Plant phylogeny drives arboreal caterpillar assemblages across the Holarctic

1. Assemblages of insect herbivores are structured by plant traits such as nutrient content, secondary metabolites, physical traits, and phenology. Many of these traits are phylogenetically conserved, implying a decrease in trait similarity with increasing phylogenetic distance of the host plant taxa. Thus, a metric of phylogenetic distances and relationships can be considered a proxy for phylogenetically conserved plant traits and used to predict variation in herbivorous insect assemblages among co‐occurring plant species.
2. Using a Holarctic dataset of exposed‐feeding and shelter‐building caterpillars, we aimed at showing how phylogenetic relationships among host plants explain compositional changes and characteristics of herbivore assemblages.
3. Our plant–caterpillar network data derived from plot‐based samplings at three different continents included >28,000 individual caterpillar–plant interactions. We tested whether increasing phylogenetic distance of the host plants leads to a decrease in caterpillar assemblage overlap. We further investigated to what degree phylogenetic isolation of a host tree species within the local community explains abundance, density, richness, and mean specialization of its associated caterpillar assemblage.
4. The overlap of caterpillar assemblages decreased with increasing phylogenetic distance among the host tree species. Phylogenetic isolation of a host plant within the local plant community was correlated with lower richness and mean specialization of the associated caterpillar assemblages. Phylogenetic isolation had no effect on caterpillar abundance or density. The effects of plant phylogeny were consistent across exposed‐feeding and shelter‐building caterpillars.
5. Our study reveals that distance metrics obtained from host plant phylogeny are useful predictors to explain compositional turnover among hosts and host‐specific variations in richness and mean specialization of associated insect herbivore assemblages in temperate broadleaf forests. As phylogenetic information of plant communities is becoming increasingly available, further large‐scale studies are needed to investigate to what degree plant phylogeny structures herbivore assemblages in other biomes and ecosystems.

     

Location and dynamics of alpha-tocopherol in model phospholipid membranes with different charges.

Studies were made on the position and dynamics of the OH-group of alpha-tocopherol in phospholipid membranes. There was no difference in the spin-lattice (T1) relaxation times at the 5a-position of alpha-tocopherol labeled with 13C- or C19F3-determined from the nuclear magnetic resonance (NMR) spectra of liposomes positively charged with stearylamine (SA) and negatively charged with dicetylphosphate (DCP). The zeta-potentials of egg yolk phosphatidylcholine (EYPC) liposomes with and without SA or DCP were not affected by incorporation of 20 mol% alpha-tocopherol, though incorporation of 10 mol% ascorbyl-palmitate decreased the zeta-potentials of EYPC and EYPC-SA liposomes. The P==O stretching band (1235 cm-1) of the phosphate group and C==O stretching band (1734 cm-1) of the acyl ester linkage in dimyristoylphosphatidylcholine (DMPC) liposomes, measured by Fourier transform-infrared (FT-IR) spectroscopy, were not changed by incorporation of alpha-tocopherol. These results suggest that no specific interaction occurred between the OH-group of alpha-tocopherol and the polar interfacial region of the bilayer. The dynamic quenching effects of n-(N-oxy-4,4'-dimethyloxazolidine-2-yl)stearic acids (n-NSs) on the intrinsic fluorescence of alpha-tocopherol were in the order 5-NS > 7-NS = 12-NS > 16-NS. Acrylamide, a water-soluble fluorescence quencher with a very low capacity to penetrate through phospholipid bilayers, had very low quenching efficiency. These results indicate that the bulk of the chromanol moiety of alpha-tocopherol is located in a position close to that occupied by the nitroxide group of 5-NS in the membranes and is poorly exposed at the membrane surface.(ABSTRACT TRUNCATED AT 250 WORDS)     

Holocene sedimentary history of some coastal plains in Hokkaido,Japan IV. Diatom assemblages in the sediments from Kushiro moor (2)

Diatom assemblages of sediments obtained from three sites on Kushiro Moor were analyzed to investigate the Holocene sedimentary history. The results showed that: 1) The Takkobu site was originally at the bottom of the paleo-Kushiro Bay, and after-wards the paleo-Takkobu Lagoon developed, became sealed off, and changed to a freshwater lake. The succession to peat moor probably began about 2000 yr B.P. at the Takkobu site. 2) The Tsurui site was originally at the bottom of the paleo-Kushiro Bay, then changed to the paleo-Kushiro Lagoon and became peat moor as a result of the first Holocene regression, which finished about 3600 yr B.P. The site then returned to a brackish lake again, probably due to the second Holocene transgression between 3600 and 3000 yr B.P., thereafter passing through brackish lake and freshwater lake stages, and eventually becaming peat moor at about 2000 yr B.P., 3) At the Chuo site, the second paleo-Kushiro Bay developed again as a result of the second Holocene transgression, which finished about 3000 yr B.P. Thereafter, brackish or freshwater lakes, rivers, and then peat moor developed in the central area of Kushiro Moor. 4) The second marine diatom zone (MD₂ Zone), which indicates the second Holocene transgression, complete by about 3000 yr B.P., is detected only at the Chuo site in the central area of Kushiro Moor.     

