An acetylenic alkaloid from the calcareous sponge Leucetta sp     

Hermawan I  de Voogd NJ  Tanaka J 《Marine drugs》2011,9(3):382-386

A new acetylenic alkaloid was isolated from the sponge Leucetta sp. The structure was established by analyzing spectroscopic data. The alkaloid showed cytotoxicity IC₅₀ 2.5 μg/mL against NBT-T2 cells.  相似文献   

Diurnal variation of tryptic activity in larval stage and development of proteolytic enzyme activities of malabar grouper (Epinephelus malabaricus) after hatching     

Aya Fujii  Yuko Kurokawa  Shin''ichiro Kawai  Kenzo Yoseda  Shigeki Dan  Aya Kai  Masaru Tanaka   《Aquaculture (Amsterdam, Netherlands)》2007,270(1-4):68-76

Diurnal variation in tryptic activity and developmental changes in proteolytic enzyme activities of malabar grouper larvae (Epinephelus malabaricus) were examined. Five different groups were prepared for the experiment of diurnal variation of tryptic activity in larvae: larvae were fed Thai-type rotifers Brachionus rotundiformis from the time of mouth opening, fed rotifers from 6 h after mouth opening, 12 h, 24 h and not fed rotifers (starved control). The experimental tanks were placed in temperature-controlled baths at 28 °C under 24 h light. Developmental changes in proteolytic activity of trypsin and pepsin-like enzyme were measured from hatching to 57 days after hatching (DAH).

The tryptic activity of all fed groups showed the same pattern, and the diurnal variation of tryptic activity was clearly observed from 3 to 6 DAH. The highest tryptic activities were found at 19:00, and the activities were lowest from 01:00 to 07:00. In contrast, that of non-fed larvae was low compared to the fed groups, however the diurnal variation of tryptic activity was shown same tendency to the fed groups. Interestingly, both groups (fed and non-fed) were exhibited a circadian rhythm under the 24 h light conditions and delaying of first-feeding. Tryptic activity of larvae notably increased from 40 to 45 DAH and markedly decreased at 52 DAH. In contrast to the tryptic activity, that of pepsin-like enzyme clearly increased from 47 to 51 DAH. The results suggest that a functional change of protein digestion occurs from 40 to 50 DAH related with metamorphosis in malabar grouper. These results could contribute to determining appropriate feeding schedules, such as feeding time, frequency and optimal time to change food items, in mass-scale production of the present species.  相似文献   

Sequence and expression analyses of cholecystokinin (CCK) precursor cDNA in the Japanese flounder (Paralichthys olivaceus)     

T. Suzuki  T. Kurokawa  D.C. McVey 《Fish physiology and biochemistry》1999,21(1):73-80

A cholecystokinin (CCK) precursor cDNA was identified from the brain of Japanese flounder (Paralichthys olivaceus). The full open reading frame was obtained by a combination of 3 and 5 RACE amplifications and encodes the 136 amino acid precursor. The Japanese flounder CCK-8 amino acid sequence was shown to be Asp-Tyr-Leu-Gly-Trp-Met-Asp-Phe, in which the methionine in the third position of mammalian and amphibian CCK-8 was replaced with leucine, similar to what has been shown in the goldfish. By RT-PCR, expression of CCK precursor mRNA was detected from the brain, stomach and proximal intestine. Whole mount in situ hybridization detected CCK mRNA in scattered cells in the proximal intestine epithelium as well as cerebrum of brain, suggesting the central nervous system and digestive system express the same CCK precursor mRNA.  相似文献   

Random sequencing of genomic DNA of <Emphasis Type="Italic">Photobacterium damselae</Emphasis> subsp. <Emphasis Type="Italic">piscicida</Emphasis>     

Hiroaki?Naka  Ikuo?Hirono  Ken?Kurokawa  Takashi?AokiEmail author 《Fisheries Science》2005,71(6):1209-1216

