Growing porcine oocyte-granulosa cell complexes acquired meiotic competence during in vitro culture     

Hashimoto S  Ohsumi K  Tsuji Y  Harauma N  Miyata Y  Fukuda A  Hosoi Y  Iritani A  Morimoto Y 《The Journal of reproduction and development》2007,53(2):379-384

The aim of this study was to establish a culture system to improve the meiotic competence of porcine oocyte-granulosa cell complexes (OGCs) obtained from preantral or early antral follicles. Porcine OGCs were recovered from follicles with diameters of 230-300 (preantral follicles), 300-500, and 500-700 mum (early antral follicles) using scalpels. The OGCs were cultured for 2 weeks in culture medium. We examined the effects of the sizes of the follicles from which OGCs were recovered, the concentrations of polyvinylpyrrolidone (PVP, 0-8%) in the culture medium, and 2 types of culture dish (Falcon 3002 vs 1007) on formation of the antrum of OGCs. After culture, the oocytes were matured for 44 h to assess their meiotic competence. OGCs recovered from small follicles (230-500 microm) required longer (P<0.05) than larger follicles to form the antrum structure. The percentage of OGCs forming the antrum structure that were cultured in 2% PVP (31%) was higher (P<0.05) than for those cultured in other PVP concentrations (0-11%). The percentages of antrum-structure formation for OGCs cultured on Falcon 3002 (83% for 2% PVP and 60% for 4% PVP) were higher (P<0.05) than those cultured on Falcon 1007 (47% for 2% PVP and 9% for 4% PVP). Furthermore, all of the intact oocytes that were obtained from culture of OGCs and that formed an antrum were in the GV stage (n=28). When these immature oocytes were cultured for 44 h, the percentage of oocytes that reached the metaphase II stage (25%, n=68) was higher (P<0.0001) than that of oocytes matured without culture (0.7%, n=137). The results of the present study show that porcine OGCs obtained from preantral or early antral follicles acquire meiotic competence in vitro.  相似文献   

Timing and uniformity of embryonic gene activation affect subsequent pre-implantation development of cloned bovine embryos     

Kasamatsu A  Saeki K  Tamari T  Iwamoto D  Tatemizo A  Matsumoto K  Hosoi Y  Iritani A 《The Journal of reproduction and development》2007,53(3):623-629

In the present study, we examined the timing of onset, intensity, and mosaicism of embryonic gene expression in bovine nuclear transfer (NT) embryos. The relationship between gene expression and early embryonic development was also examined. To monitor the gene expression of NT embryos, we produced NT embryos with bovine transfected fibroblasts carrying a firefly luciferase gene under the control of a chicken beta-actin promoter, an expression system that has previously been shown to be representative of embryonic gene expression in mice. Photon count imaging showed that luciferase luminescence began in NT embryos with fibroblasts 48 hours post fusion (hpf) and reached a plateau at the 4- to 8-cell stage at 60 hpf. Only 4- to 8-cell NT embryos luminescent by 60 hpf developed to the blastocyst stage. At 60 hpf, strongly luminescent embryos developed to the blastocyst stage at a higher rate (P<0.05) than embryos with weak or absent luminescence. However, embryos with mosaic luminescence developed at a much lower rate (P<0.05) than those with whole-embryo luminescence, even if the embryos exhibited strong luminescence. Our results indicate that precise and uniform embryonic gene expression at the 4- to 8-cell stage at 60 hpf may be closely related to development of bovine NT embryos to the blastocyst stage.  相似文献   

H1foo is indispensable for meiotic maturation of the mouse oocyte     

Furuya M  Tanaka M  Teranishi T  Matsumoto K  Hosoi Y  Saeki K  Ishimoto H  Minegishi K  Iritani A  Yoshimura Y 《The Journal of reproduction and development》2007,53(4):895-902

Oocyte-specific linker histone H1foo is localized in the oocyte nucleus, either diffusely or bound to chromatin, during the processes of meiotic maturation and fertilization. This expression pattern suggests that H1foo plays a key role in the control of gene expression and chromatin modification during oogenesis and early embryogenesis. To reveal the function of H1foo, we microinjected antisense morpholino oligonucleotides (MO) against H1foo into mouse germinal-vesicle stage oocytes. The rate of in vitro maturation of the antisense MO group was significantly lower than that of the control group. Eggs that failed to extrude a first polar body following injection of antisense MO arrested at metaphase I. Additionally, co-injection of in vitro synthesized H1foo mRNA along with antisense MO successfully rescued expression of H1foo and improved the in vitro maturation rate. There was no difference in the rate of parthenogenesis between the antisense MO and control groups. These results indicate that H1foo is essential for maturation of germinal vesicle-stage oocytes.  相似文献   

