Life history varies with migratory distance in western sandpipers Calidris mauri

The propensity of migratory waders to remain on the non-breeding grounds during the arctic breeding season ("oversummer") in their first biological year of life ("juveniles") may be latitude, and thus migratory distance dependent. We compared the extent of preparation for northward migration of western sandpipers Calidris mauri spending the non-breeding season in México and Panamá during 1995–1998. During winter residency and premigratory periods, we measured body mass and scored the extent of dull basic versus bright alternate breeding plumage of captured juveniles and adults (second biological year or older), and obtained additional plumage scores from observations of uniquely colour banded birds. Nearly all western sandpipers in México prepared for northward migration by increasing body mass and moulting into breeding plumage. In Panamá, most adults prepared for migration, but few, if any, juveniles did so. Patterns of body mass and breeding plumage development do not generally support the hypothesis that oversummering by juveniles results directly from less efficient foraging or from resource competition with adults. We suggest instead that costs directly associated with migratory distance per se influence the life history strategies of sandpipers spending the non-breeding seasons at different latitudes. This latitudinal difference should interact with the well documented sex-ratio cline in non-breeding distribution (male western sandpipers predominating in northern parts of the range and females in southern parts). This suggests that females have more conservative life histories, prioritizing first year survivorship, relative to males that instead weight first-year breeding opportunities.     

Ecuadorian Banana Farms Should Consider Organic Banana with Low Price Risks in Their Land-Use Portfolios

Organic farming is a more environmentally friendly form of land use than conventional agriculture. However, recent studies point out production tradeoffs that often prevent the adoption of such practices by farmers. Our study shows with the example of organic banana production in Ecuador that economic tradeoffs depend much on the approach of the analysis. We test, if organic banana should be included in economic land-use portfolios, which indicate how much of the land is provided for which type of land-use. We use time series data for productivity and prices over 30 years to compute the economic return (as annualized net present value) and its volatility (with standard deviation as risk measure) for eight crops to derive land-use portfolios for different levels of risk, which maximize economic return. We find that organic banana is included in land-use portfolios for almost every level of accepted risk with proportions from 1% to maximally 32%, even if the same high uncertainty as for conventional banana is simulated for organic banana. A more realistic, lower simulated price risk increased the proportion of organic banana substantially to up to 57% and increased annual economic returns by up to US$ 187 per ha. Under an assumed integration of both markets, for organic and conventional banana, simulated by an increased coefficient of correlation of economic return from organic and conventional banana (ρ up to +0.7), organic banana holds significant portions in the land-use portfolios tested only, if a low price risk of organic banana is considered. We conclude that uncertainty is a key issue for the adoption of organic banana. As historic data support a low price risk for organic banana compared to conventional banana, Ecuadorian farmers should consider organic banana as an advantageous land-use option in their land-use portfolios.     

The contribution of Rhizobium meliloti to soil denitrification

The ability of Rhizobium meliloti cells to denitrify in soils under several conditions was tested. All the strains tested were able to remove large amounts of N-NO₃ ^- from soils. Both water filled pore space above 36% and temperatures above 20°C greatly increased nitrogen losses. However, even with optimal conditions for denitrification and the highest rhizobial populations found in agricultural soils, the contribution of Rhizobium to the total denitrification was virtually negligible as compared to other soil microorganisms.To whom correspondence should be addressed     

Rice TOGO Browser: A platform to retrieve integrated information on rice functional and applied genomics

The Rice TOGO Browser is an online public resource designed to facilitate integration and visualization of mapping data of bacterial artificial chromosome (BAC)/P1-derived artificial chromosome (PAC) clones, genes, restriction fragment length polymorphism (RFLP)/simple sequence repeat (SSR) markers and phenotype data represented as quantitative trait loci (QTLs) onto the genome sequence, and to provide a platform for more efficient utilization of genome information from the point of view of applied genomics as well as functional genomics. Three search options, namely keyword search, region search and trait search, generate various types of data in a user-friendly interface with three distinct viewers, a chromosome viewer, an integrated map viewer and a sequence viewer, thereby providing the opportunity to view the position of genes and/or QTLs at the chromosomal level and to retrieve any sequence information in a user-defined genome region. Furthermore, the gene list, marker list and genome sequence in a specified region delineated by RFLP/SSR markers and any sequences designed as primers can be viewed and downloaded to support forward genetics approaches. An additional feature of this database is the graphical viewer for BLAST search to reveal information not only for regions with significant sequence similarity but also for regions adjacent to those with similarity but with no hits between sequences. An easy to use and intuitive user interface can help a wide range of users in retrieving integrated mapping information including agronomically important traits on the rice genome sequence. The database can be accessed at http://agri-trait.dna.affrc.go.jp/.     

Major histocompatibility complex and alveolar epithelial apoptosis in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterized by fibroblast expansion, and tissue remodeling. It is considered a multifactorial disease but the possible involved genes are largely unknown. Interestingly, studies regarding the possible role of major histocompatibility complex (MHC) are scanty and show contradictory results. In this study, we evaluated the polymorphisms of the MHC, locus HLA-B, -DRB1, and -DQB1 in a cohort of 75 IPF patients and 95 controls by using PCR and hybridization with sequence-specific oligonucleotide probes. In addition, we examined the effect of bronchoalveolar lavage (BAL) from IPF patients with different MHC haplotypes on alveolar epithelial growth rate by WST-1 cell viability assay and on epithelial apoptosis by flow cytometry and by cleaved caspase-3 in cell homogenates. Three haplotypes were significantly increased in IPF: (1) HLA-B*15-DRB1*0101-DQB1*0501 (OR=10.72, CI=1.43–459.6; pC=0.011); (2) HLA-B*52-DRB1*1402-DQB1*0301 (OR=4.42, CI=1.21–24.1; pC=0.024); and (3) HLA-B*35-DRB1*0407-DQB1*0302 (OR=4.73, CI=1.53–19.5; pC=0.005). BAL from patients with the later haplotype significantly reduced epithelial growth rate (∼30%) and caused epithelial cell apoptosis assayed by cleaved caspase-3 (351.7±16.5 pg/10⁶ cells versus 264±24 from controls, and 274±36.8 and 256.5±10.7 from the other haplotypes; P<0.05), and DNA breaks labeling by flow cytometry (23.7±6.9% versus 3.1±0.7% from controls, and 6.5±0.6% and 7.6±1.2% from the other two haplotypes; P<0.01). These findings suggest that some MHC polymorphisms confer susceptibility to IPF, which might be related with the induction of epithelial cell apoptosis, a critical process in the development of the disease.     