ABSTRACT:   Random sequencing of the genomic DNA of Photobacterium damselae subsp. piscicida was conducted. The sequences were assembled into 930 contigs. The total length of these contigs accounts for 37.5% of the genome of P. damselae subsp. piscicida. The contigs contain 2055 open reading frames (ORFs) that have homology with genes in the GenBank database. Furthermore, some of the ORFs have homology with reported virulence related genes, and are classified as encoding colonization factors, exotoxin, and lipopolysaccharide (LPS). Thirty-seven ORFs have homology with colonization factors. In those colonization factors, 27, three, and four ORFs have homology with polar flagellar-related genes, capsule-related genes, and others (accessory colonization factors, superoxide dismutase (Cu-Zn), MshA biogenesis protein, and heme receptor genes), respectively. Five ORFs have homology with exotoxin-related genes (2 hemolysin, phospholipase, hyaluronidase, lysophospholipase L2 genes). Further, six ORFs have homology with LPS-related genes.  相似文献   

Quantitative trait loci for rice blast resistance detected in a local rice breeding population by genome-wide association mapping     

Hiroshi Shinada  Toshio Yamamoto  Hirokazu Sato  Eiji Yamamoto  Kiyosumi Hori  Junichi Yonemaru  Takashi Sato  Kenji Fujino 《Breeding Science》2015,65(5):388-395

Plant breeding programs aim to develop cultivars with high adaptability to the specific conditions in a local region. As a result, unique genes and gene combinations have been accumulated in local elite breeding populations during the long history of plant breeding. Genetic analyses on such genes and combinations may be useful for developing new cultivars with more-desirable agronomic traits. Here, we attempted to detect quantitative trait loci (QTL) for rice blast resistance (BR) using a local breeding rice population from Hokkaido, Japan. Using genotyping data on single nucleotide polymorphisms and simple sequence repeat markers distributed throughout the whole genomic region, we detected genetic regions associated with phenotypic variation in BR by a genome-wide association mapping study (GWAS). An additional association analysis using other breeding cultivars verified the effect and inheritance of the associated region. Furthermore, the existence of a gene for BR in the associated region was confirmed by QTL mapping. The results from these studies enabled us to estimate potential of the Hokkaido rice population as a gene pool for improving BR. The results of this study could be useful for developing novel cultivars with vigorous BR in rice breeding programs.  相似文献   

Optimal sampling strategies for evaluating fruit softening after harvest in apple breeding   总被引：1，自引：0，他引：1  

Hiroshi Iwanami  Makoto Ishiguro  Nobuhiro Kotoda  Sae Takahashi  Junichi Soejima 《Euphytica》2005,144(1-2):169-175

Environmental variance components associated with year, tree, and harvest date were estimated for fruit softening after harvest in apple (Malus × domestica Borkh.) to determine their relative importance and design optimum sampling strategies to discriminate genotypes in apple breeding. Fruit were stored after harvest under 20± 2 ^∘C and 80± 5%RH. Softening was evaluated by adapting the change in firmness during storage to a linear regression and defining the regression coefficient as the softening rate. Environmental variances associated with genotype × year interaction, among trees, year × tree interaction, and among harvest dates were all very small, namely, 2.7, 0.1, 5.2, and 5.7%, respectively, to the total variance obtained from the analysis of variance for the softening rate. The variance associated with genotype, at 57.3%, was very large. On the basis of the number of fruit necessary for firmness measurements, two times harvest is an efficient strategy to determine a genotype mean for the softening.  相似文献   

Evaluation of Premature Mortality Caused by Exposure to PM2.5 and Ozone in East Asia: 2000, 2005, 2020     

Amin Nawahda  Ken Yamashita  Toshimasa Ohara  Junichi Kurokawa  Kazuyo Yamaji 《Water, air, and soil pollution》2012,223(6):3445-3459

