Spindle formation and microtubule organization during first division in reconstructed rat embryos produced by somatic cell nuclear transfer     

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   

Artificially induced tetraploid masu salmon have the ability to form primordial germ cells     

Suzu Sakao  Takafumi Fujimoto  Terumasa Kobayashi  Goro Yoshizaki  Etsuro Yamaha  Katsutoshi Arai 《Fisheries Science》2009,75(4):993-1000

Diploid gametes generated with tetraploid animals are a stepping stone to improving chromosome manipulation techniques. However, artificially induced tetraploid individuals generally die soon after hatching. Diploid gametes could be induced by in vivo cultures of tetraploid primordial germ cells (PGCs) through germ-line chimera. In the present study, characteristics of PGCs were studied in inviable tetraploid masu salmon, Oncorhynchus masou. Histological observation of tetraploid embryos revealed that the same or smaller numbers of PGCs were observed and they migrate into the genital ridges as did diploid PGCs during gonadogenesis. By whole-mount in situ hybridization using vasa messenger RNA (mRNA), 4–35 vasa-positive signals were detected in a pair of genital ridges of tetraploids. By cytological observation of genital ridge cell suspensions, several large round cells were observed, some of which extended pseudopodia. They also contained large nuclei and round granules in their cytoplasm, characteristics of PGCs. As the results suggest that inviable artificial tetraploids have PGCs, we expect to achieve diploid gamete production through surrogate propagation and tetraploid fish production.  相似文献   

Isolation of Neospora caninum from the brain of a naturally infected adult dairy cow   总被引：1，自引：0，他引：1  

Sawada M  Kondo H  Tomioka Y  Park C  Morita T  Shimada A  Umemura T 《Veterinary parasitology》2000,90(3):247-252

Neospora caninum was isolated from the brain of a 2-year-old dairy cow that had aborted confirmed N. caninum-infected fetuses on two occasions. The cow had an indirect fluorescent antibody titer of 1:1600 to N. caninum. The cow was killed 24 days after its second abortion and the brain was bioassayed for N. caninum in nude mice. Multifocal areas of perivascular cuffing and glial nodules were observed in the cerebrum and mesencephalon of the cow, but N. caninum was not identified in histological sections of the brain. All three nude mice inoculated with brain homogenate of the cow, developed emaciation and paralysis. Microscopical examination of the nude mice revealed systemic N. caninum infection with demonstrable tachyzoites in various organs. The parasites isolated from fresh mouse brain were transferred successfully into Vero cell cultures. PCR procedure on the purified tachyzoites obtained from the Vero cell cultures amplified the specific DNA sequence for N. caninum.  相似文献   

Root growth enhancement by rhizospheric aluminum treatment in Quercus serrata Thunb. seedlings     

Rie Tomioka  Asayo Oda  Chisato Takenaka 《Journal of Forest Research》2005,10(4):319-324

This article discusses the effect of aluminum on root growth of Querucus serrata Thunb. In a 9-week hydroponics experiment, the effects of various concentrations (0 to 5.0 mM) of Al on root growth were examined. Results revealed that root biomass increases with the increase in Al concentration up to 2.5 mM, and then it tended to decrease. In the next experiment, the effects of H⁺ and Al³⁺ on roots were compared in a 4-week hydroponics experiment using three treatment solutions: control (pH 6.0), −Al (without Al, pH 3.5), and +Al (with 2.5 mM Al, pH 3.5). No clear difference in the biomass and root length between the control and −Al treated roots was observed, and root and shoot biomass were increased by Al treatment. These results confirmed that the H⁺ concentration level, at a pH of 3.5, is not toxic for Q. serrata and the Al-induced increase in root biomass is not caused by the amelioration of H⁺ toxicity by Al. In the third experiment, roots were exposed to an Al solution (pH 3.6) intermittently. This treatment clarified that Al stimulated rooting and root elongation. In the fourth experiment, the effect of 1 mM Al on root growth during a 15-month period in a sand culture were examined. This experiment confirmed that Al stimulated good growth and development of root systems at appropriate concentrations. Therefore, it is considered that Al-induced root growth enhancement occurs as a long-term and short-term phenomenon.  相似文献   

Plectosporium blight of monkshood caused by <Emphasis Type="Italic">Plectosporium tabacinum</Emphasis>     

Keisuke Tomioka  Yuuri Hirooka  Toshirou Nagai  Hiroyuki Sawada  Takayuki Aoki  Toyozo Sato 《Journal of General Plant Pathology》2011,77(4):266-268

