Immunohistochemical distribution of viral antigens in pigs naturally infected with porcine teschovirus

A distribution of porcine teschovirus (PTV) antigens in pigs naturally infected with PTV is presented using the method of immunohistochemical examination. In the nervous system, PTV antigens were found in the cytoplasm of neuronal cells and glial cells distributed in the spinal ventral horn and brain stem, and also in the cytoplasm of ganglion cells in the spinal ganglion. No antigens were seen in the cerebral hemisphere. In the nervous system, the distribution of PTV antigens was consistent with lesions characteristic of nonsuppurative encephalomyelitis. In the other examined organ, PTV antigens were observed in bronchiolar epithelial cells in the lung, hepatocytes in the liver, epithelial cells in the tonsils and the myenteric nerve plexus in the small and large intestine.     

Effects of immersion salinity on the food properties of shucked oysters

The effects of immersion salinity on the food properties [water content, salinity, and free amino acid (FAA) content] of shucked oysters were analyzed. Results of a laboratory immersion experiment suggested that the molluscous parts (other than the adductor muscle) swelled in lower salinity and shrank in higher salinity. Higher FAA content was observed in oysters immersed in higher-salinity water. In the adductor muscle, water content increased and FAA content decreased markedly following immersion, regardless of salinity, probably because of intake of immersion fluid and leakage of FAAs across the cut end of the adductor muscle. Immersion salinity ranged from 0.17 to 1.54 % in shucked oyster products on the retail market. Tissue salinity was strongly correlated with immersion salinity (r = 0.904), and tissue water content was correlated negatively with immersion salinity (r = ?0.668). In addition, total FAA and taurine content of oysters were correlated with immersion salinity (r = 0.629 and 0.865, respectively). These results clearly indicate that immersion salinity is an important factor affecting the food components of shucked oysters.     

Thermal stability of the synthetic peptides with the sequence of fish fast skeletal muscle tropomyosin

Tropomyosins from fish skeletal muscle show high amino acid sequence homology, although their thermal stability is clearly different among species. In order to determine the regions that are responsible for the stability of this protein, five synthetic peptides of 30mer were synthesized by Fmoc method, based on the sequence of walleye pollack Theragra chalcogramma fast skeletal muscle tropomyosin, namely, N terminal Met¹-Lys³⁰, the variable region Asp⁸⁴-Leu¹¹³, the middle region Val¹²⁸-Ala¹⁵⁷, the region containing the conservative Cys (Leu¹⁷⁶-Lys²⁰⁵), and C terminal Asp²⁵⁵-Ile²⁸⁴. The thermal stability of these peptides was measured by circular dichroism and differential scanning calorimetry. The helical contents of these peptides were decreased in a temperature-dependent manner, although they showed no clear melting temperature, suggesting that the enthalpy necessary for the complete denaturation of these peptides was low. Peptides Asp²⁵⁵-Ile²⁸⁴ and Asp⁸⁴-Leu¹¹³ showed the highest and second highest α-helical contents, respectively, and the other peptides gave rise to lower α-helical contents.     

Chilling-induced oxidative stress and antioxidant responses in mume (Prunus mume) fruit during low temperature storage

Mume (Prunus mume Sieb. et Zucc.) fruit are harvested and consumed at the mature green stage and have a short storage life at ambient temperature. While cold temperature extends their storage life, improper refrigeration causes severe chilling injury (CI), with fruit suffering more severe CI at of 5–6 °C than at 1 °C. The objective of this research was to determine the involvement of reactive oxygen species (ROS) and antioxidant systems in fruit under chilling stress. ‘Nankou’ fruit were stored at 1 °C or 6 °C for 15 days. Hydrogen peroxide, a preventive ROS, decreased at a slower rate at 6 °C than 1 °C during storage. Malondialdehyde (MDA), an indicator of lipid peroxidation caused by ROS, increased during storage and the contents were higher in fruit stored at 6 °C than at 1 °C. On the other hand, fruit stored at 6 °C had a lower total antioxidant capacity (TAC) and lower activities of antioxidant-related enzymes including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) than at 1 °C. These results indicate that the fruit at 6 °C had more oxidative stress; thus the fruit had more severe CI symptoms than at 1 °C.     

Isolation of collagen from tiger pufferfish parts and its solubility in dilute acetic acid

Collagen was extracted from several tissues (muscle, skin, bone, alimentary tract, gill, fin, hepatopancreas, and air bladder) of the tiger pufferfish Takifugu rubripes, and the content and solubility of the collagen extracted from each tissue were examined. Collagen content in ordinary muscle was 0.95 ± 0.07 % of wet tissue, which is lower than that reported for other fish species even though tiger pufferfish meat has a tough texture. The solubility of collagen extracted from the muscle and skin was relatively high, and collagen accounted for 47.2 ± 7.8 and 70.8 ± 8.1 % of wet tissue, respectively. In contrast, the solubility of the collagen extracted from bone was the lowest of all the tissues examined, being only 5.7 ± 0.8 % of total wet tissue. The extent of hydroxylation of proline and lysine residues was also examined. In most tissues, the extent of hydroxylation of the lysine residue in insoluble collagen was higher than that of acid-soluble collagen, indicating that hydroxylysine contributes to the stability of collagen. This is the first report of collagen contents, solubility, and extent of hydroxylation of proline and lysine residues in collagen extracted from different tissues of one organism. It is possible that hydroxylysine-derived collagen cross-links play a critical role in the stability of collagen in dilute acetic acid.     

