Effects of lectin in the scleractinian coral Ctenactis echinata on symbiotic zooxanthellae

We report herein the presence of a lectin in the scleractinian coral Ctenactis (Fungia) echinata. The lectin bound preferentially to lactose, melibiose, and d-galactose. The purified lectin CecL was composed of several isolectins, and it was found to have a molecular mass of 67.4 kDa via gel filtration. Glycopeptidase F-treated CecL showed a single band at 32.5 kDa. The mass/charge ratios of the reduced CecL peaks were equivalent to half those of the native peaks. These results suggest that CecL is composed of two glycosylated polypeptides linked by interchain disulfide bonds. In a biological activity test using a zooxanthellal culture (Dinoflagellate Symbiodinium) clonally isolated from Fungia cf. fungites, CecL transformed the flagellated motile form of Symbiodinium into the nonmotile coccoid form, a form equivalent to the symbiotic stage. The activity of CecL on Symbiodinium cells was concentration dependent, and 100 μg/ml CecL arrested Symbiodinium cells in the coccoid form for 5 days. CecL also suppressed the growth of Symbiodinium cells, unlike the octocoral lectin derived from Sinularia lochmodes, which arrests Symbiodinium cells in the coccoid form but does not affect the growth of the coccoid. This result provides further evidence that coral lectins play a role in symbiont engagement and maintenance in zooxanthellae–coral symbiosis.     

Characterization of gelatinolytic enzymes in the skeletal muscle of red sea bream Pagrus major

Gelatinolytic enzymes were partially purified from the skeletal muscle of red sea bream Pagrus major and characterized to obtain information on post mortem tenderization of fish muscle. Four gelatinolytic activities, G1 (90 kDa), G2 (65 kDa), G3 (60 kDa), and G4 (100 kDa), were detected in the Q Sepharose column. G1, the major gelatinolytic enzyme, and G4 were identified as serine proteinases from results of inhibitor spectrum and substrate specificity. By contrast, G2 and G3 were found to be metalloproteinases since these were inhibited by ethylenediamine tetraacetic acid and o-phenanthroline, and activated by 4-aminophenylmercuric acetate. The optimum pH and temperature of these enzymes were in the ranges of 7–9 and 20–40°C, respectively.     

Australopithecus garhi: a new species of early hominid from Ethiopia

The lack of an adequate hominid fossil record in eastern Africa between 2 and 3 million years ago (Ma) has hampered investigations of early hominid phylogeny. Discovery of 2.5 Ma hominid cranial and dental remains from the Hata beds of Ethiopia's Middle Awash allows recognition of a new species of Australopithecus. This species is descended from Australopithecus afarensis and is a candidate ancestor for early Homo. Contemporary postcranial remains feature a derived humanlike humeral/femoral ratio and an apelike upper arm-to-lower arm ratio.     

Cities and biodiversity: Perspectives and governance challenges for implementing the convention on biological diversity (CBD) at the city level

City governments are fundamental to implement international environmental agreements, such as the convention on biological diversity (CBD). Even though many of them are not directly involved in the negotiation of international agreements, which are signed by national governments, most of those agreements are in fact implemented at the city level. The importance of city governance to tackle the challenges of biodiversity loss has increased as urban population has grown enormously in the last decades, particularly in developing countries. The way cities are designed, planned and governed influences the magnitude of their direct and indirect impacts on biodiversity.This paper analyzes the relationship between cities, local governance and biodiversity. Initially, we examine the relationships between cities and biodiversity by looking at the major influences cities have on biodiversity loss or conservation within and outside the city boundaries, as well as the benefits of biodiversity conservation to cities, such as the provision of ecosystem services. The paper then moves to understand what are the main urban processes and governance mechanisms that can be improved to make cities effective to implement the directives of the CBD.Urbanization creates new challenges for biodiversity conservation. As a large part of the world’s population moves from rural to urban areas, there are changes in the link between human activities and biodiversity, and consequently to the way we should think biodiversity conservation policies. However, scarce attention has been given to understand how to make cities more biodiversity friendly, both within the urban fabric, but particularly in faraway places.     

