Photosensitivity in mice caused by pyropheophorbide in the midgut gland of the scallop <Emphasis Type="Italic">Patinopecten yessoensis</Emphasis> observed in diarrhetic shellfish poisoning mouse bioassays

Photosensitivity was observed in the mice used in bioassays of diarrhetic shellfish poisoning. The mice were intraperitoneally injected with the extracts from the midgut glands of cultured scallops Patinopecten yessoensis gathered in early spring in Funka Bay, Hokkaido, Japan. The injections induced atypical symptoms in the mice within 24 h. The symptoms included piloerection, substantial eye discharge, swelling of the ears and head, and ear scratching. They were similar to those reported in studies of photosensitivity caused by pyropheophorbide in the midgut glands of abalones, which are herbivorous gastropods. The problematic scallops also accumulated a large amount of pyropheophorbide-a. The amount determined with high-performance liquid chromatography was 300–530 μg per 1 g of the homogenate of the midgut glands. The dose of pyropheophorbide sufficient to cause photosensitivity in a mouse is estimated to be 0.99–2.3 mg per mouse with 20-g body weight. Moreover, comparative tests in mice showed that the onset of the symptoms required light and a substantial amount of pyropheophorbide. Therefore, we determined that the observed symptoms were photosensitivity caused by pyropheophorbide. Scallops, which are suspension-feeding bivalves, can accumulate a large amount of pyropheophorbide in the midgut glands depending on the habitat environment.     

Thermal-softening properties and cooling set of water-saturated bamboo within proportional limit

Thermal-softening properties and cooling set of water-saturated bamboo were investigated using stressrelaxation measurements in heating and cooling processes, followed by residual deflection measurement. In the heating process, an obvious decrease in relative relaxation modulus due to thermal-softening of lignin was found at around 60°C. On the other hand, no clear change in the relative relaxation modulus was recognized in the cooling process. After the cooling process, about 65% and 75% of residual set was measured when the specimen was loaded on the epidermis and endodermis side, respectively. Also, residual set depended on the maximum temperature reached in the heating process and the unloaded temperature in the cooling process. From these results, it was deduced that the glass transition of lignin from the rubbery to glassy state is important to fix the deformation. Comparing thermal-softening behavior between bamboo and wood, the relative relaxation modulus of wood decreased steeply at higher temperatures than for bamboo. On the other hand, while about 75% of residual set was also found for wood, almost the same as for bamboo, the recovery of deformation with time was larger for wood than for bamboo. Part of this article was presented at the 53rd Annual Meeting of the Japan Zairyou Society, Okayama, May 2004     

Liquid-chromatographic hybrid triple–quadrupole linear-ion-trap MS/MS analysis of fatty-acid esters of dinophysistoxin-1 in bivalves and toxic dinoflagellates in Japan

Fatty-acid esters of dinophysistoxin-1 (DTX1) in scallops Patinopecten yessoensis, mussels Mytilus coruscus, and toxic dinoflagellate Dinophysis species, collected from Japanese seawater, were analyzed by liquid-chromatography mass spectrometry (LC–MS). Precursor ion monitoring, multiple reaction monitoring for 18 fatty-acid esters of DTX1, and full-scan MS/MS spectra obtained with a hybrid triple–quadrupole linear-ion-trap mass spectrometer showed that 14:0, 16:0, and 16:1 esters were the most abundant 7-O-acyl-DTX1 analogues in bivalves. Fatty-acids esters formed by conjugations at hydroxyl positions other than the 7-position of DTX1 were not detected in the bivalves. DTX1 and okadaic acid-16:0 fatty-acid esters have been reported as the most abundant ester in bivalves in several previous studies; however, we found that 7-O-16:1-DTX1 was the most abundant ester in some mussels in which 16:1 was more dominant than 16:0 in the free fatty-acid profile. Comparison between 7-O-acyl-DTX1 and free fatty-acid profiles in the same bivalve samples suggests that polyunsaturated fatty acids are selectively excluded in enzymatic acylation of DTX1. No 7-O-acyl-DTX1 was detected in any single-cell isolates of D. fortii, D. acuminata, D. mitra, D. norvegica, D. tripos, D. infundibulus, and D. rotundata.     

