging larvae became infected. No spores of E. schubergi were found in surface-washed eggs. Nosema lymantriae, a microsporidium that causes systemic infections, was transovarially transmitted. Between 35% and 72% of the progeny were infected. Vairimorpha disparis, a fat body pathogen, was not vertically transmitted. The infectivity of spores that overwintered in cadavers of infected L. dispar varied by species, placement in the environment, and weather conditions. Spores of E. schubergi were still infective after an eight month exposure period of cadavers on the ground. Spores of N. lymantriae and V. disparis remained highly infective only when cadavers overwintered under a more or less continuous snow cover for four months.     

Activation of human alveolar macrophages via P2 receptors: coupling to intracellular Ca2+ increases and cytokine secretion

Alveolar macrophages play a crucial role in the pathogenesis of inflammatory airway diseases. By the generation and release of different inflammatory mediators they contribute to both recruitment of different leukocytes into the lung and to airway remodeling. A potent stimulus for the release of inflammatory cytokines is ATP, which mediates its cellular effects through the interaction with different membrane receptors, belonging to the P2X and P2Y families. The aim of this study was to characterize the biological properties of purinoceptors in human alveolar macrophages obtained from bronchoalveolar lavages in the context of inflammatory airway diseases. The present study is the first showing that human alveolar macrophages express mRNA for different P2 subtypes, namely P2X(1), P2X(4), P2X(5), P2X(7), P2Y(1), P2Y(2), P2Y(4), P2Y(6), P2Y(11), P2Y(13), and P2Y(14). We also showed that extracellular ATP induced Ca(2+) transients and increased IL-1beta secretion via P2X receptors. Furthermore, extracellular nucleotides inhibited production of IL-12p40 and TNF-alpha, whereas IL-6 secretion was up-regulated. In summary, our data further support the hypothesis that purinoceptors are involved in the pathogenesis of inflammatory lung diseases.