Mechanical stretch-induced activation of skeletal muscle satellite cells is dependent on nitric oxide production in vitro

Mechanical stretch induces activation of cultured quiescent satellite cells and the activation response is owing to rapid release of hepatocyte growth factor (HGF) from its extracellular association with satellite cells and its subsequent presentation to the c-met receptor. We provide new evidence that the stretch activation is dependent on nitric oxide (NO) production. Stretch activation could be abolished by the addition of N ^G-nitro- L -arginine methyl ester (L-NAME), a competitive inhibitor of NO synthesis, but not by N ^G-nitro- D -arginine methyl ester hydrochloride, a less active enantiomer of L-NAME. Adding HGF to the L-NAME culture restored the activation response, indicating that L-NAME does not directly inhibit satellite cell activation, but acts upstream from the HGF release. In addition, immunoblots of satellite cell lysate revealed the presence of nitric oxide synthase. These experiments suggest that NO is involved in linking mechanical perturbation of satellite cells to chemical signaling responsible for HGF release from its sequestration in vitro .     

Preparation of calibration standards of N1-H paralytic shellfish toxin analogues by large-scale culture of cyanobacterium Anabaena circinalis (TA04)

Mouse bioassay is the official testing method to quantify paralytic shellfish toxins (PSTs) in bivalves. A number of alternative analytical methods have been reported. Some methods have been evaluated by a single laboratory validation. Among the different types of methods, chemical analyses are capable of identifying and quantifying the toxins, however a shortage of the necessary calibration standards hampers implementation of the chemical analyses in routine monitoring of PSTs in bivalves. In our present study, we studied preparation of major PST analogues as calibrants by large-scale cultivation of toxic freshwater cyanobacteria Anabaena circinalis TA04. The cells were steadily grown in 10 L bottle for 28 days. The primary N1-H toxins, C1/C2, were produced at a concentration of 1.3 ± 0.1 μmol/L. The intracellular and extracellular toxins occupied 80% and 20%, respectively. Over 220 μmol of the toxins was obtained from approximately 200 L of the culture over six months, demonstrating that it is sufficient to prepare saxitoxin analogues. The toxins were chemically converted to six N1-H analogues. Preparation of the analogues was carried out at relatively high yields (50-90%). The results indicate that our preparation method is useful to produce N1-H toxins. In our present study, detailed conditions for preparation of one of the rare N1-H analogues, gonyautoxin-5, were investigated.     

Diversity and vertical distribution of indigenous arbuscular mycorrhizal fungi under two soybean rotational systems

To evaluate the importance of arbuscular mycorrhizal fungi (AMF) to crop production, it is imperative to move beyond the plow layer to include the full soil profile impacted by plant roots. To illustrate this, we investigated the vertical distribution of AMF biomass and community structure within the top 100 cm of soil in soybean (Glycine max (L.) Merr., cv: Enrei) rotational systems cropped to wheat (Triticuma estivum L. cv: Bandowase) or left fallow using fatty acid methyl ester (FAME) biomarkers and molecular analysis, respectively. AMF biomass, as measured by concentration of C16:1cis11, declined during fallow and with increasing soil depth. Greater than 50 % of the stored AMF biomass was found at depths below 35 cm. Phylogenetic analysis revealed 16 AMF phylotypes, including nine Glomus, two Gigaspora, two Scutellospora, and one each of Diversispora, Paraglomus, and an unknown glomeromycete, at different sampling depths in this study. Cluster analysis based on the number and abundance of each AMF phylotype formed two distinct clusters separating wheat from fallow rotations. There was no distinct relationship with soil depth beyond clustering AMF communities above and below 20 cm under wheat. Redundancy analysis (RDA) and hierarchical cluster analysis demonstrated that AMF communities by soil depth within each rotation were not significantly different. However, AMF communities were clearly influenced by crop rotation, where the distribution of specific AMF phylotypes responded to the presence of the wheat crop.     

Comparison of Salmonella enterica serovar Abortusequi isolates of equine origin by pulsed-field gel electrophoresis and fluorescent amplified-fragment length polymorphism fingerprinting

Equine paratyphoid is caused by Salmonella enterica serovar Abortusequi, and manifests mainly as abortion in the mare. We compared S. Abortusequi strains isolated in Japan and other countries using pulsed-field gel electrophoresis (PFGE) and fluorescent amplified-fragment length polymorphism (FAFLP) analysis. PFGE analysis of S. Abortusequi strains gave 21-27 fragments ranging in size from 33 to 602kb. Although two PFGE profiles were observed among the 20 S. Abortusequi isolates in Japan, the restriction fragments originating from the chromosome were common between the two profiles. The similarity index of the two profiles was 90.9%, while those between Japanese and five other S. Abortusequi strains were 29.8-37.5%. On the other hand, FAFLP analysis of S. Abortusequi strains generated 64-67 amplified fragments ranging in size from 100 to 400bp. One polymorphic fragment was observed among the 20 S. Abortusequi isolates in Japan. These data indicate the close relation of this agent in Japan. S. Abortusequi strains sharing a common ancestry might have been conserved in Japan.