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TA4和EtMIC-2表达产物免疫后对感染柔嫩艾美耳球虫(Eimeria tenella)鸡增重和盲肠卵囊数的影响 总被引：3，自引：0，他引：3
实验用Etmic-2和ta4两种基因的表达产物经口服，肌注免疫鸡，然后用柔嫩艾美耳球虫攻击免疫鸡，以观察重组产物的免疫保护作用。结果表明，免疫鸡的增重均高于红对照，口服两种活菌200μg组最佳，其相对增重为96．54％，其它组为77．07％－90．30％。从盲肠卵囊数看，同样是口服两种活菌200μg组最佳，相对卵囊产量为16．58％，其它均有降低，为17．72％－94．08％，从增重与卵囊产量来看，两种重组表达产物对E.tenella球虫有一定的免疫保护作用。尤其口服活工程菌效果最佳。 相似文献
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Diane M. Beckles 《Postharvest Biology and Technology》2012,63(1):129-140
Although a large component of tomato fruit taste is sugars, the choice of tomato cultivar and the postharvest practices implemented by industry are designed to reduce crop loss and lengthen shelf-life and do not prioritize sweetness. However, because there is a growing recognition that taste and flavor are key components of tomato marketability, greater emphasis is now being placed on improving traits like sugar content. In this review the factors, both pre-, post and at harvest that influence sugar content in fruits sold at market are broadly outlined. Lines of investigation that may maximise the outcome of current practices and lead, long-term, to enhanced postharvest fruit sugar contents are suggested. 相似文献
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3株致病性鸡大肠杆菌P型菌毛结构基因的克隆、序列测定及同源性分析 总被引：1，自引：0，他引：1
用鸡致病性大肠杆菌分离株O1、O2和O78的基因组DNA做为模板，PCR分别扩增出了0．55kb的P型菌毛结构基因(papA)。将扩增得到的3个papA基因片段分别克隆进pGEM—T栽体中，转化至受体菌JM109中，用Amp／IPTG／X-gal琼脂平板蓝白菌落筛选法，得到含阳性重组子的菌株，提取质粒后用BamH Ⅰ和Sal Ⅰ双酶切进行鉴定。所得阳性重组子进行DNA序列测定，测序结果经DNA Star核酸分析软件包分析比较，结果表明，所构建的克隆质粒中均含有相应完整papA基因，其开放式阅读框架大小为549bp，编码182个氨基酸。此3株菌的P型菌毛结构基因的同源性为98.9％～100％，其中O1株和O78株的P型菌毛基因的ORF序列100％相同，O2株有2个碱基与前两者不同。 相似文献
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Objective
Pulmonary vascular remodelling is one of the important pathological bases of broiler pulmonary hypertension syndrome (PHS). Nitric oxide (NO) has been found to inhibit proliferation and to induce apoptosis in pulmonary artery smooth muscle cells (SMC) in mammals with pulmonary hypertension. The present study was conducted to evaluate the effects of NO precursor l-arginine on pulmonary vascular remodelling in broilers with pulmonary hypertension induced by cold exposure and to examine whether NO-induced apoptosis in pulmonary arteriole SMC is involved in the regulatory mechanisms.Methods
Two hundred and forty mixed-sex commercial broilers were equally assigned to three groups and reared in normal brooding temperatures before day 14. Starting on day 14 continuing until the end of the experiment, the control group was brooded in normal temperatures whereas the other two groups were subjected to low ambient temperatures with or without l-arginine added to the basal diets. Cumulative PHS mortality and body weight were recorded in each group. Right/total ventricle ratio (RV/TV), plasma NO concentration and pulmonary vascular morphological changes were analyzed. TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay was used to detect apoptosis in pulmonary arteriole SMC.Result
l-Arginine, in group A, had no effect on body weights under cold temperature condition. Birds kept in group B had increased PHS mortality, RV/TV ratio, vessel wall area/vessel total area ratios (WA/TA) and mean media thickness in pulmonary arterioles (mMTPA) (P < 0.05). Percentages of apoptotic SMC in pulmonary arterioles in group B were not altered by cold exposure (P > 0.05). Supplemental dietary l-arginine in group A elevated plasma NO level (P < 0.05), reduced PHS mortality (P < 0.05), attenuated pulmonary vascular remodelling and increased the percentages of apoptotic SMC (P < 0.05) when compared with the group B.Conclusion
Supplemental l-arginine partially inhibited pulmonary vascular remodelling that occurred secondary to increased pulmonary pressure; NO-induced apoptosis in arteriole SMC might contribute to its regulatory effect on pulmonary vascular structural changes. 相似文献36.
