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91.
Msoffe PL Minga UM Olsen JE Yongolo MG Juul-Madsen HR Gwakisa PS Mtambo MM 《Tropical animal health and production》2001,33(4):341-354
A study was conducted to determine the variations in physical characters and immunocompetence among scavenging local chicken ecotypes in Tanzania. Eighty-four adult scavenging local chickens from four eco-climatic regions of Tanzania were studied. Measurements of adult body weight, body length, shank length and egg weight and observations of plumage colour and pattern, earlobe colour, skin colour and the shape of the comb were conducted. The antibody response to sheep red blood cells, serum haemolytic complement and the cutaneous response to phytohaemagglutinin-P were assessed. Five ecotypes were identified and named Mbeya, Morogoro-medium, Ching'wekwe, Kuchi and Singamagazi. Singamagazi and Kuchi were significantly heavier, with longer shanks and heavier eggs than the other ecotypes. The average adult body weight for males ranged from 1621 g (Mbeya) to 2915 g (Singamagazi). Average female weights ranged from 1108 g (Morogoro-medium) to 2020 g (Singamagazi). Mean egg weights ranged from 37.65 g (Ching'wekwe) to 45.61 (Singamagazi). The Kuchi had mostly rose and walnut combs, while the other ecotypes were mostly single combed. In each ecotype there were chickens with a high or low antibody response to red blood cells, but there was a significant difference between the ecotypes. 相似文献
92.
O型口蹄疫病毒VP1 T细胞与B细胞表位基因双拷贝串联表达产物的免疫应答 总被引:1,自引:0,他引:1
以一株O型口蹄疫病毒(FMDV)外壳蛋白VP1基因为模板,合成与细胞免疫及体液免疫相关抗原表位肽基因:21-40肽(20AA)和141-160肽(20AA)基因序列,运用基因工程技术构建了含有串联结构21-40(20AA)~141-160(20AA)~21-40(20AA)~141-160(20AA)的2020-2020VP1融合基因表达载体r2020-2020,转化宿主菌BL21(DE3)RIL后诱导表达,表达产物经SDS-PAGE及Western Blot分析显示重组融合蛋白的分子量约为18Ku.动物实验表明,较小剂量的融合蛋白就能诱导豚鼠产生特异性T淋巴细胞增殖反应及抗FMDV中和抗体,证明该融合蛋白可同时激活细胞免疫及体液免疫反应,具有开发成为抗FMDV疫苗的应用价值. 相似文献
93.
Appa Rao Podile Hao-Jan Lin Vanisree Staniforth Paranthaman Sripriya Long-Fang Oliver Chen Teng-Yung Feng 《Physiological and Molecular Plant Pathology》2001,58(6):267
Conditional expression of harpinPsscauses yeast cell death that shares features of cell death pathway with harpinPss-mediated plant hypersensitive response (HR).Pseudomonas syringae pv.syringae 61 hrp Z gene encodes harpinPss, a 34.7 kD extracellular protein that elicits a hypersensitive response (HR) in plants. Conditional expression of either full-length or truncated hrp Z sequences under the GAL1 promoter caused cell death in Saccharomyces cerevisiae Y187. Plating of pYEUT- hrp Z transformants on a medium containing galactose resulted in complete inhibition of colony formation, whereas their growth on a glucose-based medium was unaffected. Western blot analysis confirmed the expression of harpinPssin yeast cells transformed with pYEUT- hrp Z and grown in galactose-containing medium. A time-dependent decline in the percentage of trypan blue-excluding cells in cultures of pYEUT- hrp Z transformants was observed when cultured on galactose-containing medium. Similarly, the number of viable cells reduced to about 50% within 6 h. There were similarities in the harpinPss-mediated cell death in plants and yeast cell death (YCD). Galactose-induced cell death in pYEUT-hrp Z transformants of S. cerevisiae Y187 was suppressed by a protein kinase inhibitor K252a (10 μ M). The viability of pYEUT- hrp Z transformants was prolonged in the presence of 100 U ml−1catalase suggesting a role for the oxidative burst in YCD that was further supported by the flow cytometric patterns of propidium iodide uptake by yeast cells. Overall, it appears that yeast provides a useful model system to understand the molecular mechanism of harpinPss-mediated cell death. 相似文献
94.
