A lectin from an ascomycete mushroom, Melastiza chateri: no synthesis of the lectin in mycelial isolate

Using an affinity adsorbent prepared from L-fucose and starch, a lectin was isolated from fruit bodies of an ascomycete mushroom, Melastiza chateri. The lectin was found to cross-react with antiserum against Aleuria aurantia lectin (AAL), that had been obtained from another ascomycete mushroom. The N-terminal amino acid sequence was analyzed, and among 20 residues 12 were the same as AAL. The molecular mass of the lectin estimated by SDS-PAGE was approximately 40 kDa, which is larger than that of AAL. Mycelial isolate was obtained from M. chateri by germinating ascospores, and identified by analyzing restriction fragment length polymorphisms (RFLP) of DNA. The isolate from M. chateri did not synthesize the lectin, although the isolate from A. aurantia had been known to synthesize AAL as much as the fruit body.     

Isolation and characterization of a novel 2-aminoethylphosphonyl-glycosphingolipid from the sea hare, Aplysia kurodai

A novel phosphonoglycosphingolipid named SGL-I' containing 1 mol of 2-aminoethylphosphonate residue was isolated from the skin of Aplysia kurodai using two silicic acid chromatography systems. Data obtained on methanolysis, permethylation, mild acid hydrolysis, and hydrogen fluoride treatment combined with thin-layer chromatography, gas liquid chromatography, gas chromatography-mass spectrometry, and proton magnetic resonance spectrometry showed that this glycolipid was 3-O-MeGal beta 1----3GalNAc alpha 1----3[6'-O-(2-aminoethylphosphonyl)Gal alpha 1----2]Gal beta 1----4Glc beta 1----1Ceramide. Palmitic acid, octadeca-4-sphingenine and anteiso-nonadeca-4-sphingenine are its major aliphatic components. The new glycolipid has essentially the same structure as another major phosphonoglycosphingolipid in the skin of Aplysia, SGL-II, that contains 2 mol of 2-aminoethylphosphonate residue, suggesting a metabolic relationship between the two.     

S-100 Protein in Clonal Astroglioma Cells Is Released by Adrenocorticotropic Hormone and Corticotropin-Like Intermediate-Lobe Peptide

S-100 protein in clonal GA-1 and C6 rat glioma cell lines was released in serum-free medium supplemented with adrenocorticotropic hormone (ACTH). The induction of S-100 protein release by ACTH was dose-dependent, showing a half-maximal release at about 5 microM, and the S-100 protein concentration in the medium increased sharply within 3 min, but slightly during further incubation. The S-100 protein release was apparently accompanied by a decrease in the membrane-bound form of S-100 protein in the cell. The S-100 protein release was induced not by the ACTH1-24 fragment, which exhibits the known effects of ACTH, but by the ACTH18-39 fragment, which is designated as corticotropin-like intermediate-lobe peptide (CLIP). These results indicate that the C-terminal half of ACTH is responsible for the S-100 protein release. The enhancement of S-100 protein release by ACTH was also observed in normal rat glioblasts. The release induced by ACTH was apparently specific to S-100 protein, because little release of the cytoplasmic enzymes, creatine kinase, and enolase was observed under the same conditions. High concentrations (5 mM) of dibutyryl cyclic AMP or dibutyryl cyclic GMP were also found to induce S-100 protein release; however, catecholamines (epinephrine, norepinephrine, isoproterenol, and dopamine), acetylcholine, and glutamic acid did not enhance the release.(ABSTRACT TRUNCATED AT 250 WORDS)     

Responses of rice to chronic and acute iron toxicity: genotypic differences and biofortification aspects

Background and aims

Iron (Fe) toxicity is a wide-spread stress in lowland rice production. The aim of this study was to differentiate between responses to acute Fe stress during the vegetative stage and chronic Fe stress throughout the growing period.

Methods

Six rice genotypes were tested in a semi-artificial greenhouse setup, in which acute (almost 1500 mg L^?1 Fe in soil solution during the vegetative stage) and chronic (200 to 300 mg L^?1 Fe throughout the season) Fe toxicity were simulated.

Results

Acute Fe stress induced early development of heavy leaf bronzing, whereas moderate symptoms occurred in the chronic treatment throughout the season. Grain yields were only reduced in the chronic stress treatment (?23 %) due to reductions in spikelet fertility, grain number and grain weight. Symptom formation during the early growth stages did not reflect yield responses in all genotypes. Only one genotype showed increases in grain Fe concentrations (24 % in the acute stress and 44 % in the chronic stress) compared to the control.