Estimation of Zinc and Copper Balance in Japanese Farmland Soil Associated with the Application of Chemical Fertilizers and Livestock Excreta   总被引：1，自引：0，他引：1  

Shin-ichiro Mishima  Satoru Taniguchi  Akira Kawasaki  Michio Komada 《Soil Science and Plant Nutrition》2005,51(3):437-442

We estimated the zinc (Zn) and copper (Cu) balance in Japanese farmland soil in 1997. Zinc and Cu uptake by crops amounted to 563 Mg and 108 Mg, respectively, while Zn and Cu doses from chemical fertilizer were 297 Mg and 63 Mg, respectively. Zinc and Cu contents of livestock excreta were estimated to be 2,863 Mg and 713 Mg, and 1,551 Mg and 337 Mg of this was applied to farmland soil. As a result, there was an excess of 1,285 Mg of Zn and 292 Mg of Cu in farmland soil. This excess corresponded to 0.379% of the amount of total Zn and 0.270% of the amount of total Cu in farmland soil. Even if all excess Zn and Cu was accumulated in farmland soil, it would take more than 190 years to reach the permissible upper level of Zn, based on the average Zn concentration in non-polluted farmland soil. However, the promotion of the use of livestock excreta, especially pig excreta that contain high levels of Zn and Cu, may shorten the time required to reach the level. Although there are some guidelines, the recommended dose level has not clearly determined. Conventional dose of Zn applied through chemical fertilizer and manure is lower than the recommended Zn application level. Doses may depend on plant diagnosis and we should monitor the contamination of soils and crops with Zn and Cu, or the application might depend on other indicators like the Zn/cadmium ratio.  相似文献   

Performance of Rice Cultivars in Various Sawah Ecosystems Developed in Inland Valleys, Ashanti Region, Ghana   总被引：1，自引：0，他引：1  

Joseph Ofori    Youko Hisatomi  Akira Kamidouzono  Tsugiyuki Masunaga  Toshiyuki Wakatsuki 《Soil Science and Plant Nutrition》2005,51(4):469-476

Experiments were conducted in 2001 and 2002 to evaluate the agronomic responses of 23 rice cultivars with various growth traits in order to select suitable cultivars based on the ecosystems and local farming systems, in the Ashanti region of Ghana. The ecosystems included irrigated sawah * (IS), rainfed sawah (RS) and unbunded and unleveled lowland (UBLL). Two input levels consisted of a high input level (HIL—90 kg N + 45 kg P₂O₅+ 45 kg K₂O ha⁻¹+ herbicide application at 21 d after transplanting (DAT)+ hand weeding at 42 DAT) and a low input level (LIL—20 kg N+farmers' weed control practices). The results showed that the adoption of the high input level resulted in the increase of the rice grain yield by 100% with a mean yield of 4.2 Mg ha⁻¹, compared with 2.1 Mg ha⁻¹ for the low input level. Rice yield in IS exceeded that in UBLL by 323%, whereas the yield in RS exceeded that in UBLL by 130%. Under the rainfed systems (RS and UBLL), the early maturing cultivars, WAB 208-5-HB, Emokokoo, Bouake189, PSBRC 34 and PSBRC 66 were less affected by the terminal drought that characterized the end of the rainy season, compared with the medium maturing ones such as WITA 1, WITA 3 and IR58088-16-2-2. Interspecific WAB208-5-HB ( O. glaberrima × O. sativa ) out-yielded most of the improved Oryza sativa cultivars in the UBLL ecosystem under both high and low input regimes.  相似文献   

A mixed green vegetable and fruit beverage decreased the serum level of low-density lipoprotein cholesterol in hypercholesterolemic patients   总被引：1，自引：0，他引：1  

Suido H  Tanaka T  Tabei T  Takeuchi A  Okita M  Kishimoto T  Kasayama S  Higashino K 《Journal of agricultural and food chemistry》2002,50(11):3346-3350