Electron-microscopic studies on the threshold value of calcium concentration for the release of storage granules and the acceleration of their degradation in the rat parathyroid gland

Summary To determine both a threshold value of calcium concentration (CC) for the release of storage granules and that for the acceleration of degradation of these granules, the rat parathyroid glands were perfused in situ with HEPES-Ringer solutions containing different concentration of Ca²⁺ for 10 min. With perfusates containing 0.83–1.21 mM Ca²⁺ (equivalent to 8–11 mg/dl serum calcium), the number of type-I storage granules (large core) [NSG-I] and that of type-II storage granules (small core) [NSG-II] remained unchanged. With perfusates containing 0.83 mM Ca²⁺ (7.5 mg/dl) or less, however, both NSG-I and NSG-II decreased remarkably and the former was larger than the latter. On the contrary, with perfusates containing 1.27 mM Ca²⁺ (11.5 mg/dl) or more, NSG-II increased and the ratio of NSG-I to NSG-II was changed reversely. We concluded that a thereshold value of CC required for the release of storage granules may be present between 0.88 and 0.83 mM Ca²⁺ (8 and 7.5 mg/dl) and that a threshold value of CC for accelerating the transformation of type-I granules into type-II, the degradation of storage granules, may be situated at about 1.27 mM Ca²⁺ (11.5 mg/dl). Additionally, it was suggested that both prosecretory and storage granules are not only formed at the innermost Golgi cisterna but also at the trans-Golgi network.     

A monoclonal antibody to the carbohydrate chain on human hepatocellular carcinoma-associated antigen which suppressed tumor growth in nude mice

Summary There have been few reports stating that monoclonal antibody alone inhibits human solid tumor growth in vivo. The present study demonstrated that monoclonal antibody S1 (IgG2a), which recognized the antigenic determinant of the carbohydrate moiety, showed antibody-dependent cell (or macrophage)-mediated cytotoxicity (ADCC or ADMC) in conjunction with murine splenocytes of both BALB/c and athymic mice. In vivo experiments demonstrated that the antibody S1 clearly prolonged the survival of athymic mice which had been inoculated with a human liver carcinoma cell line. In addition, the antibody S1 significantly suppressed the human hepatoma line transplanted s.c. into nude mice. ¹²⁵I-Labeled monoclonal antibody S1 revealed that the antibody accumulated significantly in the tumor mass. Many mononuclear cells were observed surrounding tumor cells when the antibody was given. This model system might be useful for analyzing the ADCC (or ADMC) mechanism in vivo.     

Ca2+-dependent Cl− efflux in tonoplast-free cells ofNitellopsis obtusa

Summary In order to demonstrate the presence of a Ca²⁺-activated Cl^–-channel in theNitellopsis plasmalemma, tonoplast-free cells were prepared and their intracellular Ca²⁺ concentration was modified by internal perfusion. An increase in the Ca²⁺ concentration caused a large Cl^– efflux with a concomitant depolarization of the membrane potential. These changes were for the most part reversible. The critical Ca²⁺ concentration was about 4.0 m. Neither the Cl^– efflux nor the membrane depolarization showed a time-dependent inactivation. A Cl^–-channel blocker, A-9-C (9-anthracenecarboxylic acid) reduced both the Cl^– efflux and the magnitude of the membrane potential depolarization. A small increase in the intracellular Ca²⁺ concentration, which is caused by membrane excitation of tonoplast-free cells is not sufficient to activate this Ca²⁺-dependent Cl^–-channel.     

Life History Studies on the Genus Trillium (Liliaceae) V. Reproductive Biology and Survivorship of Three Declinate-flowered Species

Absract Three pedicellate-declinate-flowered species of Trillium (Liliaceae), T. vaseyi and T. flexipes , were studied for their life history characteristics, e.g., stage class structures of natural populations and reproductive features, including energy allocation to reproductive activities. The populations structures of all three species showed similar depletion structures characterized by a conspicuous decrease of individuals in the small juvenile stages, as was also observed in pedicellate-erect-flowered Trillium species However, with respect to reproductive characteristics, these three declinate-flowered species showed different features from erect-flowered species, although they belong to the same pedicellate-flowered group. That is, these declinate-flowered Trillium species exhibited low seed setting rates of 30% in T. catesbaei , 45% in T. vaseyi and 34% in T. flexipes , suggesting that they possess different mating systems from erect-flowered species which showed high seed setting rates of 50–90%.     

Effects of antipyretics and anticancer drug on human cells at high temperature condition

The effects of antifebriles and anticancer drug on human vascular endothelial cells (HVE) and several cultured human cells were investigated. The HVE were isolated from umbilical cord veins by enzyme treatment and cultured successively in aerated synthetic medium, RPMI-1640, with 20% preclostrum new born calf serum. The presence of factor VIII antigen in the HVE was determined by enzyme-labeled antibody method. Cell count and protein amount were examined at regular intervals. At 3 hour-expose, sulpyrine was more toxic to the cultured cells than aspirin at 37 degrees C. The cytotoxicity of sulpyrine was markedly enhanced at 40 degrees C than at 37 degrees C. However, there was no enhancement in the cytotoxicity of aspirin at 40 degrees C. Cultured HVE and normal human fetal lung (HAIN-55) cells at 37 degrees C were sensitive to sulpyrine, and their sensitivity of the cells to the drug were markedly enhanced when they were incubated at 41 degrees C. In contrast, sensitivity of malignant human cells (HeLa cells) to sulpyrine was not found at 37 degrees C, however sensitivity of the cells to the drug was manifested at 41 degrees C of incubation. There was no effect of 5-fluorouracil (FU) on the growth of HVE and HAIN-55 cells at 41 degrees C, while HeLa cells showed high susceptibility to FU at the same temperature. The results showed the possibility that normal human cells may be sensitive to antifebrile drugs but not to anticancer drug at ordinary and high temperature, whereas malignant human cell may be susceptible to both antifebrile drugs and anticancer drug at high temperature.