Subunit Composition of Cytochrome c Oxidase in Mitochondria of Zea mays

Cytochrome c oxidase has been purified from Zea mays mitochondria by a solubilization with dodecyl maltoside followed by a simple and rapid two step fast protein liquid chromatographic method involving anion exchange on Mono Q and size exclusion chromatography on Superose 12. The preparation obtained was resolved by urea sodium dodecyl sulfate-polyacrylamide gel electrophoresis and had a subunit composition comprising polypeptides of apparent molecular masses of 48, 31, and 25 kilodaltons at least one at 16 and 11 kilodaltons and three subunits below 10 kilodaltons. Comparison with a purified yeast cytochrome c oxidase revealed that the four largest subunits showed similar electrophoretic mobilities. Subunits I and II cross-reacted with antibodies raised against the yeast homologous polypeptides. Polypeptides of the plant ubiquinone:cytochrome c reductase complex have also been identified by cross-reaction with antibodies raised against yeast cytochrome b and c₁ subunits and by inference from comigration.     

Investigation of cis-acting sequences regulating expression of the gene encoding yolk protein 3 in Drosophila melanogaster.

Summary The regulatory sequences leading to the ovarian and fat body expression of yolk proteins 1 and 2 (YP1 and 2) of Drosophila melanogaster have been characterised in some detail. These genes (yp1 and yp2) share many enhancer elements, and some important regulatory sequences lie within the coding regions. We have begun to investigate the cis-regulation of the gene encoding yolk protein 3 (yp3). We describe a system for P element transformation using the complete and unaltered yp3 gene rather than reporter genes and describe sequences conferring correct expression in the ovary and carcass.     

Maintenance of the cellobiose utilization genes of Escherichia coli in a cryptic state

The genes for cellobiose utilization are normally cryptic in Escherichia coli. The cellobiose system was used as a model to understand the process by which silent genes are maintained in microbial populations. Previously reported was (1) the isolation of a mutant strain that expresses the cellobiose-utilization (Cel) genes and (2) that expression of those genes allows utilization of three beta- glucoside sugars: cellobiose, arbutin, and salicin. The Cel gene cluster has now been cloned from that mutant strain. In the course of locating the Cel genes within the cloned DNA segment, it was discovered that inactivation of the Cel-encoded hydrolase rendered the host strain sensitive to all three beta-glucosides as potent inhibitors. This sensitivity arises from the accumulation of the phosphorylated beta- glucosides. Because even the fully active genes conferred some degree of beta-glucoside sensitivity, the effects of cellobiose on a series of five Cel+ mutants of independent origin were investigated. Although each of those strains utilizes cellobiose as a sole carbon and energy source, cellobiose also acts as a potent inhibitor that reduces the growth rate on glycerol 2.5-16.5-fold. On the other hand, wild-type strains that cannot utilize cellobiose are not inhibited. The observation that the same compound can serve either as a nutrient or as an inhibitor suggests that, under most conditions in which cellobiose will be present together with other resources, there is a strong selective advantage to having the cryptic (Cel0) allele. In those environments in which cellobiose is the sole, or the best, resource, mutants that express the genes (Cel+) will have a strong selective advantage. It is suggested that temporal alternation between these two conditions is a major factor in the maintenance of these genes in E. coli populations. This alternation of environments and fitnesses was predicted by the model for cryptic-gene maintenance that was previously published.      

The development and characterization of an anti‐haemolymph antiserum for the detection of mollusc remains within carabid beetles

Molluscan haemolymph was evaluated as an antigen for the detection, by enzyme‐linked immunosorbent assay (ELISA), of mollusc proteins within the crop contents of carabid beetles, using an anti‐haemolymph antiserum. The value of using a narrow range of prey‐specific immunogens, rather than whole‐body macerates, was discussed. Predators and potential prey were tested by a quantitative indirect ELISA, with separate evaluation of antigen reactions with non‐specific and specific antibodies. The assay proved to be capable of detecting less than 1 ng of haemolymph protein and the antiserum reacted strongly with all molluscs tested. Initial cross‐reactions with earthworms were effectively eliminated by absorption. A range of invertebrates was tested, and a significance level established relative to the invertebrates giving the strongest cross‐reaction, which proved to be wolf spiders Pardosa sp. Harvestmen (Opiliones), that initially gave strong reactions to the antiserum, were shown to have fed upon molluscs. Laboratory tests on the crop contents of slug‐fed beetles demonstrated clear detection for at least 4 days after feeding.     

