FReD: the Floral Reflectance Database - a web portal for analyses of flower colour

Background: Flower colour is of great importance in various fields relating to floral biology and pollinator behaviour. However, subjective human judgements of flower colour may be inaccurate and are irrelevant to the ecology and vision of the flower's pollinators. For precise, detailed information about the colours of flowers, a full reflectance spectrum for the flower of interest should be used rather than relying on such human assessments. Methodology/Principal Findings: The Floral Reflectance Database (FReD) has been developed to make an extensive collection of such data available to researchers. It is freely available at http://www.reflectance.co.uk. The database allows users to download spectral reflectance data for flower species collected from all over the world. These could, for example, be used in modelling interactions between pollinator vision and plant signals, or analyses of flower colours in various habitats. The database contains functions for calculating flower colour loci according to widely-used models of bee colour space, reflectance graphs of the spectra and an option to search for flowers with similar colours in bee colour space. Conclusions/Significance: The Floral Reflectance Database is a valuable new tool for researchers interested in the colours of flowers and their association with pollinator colour vision, containing raw spectral reflectance data for a large number of flower species

Nanostructured 3D Constructs Based on Chitosan and Chondroitin Sulphate Multilayers for Cartilage Tissue Engineering

Nanostructured three-dimensional constructs combining layer-by-layer technology (LbL) and template leaching were processed and evaluated as possible support structures for cartilage tissue engineering. Multilayered constructs were formed by depositing the polyelectrolytes chitosan (CHT) and chondroitin sulphate (CS) on either bidimensional glass surfaces or 3D packet of paraffin spheres. 2D CHT/CS multi-layered constructs proved to support the attachment and proliferation of bovine chondrocytes (BCH). The technology was transposed to 3D level and CHT/CS multi-layered hierarchical scaffolds were retrieved after paraffin leaching. The obtained nanostructured 3D constructs had a high porosity and water uptake capacity of about 300%. Dynamical mechanical analysis (DMA) showed the viscoelastic nature of the scaffolds. Cellular tests were performed with the culture of BCH and multipotent bone marrow derived stromal cells (hMSCs) up to 21 days in chondrogenic differentiation media. Together with scanning electronic microscopy analysis, viability tests and DNA quantification, our results clearly showed that cells attached, proliferated and were metabolically active over the entire scaffold. Cartilaginous extracellular matrix (ECM) formation was further assessed and results showed that GAG secretion occurred indicating the maintenance of the chondrogenic phenotype and the chondrogenic differentiation of hMSCs

Do Queens of Bumblebee Species Differ In Their Choice Of Flower Colour Morphs Of Corydalis Cava (Fumariaceae)?

International audienceAbstractBumblebee queens require a continuous supply of flowering food plants from early spring for the successful development of annual colonies. Early in spring, Corydalis cava provides essential nectar and pollen resources and a choice of flower colour. In this paper, we examine flower colour choice (purple or white) in C. cava and verify the hypothesis that bumblebee queens differ in their choice of flower colour. A total of 10,615 observations of flower visits were made in spring 2011 and spring 2014 near Poznań, western Poland. Our results suggest that Bombus lucorum/cryptarum used purple flowers less, while Bombus terrestris used purple flowers more and Bombus hortorum showed no preference. Therefore, the colour morphs of C. cava are probably co-evolutionary adaptations to the development of another part of the insect community which has different colour preferences

Molecular, serological and biological variation among chickpea chlorotic stunt virus isolates from five countries of North Africa and West Asia

Chickpea chlorotic stunt virus (CpCSV), a proposed new member of the genus Polerovirus (family Luteoviridae), has been reported only from Ethiopia. In attempts to determine the geographical distribution and variability of CpCSV, a pair of degenerate primers derived from conserved domains of the luteovirus coat protein (CP) gene was used for RT-PCR analysis of various legume samples originating from five countries and containing unidentified luteoviruses. Sequencing of the amplicons provided evidence for the occurrence of CpCSV also in Egypt, Morocco, Sudan, and Syria. Phylogenetic analysis of the CP nucleotide sequences of 18 samples from the five countries revealed the existence of two geographic groups of CpCSV isolates differing in CP sequences by 8–10%. Group I included isolates from Ethiopia and Sudan, while group II comprised those from Egypt, Morocco and Syria. For distinguishing these two groups, a simple RFLP test using HindIII and/or PvuII for cleavage of CP-gene-derived PCR products was developed. In ELISA and immunoelectron microscopy, however, isolates from these two groups could not be distinguished with rabbit antisera raised against a group-I isolate from Ethiopia (CpCSV-Eth) and a group-II isolate from Syria (CpCSV-Sy). Since none of the ten monoclonal antibodies (MAbs) that had been produced earlier against CpCSV-Eth reacted with group-II isolates, further MAbs were produced. Of the seven MAbs raised against CpCSV-Sy, two reacted only with CpCSV-Sy and two others with both CpCSV-Sy and -Eth. This indicated that there are group I- and II-specific and common (species-specific) epitopes on the CpCSV CP and that the corresponding MAbs are suitable for specific detection and discrimination of CpCSV isolates. Moreover, CpCSV-Sy (group II) caused more severe stunting and yellowing in faba bean than CpCSV-Eth (group I). In conclusion, our data indicate the existence of a geographically associated variation in the molecular, serological and presumably biological properties of CpCSV

Mucosal immunization with PspA (Pneumococcal surface protein A)-adsorbed nanoparticles targeting the lungs for protection against pneumococcal infection

