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31.
Data on enzyme polymorphism and blood group polymorphism were examined with special reference to molecular evolution, by using a statistic that depends on neither population structure nor other ecological factors. The data of the former are consistent with the hypothesis of neutral mutant and random genetic drift, whereas the latter are in accord with the hypothesis of balanced selection. 相似文献
32.
Rice Full-Length cDNA Consortium;National Institute of Agrobiological Sciences Rice Full-Length cDNA Project Team Kikuchi S Satoh K Nagata T Kawagashira N Doi K Kishimoto N Yazaki J Ishikawa M Yamada H Ooka H Hotta I Kojima K Namiki T Ohneda E Yahagi W Suzuki K Li CJ Ohtsuki K Shishiki T;Foundation of Advancement of International Science Genome Sequencing & Analysis Group Otomo Y Murakami K Iida Y Sugano S Fujimura T Suzuki Y Tsunoda Y Kurosaki T Kodama T Masuda H Kobayashi M Xie Q Lu M 《Science (New York, N.Y.)》2003,301(5631):376-379
33.
Kassai Y Munne P Hotta Y Penttilä E Kavanagh K Ohbayashi N Takada S Thesleff I Jernvall J Itoh N 《Science (New York, N.Y.)》2005,309(5743):2067-2070
Mammalian tooth crowns have precise functional requirements but cannot be substantially remodeled after eruption. In developing teeth, epithelial signaling centers, the enamel knots, form at future cusp positions and are the first signs of cusp patterns that distinguish species. We report that ectodin, a secreted bone morphogenetic protein (BMP) inhibitor, is expressed as a "negative" image of mouse enamel knots. Furthermore, we show that ectodin-deficient mice have enlarged enamel knots, highly altered cusp patterns, and extra teeth. Unlike in normal teeth, excess BMP accelerates patterning in ectodin-deficient teeth. We propose that ectodin is critical for robust spatial delineation of enamel knots and cusps. 相似文献
34.
Ujihara T Taniguchi F Tanaka J Hayashi N 《Journal of agricultural and food chemistry》2011,59(5):1557-1564
To develop cleaved amplified polymorphic sequence (CAPS) markers for cultivar identification of the tea leaf, 5 primer pairs designed on the basis of genes that encode proteins related to nitrogen assimilation and 26 primer pairs based on expressed sequence tag (EST) sequences of the root of tea plant were screened. From combinations of primer pair and restriction enzyme that showed polymorphism among tea plants, 16 markers were selected and applied to DNA fingerprinting of Japanese tea cultivars. Sixty-three cultivars, except for a bud sport (Kiraka) and its original cultivar (Yabukita) and a pair that was the progeny of the same crossing parent (Harumoegi and Sakimidori), were distinguished from one another. By combining the 16 markers with previously developed CAPS markers and observing the physical appearance, 67 cultivars were distinguishable. The cultivars involve approximately 95% of total tea cultivating area in Japan; therefore, about 95% of tea leaves produced in Japan can be authenticated by labeling their cultivars. 相似文献
35.
The irreplaceability index is used for determining the priority of sites for conservation. We propose three new and simple algorithms for calculating it from presence/absence data without any statistical assumptions when the representative combination size is the minimum. The rare species algorithm gives accurate results but takes the longest calculation time. The species richness algorithm gives approximated results and takes the shortest calculation time. The combined algorithm is intermediate in accuracy and calculation time. We applied the combined algorithm to real data of butterflies in the Kanto district, central Japan, and derived irreplaceability values. 相似文献
36.
Tandang MR Adachi M Inui N Maruyama N Utsumi S 《Journal of agricultural and food chemistry》2004,52(22):6810-6817
The primary structure of Brassica napus procruciferin 2/3a was engineered to elucidate structure-function relationships and to improve the functionality of cruciferin. The following mutants were constructed: (1) C287T, (2) DeltaII, variable region II was deleted; (3) C287T/DeltaII, mutation involving (1) and (2); (4) DeltaIV + A1aIV; and (5) DeltaIV + A3IV, variable region IV was replaced with variable region IV containing many charged residues from soybean glycinin A1aB1b and A3B4 subunits. Differential scanning calorimetry analysis revealed that the A1aIV region has a more favorable interaction with the procruciferin molecule than does A3IV as well as the original regions. On the basis of heat-induced precipitation analysis, it was concluded that replacement of the free cysteine residue with threonine (C287T) and insertion of charged regions (DeltaIV + A1aIV and DeltaIV + A3IV) could lead procruciferin to form soluble aggregates after heating. Low solubility was observed in mutants DeltaIV + A3IV, DeltaII, and C287T/DeltaII, especially between pH 4 and 6 at mu = 0.08, but not in DeltaIV + A1aIV, indicating that the number of acidic amino acid residues and the high number of glutamine residues are important factors for solubility at mu = 0.08. None of the mutants showed any improvements in emulsifying ability, indicating that destabilization and addition of the hydrophilic region are not effective for emulsification. The insertion of the A1aIV region in procruciferin made the molecule more susceptible to alpha-chymotrypsin. 相似文献
37.
