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排序方式: 共有264条查询结果,搜索用时 31 毫秒
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2.
Yamazaki T Kobayakawa S Yamagata K Abe K Baba T 《The Journal of reproduction and development》2007,53(5):1035-1041
To elucidate the molecular dynamics of HP1beta in mouse preimplantation embryos, we examined the localization, dynamics, and mobility of HP1beta in the (pro)nucleus by live cell imaging. Time-lapse observation revealed that the chromatin association of HP1beta is regulated in a cell cycle-dependent manner. HP1beta was localized in the interphase nucleus and was dynamically dissociated from the nucleus during the metaphase stage. The HP1beta assembly and clustered heterochromatin structure were both found in the nuclei of 2-cell and later-stage embryos. Moreover, fluorescent recovery after photobleaching analysis implied that HP1beta is more freely mobile in the pronucleus of the 1-cell embryo than in the 4-cell nucleus. These results suggest that the chromatin configuration may be regulated by the stability and mobility of chromatin-associated proteins including HP1beta during early embryonic stages. 相似文献
3.
Hiroharu Murakami Seiya Tsushima Takayuki Akimoto Yukiko Kuroyanagi Yoshihiro Shishido 《Soil Science and Plant Nutrition》2013,59(8):1307-1311
The effect of the plowing of clubbed roots of cracifers on the population of Plasmodiophora brassicae in soil was quantitatively studied by measuring the number of resting spores produced in the diseased plants. Though the mean number of resting spores per diseased plant increased with the increase of the disease severity, it remained almost identical for the disease severity classified into category 3 among host species and cultivars tested. Mean number of resting spores per diseased plant ranged from 9.3 to 10.9 (log) regardless of the value of the disease index. When the number of resting spores in soil was calculated based on these data and plant cultivation methods, the values were equivalent to 4.8-6.4 resting spores g-1soil (log)where clubroot disease occurred severely. The value of the disease index of Chinese cabbage plants grown in the pots where clubbed roots of initially grown plants had been plowed into soil (plowing plot) was higher than that in the pots where no plants had been grown (control plot) and where the clubbed roots of initial plants had been removed (removal plot). Though the number of resting spores of P. brassicae in soil decreased by 14% of the inocoKum concentration immediately after the inoculation, the number of spores after the first cultivation in the removal plot was similar to that in the control plot. On the other hand, the number of resting spores in the plowing plot increased significantly compared with that in the control plot. The plowing of clubbed roots into soil resulted in the increase of the population of P. brassicae and disease severity of clubroot in subsequent cultivation in the field. The results corresponded to the values estimated based on the number of resting spores in soil in relation to each value of the disease index. 相似文献
4.
Shinsuke MORI Akira KAWASAKI Satoru ISHIKAWA Tomohito ARAO 《Soil Science and Plant Nutrition》2009,55(2):294-299
Radioisotope techniques are well known as methods for evaluating symplastic ion absorption in roots. In the present study, a new method for evaluating symplastic cadmium (Cd) absorption in plant roots was developed using the enriched isotopes 113 Cd and 114 Cd. Seedlings of Solanum melongena were exposed to an enriched isotope solution of 113 Cd at 25°C for 30 min. The roots were excised from each seedling and were then immersed in a cold buffer solution without Cd at 2°C for 120 min to suppress the metabolic activity of the roots. Finally, the roots were treated with a cold buffer solution containing enriched stable isotope 114 Cd at 2°C for 120 min, whereby the apoplastically bound 113 Cd was desorbed. We tested the validity of our method for evaluating symplastic Cd in roots compared with the conventional method based on differences in the amount of Cd absorbed at 2°C and 25°C using unlabeled Cd. There was no difference in the symplastic Cd content of the roots between the two methods. These results indicate that it is possible to evaluate the symplastic Cd content in roots using the enriched isotopes 113 Cd and 114 Cd. 相似文献
5.
Akihiro Okamura Yoshiaki Yamada Noriyuki Horie Tomoko Utoh Naomi Mikawa Satoru Tanaka Katsumi Tsukamoto 《Fisheries Science》2008,74(3):642-648
ABSTRACT: The effects of silvering state of wild female Japanese eels Anguilla japonica on the success of induced maturation and the following spawning were examined. Thirty-eight females, collected in Mikawa Bay, were divided into four stages based on their silvering state: yellow (Y1), late-yellow (Y2), silver (S1) and late silver eels (S2). Despite injections of salmon pituitary extract (SPE) through the standard technique, Y1 and Y2 eels did not respond to the treatment with undeveloped gonad (gonad-somatic index [GSI]: 0.3–0.9), and all these females died by 5 weeks, probably due to an abnormal physiological condition. Most S1 (81%) and S2 eels (100%) matured completely (GSI: 17.8–51.4), and finally spawned successfully (69% for S1, 89% for S2). S2 eels fully matured with oocytes of over 750 μm in diameter by significantly smaller number of injections of SPE (5–6 times) than the case of S1 eels (6–8 times). The amount of eggs released by S2 eels (0.65 ± 0.11 g/fish per body weight [BW]) was significantly larger than those by S1 eels (0.54 ± 0.09 g/fish per BW). There was no difference in fertilization and hatching rates between eggs released by S1 eels and those of S2 eels. These results indicate that the success of induced maturation and spawning in wild female Japanese eels depends on their silvering state, and matured eggs can be obtained efficiently through the use of S2 eels rather than other stages. 相似文献
6.