Burden of pneumonia caused by Streptococcus pneumoniae remains high despite the availability of conjugate vaccines. Mucosal immunization targeting the lungs is an attractive alternative for the induction of local immune responses to improve protection against pneumonia. Our group had previously described the development of poly(glycerol adipate-co-ω-pentadecalactone) (PGA-co-PDL) polymeric nanoparticles (NPs) adsorbed with Pneumococcal surface protein A from clade 4 (PspA4Pro) within L-leucine microcarriers (nanocomposite microparticles-NCMPs) for mucosal delivery targeting the lungs (NP/NCMP PspA4Pro). NP/NCMP PspA4Pro was now used for immunization of mice. Inoculation of this formulation induced anti-PspA4Pro IgG antibodies in serum and lungs. Analysis of binding of serum IgG to intact bacteria showed efficient binding to bacteria expressing PspA from clades 3, 4 and 5 (family 2), but no binding to bacteria expressing PspA from clades 1 and 2 (family 1) was observed. Both mucosal immunization with NP/NCMP PspA4Pro and subcutaneous injection of the protein elicited partial protection against intranasal lethal pneumococcal challenge with a serotype 3 strain expressing PspA from clade 5 (PspA5). Although similar survival levels were observed for mucosal immunization with NP/NCMP PspA4Pro and subcutaneous immunization with purified protein, NP/NCMP PspA4Pro induced earlier control of the infection. Conversely, neither immunization with NP/NCMP PspA4Pro nor subcutaneous immunization with purified protein reduced bacterial burden in the lungs after challenge with a serotype 19F strain expressing PspA from clade 1 (PspA1). Mucosal immunization with NP/NCMP PspA4Pro targeting the lungs is thus able to induce local and systemic antibodies, conferring protection only against a strain expressing PspA from the homologous family 2

The ontogeny of bumblebee flight trajectories: From naïve explorers to experienced foragers

Understanding strategies used by animals to explore their landscape is essential to predict how they exploit patchy resources, and consequently how they are likely to respond to changes in resource distribution. Social bees provide a good model for this and, whilst there are published descriptions of their behaviour on initial learning flights close to the colony, it is still unclear how bees find floral resources over hundreds of metres and how these flights become directed foraging trips. We investigated the spatial ecology of exploration by radar tracking bumblebees, and comparing the flight trajectories of bees with differing experience. The bees left the colony within a day or two of eclosion and flew in complex loops of ever-increasing size around the colony, exhibiting Lévy-flight characteristics constituting an optimal searching strategy. This mathematical pattern can be used to predict how animals exploring individually might exploit a patchy landscape. The bees’ groundspeed, maximum displacement from the nest and total distance travelled on a trip increased significantly with experience. More experienced bees flew direct paths, predominantly flying upwind on their outward trips although forage was available in all directions. The flights differed from those of naïve honeybees: they occurred at an earlier age, showed more complex looping, and resulted in earlier returns of pollen to the colony. In summary bumblebees learn to find home and food rapidly, though phases of orientation, learning and searching were not easily separable, suggesting some multi-tasking

Processes and patterns of oceanic nutrient limitation

Microbial activity is a fundamental component of oceanic nutrient cycles. Photosynthetic microbes, collectively termed phytoplankton, are responsible for the vast majority of primary production in marine waters. The availability of nutrients in the upper ocean frequently limits the activity and abundance of these organisms. Experimental data have revealed two broad regimes of phytoplankton nutrient limitation in the modern upper ocean. Nitrogen availability tends to limit productivity throughout much of the surface low-latitude ocean, where the supply of nutrients from the subsurface is relatively slow. In contrast, iron often limits productivity where subsurface nutrient supply is enhanced, including within the main oceanic upwelling regions of the Southern Ocean and the eastern equatorial Pacific. Phosphorus, vitamins and micronutrients other than iron may also (co-)limit marine phytoplankton. The spatial patterns and importance of co-limitation, however, remain unclear. Variability in the stoichiometries of nutrient supply and biological demand are key determinants of oceanic nutrient limitation. Deciphering the mechanisms that underpin this variability, and the consequences for marine microbes, will be a challenge. But such knowledge will be crucial for accurately predicting the consequences of ongoing anthropogenic perturbations to oceanic nutrient biogeochemistry. © 2013 Macmillan Publishers Limited. All rights reserved

Rise and Fall of an Anti-MUC1 Specific Antibody

So far, human antibodies with good affinity and specificity for MUC1, a transmembrane protein overexpressed on breast cancers and ovarian carcinomas, and thus a promising target for therapy, were very difficult to generate.A human scFv antibody was isolated from an immune library derived from breast cancer patients immunised with MUC1. The anti-MUC1 scFv reacted with tumour cells in more than 80% of 228 tissue sections of mamma carcinoma samples, while showing very low reactivity with a large panel of non-tumour tissues. By mutagenesis and phage display, affinity of scFvs was increased up to 500fold to 5,7×10(-10) M. Half-life in serum was improved from below 1 day to more than 4 weeks and was correlated with the dimerisation tendency of the individual scFvs. The scFv bound to T47D and MCF-7 mammalian cancer cell lines were recloned into the scFv-Fc and IgG format resulting in decrease of affinity of one binder. The IgG variants with the highest affinity were tested in mouse xenograft models using MCF-7 and OVCAR tumour cells. However, the experiments showed no significant decrease in tumour growth or increase in the survival rates. To study the reasons for the failure of the xenograft experiments, ADCC was analysed in vitro using MCF-7 and OVCAR3 target cells, revealing a low ADCC, possibly due to internalisation, as detected for MCF-7 cells.Antibody phage display starting with immune libraries and followed by affinity maturation is a powerful strategy to generate high affinity human antibodies to difficult targets, in this case shown by the creation of a highly specific antibody with subnanomolar affinity to a very small epitope consisting of four amino acids. Despite these "best in class" binding parameters, the therapeutic success of this antibody was prevented by the target biology