Predation by neogastropods on <Emphasis Type="Italic">Turbo cornutus</Emphasis> juveniles and other small gastropods inhabiting coralline algal turfs

To understand the effects of predation by gastropods on juveniles of the Japanese spiny turban snail Turbo cornutus, a field survey and laboratory experiments were conducted. The species compositions of the order Neogastropoda inside turfs of articulated coralline algae (ACA) on the east coast of Sagami Bay were surveyed monthly, and the dominant species inside the ACA turfs were identified. Laboratory experiments were conducted to examine the effects of predation by the dominant neogastropods on small gastropods in ACA turfs. Turban snails, which inhabit ACA turfs during their juvenile stages, were predated by two muricid gastropods, Ergalatax contractus and Thais bronni, with the predation rate of E. contractus being significantly higher than that of T. bronni. While E. contractus could also predate two other species of gastropods, Anachis misera and Cantharidus japonicus, the predation rates on these two snails were significantly lower than on T. cornutus. The observed defensive behaviors were different among the three prey species, and the defensive strategy related to the calcified operculum of T. cornutus was not efficient against predation by E. contractus. It is concluded that the predation by E. contractus represents an important factor in the mortality of juvenile turban snails inside ACA turfs.     

Screening of Dried Plant Seed Extracts for Adiponectin Production Activity and Tumor Necrosis Factor-Alpha Inhibitory Activity on 3T3-L1 Adipocytes

To search for dried plant seeds with potent anti-diabetes activity, we conducted a large scale screening for inhibitory activity on tumor necrosis factor-alpha and facilitating activity on adiponectin production in vitro. These activities in 3T3-L1 adipocytes were screened from ethanol extracts of 20 kinds of dried plant seed marketed in Japan. komatsuna (Brassica rapa var. perviridis), common bean (Phaseolus vulgaris L.), qing geng cai (Brassica rapa var. chinensis), green soybean (Glycine max), spinach (Spinacia oleracea L.) and sugar snap pea (Pisum sativum L.) markedly enhanced adiponectin production (11.3 ~ 12.7 ng/ml) but Japanese radish (Raphanus sativus), edible burdock (Arctium lappa L.), bitter melon (Momordica charantia) and broccoli (Brassica oleracea var. italica) did not (0.9 ~ 2.7 ng/ml). All adiponectin-production-enhancing seeds except spinach (2.7 pg/ml) and okra (Abelmoschus esculentus) (6.6 pg/ml) effectively decreased tumor necrosis factor-alpha levels (0.0 pg/ml). We further examined the effects on free radical scavenging activities in the dried seed extracts. Although scavenging activity correlated well with total phenolic content of samples, no correlation was observed with adiponectin production. These results point to the potential of dried seed extracts as a means to modify the activity of tumor necrosis factor-alpha for the adiponectin production.     

Decomposition of organic matter and nutrient mineralisation in wood ant (<Emphasis Type="Italic">Formica rufa</Emphasis> group) mounds in boreal coniferous forests of different age

Wood ants (Formica rufa group) are dominating ecosystem elements of the boreal region due to their wide and abundant occurrence. They collect and concentrate organic material from the surrounding forest floor by building large above-ground mounds. These mounds have higher temperature and lower water content than the surrounding forest floor. We studied how these peculiar environmental conditions affected mass loss and carbon (C), nitrogen (N), phosphorus (P) and potassium (K) mineralisation of organic matter in boreal Norway spruce (Picea abies L. Karst.)-dominated mixed forest stands of four different age classes (5-, 30-, 60-, and 100-year-old) situated in eastern Finland using the litter bag technique. Norway spruce needle litter was incubated in inhabited and abandoned wood ant mounds as well as on the surrounding forest floor. We expected decomposition to be extremely slow due to the dryness of the mounds. Mass losses inside inhabited mounds were lower compared to the surrounding forest floor (on average 30 vs 50% after 2 years) but not as low as we expected, which might be a result of ant and microbial activity in the mounds. Decomposition in the abandoned mounds proceeded similarly as on the forest floor. Nutrient mineralisation proceeded more slowly in the ant mounds than on the surrounding forest floor. Mineralisation occurred for all studied nutrients in the ant mounds, except for N, which net amount remained stable during the years of the experiment. When wood ant mounds are abandoned and their porous and dry structure is no longer maintained by the ants, their decomposition is accelerated, and nutrients may be available for uptake by plants, although the nutrient mineralisation seems still to remain lower compared to the surrounding forest floor. However, eventually the mound material will be decomposed and nutrients mineralised, thus providing a nutrient hot spot increasing the heterogeneity of forest floor nutrient availability.     