Antioxidative, antimutagenic, and anticarcinogenic activities of rice bran extracts in chemical and cell assays 总被引:4,自引:0,他引:4
Nam SH Choi SP Kang MY Kozukue N Friedman M 《Journal of agricultural and food chemistry》2005,53(3):816-822
Ethanol-water (70:30 v/v) extracts from rice brans removed from seeds of two blackish-purple pigmented (Sanhaehyanghyulla and Suwon 415) and one nonpigmented (Chuchung) brown rice cultivars were evaluated for antioxidative, anti-tumor-promoting, and anticarcinogenic activities in chemical assays and in mammalian cells (human leukemia HL-60, marmoset B lymphoblastoid B95-8, and Chinese hamster V79 lung cells) by the following tests: inhibition of xanthine oxidase activity; chelation of ferrous ions; reduction of potassium ferricyanide; scavenging of superoxide anions, hydroxyl radicals, and intracellular peroxides; inhibition of 4-nitroquinoline N-oxide-induced mutagenesis; and inhibition of phorbol ester-induced tumor promotion. The extracts from the pigmented rice seeds had generally higher activities in all tests than did the extract from the nonpigmented variety. The results suggest that brans from pigmented rice varieties may provide a source of new natural antioxidants and anticarcinogens and that such rice cultivars with high antioxidative potential also provide a genetic resource for the development of new, improved rice cultivars that may make it possible to enhance both the nutritional and medical value of rice-based diets. 相似文献
38.
Glycoalkaloids and metabolites inhibit the growth of human colon (HT29) and liver (HepG2) cancer cells 总被引:4,自引:0,他引:4
Lee KR Kozukue N Han JS Park JH Chang EY Baek EJ Chang JS Friedman M 《Journal of agricultural and food chemistry》2004,52(10):2832-2839
As part of an effort to improve plant-derived foods such as potatoes, eggplants, and tomatoes, the antiproliferative activities against human colon (HT29) and liver (HepG2) cancer cells of a series of structurally related individual compounds were examined using a microculture tetrazolium (MTT) assay. The objective was to assess the roles of the carbohydrate side chain and aglycon part of Solanum glycosides in influencing inhibitory activities of these compounds. Evaluations were carried out with four concentrations each (0.1, 1, 10, and 100 microg/mL) of the the potato trisaccharide glycoalkaloids alpha-chaconine and alpha-solanine; the disaccharides beta(1)-chaconine, beta(2)-chaconine, and beta(2)-solanine; the monosaccharide gamma-chaconine and their common aglycon solanidine; the tetrasaccharide potato glycoalkaloid dehydrocommersonine; the potato aglycon demissidine; the tetrasaccharide tomato glycoalkaloid alpha-tomatine, the trisaccharide beta(1)-tomatine, the disaccharide gamma-tomatine, the monosaccharide delta-tomatine, and their common aglycon tomatidine; the eggplant glycoalkaloids solamargine and solasonine and their common aglycon solasodine; and the nonsteroidal alkaloid jervine. All compounds were active in the assay, with the glycoalkaloids being the most active and the hydrolysis products less so. The effectiveness against the liver cells was greater than against the colon cells. Potencies of alpha-tomatine and alpha-chaconine at a concentration of 1 microg/mL against the liver carcinoma cells were higher than those observed with the anticancer drugs doxorubicin and camptothecin. Because alpha-chaconine, alpha-solanine, and alpha-tomatine also inhibited normal human liver HeLa (Chang) cells, safety considerations should guide the use of these compounds as preventative or therapeutic treatments against carcinomas. 相似文献
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