Isolation and functional analysis of the CjNdly gene, a homolog in Cryptomeria japonica of FLORICAULA/LEAFY genes

We report the isolation and characterization of CjNdly, a homolog in Japanese cedar (Cryptomeria japonica D. Don) of the FLORICAULA/LEAFY (FLO/LFY) genes. We determined the entire nucleotide sequence of CjNdly, including short 5'- and 3'-untranslated regions. The deduced amino acid sequence was similar to those of the products of the FLO/LFY genes from other species. The nucleotide sequence showed the closest homology to that of the NEEDLY gene in Pinus radiata D. Don. Although no proline-rich region has been reported previously in homologous gene products from gymnosperms, we found such a region at the amino-terminal end of the deduced amino acid sequence encoded by CjNdly. We detected the expression of CjNdly in both reproductive and vegetative tissues and organs of C. japonica. Heterologous expression of CjNdly in transgenic tobacco plants induced precocious flowering of regenerating shoots on agar-solidified medium and flowers with an abnormal phenotype, namely, petal-like stamens. Our findings suggest that the CjNdly gene may have important roles in flower development in Japanese cedar, resembling those of its angiosperm homologs.     

Mutation induction with ion beam irradiation of lateral buds of chrysanthemum and analysis of chimeric structure of induced mutants

We compared the effects of ion beam and gamma ray irradiation on mutation induction in axillary buds of chrysanthemum, and analyzed the chimeric structure of the resulting mutants. Axillary buds were irradiated with carbon ions at 2 Gy (mean linear energy transfer 122 keV/μm), helium ions at 10 Gy (mean 9 keV/μm), and gamma rays at 80 Gy, all of which have the similar effects on survival. The lower five nodes of the shoots elongating from the irradiated buds were cut one by one, and new shoots were allowed to grow from the axillary buds. This procedure was repeated twice, and flower color mutation was investigated. Chimeric structure was analyzed by comparing the flower color of mutants to that of plants regenerated from the roots. Flower color mutants emerged at a high frequency (17.4–28.8%), and there were no significant differences in the mutation frequency between the treatments. All the flower color mutants induced with gamma rays were periclinal chimeras. In contrast, some mutants obtained with ion beams had the same flower color as that of the plants derived from the roots. This suggests that they were solid mutants, where both LI and LIII tissues were derived from the same mutated cell. Solid mutants were also obtained when irradiated with 5 Gy of helium ions, which had less effect on survival and mutation than other treatments. Factors for obtaining solid mutants only with ion beams are also discussed.     

Miticidal pyrethroids having an isobutyranilidoxime ether skeleton

Isobutyranilidoxime meta-phenoxybenzyl ethers and related compounds were synthesized. Their insecticidal activities measured against Periplaneta americana by injection were lower than that of phenothrin by factors of at least 1/60. However, some compounds were comparable to or only slightly less potent than phenothrin and tetramethrin in miticidal activity tested by a contact method against Dermatophagoides farinae, D. pteronyssinus and Tyrophagus putrescentiae. © 1998 SCI     

Silkworm recombinant bovine zona pellucida protein 4 (bZP4) as a potential female immunocontraceptive antigen; impaired sperm-oocyte interaction and ovarian dysfunction

Porcine zona pellucida proteins (ZPs) have been utilized as female immunocontraceptive antigens. The purpose of this study was to explore the potential use of silkworm recombinant bovine ZP4 as an alternative. When the protein was injected with monophosphoryl lipid A (MPL) – an immuno-stimulative agent – into two female goats, marked elevation of the anti-ZP4 titer was detected. Application of the purified specific IgG to a porcine in vitro fertilization system reduced the sperm penetration rate. In one goat, the cyclic profile of serum progesterone disappeared as the anti-ZP4 titer increased. Histological examination of the ovaries revealed degeneration of antral follicles with sparse infiltration of inflammatory cells in the theca, indicating that autoimmune oophoritis had been induced. Together, the present results suggest that recombinant ZP4 disturbs fertilization and exerts a pathogenic effect on follicle development in goats, thus indicating its potential as a female immunocontraceptive antigen.     

Cytological study of a male-sterile Cryptomeria japonica that does not release microspores from tetrads

To determine the mechanism of male-sterility Cryptomeria japonica tree Shindai3, the process of microspore development was observed under light and fluorescence microscopy. Microspore development in the Shindai3 was normal until the tetrad stage, but separation of the microspores from the tetrads was not observed even after callose had been degraded. In contrast to the microspore stage in a male-fertile tree, amorphous substances were observed around tetrads in the Shindai3, and the amount of the amorphous substance increased from the middle of November to the middle of December. The substances are hypothesized to prevent the separation of individual microspores from tetrads by inducing adhesion between microspore cells within the tetrad or enclosing the tetrads. The form of the tetrads in the Shindai3 was maintained until just before the pollen dispersal season, but they ultimately degenerated. The results of this study indicate that the mechanism causing male sterility in Shindai3 differs from that previously reported for other male-sterile trees of C. japonica.