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排序方式: 共有441条查询结果,搜索用时 15 毫秒
1.
Eiji Tanaka Chihiro Tanaka Atsushi Ishihara Yasumasa Kuwahara Mitsuya Tsuda 《Journal of General Plant Pathology》2003,69(1):1-6
Aciculosporium take (Ascomycota; Clavicipitaceae) is a causal agent of witches' broom of
bamboo plants. The symptoms of this disease are believed to be induced by plant
hormones, particularly auxins. Indole-3-acetic acid (IAA) was identified in
cultures of this fungus in an l-tryptophan-supplemented liquid medium.
IAA production was confirmed on 30 isolates of A. take from various
hosts and locations at levels up to 1 mg/l. The biosynthetic pathway of
IAA in A. take culture was examined by analyzing intermediate products
and by feeding experiments. The results showed that the indole-3-pyruvic acid
pathway (l-tryptophan → indole-3-pyruvic acid → indole
acetaldehyde → IAA) was the dominant pathway in A. take.
Received: June 3, 2002 / Accepted: July 25, 2002 相似文献
2.
Tomioka I Mizutani E Yoshida T Sugawara A Inai K Sasada H Sato E 《The Journal of reproduction and development》2007,53(4):835-842
The present study was conducted to demonstrate the spindle formation and behavior of chromosomes and microtubules during first division in reconstructed rat embryos produced by somatic cell nuclear transfer (SCNT) with cumulus cell nuclei. To demonstrate the effect of oocyte aging after ovulation on the cleavage of SCNT embryos, micromanipulation was carried out 11, 15 and 18 h after injection of hCG. SCNT oocytes were activated by incubation in culture medium supplemented with 5 microM ionomycin for 5 min followed by treatment with 2 mM 6-dimethylaminopurine (6-DMAP) in mR1ECM for 2-3 h. For immunocytochemical observation, the SCNT embryos were incubated with monoclonal anti-alpha-tubulin antibody and then fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse IgG. Cleavage rates were significantly higher for oocytes collected after 15 and 18 h rather than for those collected 11 h after injection of hCG (56 and 53%, respectively vs. 28%; P<0.05). Premature chromosome condensation occurred before activation of the SCNT oocytes, but adequate spindle formation was only rarely observed. The distribution of microtubules in SCNT embryos after activation was different from those of fertilized and parthenogenic oocytes, i.e., a dense microtubule organization shaped like a ring was observed. Eighteen to 20 h post-activation, most SCNT embryos were in the 2-cell stage, but no nucleoli were clearly visible, which was quite different from the fertilized oocytes. In addition, first division with and without small cellular bodies containing DNA was observed in the rat SCNT embryos in some cases. The present study suggests that reorganization of transferred nuclei in rat SCNT embryos may be inadequate in terms of formation of the mitotic assembly and nucleolar reorganization. 相似文献
3.
Noriyuki Koizumi Atsushi Mori Takuya Mineta Eiji Sawada Keiji Watabe Takeshi Takemura 《Paddy and Water Environment》2017,15(4):723-730
Fecal DNA samples from the red-eared slider and Reeves’ pond turtle, suspected pests of lotus root paddies, were used to identify the plant species eaten by these turtles in order to develop a strategy for rural ecosystem conservation. The fecal samples were obtained from young and adult individuals (mostly female) of both species living in agricultural canals surrounding lotus root paddies in Tokushima Prefecture, Japan. The samples were screened for the presence or absence of DNA from nine plant species using PCR and plant species-specific primers for the rbcL gene of chloroplast DNA. In the red-eared slider, our analysis identified seven plant species in the fecal DNA samples of adults and three plant species in those of young individuals. In Reeves’ pond turtle, our analysis identified two plant species from adult fecal samples and one species from those of young individuals. Thus, adult red-eared sliders consume a greater range of plants than young red-eared sliders or Reeves’ pond turtles. Both turtle species, independently of age, consumed lotus plants and were likely to cause feeding damage to lotus roots. Considering the plant species detected in adult red-eared sliders and these plant habitats, we suggest that this adult turtle is likely to travel between the agricultural canals and the lotus root paddies. These findings will help the development of strategies for preventing damage to lotus roots by these turtles; furthermore, they indicate that fecal DNA analysis will be applicable to investigation of the feeding habits of other animal species. 相似文献
4.
