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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
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Extensive Screening for Edible Herbal Extracts with Potent Scavenging Activity against Superoxide Anions 总被引：1，自引：2，他引：1
Saito K Kohno M Yoshizaki F Niwano Y 《Plant foods for human nutrition (Dordrecht, Netherlands)》2008,63(2):65-70
To search for edible herbal extracts with potent antioxidant activity, we conducted a large scale screening based on the superoxide scavenging activity. That is, scavenging activity against superoxide anions were extensively screened from ethanol extracts of approximately 1,000 kinds of herbs by applying an electron spin resonance (ESR)-spin trapping method. Among them we chose four edible herbal extracts with prominently potent ability to reduce the signal intensity of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)-OOH, a spin adduct formed by DMPO and superoxide anion. They are the extracts from Punica granatum (Peel), Syzygium aromaticum (Bud), Mangifera indica (Kernel), and Phyllanthus emblica (Fruit), and are allowed to be used as foodstuffs according to the Japanese legal regulation. The ESR-spin trapping method coupled with steady state kinetic analysis showed that all of the four extracts directly scavenge superoxide anions, and that the superoxide scavenging potential of any of the extracts was comparable to that of L-ascorbic acid. Furthermore, polyphenol determination indicates that the activity is at least in part attributable to polyphenols. These results with such large scale screening might give useful information when choosing a potent antioxidant as a foodstuff. 相似文献
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Many salmonids have become at risk of extinction. For teleosts whose eggs cannot be cryopreserved, developing techniques other than egg cryopreservation to save genetic resources is imperative. In this study, spermatogonia from rainbow trout were intraperitoneally transplanted into newly hatched sterile triploid masu salmon. Transplanted trout spermatogonia underwent spermatogenesis and oogenesis in male and female recipients, respectively. At 2 years after transplantation, triploid salmon recipients only produced trout sperm and eggs. With use of these salmon as parents, we successfully produced only donor-derived trout offspring. Thus, by transplanting cryopreserved spermatogonia into sterile xenogeneic recipients, we can generate individuals of a threatened species. 相似文献
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Inokuma H Yoshizaki Y Matsumoto K Okuda M Onishi T Nakagome K Kosugi R Hirakawa M 《Veterinary parasitology》2004,121(3-4):341-346
A total of 80 free-roaming dogs on Okinawa Island, Japan, were examined for Babesia infection using the polymerase chain reaction (PCR) and sequence analysis. Of 80 samples, 12 were positive in a Babesia genus-specific PCR. Consequent species-specific PCR for B. canis and B. gibsoni revealed that 5 (6.3%) and 7 (8.8%) dogs were infected with B. canis and B. gibsoni, respectively. Sequence analysis of the PCR products revealed that the 18S rRNA gene sequence of B. canis detected from dogs in Okinawa was very close to B. canis vogeli with sequence similarity of 99.94%. 相似文献
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Hideaki Endo Tadayoshi Muramatsu Goro Yoshizaki Huifeng Ren Hitoshi Ohnuki 《Fisheries Science》2012,78(2):391-398
A label-free immunosensor for detecting the oocyte maturation-inducing hormone 17, 20β-dihydroxy-4-pregnen-3-one (DHP), was
developed. A principle of the sensor system was based on differences in electrochemical activity changed by an immunoreaction
in the absence and presence of DHP. For preparation of the immunosensor, anti-DHP IgG was immobilized on an Au working electrode
modified with a self-assembled monolayer of 3-mercaptopropionic acid. The sensor was immersed into a sample solution containing
DHP. DHP was determined by cyclic voltammetry. The immunosensor showed a specific response to DHP, and the oxidation peak
current linearly decreased in the range of 7.8–500 pg ml−1 with a correlation coefficient of 0.996. The sensor system was applied to determine the DHP levels in plasma of goldfish
and was compared with the DHP levels of the same samples determined using an ELISA as the conventional method. Good correlation
was obtained between values determined using both methods in the range of 0.1–7.7 ng ml−1 (correlation coefficient 0.876). These findings suggest that the proposed label-free immunosensor can be used to analyze
DHP levels in fish plasma samples. 相似文献
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Eastern little tuna,Euthynnus affinis (Cantor, 1849) mature and reproduce within 1 year of rearing in land‐based tanks 
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下载免费PDF全文 Ryosuke Yazawa Yutaka Takeuchi Kenta Satoh Yuri Machida Kotaro Amezawa Naoki Kabeya Yukinori Shimada Goro Yoshizaki 《Aquaculture Research》2016,47(12):3800-3810
Eastern little tuna (ELT, Euthynnus affinis) is expected to see use as a novel aquaculture species due to its rapid growth and high economic value. In this study, closing of the complete life cycle of ELT in land‐based tanks was successfully carried out. Seed production of a first generation (F1) derived from wild‐caught ELT broodstock was conducted in 2010, 2011 and 2012. Survival percentages of F1 ELT at 365 days post hatching for the 2010, 2011 and 2012 year classes were 0.9%, 0.4% and 6.3% respectively. On average, F1 ELT were approximately 40 cm in total length and weighed 1500 g by the time they reached 1 year of age. Successful artificial induction of spawning was achieved in 1‐year‐old F1 ELT using a gonadotropin‐releasing hormone analogue (GnRHa). Induction of spawning was successful at the first administration of GnRHa in the 2010, 2011 and 2012 year classes. First spawning was observed at 4 or 5 days post implantation, which indicated that oogenesis and spermatogenesis progressed within 1 year of rearing in land‐based tanks. During spawning periods, the average number of fertilized eggs and the average number of hatched larvae per spawning event in the 2010, 2011 and 2012 year classes were 20,480 eggs day?1 and 177 larvae day?1, 39,423 eggs day?1 and 9347 larvae day?1, and 819,555 eggs day?1 and 674,445 larvae day?1 respectively. Therefore, it was concluded that both male and female ELT reared in land‐based tanks were capable of reproduction at 1 year of age. 相似文献
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