Generation of mouse induced pluripotent stem cells without viral vectors   总被引：4，自引：0，他引：4  

Okita K  Nakagawa M  Hyenjong H  Ichisaka T  Yamanaka S 《Science (New York, N.Y.)》2008,322(5903):949-953

Induced pluripotent stem (iPS) cells have been generated from mouse and human somatic cells by introducing Oct3/4 and Sox2 with either Klf4 and c-Myc or Nanog and Lin28 using retroviruses or lentiviruses. Patient-specific iPS cells could be useful in drug discovery and regenerative medicine. However, viral integration into the host genome increases the risk of tumorigenicity. Here, we report the generation of mouse iPS cells without viral vectors. Repeated transfection of two expression plasmids, one containing the complementary DNAs (cDNAs) of Oct3/4, Sox2, and Klf4 and the other containing the c-Myc cDNA, into mouse embryonic fibroblasts resulted in iPS cells without evidence of plasmid integration, which produced teratomas when transplanted into mice and contributed to adult chimeras. The production of virus-free iPS cells, albeit from embryonic fibroblasts, addresses a critical safety concern for potential use of iPS cells in regenerative medicine.  相似文献   

Single-locus EST-SSR markers for characterization of population genetic diversity and structure across ploidy levels in switchgrass (<Emphasis Type="Italic">Panicum virgatum</Emphasis> L.)     

Miki Okada  Christina Lanzatella  Christian M. Tobias 《Genetic Resources and Crop Evolution》2011,58(6):919-931

Polyploidy, ploidal variation between populations, and aneuploidy within some populations complicate population genetic analyses in switchgrass. We report 21 genic-simple sequence repeat marker loci with single-locus disomic segregation in tetraploids and apparently tetrasomic inheritance in octoploids, thus allowing population genetic analyses across ploidy levels. Based on 472 individuals sampled over four tetraploid and eight octoploid cultivars, six to 55 alleles were detected per locus with an average of 24.1. Genetic diversity was greater in octoploids than tetraploids, as expected from polysomic inheritance. One tetraploid cultivar displayed comparable diversity to the least diverse octoploid cultivars, suggesting breeding history or population history in the native stands of origin may have also affected within-cultivar diversity. Amplicon number at each locus and population relationships suggest autopolyploid origin of octoploids within upland tetraploids with significant cultivar differentiation. However, model-based Bayesian clustering of individuals indicated that closely related octoploid cultivars are difficult to identify, possibly due to slowed differentiation by polysomic inheritance. The analysis of the sampling effect indicated addition of loci is more effective for cultivar identification than more individuals sampled per cultivar. Discriminating power of loci tended to correlate with their variability. The eight loci with greatest discriminatory power within tetraploids were equally successful as 20 loci at identifying the four tetraploid cultivars. The set of markers reported in this study are useful for characterization of switchgrass germplasm and identifying population structure for association studies.  相似文献   

Isolation of a novel receptor cDNA establishes the existence of two PDGF receptor genes   总被引：82，自引：0，他引：82  

T Matsui  M Heidaran  T Miki  N Popescu  W La Rochelle  M Kraus  J Pierce  S Aaronson 《Science (New York, N.Y.)》1989,243(4892):800-804

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Evaluation of seed yield and seed yield components in red–yellow (Pisum fulvum) and Ethiopian (Pisum abyssinicum) peas     

Aleksandar Mikić  Vojislav Mihailović  Miodrag Dimitrijević  Sofija Petrović  Branko Ćupina  Vuk Đorđević  Valentin Kosev  Branko Milošević  Živko Jovanović  Željko Milovac 《Genetic Resources and Crop Evolution》2013,60(2):629-638