Molecular cloning of two Haemaphysalis longicornis cathepsin L-like cysteine proteinase genes.

Immunological protection of mammalian hosts against tick infestation has been proposed as the most sustainable alternative tick control method to the current use of acaricides which has several limitations. The success of this method is dependent on the identification of key molecules for use as tick vaccine antigens. Proteolytic enzymes are involved in a wide range of cellular processes in eukaryotes such as development regulation and nutrition, thus they can be considered as good target antigens for a tick vaccine. In the present study we used primers designed based on the consensus amino acid motifs flanking the conserved active sites C25 and N175 present in all papain-like cysteine proteinases to amplify by polymerase chain reaction, sequence and characterize two Haemaphysalis longicornis tick cysteine proteinase genes. Based on the nucleotide and deduced amino acid sequences, both genes were identified as members of the cysteine proteinase gene family by presence in their sequences of consensus motifs flanking the conserved active sites C25, H150 and N175 that are present in all papain-like cysteine proteinases. Both genes are about 1.2 kb in size and show high sequence homology predominantly to invertebrate cathepsin L-like cysteine proteinases.     

Relationship between retinoic acid receptor alpha gene expression and growth-inhibitory effect of all-trans retinoic acid on canine tumor cells

Retinoids show antitumor effects on human acute promyelocytic leukemia and other tumors via retinoid receptors. In dogs, the role of retinoid receptors in inhibiting tumor development remains unclear. To evaluate the correlation between the degree of expression of retinoic acid receptor alpha (RARalpha) mRNA and the antiproliferative effects of all-trans retinoic acid (ATRA) treatments, expression analysis of RARalpha mRNA and cell growth inhibition assay were performed on 17 established canine tumor cell lines, including 6 mammary gland tumor (MGT) cell lines, 3 osteosarcoma cell lines, 5 melanoma cell lines, and 3 mast cell tumor (MCT) cell lines. Among the cell lines investigated, all 3 MCT cell lines showed high expression of RARalpha, and the most effective cell growth inhibition was observed in ATRA-treated MCT cell lines. However, remarkable antiproliferative effects of ATRA treatments were not observed on other tumor cell lines with moderate or low RARalpha mRNA expression. As a result of the relationship between RARalpha mRNA expression and ATRA treatment with regression analysis, statistically significant correlation was suggested. Furthermore, real-time quantitative polymerase chain reaction analysis of RARalpha was performed on MCT tissue samples of dogs with spontaneous disease, and 5 of 9 tissues showed high expression. These results suggest that ATRA may be an effective antitumor agent for MCT in dogs, and that prior measurement of expression of RARalpha mRNA may be a good indicator of the effectiveness of ATRA treatment.     

Detection of the meq gene in the T cell subsets from chickens infected with Marek's disease virus serotype 1

The meq gene was thought to be only detected in Marek's disease virus serotype 1 (MDV 1) including a very virulent strain, Md5, while L-meq, in which a 180-bp sequence is inserted into the meq open reading frame, is found in other strains of MDV 1, such as CVI 988/R6. However, both meq and L-meq were previously detected by PCR in chickens infected with MDV 1, suggesting that MDV 1 may consists of at least two subpopulations, one with meq, the other with L-meq. To further analyze these subpopulations, we analyzed the time course changes in distribution of these subpopulations among T cell subsets from chickens infected with MDV 1. Both meq and L-meq were detected in CD4+ and CD8+ T cells infected with strain Md5 or CVI 988/R6. The shift in MDV subpopulations from one displaying meq to the other displaying L-meq and/or the conversion from meq to L-meq occurred mainly in the CD8+ T cell subset from Md5-infected chickens. PCR products corresponding to L-meq rather than meq were frequently amplified from the CD8+ T cell subset from CVI 988/R 6 -infected chickens. These results suggest that a dominant subpopulation of MDV 1 changes depending on the T cell subsets, and that L-meq is dominantly present in the CD8+ T cells which play a role in the clearance of pathogenic agents.     

