Loss of imprinting of Igf2 alters intestinal maturation and tumorigenesis in mice

Loss of imprinting (LOI) of the insulin-like growth factor II gene (IGF2) is an epigenetic alteration that results in a modest increase in IGF2 expression, and it is present in the normal colonic mucosa of about 30% of patients with colorectal cancer. To investigate its role in intestinal tumorigenesis, we created a mouse model of Igf2 LOI by crossing female H19+/- mice with male Apc+/Min mice. Mice with LOI developed twice as many intestinal tumors as did control littermates. Notably, these mice also showed a shift toward a less differentiated normal intestinal epithelium, reflected by an increase in crypt length and increased staining with progenitor cell markers. A similar shift in differentiation was seen in the normal colonic mucosa of humans with LOI. Thus, altered maturation of nonneoplastic tissue may be one mechanism by which epigenetic changes affect cancer risk.     

Identification of quantitative trait loci associated with shoot sodium accumulation under low potassium conditions in rice plants

Sodium (Na) application has marked beneficial effects on plant growth when the potassium (K) supply is low. Under low K supply, three japonica rice (Oryza sativa L.) cultivars, Koshihikari, Nipponbare, and Sasanishiki, accumulated more Na than three indica cultivars, IR36, IR64, and Kasalath, and the effect of Na application on growth was greater in japonica Koshihikari plants than in indica IR64 plants. A quantitative trait locus (QTL) analysis using a population of backcross inbred lines derived from japonica Koshihikari and indica Kasalath identified two significant loci associated with shoot Na concentration on chromosomes 3 and 6. The quantitative trait locus for shoot Na accumulation on chromosome 6 was confirmed in a population of chromosome segment substitution lines. The major QTL detected in this study could be useful for increasing crop productivity under low K input.     

Effects of Oral Administration of Fucoidan Extracted from Cladosiphon okamuranus on Tumor Growth and Survival Time in a Tumor-Bearing Mouse Model

We evaluated the anti-tumor activities of the oral administration of fucoidan extracted from Cladosiphon okamuranus using a tumor (colon 26)-bearing mouse model. The materials used included low-molecular-weight fucoidan (LMWF: 6.5–40 kDa), intermediate-molecular-weight fucoidan (IMWF: 110–138 kDa) and high-molecular-weight fucoidan (HMWF: 300–330 kDa). The IMWF group showed significantly suppressed tumor growth. The LMWF and HMWF groups showed significantly increased survival times compared with that observed in the control group (mice fed a fucoidan-free diet). The median survival times in the control, LMWF, IMWF and HMWF groups were 23, 46, 40 and 43 days, respectively. It was also found that oral administration of fucoidan increased the population of natural killer cells in the spleen. Furthermore, from the results of the experiment using Myd-88 knockout mice, it was found that these effects are related to gut immunity. These results suggest that fucoidan is a candidate anti-tumor functional food.     

A simple, rapid method for gizzerosine analysis in fish meal by paper electrophoresis

We established a simple, rapid method for gizzerosine analysis in fish meal. Gizzerosine was extracted from fish meal with 0.1?N HCl solution. Samples and standard gizzerosine solutions were absorbed onto a paper disc, which was then set on electrophoresis paper for 18?min, and the paper was dried. Gizzerosine was visualized with Pauly??s reagent, and the intensity of the colored spots was digitized and calculated by image processing method software. We achieved successful separation of gizzerosine from other Pauly??s reagent-positive components in fish meal extracts. The linearity of gizzerosine estimation using this method was within the range 30?C1000?ng (R ²?=?0.99). Gizzerosine was satisfactorily detected and completely separated from histamine and other Pauly??s reagent-positive compounds. This method does not require expensive instruments or tedious pretreatment to eliminate interfering compounds, such as histamine or histidine. It also uses less reagent compared with high-performance liquid chromatography. Moreover, it is a simple, rapid, sensitive, and reproducible method. It is suitable for monitoring gizzerosine in fish meal products that contain as little as 10?ppm gizzerosine.     

Effects of the lateral growth rate on wood quality parameters of Eucalyptus grandis from different latitudes in Brazil and Argentina

Climate change resulting from increased atmospheric carbon dioxide (CO₂) and shortages of fossil fuels such as petroleum are major problems worldwide. Under these conditions, demand for woody biomass resources is increasing. We investigated the feasibility of using fast-growing Eucalyptus grandis for material production. Samples of E. grandis were collected from four plantations in different latitude divisions, including tropical and subtropical Brazil and subtropical Argentina. Various xylem qualities were measured and related to the lateral growth rate. Lateral growth rate did not significantly affect the longitudinal released strain of the surface growth stresses or the xylem density at any of the sampling sites. Higher lateral growth rate, higher values of xylem density, and lower absolute values of the released strain were observed in plantations closer to the equator. Higher growth rates in tropical climate promote longer fiber length. In subtropical plantations, smaller diameter trees will produce tension wood with smaller microfibril angles. Planting E. grandis closer to the equator thus produces higher quality wood than in plantations at lower latitudes.     

Changes in micropores in dry wood with elapsed time in the environment

To investigate the changes in microstructures of wood with elapsed time in the environment, CO₂ adsorption onto dry wood was measured at ice-water temperature (273 K) for samples aged from 0.1 years to over 1000 years. The micropore size distribution was obtained using the Horvath-Kawazoe method. Micropores smaller than 0.6 nm in wood decreased in number with elapsed time in the environment, and a negative correlation was found between cumulative pore volume for pores smaller than 0.6 nm and elapsed time in the environment. Cumulative pore volume in the 1000-year sample was almost half of that in the 0.1- year sample. Micropores smaller than 0.6 nm in wood with a few decades or more of elapsed time increased in number after rewetting and drying. Consequently, microstructures of wood with longer time elapsed in the environment were considered to be more stable, because of longer-term thermal motion and possibly more repeated moisture adsorption and desorption and/or temperature variation in the environment.     

Improved physical control of glyphosate‐resistant Italian ryegrass (Lolium multiflorum) on rice paddy levees in Japan

Italian ryegrass ( Lolium multiflorum Lam.) is a non‐native annual winter grass that has seriously infested rice paddy levees and wheat fields in Japan. Recently, glyphosate‐resistant Italian ryegrass was found on paddy levees in central Japan, thereby making control of the grass by using glyphosate less effective. In this study, physical control methods were tested that combined the timing and frequency of mowing in order to more effectively control glyphosate‐resistant Italian ryegrass on rice paddy levees. A 3 year field experiment was conducted from 2012 to 2014 in a western region of Shizuoka Prefecture, where glyphosate‐resistant Italian ryegrass has become dominant. Five treatments were tested: (i) mowing once before the flowering of the grass (i.e. conventional mowing measure); (ii) mowing once during flowering; (iii) mowing twice during flowering; (iv) glyphosate application before flowering (i.e. one of the conventional mowing measures); and (v) no treatment. The above‐ground biomass, seed production, soil seed bank and seedling occurrence of Italian ryegrass were measured to determine the effectiveness of these treatments. Mowing during the flowering period resulted in reduced above‐ground biomass, seed production and soil seed bank when compared with the other treatments. Additionally, mowing twice during the flowering period resulted in a lower seedling density than mowing once. The results suggest that, in this region, physical control by mowing during the flowering period would be more effective than conventional measures for controlling glyphosate‐resistant Italian ryegrass.