Severe blight of potted seedlings of monkshood caused by Plectosporium tabacinum was found in glasshouses in Kagawa Prefecture in southwest Japan in May 2001. Root rot and browning of stem bases were followed by wilting and yellowing of leaves, then blighting of leaves, flower buds and stems. A fungus was isolated from diseased plants and confirmed to cause the disease. The new disease was named “Plectosporium blight of monkshood”.  相似文献   

An application of the image analyzer to the soft radiogram of the third metacarpus in horses     

T Yoshihara  M Kaneko  M Oikawa  R Wada  Y Tomioka 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1989,51(1):184-186

  相似文献   

Rhizoctonia blight of turnip green caused by Rhizoctonia solani AG-4 HG-III     

Hiroyuki Sekiguchi  Takeshi Toda  Erika Sato  Keisuke Tomioka  Hiroharu Murakami  Ryota Amemiya  Naoyuki Hirako  Masato Nakata  Mitsuro Hyakumachi  Seiya Tsushima 《Journal of General Plant Pathology》2015,81(6):454-456

  相似文献   

Anthracnose of Madagascar periwinkle caused by species belonging to the Colletotrichum gloeosporioides species complex     

Keisuke Tomioka  Junji Nishikawa  Jouji Moriwaki  Toyozo Sato 《Journal of General Plant Pathology》2013,79(5):374-377

Severe blight of stems was found on Madagascar periwinkle (Catharanthus roseus) in Shizuoka and Okinawa prefectures, Japan, in July 2003 and September 2004, respectively. Similar fungi were isolated from the diseased plants. The isolated fungi caused the disease after inoculation and subsequently were reisolated from diseased tissues. The fungi were identified as species closely related to C. siamense or C. tropicale according to sequences of the β-tubulin-2 gene, indicating that they belong to the Colletotrichum gloeosporioides species complex. This is the first report specifying the genetic relationships of the pathogens of Madagascar periwinkle anthracnose in the complex.  相似文献   

Effects of calcium on cadmium uptake and transport in the tree species Gamblea innovans     

Naoko Hayakawa  Rie Tomioka 《Soil Science and Plant Nutrition》2013,59(5):691-695

The effect of calcium (Ca) on cadmium (Cd) accumulation in plants was investigated using Gamblea innovans Sieb. & Zucc., a deciduous tree species that is an accumulator plant for Cd and zinc (Zn). Saplings of G. innovans were grown for 3 months and fed with solutions containing only Ca (+Ca), both Ca and Cd (Ca+Cd), or only Cd (+Cd). The Ca concentration in roots was higher in both treatments containing Cd alone (+Cd) and Ca+Cd compared to roots treated with Ca alone (+Ca). In addition, the Cd concentration in roots was higher in the Ca+Cd treatment than the Cd treatment. This showed that the presence of Ca²⁺ in the rhizosphere relates with Cd uptake into roots. The result that the transport of Cd from roots through stem to leaves was suppressed by Ca treatment indicates that the presence of Ca regulates Cd transport from the roots. A clear correlation between Cd and Zn concentrations in leaves suggests a possibility that the Cd treatment accelerates the transport of Zn into leaves via the same protein transporter in this species.  相似文献   

Time course study of aluminum-induced callose formation in barley roots as observed by digital microscopy and low-vacuum scanning electron microscopy     

Maiko Kaneko  Etsuro Yoshimura  Naoko K. Nishizawa  Satoshi Mori 《Soil Science and Plant Nutrition》2013,59(3):701-712

To clarify the mechanism(s) involved in the short-term inhibition of root elongation by AI, we monitored the morphological changes of barley roots by digital microscopy. Within 30 min after exposure to 37 µM AI, the surface of the root epidermis in the region of a distance of 1.5 mm from the root tip became rough and began to show signs of damage. After 38 min, callose was rapidly excreted from the junction between the root cap and the root epidermis, and formed a spherical lump approximately 60 µm in diameter. The fine structure of the callose deposits on the root surface was analyzed by low-vacuum scanning electron microscopy. After 50 min, there was a significant increase in the callose contents in the distal 0.6 mm part. At the same time, root elongation stopped completely. Fluorescence staining indicated that callose was localized on the surface of the cell elongation area (the elongation zone of primary roots and root hairs), but not on the surface of the meristem. The root growth reduction associated with AI treatment may be due to the use of sugar substrates for callose formation instead of cellulose formation.  相似文献