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291.
稳定遗传表达分析是一种植物中常用的整体解析基因的方式。有多种转化方式可供选择,也可根据所需要的获得的转基因植物材料选择受体材料。但是由于稳定遗传转化周期较长且大部分材料不适合于进行荧光观察,所以在一些基因的研究中逐渐被瞬时表达分析系统。虽然瞬时表达分析用时短,但是转化效率受到多方面的限制,转化材料无法保存。目前由于植物悬浮培养细胞材料均一,增殖迅速并且可以满足大批量研究需求逐渐成为植物研究中的热点材料。以此同时,在亚细胞定位方面,悬浮培养细胞还是良好的应用材料。采用农杆菌介导法进行植物悬浮培养细胞的转化中方法较为成熟,但是获得纯净的转基因细胞系的转化周期较长。在本研究中针对上述问题我们建立了一种转化时间短,转化效率高的植物悬浮培养细胞稳定遗传转化体系。同时将这个体系应用到基因的亚细胞定位当中进行蛋白质快速定位分析。  相似文献   
292.
Aliphatic (2E)-alkenals and alkanals characterized from the fresh leaves of the coriander Coriandrum sativum L. (Umbelliferae) were found to possess bactericidal activity against Salmonella choleraesuis ssp. choleraesuis ATCC 35640. (2E)-Dodecenal (C(12)) was the most effective against this food-borne bacterium with the minimum bactericidal concentration (MBC) of 6.25 microg/mL (34 microM), followed by (2E)-undecenal (C(11)) with an MBC of 12.5 microg/mL (74 microM). The time-kill curve study showed that these alpha,beta-unsaturated aldehydes are bactericidal against S. choleraesuis at any growth stage and that their bactericidal action comes in part from the ability to act as nonionic surfactants.  相似文献   
293.
Since the available concentration of single‐copy fetal genes in maternal blood DNA is sometimes lower than detection limits by PCR methods, the development of specific and quantitative PCR detection methods for fetal DNA in maternal blood is anticipated, which may broaden the methods that can be used to monitor pregnancy. We used the TaqMan qPCR amplification for DYS14 multi‐copy sequence and the SRY gene in maternal blood plasma (cell‐free DNA) and fractional precipitated blood cells (cellular DNA) from individual cynomolgus monkeys at 22 weeks of pregnancy. The availability of cell‐free fetal DNA was higher in maternal blood plasma than that of cellular DNA from fractional precipitated blood cells. There was a significantly higher (P < 0.001) mean copy number of fetal male DYS14 from maternal plasma (4.4 × 104 copies/mL) than that of detected fetal cellular DNA from fractional blood cell pellets. The sensitivity of the DYS14 PCR assay was found to be higher than that of the SRY assay for the detection of fetal DNA when its presence was at a minimum. The DYS14 assay is an improved method for quantifying male fetal DNA in circulating maternal blood in the primate model.  相似文献   
294.
It has long been hoped that sea urchins could be served to visitors to seafood restaurants, hotels, and summer festivals in Rausu, located in the world natural heritage site ??Shiretoko,?? during the summer tourist season. However, to date this has not been feasible because of the sea urchin spawning season (July?CSeptember), during which the quality of the gonads, the edible part of the sea urchin, decreases due to maturation. In this study, we examined the possibility of suppressing gonadal maturation and maintaining high-quality sea urchin gonads by low-temperature rearing using deep-sea water. Unripe sea urchins captured before the spawning season were reared under two temperature conditions from June to September. In those groups reared at ambient temperatures (2.8?C19.6?°C), gametogenesis in both sexes progressed rapidly with increased temperature, and almost all sea urchins reached full maturity by late July. In contrast, in groups reared at low temperatures (2.1?C5.1?°C), gametogenesis progressed slowly and >60?% of the sea urchins did not reach maturity even by early September. The feeding experiment also revealed that feeding with live Saccharina diabolica could increase the gonadal volume efficiently under low-temperature rearing conditions. These results demonstrate that low-temperature rearing, supplemented with feeding, is effective in suppressing gametogenesis to allow for the harvesting of high-quality sea urchins during the summer tourist season.  相似文献   
295.
The molecular structure and pasting properties of starches from eight buckwheat cultivars were examined. Rapid viscograms showed that buckwheat starches had similar pasting properties among cultivars. The actual amylose content was 16–18%, which was lower than the apparent amylose content (26–27%), due to the high iodine affinity (IA) of amylopectin (2.21–2.48 g/100 g). Amylopectins resembled each other in average chain‐length (23–24) and chain‐length distributions. The long‐chains fraction (LC) was abundant (12–13% by weight) in all the amylopectins, which was consistent with high IA values. The amyloses were also similar among the cultivars in number‐average DP 1,020–1,380 with 3.1–4.3 chains per molecule. The molar‐based distribution indicated that all the amyloses comprised two molecular species differing in molecular size, although the weight‐based distribution showed a single species. A comparison of molecular structures of buckwheat starches to cereal starches indicated buckwheat amylopectins had a larger amount of LC, and their distributions of amylose and short chains of amylopectin on molar basis were similar to those of wheat and barley starches.  相似文献   
296.
The determination of damaged starch and diastatic activity in flour was studied using a flow-injection analysis (FIA) biosensor system. The system consisted of an oxygen electrode and an immobilized enzyme column containing purified glucoamylase and glucose oxidase immobilized on activated aminopropyl glass beads. The biosensor system has an optimum pH between 6.5 and 7.5 and an optimum temperature of 35°C for glucose measurement. The response of the FIA biosensor was linear up to 1.000 g/L of glucose with a lower detection limit of 0.025 g/L. Each assay took about 20 min, and the system showed good reproducibility (r = 0.998, n = 8). When applied to the measurement of damaged starch and diastatic activity in wheat flour, the results obtained agreed with those obtained using the conventional methods of measurement. This biosensor system is a rapid practical alternative for the measurement of damaged starch and diastatic activity in wheat flour.  相似文献   
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