Growth and water quality for growing-out of juvenile spotted Babylon, Babylonia areolata, at different water-exchange regimes in a large-scale operation of earthen ponds

Growth and water quality for growing-out of juvenile spotted Babylon, Babylonia areolata, were determined at three water-exchange regimes of 7-, 15- and 30-day intervals in large-scale operation of earthen ponds over a 5-month period. Results showed that growth was significantly different among the water-exchange treatments (P < 0.05). The higher body weight gains and shell length increments were observed in snails held at water exchange of 7- and 15-day intervals when compared with those held at water exchange of 30-day intervals. At the end of the experiment, average body weight gains were 4.22, 3.73 and 2.77 g for snails held in water-exchange treatments of 7-, 15- and 30-day intervals, respectively, and 16.63, 15.04 and 13.78 mm for those of shell length increments, respectively, The average final survivals were 83.60, 80.90 and 74.20% for snails held in water-exchange treatments of 7-, 15- and 30-day intervals, respectively. Seawater temperature, salinity, pH, dissolved oxygen, nitrite–nitrogen and ammonia–nitrogen had gradually changed throughout the culture period for all water-exchange treatments. With one exception, the total alkalinity showed the greatest changes during the culture period for all water-exchange treatments ranging from 58.67–97.50 mg/l.     

Amberjack <Emphasis Type="Italic">Seriola dumerili</Emphasis> interleukin-10 negatively suppresses host cell-mediated immunity

Interleukin-10 (IL-10) is an anti-inflammatory cytokine and negatively regulates cell-mediated immunity (CMI) induction by inhibiting cytokine production in type 1 T helper cells. IL-10 genes have been isolated from several fish, and inflammatory cytokine inhibition by IL-10 has been well examined. However, a CMI regulator of IL-10 in fish has not yet been identified. In this study, we cloned the IL-10 gene in amberjack Seriola dumerili and analyzed its function using its recombinant protein (rIL-10). In an in vitro culture experiment, gene expression of inflammatory cytokines was suppressed in leukocytes incubated with rIL-10 compared with cells that only received Nocardia seriolae stimulation. This result suggests amberjack IL-10 has conserved function as an inflammatory cytokine inhibitor. Bactericidal activity of amberjack cells against intracellular pathogen stimulation was decreased in a rIL-10 dose-dependent manner. Furthermore, a significant reduction in the T-bet/GATA-3 ratio was observed in N. seriolae living cell (LC)?+?rIL-10-injected fish. Taken together, these results suggest amberjack rIL-10 suppresses CMI induction both in vitro and in vivo. In addition, the number of IgM⁺ cells among spleen leukocytes in N. seriolae?+?rIL-10-injected fish was higher than in only N. seriolae LC, suggesting that Th2-dominant immunity was induced by adding rIL-10.     

Change in Morphology of Spermatozoa from Dismount Semen during the Breeding Season in Thoroughbred Stallions in Japan

To clarify the physiological changes of sperm morphology in active Thoroughbred stallions during the breeding season, we examined the dismount semen collected from the penile urethra immediately after service. The spermatozoa were analyzed for relationships between the morphology and the stallion’s age or the number of services. Seasonal variation was apparent in the rate of the sperm tail abnormalities, spermatozoa with cytoplasmic droplets, appearance of medusa cells, and sperm head length. Area and width of the sperm head correlated negatively with age (P<0.05). The rate of appearance of medusa cells and the length of the sperm head were positively related to the number of services (P<0.05), and the aspect ratio was negatively related (P<0.01).     