Shiori Fujiwara Yuko Yamaguchi Tsubasa Saito Tomomi Nakazawa Kazutoshi Tamura 《Journal of toxicologic pathology》2022,35(1):99
This case report describes a case of spontaneous pancreatic islet cell carcinoma with vascular invasion in a 110-week-old male F344 rat. Histologically, a pancreatic nodule consisting of tumor cells and many blood-rich vessels, and covered with a fibrous capsule showed local invasion in the capsule and adjacent acinar tissues, encircling a large duct-like structure (DS). The tumor was composed of well-differentiated tumor cells resembling normal pancreatic islet cells, which had small round nuclei and eosinophilic cytoplasm. Mitotic figures were rare. Immunohistochemistry revealed that the tumor cells were positive for insulin. Although endothelial cells were not detected, the DS wall showed cells positive for α-smooth muscle actin and elastic fibers, suggesting that the DS is the pancreatic artery. This is a rare case of islet cell carcinoma consisting of well-differentiated tumor cells with invasion of the pancreatic artery in a rat. 相似文献
5.
日本冲绳岛琉球松林台风干扰后的群落特点 总被引:3,自引:0,他引:3
为阐述亚热带地区琉球松林受到干扰后的演替规律,就日本冲绳地区琉球松人工林在强台风干扰后,林分结构和树种组成特点进行了调查分析。结果表明,琉球松林经台风干扰后演替形成两种群落类型,即琉球松-峨嵋木荷群落和琉球松-峨嵋木荷-蕨类群落;两者在林分结构和树种组成特点方面差异明显。琉球松-峨嵋木荷群落中,出现乔灌树种26种(DBH≥3.0cm),树种多样性指数为2.55,林下植被特别是草本层盖度低,没有蕨类植物分布。而琉球松-峨嵋木荷-蕨类群落中,出现乔灌树种33种,树种多样性指数为3.51,林下植被特别是草本层发育较好,并有大量蕨类植物分布,其盖度达55%。此外,经受干扰的琉球松林出现了大量的较耐荫的常绿阔叶树种,尤其是山茶科和樟科的树种,而没有出现本地天然常绿阔叶林的优势树种壳斗科的栲类(Castanopsis spp.)。充分说明强台风干扰促进了琉球松林向常绿阔叶林演替。 相似文献
6.
Cadmium transport and tolerance in rice: perspectives for reducing grain cadmium accumulation 总被引:10,自引:0,他引:10
In recent decades, numerous studies have attempted to project the impact of hypothesised anthropogenic climate change on rice production. In this study, we offer a comprehensive review of our current understanding related to temperature, CO2, and water-demand parameters in rice growth models. As to future rice yield, night time temperature should be focused in the models as well as day time temperature owing to the contribution of temperature on the night time respiration. Furthermore, although CO2-enhanced photosynthesis is critical for the accurate prediction of rice production in a higher CO2 atmosphere, we found that recent well-developed photosynthesis-stomatal model cannot realize the variation of CO2 stomatal sensitivity with humidity conditions. To estimate water stress under projected climate-change conditions, rice growth model should be required to link with water resource model, which includes natural processes and anthropogenic regulations. The understanding of abilities and limitations in the models is important not only to improve the schemes that models employ, but to also critically review the simulated results. 相似文献
7.
Eiji Tanaka 《Fisheries Science》2014,80(6):1129-1144
The paper compiles a catch history of Japanese eels Anguilla japonica in East Asia and some Japanese relative abundance series. Maximum likelihood estimates of stock abundance of eels have been obtained using the abundance series and various biological parameters, such as growth, maturity and natural mortality. Age- and sex-structured models have been used to express the dynamics of stock abundance, and the Beverton and Holt model has been used to express the relationship between stock and recruitment. Data for estimations are standardized catch per unit effort of commercial fishery for exploitable stock (1954–2006 and 1968–2008) and for glass eel (1954–2010, 1972–2004, and 1973–1997). From the results of the base case scenario of estimations, the estimated stock size of individuals aged ≥1 year was 18.7 thousand tons in 2010, which was 24 % of the carrying capacity. The estimated stock size has recovered since 1990. Maximum sustainable yield was 4,180 tons if only the exploitable stock were utilized, and 266 tons if only the glass eel were utilized. These results and issues relating to estimation and management for reducing the fishery impact on stock are discussed. 相似文献
8.
9.
Pathological observations of feline mast cell tumor 总被引:1,自引:0,他引:1
10.
Enose Y Miyake A Ido E Hayami M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(2):283-286
Human immunodeficiency virus (HIV) infects lymphocytes and macrophages via CD4 and chemokine receptors. In this study, the infectivity of a chimeric simian and human immunodeficiency virus (SHIV) having a CCR5-specific HIV-1 envelope gene was examined. A SHIV strain termed SHIV-JRFL could enter cells via CD4 with a chemokine receptor CCR5, not CXCR4, and the viral replication was suppressed by recombinant human RANTES, one of beta-chemokines. The intravenous inoculation of SHIV-JRFL into two rhesus macaques resulted in a systemic infection, though it was rather weak. During the early infection, the production of RANTES from Con A-stimulated PBMCs of the infected monkeys increased. These results suggested that beta-chemokine has the potential to limit the infectivity of an R5-type SHIV. 相似文献