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   

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   

A Study on Borna Disease Virus Infection in Domestic Cats in Japan     

Azusa SOMEYA  Ryoko FUKUSHIMA  Michiko YOSHIDA  Yasuyuki TANAHASHI  Tangmunkhong PRAPEUK  Reiko IIZUKA  Hiroshi HIRAMI  Atsushi MATSUDA  Shunichi TAKAHASHI  Goro KURITA  Takashi KIMURA  Misuzu SEO  Masayuki FUNABA  Yoshii NISHINO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(8):1157-1160

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Analysis of wheat-Thinopyrum intermedium derivatives with BYDV-resistance     

Zhi-Shan Lin  Zhi-Fu Cui  Xiang-Yan Zeng  You-Zhi Ma  Zeng-Yan Zhang  Toshiki Nakamura  Goro Ishikawa  Kazuhiro Nakamura  Hisashi Yoshida  Zhi-Yong Xin 《Euphytica》2007,158(1-2):109-118

Chromosome compositions of seven lines, derived from hybrids between a wheat cultivar and the wheat-Thinopyrum intermedium addition line Z6, with barley yellow dwarf virus (BYDV) resistance, were determined by genomic in situ hybridization, cytogenetic and SSR assays. The results showed that line N522 was a disomic addition line, lines N420 and N439 were 2Ai-2(2B) chromosome substitution lines, lines N431 and N452 were 2Ai-2(2D) chromosome substitution lines, line N523 was a 2Ai-2S(2D) ditelosomic substitution line, and line N530 was a double ditelosomic line with the mitotic chromosome number of 2n = 40 + 4t. One pair of telosomes in line N530 lacked several proximal SSR markers of chromosome 2AS, but possessed certain terminal markers, which were consistent with an acrocentric structure, and the other pair of chromosome arms were presumably 2Ai-2S telosomes with BYDV-resistance. These wheat-Th. intermedium lines provide useful genetic resources for developing alien chromosome translocation lines.  相似文献   

Comparative Evaluation on Nitrogen Saturation of Forest Catchments in Japan and Northeastern United States     

Nobuhito Ohte  Myron J. Mitchell  Hideaki Shibata  Naoko Tokuchi  Hiroto Toda  Goro Iwatsubo 《Water, air, and soil pollution》2001,130(1-4):649-654

To analyze the differences in the status and processes of nitrogen saturation in Japan and northeastern United States, we examined the hydrobiogeochemistry of nitrogen of forested watersheds in these regions. Two distinct differences were found between watersheds in Japan compared with those in US. 1) In Japanese watersheds, marked decreases of NO₃ ^? concentration in surface waters during the summer growing season were not found and NO₃ ^? concentrations sometimes increased especially in the summer at nitrogen saturated sites. This contrast with watersheds in US where decreases in NO₃ ^? concentration during the summer are commonly observed except those watersheds in advanced stages of nitrogen saturation. These differences in NO₃ ^? concentration relationships can be attributed to climatic differences, with Japan having high precipitation and high discharge during the summer, while in many regions of North America lowest discharges are found in the summer. The climatic regime in Japan leads to high rates of mineralization and the rapid transport of NO₃ ^? to streams in summer. 2) Japanese watersheds, even those with high NO₃ ^? concentrations in surface waters, show little evidence of acidification. This is in contrast to sites in US where increased NO₃ ^? concentrations, especially during episodic events, result in surface water acidification.  相似文献   

Production of trout offspring from triploid salmon parents     

Okutsu T  Shikina S  Kanno M  Takeuchi Y  Yoshizaki G 《Science (New York, N.Y.)》2007,317(5844):1517

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   

微波干燥稻谷和糙米的能量效率     

董铁有  木村俊范  吉崎繁  川上友晖 《农业工程学报》2002,18(5):43-47

对厚层及均匀平铺载荷条件下稻谷和糙米的微波干燥过程中的能量效率问题进行了研究。根据本研究的实验数据,如果干燥方法和工艺安排合理,微波干燥稻谷和糙米可达到较高的能量效率,甚至可达到高于传统干燥方法。在微波干燥过程中安排一定的间歇时间以发挥照射后期作用、间歇照射作用或缓苏作用,可以有效地提高微波干燥过程中的能量效率。有2h间歇的干燥工艺的能量效率是没有间歇的干燥工艺的能量效率的5倍。载荷形式对微波干燥过程中的能量效率影响也较大。微波干燥中建议采用薄层载荷形式。  相似文献   

Clinical observations of Babesia gibsoni infection with low parasitaemia confirmed by PCR in dogs     

Inokuma H  Okuda M  Yoshizaki Y  Hiraoka H  Miyama T  Itamoto K  Une S  Nakaichi M  Taura Y 《The Veterinary record》2005,156(4):116-118

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Molecular survey of Babesia infection in dogs in Okinawa, Japan     

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   

Soil solution chemistry at different positions on slope in a conifer plantation forest     

Naoko Tokuchi  Goro Iwatsubo 《Journal of Forest Research》1999,4(2):99-106

It is known that soil property varies along the slope. It suggests that soil solution chemistry also differs topographically. To determine the variation in soil solution chemistry within one watershed, soil solution chemistry at the different positions of the slope was investigated. Soil N transformation changed along the slope. NH₄ ⁺ ratio to inorganic N (NH₄ ⁺ + NO₃ ⁻) increased upslope. The tendency was verified by laboratory incubation. After incubation most of the mineralized N was nitrified at the lower part of the slope, while little nitrification occurred at the upper part of the slope. At the ridge and the backslope inorganic N form in soil solution was concomitant with inorganic N form by incubation. At the ridge NH₄ ⁺ was predominant form in soil solution, at that time major anion was sea salt originated Cl⁻. From this, soil solution chemistry seems to be regulated by the external nutrient source at the ridge. In the second year of lysimeter installation NO₃ ⁻ concentration increased in both sites and the ratio of NH₄ ⁺ to inorganic N decreased. It was considered due to the effect of lysimeter installation. The lag time and the magnitude of NO₃ ⁻ increase were different between the ridge and the backslope. It would be related with soil N transformation in pre-disturbance. The influence of disturbance were shown in other solute concentrations of soil solution.  相似文献