GLUT1 and CAIX expression profiles in breast cancer correlate with adverse prognostic factors and MCT1 overexpression

The goal of the present work was to evaluate the correlation of glucose transporter 1 (GLUT1) and carbonic anhydrase IX (CAIX) with the monocarboxylate transporters 1 (MCT1) and 4 (MCT4) and their chaperone, CD147, in breast cancer. The clinico-pathological value of GLUT1 and CAIX was also evaluated. For that, we analysed the immunohistochemical expression of GLUT1 and CAIX, in a large series of invasive breast carcinoma samples (n=124), previously characterized for MCT1, MCT4 and CD147 expression. GLUT1 expression was found in 46% of the cases (57/124), while CAIX was found in 18% of the cases (22/122). Importantly, both MCT1 and CD147, but not MCT4, were associated with GLUT1 and CAIX expression. Also, GLUT1 and CAIX correlated with each other. Concerning the clinico-pathological values, GLUT1 was associated with high grade tumours, basal-like subtype, absence of progesterone receptor, presence of vimentin and high proliferative index as measured by Ki-67. Additionally, CAIX was associated with large tumour size, high histological grade, basal-like subtype, absence of estrogen and progesterone receptors and presence of basal cytokeratins and vimentin expression. Finally, patients with CAIX positive tumours had a significantly shorter disease-free survival. The association between MCT1 and both GLUT1 and CAIX may result from hypoxia-mediated metabolic adaptations, which confer a glycolytic, acid-resistant and more aggressive phenotype to cancer cells.     

Localization and expression of BCAT during pregnancy and lactation in the rat mammary gland

During lactation, branched-chain aminotransferase (BCAT) gene expression increases in the mammary gland. To determine the cell type and whether this induction is present only during lactation, female rats were randomly assigned to one of three experimental groups: pregnancy, lactation, or postweaning. Mammary gland BCAT activity during the first days of pregnancy was similar to that of virgin rats, increasing significantly from day 16 to the last day of pregnancy. Maximal BCAT activity occurred on day 12 of lactation. During postweaning, BCAT activity decreased rapidly to values close to those observed in virgin rats. Analyses by Western and Northern blot revealed that changes in enzyme activity were accompanied by parallel changes in the amount of enzyme and its mRNA. Immunohistochemical studies of the mammary gland showed a progressive increase in mitochondrial BCAT (mBCAT)-specific staining of the epithelial acinar cells during lactation, reaching high levels by day 12. Immunoreactivity decreased rapidly after weaning. There was a significant correlation between total BCAT activity and milk production. These results indicate that the pattern of mBCAT gene expression follows lactogenesis stages I and II and is restricted to the milk-producing epithelial acinar cells. Furthermore, BCAT activity is associated with milk production in the mammary gland during lactation.     

Some physical properties of teosinte (Zea mays subsp. parviglumis) pollen

In parts of the world where teosinte and maize are grown in close proximity, there is concern about gene flow between them. Pollen is the primary vehicle for gene flow. Quantifying the biophysical properties of pollen, such as its settling speed and dehydration rate, is important for evaluating outcrossing potential. These properties were measured for teosinte (Zea mays subsp. parviglumis) pollen. Pollen was found to have an average settling speed of 0.165 m s(-1), which agrees well with theoretical values based on the size of the pollen grains. The conductance of the pollen wall for water was derived from the time rate of change of pollen grain size and gave an average conductance of 3.42x10(-4) m s(-1). Water potential, psi, of teosinte pollen was determined at various values of relative water content (dry-weight basis), theta, by using a thermocouple psychrometer and by allowing samples of pollen to come to vapour equilibrium with various saturated salt solutions. Non-linear regression analysis of the data yielded psi (MPa) = -4.13 theta(-1.23) (r2=0.77). Results for conductance and psi were incorporated into a model equation for the rate of water loss from pollen grains, which yielded results that agreed well (r2=0.96) with observations of water loss from pollen grains in air. The data reported here are important building blocks in a model of teosinte pollen movement and should be helpful in establishing the main factors influencing the degree and the direction of pollination between teosinte populations and between maize and teosinte.     

Reduced adipose tissue mass and hypoleptinemia in iNOS deficient mice: effect of LPS on plasma leptin and adiponectin concentrations

The AAA+ chaperone ClpB solubilizes in cooperation with the DnaK chaperone system aggregated proteins. The mechanistic features of the protein disaggregation process are poorly understood. Here, we investigated the mechanism of ClpB/DnaK-dependent solubilization of heat-aggregated malate dehydrogenase (MDH) by following characteristics of MDH aggregates during the disaggregation reaction. We demonstrate that disaggregation is achieved by the continuous extraction of unfolded MDH molecules and not by fragmentation of large MDH aggregates. These findings support a ClpB-dependent threading mechanism as an integral part of the disaggregation reaction.