Red–yellow (Pisum fulvum Sibth. et Sm.) and Ethiopian (Pisum abyssinicum A. Br.) peas have become of increasing interest to breeders in the last decade, as they have been found to be partially or completely tolerant to various biotic stresses, such as to attack by pea weevil, mildew blight or rust. A trial was carried out at the Institute of Field and Vegetable Crops at Rimski ?an?evi from 2005 to 2007, with 13 accessions each of red–yellow and Ethiopian peas sown at 100 viable seeds m^?2, in plots of 0.5 m². Seed yield per plant in red–yellow pea was significantly and positively correlated with seed number per plant (r = 0.881**), pod number per plant (r = 0.839**) and number of fertile nodes (r = 0.820**). The highest positive correlation among the agronomic characteristics in Ethiopian pea was between number of fertile nodes and number of pods (r = 0.937**). Seed yield in Ethiopian pea was highly significantly correlated with number of seeds (r = 0.807**), pods (r = 0.692*), and fertile nodes (r = 0.638*). The results suggest that plant morphology of the progenies between red–yellow or Ethiopian peas and grain-type common pea could not differ significantly from that of individual parents. That means that it could be possible to develop hybrid lines that could keep the desirable morphological traits of grain-type common pea, such as lodging-tolerance and high seed yields, and to make an introgression of a specific resistance from wild pea taxa, especially by back-crosses with the former. However, one must always be aware of unpredicted outcomes as a result of rather different genetic basis of individual seed yield components.  相似文献   

Investigations on the water economy of volcanic ash soils     

Kakuzo Kitagishi  Tadashi Okita 《Soil Science and Plant Nutrition》2013,59(1):178-181

To elucidate the influence of climate and vegetation upon the vertical distribution of soil moisture and its seasonal change is one of the fundamental problems in the studies on water economy of volcanic ash soils, that cover the larger parts of Japan, and have characteristic soil-water system.¹⁾ Few data are now available in this field, despite the fact that management of volcanic ash soils is practically one of the most urgent problems in Japan.  相似文献   

Soil formation of new lahar materials derived from Mt. Pinatubo     

Reina Sasaki  Masao Yoshida  Yutaka Ohtsu  Miki Miyahira  Hiroyuki Ohta  Makiko Watanabe 《Soil Science and Plant Nutrition》2013,59(4):575-582

The early stage of weathering / soil formation processes from new volcanic mudflow (new lahar materials) brought from Mt. Pinatubo was examined. For this purpose, comparative studies on the physical / chemical characteristics of the new lahar materials and soils formed by the deposition of old lahar materials were conducted. Original soils contained less coarse sand, more silt, and clay than the new lahar materials. Increase in the clay content of the original soils reflected the progression of weathering. The occurrence of a higher leaching process of Fe, Ca, and Mg and of a moderate accumulation of organic matter in the original soils was suggested, based on the differences in the soil elemental composition and chemical properties. Values of base saturation and phosphate absorption coefficient (PAC) of the new lahar materials were 388% and 44, while those of all the original soils ranged 15–160% and 55–894, respectively. With the progression of weathering, the PAC value tended to increase gradually while the base saturation value decreased abruptly under the environmental conditions prevailing in the Philippines.  相似文献   

Effects of astaxanthin‐enriched yeast on mucosal IgA induction in the jejunum and ileum of weanling mice     

Tatsuhiko Nagayama  Miki Sugimoto  Shuntaro Ikeda  Shinichi Kume 《Animal Science Journal》2014,85(4):449-453

The present study was conducted to clarify the effects of astaxanthin‐enriched yeast on the concentration of immunoglobulin A (IgA), the numbers of IgA antibody‐secreting cells (ASC) and the messenger RNA (mRNA) expression of IgA C‐region in the jejunum and ileum of weanling mice. Weanling mice were fed rodent feed or astaxanthin‐enriched yeast‐supplemented rodent feed for 7, 14 or 21 days. Supplemental astaxanthin‐enriched yeast increased the numbers of IgA ASC in the jejunum and ileum after 7, 14 and 21 days of treatment. Supplemental astaxanthin‐enriched yeast increased IgA concentrations in the jejunum after 21 days of treatment, but IgA concentrations in the ileum were not affected by the treatment. The mRNA expressions of IgA C‐region in the jejunum after 14 and 21 days of treatment and the ileum after 14 days of treatment were enhanced by supplementation of astaxanthin‐enriched yeast. These results indicate that supplementation of astaxanthin‐enriched yeast is effective to enhance the numbers of IgA ASC in the jejunum and ileum and IgA concentrations in the ileum of weanling mice.  相似文献   