柔嫩艾美耳球虫TA4抗原基因cDNA在乳酸乳球菌中的克隆与表达 总被引：2，自引：2，他引：2
用PCR技术特异扩增了柔嫩史美耳球虫TA4抗原基因cDNA序列，克隆至质粒pMD18-T中，获得重组质粒pMD18-T-TA4，采用KpnⅠ／SacⅠ双酶切法及PCR确认正确后，将TA4基NcDNA目的片段亚克隆到乳酸乳球菌表达载体pMG36n中，电穿孔法转化乳酸乳球菌LM0230，获得重组质粒pMG36n-TA4，采用KpnⅠ／SacⅠ双酶切法及DNA测序证明cDNA序列完全正确。获得TA4乳酸乳球菌表达株，经SDS—PAGE电泳分析，结果表明表达产物与预期大小的TA4蛋白分子量一致。 相似文献
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Cucumber fruits (Cucumis sativus L., cv. Trópico F1) grown on perlite substrate and NFT (Nutrient Film Technique) were harvested during two seasons (winter and spring) to monitor the effects of climatic conditions and hydroponic growth systems on fruit quality at harvest. The best fruit quality at harvest, as measured by lightness and hue angle parameters, was obtained during the 3 weeks following the first winter picking. When values of a parameter of preharvest climate value called G* were lower than 0.4 MJ m−2 °C day−1 interval−1, the cucumber achieved its optimum quality at harvest, as measured by the dark green color of the skin. NFT-grown fruits showed darker and greener skin color (higher hue angle and lower lightness) compared with perlite-grown fruit, irrespective of the season considered. During the winter season, the plant transpiration rate was 30% higher in perlite than in NFT culture, which correlates with higher differences in G* and 40% additional yield in perlite. However, in spring G* was not sensitive enough to discriminate between the two hydroponic systems. In general, fruit quality at harvest in spring was lower than during the winter, due to flesh whitening, higher longitudinal and equatorial calibers, and slightly higher pH, as well as worse epidermal color coordinates (ranging from the dark and dull green color typical of winter fruit to light and a vivid green-yellow color). During the spring season, NFT-grown fruit were less acid than perlite-grown fruit with no apparent correlation with the climatic conditions or fruit nutrition. 相似文献
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普通核雄性不育性能够满足对理想不育系选育的要求，是水稻等作物杂种优势利用的理想遗传元件。只要能解决其不育系繁殖问题，是理想的杂种优势利用方式。通过普通核雄性不育性的可育基因质体转化，将可育基因转移到存在于细胞质中的质体基因组中，可创造普通核雄性不育系的保持系，繁殖出普通核雄性不育系，从而实现三系法利用杂种优势；利用可产生雄性不育性的基因如TA29-barnase通过质体转化，向质体基因组中转移，产生由细胞质中转基因雄性不育基因控制的雄性不育系，任何常规品种都能作为其保持系，转barstar可育基因系(或常规品种)作为恢复系(或父本)，可同样实现三系法利用杂种优势。上述两种途径都是创造植物杂种优势利用的新途径。 相似文献
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[目的]构建以pUC19质粒为基础可利用XcmⅠ内切酶制备的T载体。[方法]化学合成2条含有双XcmI酶切位点的互补寡聚核苷酸链,经过变性、复性后克隆入pUC19质粒的HindⅢ和BamHⅠ位点之间,通过XcmI酶切后得到一个线性化的带有3末端突出一个T碱基的T载体。[结果]经TA克隆验证,制备的pUC19-HB-T载体对PCR产物的克隆率达到95%以上。[结论]所构建的pUC19-HB-T载体可用于PCR产物的克隆、测序及后续分子生物学操作。 相似文献
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