The aim of this study is to assess the premature mortality risks caused by exposure to particulate matter with aerodynamic diameter less than 2.5???m (PM_2.5) and ozone elevated concentrations for the years?2000, 2005, and 2020 in East Asia. The spatial distributions and temporal variations of PM_2.5 and ozone concentrations are simulated using the Models-3 Community Multiscale Air Quality Modeling System coupled with the Regional Emission Inventory in Asia. The premature mortality risks caused by exposure to PM_2.5 and ozone are calculated based on a relative risk (RR) value of 1.04 (95?% confidence interval (CI): 1.01?C1.08) for PM_2.5 concentrations above the annual mean limit of 10???g?m^?3 taken from the World Health Organization?CAir Quality Guideline and based on a RR value of 1.003 (95?% CI: 1.001?C1.004) for ozone concentration above 35?ppb of the SOMO35 index (the sum of ozone daily maximum 8-h mean concentrations above 35?ppb). We demonstrate one of the implications of the policy making in the area of environmental atmospheric management in East Asia by highlighting the annual premature mortalities associated with exposure to PM_2.5 concentrations that just meet an annual mean concentration of 10???g?m^?3, as well as ozone concentrations that have a daily zero SOMO35 index in vulnerable places. Our results point to a growing health risk that may endanger human life in East Asia. We find that the effect of PM_2.5 on human health is greater than the effect of ozone for the age group of 30?years and above. We estimate the corresponding premature mortality due to the effects of both ozone and PM_2.5 in East Asia for the years?2000 and 2005 to be around 316,000 and 520,000 cases, respectively. For future scenarios of the year?2020, policy succeed case, reference, and policy failed case, the estimated annual premature mortality rates are 451,000, 649,000, and 1,035,000 respectively.  相似文献   

Lack of exposed ice inside lunar south pole Shackleton Crater   总被引：2，自引：0，他引：2  

Haruyama J  Ohtake M  Matsunaga T  Morota T  Honda C  Yokota Y  Pieters CM  Hara S  Hioki K  Saiki K  Miyamoto H  Iwasaki A  Abe M  Ogawa Y  Takeda H  Shirao M  Yamaji A  Josset JL 《Science (New York, N.Y.)》2008,322(5903):938-939

The inside of Shackleton Crater at the lunar south pole is permanently shadowed; it has been inferred to hold water-ice deposits. The Terrain Camera (TC), a 10-meter-resolution stereo camera onboard the Selenological and Engineering Explorer (SELENE) spacecraft, succeeded in imaging the inside of the crater, which was faintly lit by sunlight scattered from the upper inner wall near the rim. The estimated temperature of the crater floor, based on the crater shape model derived from the TC data, is less than approximately 90 kelvin, cold enough to hold water-ice. However, at the TC's spatial resolution, the derived albedo indicates that exposed relatively pure water-ice deposits are not on the crater floor. Water-ice may be disseminated and mixed with soil over a small percentage of the area or may not exist at all.  相似文献   

Disease resistance and hypocholesterolemia in yellowtail Seriola quinqueradiata fed a non-fishmeal diet     

Masashi Maita  Junichi Maekawa  Koh-ichi Satoh  Kunihiko Futami  Shuichi Satoh 《Fisheries Science》2006,72(3):513-519

ABSTRACT:   The physiology of yellowtail fed a non-fishmeal diet was examined, with a specific interest in the role of taurine in disease resistance and cholesterol metabolism. Decrease of disease resistance in fish fed a non-fishmeal diet was confirmed by mortality due to natural infection with pseudotuberculosis and artificial infection with Lactococcus garvieae . It is suggested that the most important symptoms related to decrease of disease resistance in fish fed a non-fishmeal diet is anemia. Anemia was improved by supplementation with taurine. Significant elevation of relative expression of HMG-CoA reductase mRNA in fish fed a non-fishmeal diet suggests that cholesterol synthesis would be activated and not dysfunctional. Plasma cholesterol of these fish was elevated to the levels of control fish by supplementation of both cholesterol and taurine. These results suggest that hypocholesterolemia observed in fish fed a non-fishmeal diet compared with a fishmeal diet would be caused by insufficient dietary cholesterol and decrease of endogenous cholesterol due to the lack of dietary taurine.  相似文献