Caroline Hennin Elke Diederichsen Monica Hfte 《Physiological and Molecular Plant Pathology》2001,59(6):287
Tomato and transgenic oilseed rape plants expressing the Cf-9 resistance gene develop a hypersensitive response (HR) after injection of the corresponding Avr9 gene product. It was investigated whether induction of a HR conferred resistance to different fungal pathogens in tomato and oilseed rape. Induction of an AVR9 mediated HR at the pathogen infection site delayed the development of the biotrophs Oidium lycopersicum in tomato and Erysiphe polygoni in oilseed rape, but enhanced the development of the necrotrophs Botrytis cinerea and Alternaria solani in tomato and Sclerotinia sclerotiorum in oilseed rape. Interestingly, delayed fungal disease development was observed in plant tissues surrounding the HR lesion regardless of whether a necrotrophic or biotrophic pathogen was used. In tomato, AVR9 injection induced systemic expression of PR1, PR2 and PR3 defence genes but did not induce systemic resistance to O. lycopersicum, B. cinerea or A. solani. In oilseed rape, AVR9 injection temporarily induced systemic resistance to Leptosphaeria maculans and E. polygoni, but did not induce detectable systemic expression of PR1, PR2 or Cxc750. These results give new insights into the potential uses of an induced HR to engineer disease resistance. 相似文献
95.
96.
本文测定了棉蚜及棉花嫩梢不同溶剂提取液对中华通草蛉捕食行为的影响。结果表明,棉花受害嫩梢及未受害嫩梢提取液对中华通草蛉幼虫捕食行为无明显影响;棉蚜虫体浆液、棉蚜水提液,均含有很强的利它素活性物质,而棉蚜无水乙醇提取液利它素活性物质含量甚微,中华通草蛉各龄幼虫对棉蚜水提液均表现有明显的滞留和调转行为。 相似文献
97.
98.
The ovipositional response ofHelicoverpa armigera (Hübner) to different cotton varieties and species was studied under caged conditions. Maximum oviposition (51.6 eggs/female)
was recorded on LH 900, a variety ofGossypium hirsutum, and minimum oviposition (3.0 eggs/female) on G 27, a variety ofG. arboreum. Oviposition, in general, was low (3 to 6.5 eggs/female) onarboreum cottons as compared withhirsutum. Of the number of factors found to affect the oviposition ofH. armigera, the trichome length on the upper surface of the leaf, rather than the density, was positively correlated (r = 0.687*). Among
different months in the cropping season, oviposition was maximum (552.7) during April. Oviposition was higher on leaves than
on other plant parts. 相似文献
99.
100.
The object of this investigation was to study luteinizing hormone (LH) response to different doses of synthetic gonadotropin-releasing hormone (GnRH) in prepubertal gilts. Four crossbred prepubertal gilts, 128–134 days old and body weight 57–63 kg, were used in this study. Four doses, 0. 5, 25 and 125 μg, of GnRH were administered via a jugular vein catheter in a latin square design. Each treatment consisted of 3 injections at 90 min intervals. Frequent blood samples were taken during a period of 90 min before up to 90 min after treatment. Total LH responses were measured from post-treatment samples as the area under the curve above base level obtained from pre-treatment samples. A positive relationship between GnRH dose and LH release was obtained in all gilts, except for 1 treatment given to a gilt with high plasma level of oestradiol-17β on the day of treatment. This study has demonstrated the responsiveness of the pituitary gland by LH release to different doses of GnRH in 4.5-month-old prepubertal gilts. 相似文献