Intermittent Explosive Disorder amongst Women in Conflict Affected Timor-Leste: Associations with Human Rights Trauma,Ongoing Violence,Poverty, and Injustice

Introduction

Women in conflict-affected countries are at risk of mental disorders such as posttraumatic stress disorder and depression. No studies have investigated the association between experiences of abuse and injustice and explosive anger amongst women in these settings, and the impact of anger on women''s health, family relationships and ability to participate in development.

Methods

A mixed methods study including an epidemiological survey (n = 1513, 92.6% response) and qualitative interviews (n = 77) was conducted in Timor-Leste. The indices measured included Intermittent Explosive Disorder, posttraumatic stress disorder; severe distress; days out of role (the number of days that the person was unable to undertake normal activities); gender-specific trauma; conflict/violence; poverty; and preoccupations with injustice.

Results

Women with Intermittent Explosive Disorder (n = 184, 12.2%) were more disabled than those without the disorder (for >5 days out of role, 40.8% versus 31.5%, X² ₍₂₎  = 12.93 p = 0.0016). Multivariable associations with Intermittent Explosive Disorder, controlling for the presence of PTSD, psychological distress and other predictors in the model, included the sense of being sick (OR 1.73; 95% CI 1.08–2.77); victimization as a result of helping the resistance movement (OR 2.33, 95% CI 1.48–3.68); war-related trauma specific to being a woman (OR 1.95, 95%, CI 1.09–3.50); ongoing family violence and community conflict (OR 1.88, 95% CI 1.27–2.77); extreme poverty (OR 1.23, 95%, CI 1.08–1.39); and distressing preoccupations with injustice (relating to 2/3 historical periods, OR 2.10, 95% CI 1.35–3.28). In the qualitative study, women elaborated on the determinants of anger and its impact on their health, family and community functioning, child-rearing, and capacity to engage in development. Women reflected on the strategies that might help them overcome their anger.

Conclusions

Intermittent Explosive Disorder is prevalent and disabling amongst women in conflict-affected Timor-Leste, impacting on their health, child-rearing and ability to participate fully in socio-economic development.     

A comparison of two novel alcohol dehydrogenase enzymes (ADH1 and ADH2) from the extreme halophile Haloferax volcanii

Haloarchaeal alcohol dehydrogenases are exciting biocatalysts with potential industrial applications. In this study, two alcohol dehydrogenase enzymes from the extremely halophilic archaeon Haloferax volcanii (HvADH1 and HvADH2) were homologously expressed and subsequently purified by immobilized metal-affinity chromatography. The proteins appeared to copurify with endogenous alcohol dehydrogenases, and a double Δadh2 Δadh1 gene deletion strain was constructed to prevent this occurrence. Purified HvADH1 and HvADH2 were compared in terms of stability and enzymatic activity over a range of pH values, salt concentrations, and temperatures. Both enzymes were haloalkaliphilic and thermoactive for the oxidative reaction and catalyzed the reductive reaction at a slightly acidic pH. While the NAD⁺-dependent HvADH1 showed a preference for short-chain alcohols and was inherently unstable, HvADH2 exhibited dual cofactor specificity, accepted a broad range of substrates, and, with respect to HvADH1, was remarkably stable. Furthermore, HvADH2 exhibited tolerance to organic solvents. HvADH2 therefore displays much greater potential as an industrially useful biocatalyst than HvADH1.     

Some aspects of forest soil and litter ecology in the Dawyck Cryptogamic Sanctuary with a particular reference to fungi

Here we report on ecology and biodiversity of fungi in a unique mycological sanctuary in Britain, where data on species composition have been collected since 1994. To complement the biodiversity data by the information on the fungal ecological interactions and their role in the overall ecosystem functioning, soil properties and the composition of forest litter and field layer, bacterial population numbers and fungal biomass (in terms of ergosterol) were measured in 8 plots covered with different vegetations (beech, birch, birch-oak-beech, grass) over a May–Aug. period, and the results were analysed by correlation analysis and stepwise regression modelling together with data on protozoa and nematodes available from parallel research. The results highlighted the complexity of factors influencing temporal dynamics and spatial variability of fungal biomass in soil and forest litter. Most of the registered interactions appeared to be transient, and this should be taken into account while interpreting environmental observations. Interpretation of the specific relationships is given and implications for further research and overall ecosystem functioning are discussed.