Atmospheric carbon dioxide concentration within a narrow valley in a forested catchment area

In order to investigate atmospheric carbon dioxide (CO₂) accumulation as a cool air pool in hilly terrain, two-dimensional cross-sectional profile of CO₂ concentration and air temperature was measured for 20 days in summer in a 0.8-ha forested catchment. CO₂ concentration was vertically stratified within the valley, with a slight increase near valley sidewalls compared to the valley center, except during the nights under calm or weak ambient wind conditions. In the daytime, the constantly higher CO₂ concentration at the valley bottom was associated with temperature inversion below the canopy, which could suppress vertical CO₂ dissipation and leaded to vertical stratification, and with limited CO₂ consumption by photosynthesis due to insufficient radiation. In the nighttime, the vertical CO₂ concentration difference within the valley was related to strength of temperature inversion, which was correlated with ambient wind speed. On windy nights, relatively warmer ambient wind covered the cooler valley, to form a temperature inversion, thus confining CO₂ to the lower part of the valley. On calm nights, thermal lapse not the inversion layer resulted from radiative cooling of the canopy, and homogeneous CO₂ concentration within the valley was observed. A large CO₂ storage change within the valley was calculated compared with that of forests on flat terrain. In particular, the vertical change of CO₂ storage calculated with only the center of the valley was much larger than the cross-sectional change of CO₂ storage with the entire valley due to excluding of side parts of the valley with lower CO₂ concentration.     

Possibilities of direct introgression from Brassica napus to B. juncea and indirect introgression from B. napus to related Brassicaceae through B. juncea

The impact of genetically modified canola (Brassica napus) on biodiversity has been examined since its initial stage of commercialization. Various research groups have extensively investigated crossability and introgression among species of Brassicaceae. B. rapa and B. juncea are ranked first and second as the recipients of cross-pollination and introgression from B. napus, respectively. Crossability between B. napus and B. rapa has been examined, specifically in terms of introgression from B. napus to B. rapa, which is mainly considered a weed in America and European countries. On the other hand, knowledge on introgression from B. napus to B. juncea is insufficient, although B. juncea is recognized as the main Brassicaceae weed species in Asia. It is therefore essential to gather information regarding the direct introgression of B. napus into B. juncea and indirect introgression of B. napus into other species of Brassicaceae through B. juncea to evaluate the influence of genetically modified canola on biodiversity. We review information on crossability and introgression between B. juncea and other related Brassicaseae in this report.     

Chlorogenic acid supplementation during in vitro maturation improves maturation,fertilization and developmental competence of porcine oocytes

Chlorogenic acid (CGA) is a quinic acid conjugate of caffeic acid, and a phytochemical found in many fruits and beverages that acts as an antioxidant. The present study investigated the effects of CGA supplementation during in vitro maturation (IVM), on in vitro development of porcine oocytes, to improve the porcine in vitro production (IVP) system. Oocytes were matured either without (control) or with CGA (10, 50, 100 and 200 μM). Subsequently, the matured oocytes were fertilized and cultured in vitro for 7 day. The rates of maturation, fertilization and blastocyst formation of oocytes matured with 50 μM CGA were significantly (p < .05) higher than those of the control oocytes. Hydrogen peroxide (H₂O₂) is one of the reactive oxygen species and induces DNA damage in porcine oocytes. When oocytes were matured with 1 mM H₂O₂ to assess the protective effect of CGA, 50 μM CGA supplementation improved the maturation rate and the proportion of DNA‐fragmented nuclei in oocytes compared with control oocytes matured without CGA. Moreover, when oocytes were matured with either 50 μM CGA (control) or caffeic acid (10, 50 and 100 μM), the rates of maturation, fertilization and the blastocyst formation of oocytes matured with 50 μM CGA were similar to those of oocytes matured with 10 and 50 μM caffeic acid. Our results suggest that CGA has comparable effects to caffeic acid, and IVM with 50 μM CGA is particularly beneficial to IVP of porcine embryos and protects oocytes from DNA damage induced by oxidative stress. Supplementation of CGA to the maturation medium has a potential to improve porcine IVP system.