The effects of a canned mixed green vegetable and fruit beverage, containing broccoli (Brassica oleracea L. var. botrytis L.) and cabbage (Brassica oleracea L. var. capitata L.) as main materials, on serum lipid levels in hypercholesterolemic patients were investigated. Thirty-one adult subjects were administered two cans of the beverage (160 g/can) per day for 3 weeks. Their serum total cholesterol (TC) levels significantly decreased from 6.7 +/- 0.8 to 6.1 +/- 0.6 mmol/L, and, more strikingly, the level of low-density lipoprotein cholesterol (LDL-C) significantly decreased from 4.4 +/- 0.8 to 3.8 +/- 0.7 mmol/L. At 9 weeks after the cessation of the administration, these levels had returned to the preadministration levels. Furthermore, 14 other subjects who were administered one can of the sample for 12 weeks also showed a significant reduction in the levels of serum TC and LDL-C. Thus, daily consumption of this mixed green vegetable and fruit beverage may be useful in lowering serum TC and LDL-C levels in hypercholesterolemic patients.  相似文献   

Monosaccharide composition of four humus fractions in an Andosol and a Cambisol     

Kazuhito ITOH  Akira WATANABE  Kiyoshi TSUTSUKI  Shozo KUWATSUKA 《Soil Science and Plant Nutrition》2007,53(1):7-11

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Temporal changes in humic acids in cultivated soils with continuous manure application     

Akira WATANABE  Shigeki KAWASAKI  Shigeyuki KITAMURA  Shigekata YOSHIDA 《Soil Science and Plant Nutrition》2007,53(5):535-544

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Carbon dynamics of rhizodeposits, root- and shoot-residues in a rice soil     

Yahai Lu  Akira WatanabeMakoto Kimura 《Soil biology & biochemistry》2003,35(9):1223-1230

A laboratory incubation experiment was conducted to investigate the fates of plant-derived C during the simulated fallow period in a rice soil. The ¹³C labelled soil and plant materials were used to follow the residue decomposition and its effect on soil organic C (SOC) dynamics under the conditions of either incorporation into soil or intact root systems. The soils were incubated at 15 °C for 240 d and destructive sampling was conducted at 60, 150 and 240 d. To observe the temperature effect, one batch of incubation was shifted from 15 to 25 °C during the last 45 d (between 195 and 240 d). The results showed that the decomposition of the incorporated residues could be divided into two phases: an initial rapid phase followed by a slower phase of decomposition. The decomposition of straw residues was faster than root residues: with 73% of the straw residue being decomposed, compared with 56% of the root residue over 240-d incubation at 15 °C. The water-soluble organic C and microbial biomass C significantly increased after residue incorporation. The total SOC contents, however, slightly decreased, although significant amounts of straw C (14.2%) and root C (8.7%) were found in SOC at the end of incubation, suggesting that the degradation of native SOC occurred concomitantly. Similar to decomposition of the incorporated residues, the organic substances derived from rhizodeposition of the previous season were mineralized rapidly at first and then slowly. The decomposition of the intact root system, however, was extremely slow. This result suggested that the intact root system conserved more organic C in soils compared with the incorporation of fresh residues. Increase of temperature from 15 to 25 °C during the last 45-days of incubation significantly promoted the residue decomposition.  相似文献   

Preference of three collembolan species for fruit-bodies of three species of basidiomycete fungi     

Taizo Nakamori  Akira Suzuki   《Pedobiologia》2005,49(2):119-125

We examined whether co-existing Hypogastrura species feeding on fruit-bodies show differences in utilization of fruit-bodies, and whether their utilization reflect their preferences for basidiomycete species, by field surveys and bait-trap experiments. In field surveys, the relative densities of the collembolans, Hypogastrura denisana, H. denticulata, and Hypogastrura sp. 1, on the selected basidiomycete species, Cortinarius salor, Lactarius quietus, and Russula emetica, differed significantly between the collembolan species. In bait-trap experiments using fruit-bodies of the three basidiomycete species as bait, the relative densities of the three collembolan species on the basidiomycete species differed significantly between the collembolan species and these differences were similar to the differences observed in the field surveys. These results suggest that the three collembolan species have differential preferences for fruit-bodies of the three selected basidiomycete species, and that the preferences relate to their utilization of fruit-bodies.  相似文献