Conclusions

Contrasting genotypes responded differently to acute and chronic Fe toxicity, and one genotype showed consistent tolerance and the ability to translocate excess Fe into grains. These traits can be useful in the adaptive breeding of rice for Fe toxic environments.

     

Maintenance of Bone Homeostasis by DLL1‐Mediated Notch Signaling

Adult bone mass is maintained through a balance of the activities of osteoblasts and osteoclasts. Although Notch signaling has been shown to maintain bone homeostasis by controlling the commitment, differentiation, and function of cells in both the osteoblast and osteoclast lineages, the precise mechanisms by which Notch performs such diverse and complex roles in bone physiology remain unclear. By using a transgenic approach that modified the expression of delta‐like 1 (DLL1) or Jagged1 (JAG1) in an osteoblast‐specific manner, we investigated the ligand‐specific effects of Notch signaling in bone homeostasis. This study demonstrated for the first time that the proper regulation of DLL1 expression, but not JAG1 expression, in osteoblasts is essential for the maintenance of bone remodeling. DLL1‐induced Notch signaling was responsible for the expansion of the bone‐forming cell pool by promoting the proliferation of committed but immature osteoblasts. However, DLL1‐Notch signaling inhibited further differentiation of the expanded osteoblasts to become fully matured functional osteoblasts, thereby substantially decreasing bone formation. Osteoblast‐specific expression of DLL1 did not alter the intrinsic differentiation ability of cells of the osteoclast lineage. However, maturational arrest of osteoblasts caused by the DLL1 transgene impaired the maturation and function of osteoclasts due to a failed osteoblast‐osteoclast coupling, resulting in severe suppression of bone metabolic turnover. Taken together, DLL1‐mediated Notch signaling is critical for proper bone remodeling as it regulates the differentiation and function of both osteoblasts and osteoclasts. Our study elucidates the importance of ligand‐specific activation of Notch signaling in the maintenance of bone homeostasis. J. Cell. Physiol. 232: 2569–2580, 2017. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals Inc.     

Selective inhibitors of germination of legume seeds in activated sludge compost

Water extracts of the compost produced from activated sludge and coffee residue were found to be selectively inhibitory to seed germination of some legumes. Germination rate of white clover (Trifolium repens L.), red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) seeds were reduced to 2, 29 and 73% of the control, respectively, by water extracts of the compost (20 g l^–1). However, the extracts did not show any inhibition to seed germination of sorghum (Sorghum bicolor Moench), African millet (Eleusine coracana Gaertn.), and Komatsuna (Brassica rapa L.) at the same concentration. The inhibitors in the compost extracts were separated by ion-exchange chromatography and reverse-phase high performance liquid chromatography (HPLC) and the inhibitory activities of seed germination were tested with white clover seeds. Five inhibitors were isolated and identified as 3,4-dichlorophenylacetic acid (3,4-DCP), 3,4-dichlorobenzoic acid (3,4-DCB), 3,4,5-trichlorophenylacetic acid, 3,4,5-trichlorobenzoic acid and mono-2-ethylhexylphthalate by ¹H-, ¹³C-NMR spectroscopy and mass spectrometry. The inhibitory activities of some authentic chemicals of the inhibitors and the related compounds were compared. The results indicated that the main inhibitor in the compost could be 3,4-DCB, which was contained at the concentration of 6.58 mg kg^–1 compost and showed the strongest inhibitory effect on seed germination of white clover among the tested compounds.     

Separation of Lepidopterous Sex Pheromones by Reversed-phase Thin Layer Chromatography and High Performance Liquid Chromatography

Bis(4-chloro-2-ethylphenyl) phenylphosphonate was metabolically transformed into the cor-responding cyclic ester, i.e., 6-chloro-4-methyl-2-phenyl-4/f-1,3,2-benzodioxaphosphorin 2-oxide, in houseflies in vivo. In a p-unsubstituted analog, hydroxylation at the para-position of an ester linkage occurred preferably to alpha-hydroxylation with subsequent cyclization. The cyclization was diastereomerically selective, giving predominantly the cis ester. The biological activities of synthesized and related cyclic esters were similar to but weaker than saligenin cyclic phosphorus esters lacking a methyl group at the 4-position.     

Living in tiny fragments: a glimpse at the ecology of Goodman’s mouse lemurs (Microcebus lehilahytsara) in the relic forest of Ankafobe,Central Highlands,Madagascar

Primates - Habitat fragmentation is one of the major types of anthropogenic change, though fragmented landscapes predate human intervention. At present, the Central Highlands of Madagascar are...