Confirmation of yessotoxin production by the dinoflagellate <Emphasis Type="Italic">Protoceratium reticulatum</Emphasis> in Mutsu Bay

ABSTRACT:   Yessotoxin (YTX) is a shellfish toxin and its contamination in bivalves has seriously damaged shellfish industries. The biogenetic origin of YTX was identified as the dinoflagellate Protoceratium reticulatum (Claparède et Lachmann) Bütschli collected in New Zealand and Yamada Bay, Iwate in Japan. Scallops cultured in Mutsu Bay, Japan, were frequently contaminated with YTX, however, occurrence of P. reticulatum in this bay and YTX production by the local strains have not been investigated. Eight strains of P. reticulatum , isolated from the bay, were cultured in the laboratory, and analyzed by fluorometric high-pressure liquid chromatography and liquid chromatography/mass spectrometry methods for YTX production and composition. All strains tested were confirmed to produce YTX, and none of them produced known YTX analogs. Toxin amount and composition differed from strain to strain. This result is also confirmation of one of the biogenetic origins of YTX in Mutsu Bay.     

Quantification of lipophilic toxins associated with diarrhetic shellfish poisoning in Japanese bivalves by liquid chromatography-mass spectrometry and comparison with mouse bioassay

ABSTRACT:   Quantification of lipophilic toxins in bivalves associated with diarrhetic shellfish poisoning was investigated by liquid chromatography–mass spectrometry (LC–MS). Using a C8-silica reversed phase column and a mobile phase of aqueous acetonitrile containing 2 mM ammonium formate and 50 mM formic acid, okadaic acid, dinophysistoxin-1, 7- O -palmitoyldinophysistoxin-1, pectenotoxin-1, pectenotoxin-2, pectenotoxin-6, pectenotoxin-2 seco-acid, yessotoxin, and 45-hydroxyyessotoxin in bivalves were quantified by LC–MS in the negative mode. When the crude 90% methanol extracts were analyzed by LC–MS, there were no significant effects from bivalve matrices on the quantification of toxins. More than 200 bivalve samples collected from various production areas in Japan were analyzed by LC–MS. Pectenotoxin-6 and dinophysistoxin-1 were the dominant toxins in scallops and mussels, respectively. Yessotoxin and 45-hydroxyyessotoxin were also detected in both species. Comparison of the quantitative results obtained for these bivalve samples between LC–MS and mouse bioassay indicates that LC–MS is suitable for routine monitoring of lipophilic toxins in Japanese bivalves.     

Development of room-temperature curing aqueous emulsion-type acrylic adhesive I: effect of monomer composition on the initial adhesive strength

For the purpose of developing a new aqueous emulsion-type adhesive for wood or paper use that does not release formaldehyde or volatile organic solvents, a honeymoon-type acrylic adhesive was examined. An adhesive system consisting of acrylic monomers copolymerized with functional monomers and a cross-linking agent was selected for the purposes of increasing initial adhesive strength and ensuring room-temperature curing. The initial adhesive strength increased by the use of cross-linkers such as dihydrazides and also polymeric methylene diphenyl diisocyanate (pMDI). Thus an adhesive with reasonable to good initial adhesive strength and room-temperature curing was obtained. The effect of pMDI on the initial adhesive strength was not significant and decreased when the amount of acrylamide in a copolymer was high.     

低温胁迫和氮素营养对番茄畸形果发生的影响

研究表明,番茄幼苗生长点的碳、氮水平因氮肥的多寡而异,且经低温胁迫之后变化急剧。氮素较多（4 ～8mmol/L）和低温胁迫（3～8℃）,产生畸形果30%左右。氮素较多加之较低温度胁迫（3～5℃）,会显著加重畸形程度,畸形果病情指数达17.5%以上;低氮(2mmol/L)低温胁迫时,产生椭圆果和链斑果较多,合计达到88.7% ～90.6%;中氮(4mmol/L)或高氮(8mmol/L)低温胁迫时,产生窗孔果、顶裂果的比率增大。不同类型的畸形果单果重差异明显。     

Mapping of expressed sequence tag markers with a cDNA-amplified fragment length polymorphism method in Japanese quail (Coturnix japonica)

In our previous study, a Kobe‐NIBS Japanese quail (KNQ) linkage map was constructed mainly using amplified fragment length polymorphism (AFLP) markers. In order to compare chicken and quail chromosomes, we developed expressed sequence tag (EST) markers derived from cDNA‐AFLP fragments and localized these markers on the linkage map. Using a total of 128 AFLP primer combinations, 24 polymorphic bands were obtained between a neurofilament‐deficient mutant quail line male and a muscular disorder quail line female, which were the parents of the KNQ resource family. Nine of the 24 markers were mapped by linkage analysis. These markers were mapped to seven linkage groups, namely 1, 2, 3, 6, 8, 15 and 42. A subsequent homology search using chicken genome sequences strongly suggests that these linkage groups correspond with chicken chromosomes 1, 2, 3, 5, 15, 23 and 26.     

Pinpointing the candidate region for muscular dystrophy in chickens with an abnormal muscle gene

Muscular dystrophies, a group of inherited diseases with the progressive weakness and degeneration of skeletal muscle, contain genetically variable diseases. Though chicken muscular dystrophy with abnormal muscle (AM) has long been known, the gene responsible has not yet been identified. In this study, a resource family for AM was established with 487 F2 individuals and 22 gene markers, including microsatellite and insertion–deletion markers, were developed. The haplotypes were analyzed with these markers for the candidate region of GGA2q described in a previous study. The candidate region was successfully narrowed down to approximately 1Mbp. The region included seven functional genes predicted as the most likely AM candidates.     

In vitro studies of controlling tomato puffiness by growth regulators

Tomato puffiness, which occurs after auxin spray under field conditions, was investigated by using the in vitro fruit culture technique. Tomato flowers were cultured in the medium with HCPA for 3 days to induce parthenocarpy and then transferred to other media containing growth regulators.2,4-D supplemented to the basal medium increased fruit weight and degree of puffiness. It was most influential when applied in the early developmental stage.Chemicals such as CCC, SADH, TIBA, which would lower auxin level in the fruit, counteracted puffiness. CCC did not decrease fruit weight, unlike TIBA and SADH.GA₃ also induced puffiness with extremely poor development of locule tissue, apparently different from auxin-induced puffiness. Gibberellin-induced puffiness could not be corrected by CCC.Although BA slightly promoted fruit growth, the effect on puffiness remained unclear.CCC and BCB treatments to potted plants were also successful in correcting puffiness of auxin-treated fruits.