Hatsugai N Kuroyanagi M Yamada K Meshi T Tsuda S Kondo M Nishimura M Hara-Nishimura I 《Science (New York, N.Y.)》2004,305(5685):855-858
Programmed cell death (PCD) in animals depends on caspase protease activity. Plants also exhibit PCD, for example as a response to pathogens, although a plant caspase remains elusive. Here we show that vacuolar processing enzyme (VPE) is a protease essential for a virus-induced hypersensitive response that involves PCD. VPE deficiency prevented virus-induced hypersensitive cell death in tobacco plants. VPE is structurally unrelated to caspases, although VPE has a caspase-1 activity. Thus, plants have evolved a regulated cellular suicide strategy that, unlike PCD of animals, is mediated by VPE and the cellular vacuole. 相似文献
7.
Kawai S Matsumoto J Aikawa M Matsuda H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(5):629-631
In the present study, we investigated plasma levels of soluble intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) in seven Japanese macaques (Macaca fuscata) infected with Plasmodium coatneyi. Concentrations of sICAM-1 and sVCAM-1 were significantly elevated in the severe phase; the levels were maximally increased up to six times and three times those before infection, respectively. We subsequently examined kinetic profiles of sICAM-1 and sVCAM-1 concentration in plasma obtained from two infected monkeys. Both infected monkeys had markedly increased levels of these adhesion molecules when they exhibited severe clinical signs correlated with rapid increase in parasitemia. These results suggest that the elevation of levels of sICAM-1 and sVCAM-1 is a critical step in the pathogenesis of severe malaria in vivo. 相似文献
8.
Katamoto H Yamada Y Nishizaki S Hashimoto T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(9):1001-1002
The influence of the season on serum vitamin A, E and beta-carotene concentrations was studied in Japanese Black breeding cattle. Blood samples were collected from 13 cows once a month for a year to determine the serum vitamin concentrations. Mean serum concentrations (+/- SE) of retinol, alpha-tocopherol and beta-carotene were 21.3 +/- 0.5 microg/dl (range 9.9 to 44.9), 215.9 +/- 8.0 microg/dl (range 59.7 to 551.6) and 67.3 +/- 5.1 microg/dl (range 10.6 to 425.2), respectively. All these concentrations were lower than the recommended levels. Serum retinol and alpha-tocopherol concentrations in summer were lower than those in winter. These results suggest that the vitamin A, E and beta-carotene status of Japanese Black breeding cows is inadequate, and feeding high quality forages or dietary vitamin supplementation during summer should be recommended. 相似文献
9.
Lens formation in the absence of optic cup in rat embryos irradiated with soft X-ray 总被引:1,自引:0,他引:1
In order to investigate the effect of soft X-ray irradiation on ocular development, pregnant rats were exposed to a single 12.5 Gy irradiation on embryonic day 9 (ED 9). The embryos obtained by laparotomy on ED 12 and 21 were examined for ocular abnormalities under a binocular stereo-microscope and a light microscope. The ED 12 embryos were stained with osmium tetroxide to facilitate the observation. The stereo-microscopic examination on ED 12 and 21 revealed various types of ocular abnormalities characterized primarily by aplasia or hypoplasia of the optic cup and invaginated lens placode. The light microscopic examination further confirmed these findings histomorphologically, and the hypoplastic abnormalities were classified into three types: (1) hypoplasia of the optic cup and invaginated lens placode, (2) complete malformation of the optic cup and hypoplasia of the invaginated lens placode, and (3) complete malformation of the optic cup and invaginated lens placode. Because the lens was formed in the complete absence of the retina, the development and differentiation of the retina and lens do not seem to be tightly synchronized. Thus, this sequential analysis on ocular abnormalities during the early stage of development supports the notion that the presence of the retina is not always necessary for the development of the lens. 相似文献
10.
Nagase N Sasaki A Yamashita K Shimizu A Wakita Y Kitai S Kawano J 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(3):245-250
From April 1999 to December 2000, a survey was made on the distribution of Staphylococcus species on the skin of 7 kinds of animals and humans. Staphylococci were isolated from 12 (100%) of 12 pigs, 17 (89.5%) of 19 horses, 30 (100%) of 30 cows, 73 (90.1%) of 81 chickens, 10 (40%) of 25 dogs, 23 (76.7%) of 30 laboratory mice, 20 (52.6%) of 38 pigeons, and 80 (88.9%) of 90 human beings. The predominant staphylococci isolated from a variety of animal species were novobiocin-resistant species, S. xylosus and S. sciuri regardless of the animal host species. The novobiocin-resistant species including S. xylosus and S. sciuri were only occasionally isolated from human skin. The predominant staphylococci found on human skin were novobiocin-sensitive species, S. epidermidis (63.8%), followed by S. warneri (28.8%) and S. hominis (13.8%). The results suggest that the staphylococcal flora inhabiting animal skin are different from those of human skin in regard to the predominant species isolated. In this study, we used pulsed-field gel electrophoresis to examine the chromosomal polymorphisms of S. epidermidis isolated most frequently from human skin. Strains of S. epidermidis showed the greatest genomic diversity in their fragment patterns. 相似文献