Cloning and characterization of cDNA encoding a prohibitin-like protein from Theileria orientalis

A cDNA clone encoding a prohibitin-like protein (Toprh) was isolated from a piroplasm cDNA library of Theileria orientalis and its nucleotide sequence was determined. An open reading frame, encoding a polypeptide of 278 amino acid residues, was found in Toprh cDNA sequence. An intron of 89 bp was identified when this cDNA clone was compared with the Toprh gene in the genome of T. orientalis. The deduced amino acid sequence of Toprh shares 93.8, 93.1 and 69.1% identities with the prohibitins of T. parva (from chromosome 1), T. annulata (from chromosome 1), and Plasmodium falciparum, (from chromosome 10), respectively. By Western blot analysis, Toprh was found to be expressed in the piroplasm stage of the parasites.     

Identification and characterization of peptides binding to newcastle disease virus by phage display

Three individual peptide sequences, EVSHPKVG, WVTTSNQW, and SGGSNRSP, which have potentials to bind to Newcastle disease virus (NDV), were identified by the biopanning method using phage display technology. The binding specificities of these peptides presented on phages were confirmed by ELISA competition assay using chicken anti-NDV antiserum. The synthetic peptides designed based on these results partially neutralized the infection of NDV in vitro. The peptide-motives identified here have the potential to lead to the identification of novel molecules that inhibit the NDV infection independent of the immune system.     

Random sequencing of cDNA library derived from partially-fed adult female Haemaphysalis longicornis salivary gland

A cDNA library was constructed from salivary glands of partially-fed adult female Haemaphysalis longicornis (hard tick). Randomly selected clones were sequenced and a total of 633 sequences were analyzed by bioinformatic programs. The sequences were grouped into 213 clusters, with each cluster being considered to be composed of mRNAs derived from the same gene or closely related genes. About 36% of the mRNA sequences showed significant similarity to known proteins in the non-redundant protein database by the NCBI blastx program and appeared to be coding for functional predicted proteins, whereas the remaining 64% had no similar sequences. Two thirds of the predicted proteins were annotated as basic cellular proteins (housekeeping proteins). Among the functional predicted protein sequences, other than the housekeeping proteins, several protease inhibitors including anticoagulants, two metalloproteases and a potential immunosuppressive protein could be identified. These proteins may play important roles during tick feeding and could be novel anti-tick vaccine candidates.     

Physiological and physico-chemical changes in green papaya (Carica papaya L. ‘Kaek Noul’) shreds taken from the outer or inner mesocarp

This study compared physiological and physico-chemical changes in shreds of green papaya (Carica papaya L. ‘Kaek Noul’), taken from inner and outer mesocarp tissues, during storage at 7ºC for up to 8 d. Reductions in the flesh firmness of shreds, microstructure, colouration, dry matter content (DMC), and fresh weight (FW) loss, and in the rates of respiration, ethylene production, and enzyme activities were measured. The rapid loss of firmness of green papaya ‘Kaek Noul’ shreds taken from the inner mesocarp was attributed to the larger and more loosely arranged cells of the inner mesocarp compared to the smaller and compact cells of the outer mesocarp. Shreds taken from the outer mesocarp had a higher DMC [6.21–6.77% (w/w)] than those from the inner mesocarp [5.83–6.34% (w/w)] during storage at 7ºC. FW loss was higher for shreds from the inner mesocarp than from the outer mesocarp (0.89–1.12% vs. 0.39–1.00%, respectively). Colour values (h°) were lower at the end of storage for shreds from the inner mesocarp than shreds from the outer mesocarp (104.38° and 111.94°, respectively). Moreover, scanning electron micrographs of shreds from inner mesocarp and outer mesocarp tissues showed that the slower loss of firmness in shreds from the outer mesocarp could be attributed to having smaller and more compact cells, as well as to lower ethylene production by the outer mesocarp. However, this was not related to cellulase activity. This study indicated why processors prefer to use shreds from the outer mesocarp of green papaya.