Effects of high potassium chloride supplementation on water intake and bodyweight gains in pregnant and lactating mice     

Miki Sugimoto  Shuntaro Ikeda  Shin‐ichi Kume 《Animal Science Journal》2013,84(6):502-507

Thirty‐one ICR pregnant mice were assigned to a control or a potassium chloride (KCl) diet group to clarify the effects of KCl supplementation on water intake, bodyweight gains and serum components in pregnant and lactating mice, and 5% KCl was supplemented in KCl diets from 6.5 days post coitus to 1 or 14 days after parturition. Feed intake was not affected by treatment, but supplemental KCl decreased bodyweight gains of lactating mice and their neonatal mice. Water intake and urine volume of KCl supplemented mice were significantly higher than those of control mice during pregnancy and supplemental KCl decreased serum urea N in pregnant mice. Supplemental KCl increased water intake drastically in lactating mice immediately after parturition and increased serum K at 14 days after parturition. Histological alteration using hematoxylin–eosin was not found in the kidney of each mouse at 1 or 14 days after parturition. These results indicate that high KCl supplementation accelerates water intake in lactating mice and prevents bodyweight gains of maternal and neonatal mice during lactation.  相似文献   

Wood friction characteristics during exposure to high pressure: influence of wood/metal tool surface finishing conditions     

Masako Seki  Hiroyuki Sugimoto  Tsunehisa Miki  Kozo Kanayama  Yuzo Furuta 《Journal of Wood Science》2013,59(1):10-16

Friction that arises during processing for the deformation of wood under relatively high pressure levels (ca. >1 MPa) is an important factor to be taken into account when wood is processed. However, few studies on such friction have been published. The present study was undertaken to evaluate the influence of surface finishing conditions on the nominal friction coefficient (μ) of the wood and metal tool surfaces. Sticking friction was likely to arise on a relatively coarse metal surface, and the type of metal tool surface finishing was found to have large impact on the friction mechanism. The friction characteristics during exposure to high pressure seem to be affected not only by the interface contact characteristics, but also by the deformation characteristics of wood during compressive load or measurement. The value of μ on water-saturated wood was equal or higher than that on dry wood, which suggests that the contact characteristics between these two types of wood are significantly different. The water content in wood was shown to affect both the interface contact and deformation characteristics of wood. The value of μ was not significantly affected by the wood surface finishing conditions; however, changes in μ during sliding differed slightly, depending on the finishing conditions.  相似文献   

GtxA from Gallibacterium anatis, a cytolytic RTX-toxin with a novel domain organisation     

Bodil Marie Kristensen  Dorte Frees    Anders Miki Bojesen 《Veterinary research》2010,41(3)

Gallibacterium anatis is a pathogen in chickens and other avian species where it is a significant cause of salpingitis and peritonitis. We found that bacterial cells and cell-free, filter-sterilised culture supernatant from the haemolytic G. anatis biovar haemolytica were highly cytotoxic towards avian-derived macrophage-like cells (HD11). We obtained the genome sequence of G. anatis 12656-12 and used a rational approach to identify a gene predicted to encode a 2026 amino acid RTX-toxin, which we named GtxA (Gallibacterium toxin). The construction of a gtxA knock-out mutant showed gtxA to be responsible for G. anatis’ haemolytic and leukotoxic activity. In addition, Escherichia coli expressing gtxA and an adjacent acyltransferase, gtxC, became cytolytic. GtxA was expressed during in vitro growth and was localised in the extracellular protein fraction in a growth phase dependent manner. GtxA had an unusual modular structure; the C-terminal 1000 amino acids of GtxA were homologous to the classical pore-forming RTX-toxins in other members of Pasteurellaceae. In contrast, the N-terminal approximately 950 amino acids had few significant matches in sequence databases. Expression of truncated GtxA proteins demonstrated that the C-terminal RTX-domain had a lower haemolytic activity than the full-length toxin, indicating that the N-terminal domain was required for maximal haemolytic activity. Cytotoxicity towards HD11 cells was not detected with the C-terminal alone, suggesting that the N-terminal domain plays a critical role for the leukotoxicity.  相似文献