Coccidiosis immunization: effects of mushroom and herb polysaccharides on immune responses of chickens infected with Eimeria tenella

An experiment was conducted to investigate the effects of polysaccharide extracts (E) of two mushrooms, Lentinus edodes (LenE) and Tremella fuciformis (TreE), and an herb, Astragalus membranaceus (AstE), on the immune responses of chickens infected with Eimeria tenella. A total of 180 broiler chickens were assigned to nine groups: three groups were fed with each of the extracts (LenE, TreE, and AstE), three groups were fed with the extracts and immunized with live oocyst vaccine (LenE+V, TreE+V, and AstE+V), a group was immunized with the vaccine only, and there were two controls (E. tenella-infected and noninfected groups). The oocyst vaccine was given at 4 days of age, and the extracts (1 g/kg of the diet) were supplemented from 8 to 14 days of age. At 18 days of age, all birds except those in the noninfected group were infected with 9 x 10(4) sporulated oocysts. The results showed that at 7 days postinfection (p.i.), birds fed the extracts without vaccination had lower body weight (BW) gain than those given the vaccine only. However, the extracts in conjunction with the vaccine significantly enhanced BW gain of the infected chickens compared with the vaccine group. Of the three extracts, LenE and TreE showed a better growth-promoting effect. The extracts largely increased oocyst excretion of droppings during the primary response postvaccination. The cecal peak oocyst output and lesion scores measured at 7 days p.i. were higher in the groups fed the extracts than in the group immunized with the vaccine only, whereas those of the groups fed with the extracts and immunized with the vaccine were not significantly different from the vaccine group. Of the three extracts, both LenE- and AstE-fed groups showed lower cecal oocyst output. Thus, as compared with the extracts, the live, attenuated vaccine showed better results with significantly increased immune response in coccidial infected birds. The polysaccharide extracts may prove useful against avian coccidiosis, and, particularly when they are used in conjunction with vaccine, they have shown preliminary promise against the experimental coccidial infection.     

昆明地区梨煤污病发生规律与防治

梨煤污病由仁果粘壳孢[Gloeodes pomigena(Schw.)Collby.]引起,主要危害梨果实.在果皮表面形成一层水痕状黑灰色霉状物,菌丝着生于果实表面,少数菌丝侵入到果皮下层,严重影响梨外观品质[1].该病1998年来在昆明地区砀山酥梨上发生,危害严重,未防治果园病果率达100%.现将梨煤污病发生规律调查和药剂防治试验报道如下.     

动物疫病区域化管理国际规则及实践研究

世界各地自然环境和气候条件不尽相同,畜牧业生产水平参差不齐,动物疫病流行情况各不相同,要求在全世界范围内采取相同的疫病控制措施,或在一国部分地区发生疫情时,就断然禁止该国全国范围内的易感动物及其产品出口,即采取风险     

潮土区不同品种花生的干物质积累与氮磷钾养分需求的差异分析

采用大田随机区组设计,在麦套花生种植区潮土上,研究不同品种花生干物质积累和氮磷钾养分需求的差异,为科学施用氮磷钾肥料提供技术支撑。结果表明,花生干物质的阶段积累量和积累速率呈抛物线变化趋势,花针后期最大,施肥能增加花生不同生长发育阶段干物质的积累量和积累速率,‘豫花9719’的最大,分别为3687.0 kg/hm²、184.3 kg/(hm²·d)。花生氮钾阶段积累量、阶段积累速率呈抛物线变化趋势,‘豫花9326’的磷呈双峰曲线变化趋势,‘豫花9719’、‘豫花9620’的磷呈抛物线变化趋势。每形成100 kg荚果,‘豫花9719’所需的氮(N)、磷(P₂O₅)、钾(K₂O)养分量最大,为3.877、1.103、1.456 kg,‘豫花9620’ 所需的氮(N)、钾(K₂O)养分量最小,为3.773、1.375 kg,‘豫花9326’所需的磷(P₂O₅)养分量最小,为1.058 kg;与氮养分相比,‘豫花9620’所需的磷养分比例最大,‘豫花9326’所需的磷养分比例最小,‘豫花9719’所需的钾养分比例最大,‘豫花9620’所需的钾养分比例最小。在N、P₂O₅、K₂O施用量分别为180、120、150 kg/hm²条件下,‘豫花9620’是氮、钾需求量小而磷需求量大的品种,‘豫花9326’是磷需求量小的品种,‘豫花9719’是氮、钾需求量大的品种。     

香樟胚性愈伤组织遗传转化体系建立

通过根癌农杆菌介导的遗传转化方法,建立香樟胚性愈伤组织遗传转化体系.结果表明:以胚性愈伤组织为受体,能取得比较理想的转化效果;50 mg·L-1的潮霉素对胚性愈伤组织有很好的筛选效果;根癌农杆菌OD600为0.6时,能获得较高的转化率;侵染时间提高为40min时,对提高转化效率有显著的效果;共培养3 d能够得到较好的转化效率.对转基因香樟愈伤组织进行PER检测,结果表明GUS基因已整合到香樟胚性愈伤组织的基因组中.     

鸡β-防御素3(Gal-3)基因的克隆、表达及抑菌活性研究

【目的】克隆和表达鸡β-防御素3(Gal-3)基因,并对其抑菌活性进行研究,为寻找替代抗生素的抗菌肽提供试验依据。【方法】利用RT-PCR方法,从鸡心脏中分离并克隆了鸡Gal-3基因,将其与分子伴侣基因SUMO相融合,再将该融合基因与原核表达载体pET-20b连接后转化至BL21(DE3)宿主细胞中,经IPTG诱导后,对表达产物进行SDS-PAGE和Western blot分析;最后,对Gal-3融合蛋白进行纯化,并对表达产物进行体外抑菌试验。【结果】通过RT-PCR扩增获得了约240bp的鸡Gal-3基因,经IPTG诱导获得约26ku的蛋白。IPTG在终浓度为0.6mmol/L,33℃诱导4h,诱导时菌体A600为0.6,蛋白表达量最高,且多数以可溶形式存在,33℃上清中的蛋白含量比37℃上清高。纯化的蛋白对大肠埃希菌和金黄色葡萄球菌均有明显的抑菌活性。【结论】成功克隆并表达了鸡Gal-3基因,其原核表达产物对大肠埃希菌和金黄色葡萄球菌具有一定的抑菌活性。     

紫薇籽油脂肪酸组成的GC/MS分析

紫薇是我国夏季重要观花树种,栽培广泛。为了开发和利用紫薇籽油,采用冷榨法从紫薇种子中榨取了油脂,并采用GC/MS对堇薇、红薇、银薇3个不同品种群紫薇籽油的脂肪酸组成进行了测定。分析结果表明,不同品种群紫薇籽油均含有相同的17种脂肪酸,不同品种群脂肪酸含量有差异,其中堇薇品种群不饱和脂肪酸总含量最高,为86.57％,该品种群饱和脂肪酸总含量最低,为13.05％;不饱和脂肪酸的主要成分是亚油酸和油酸,其中亚油酸含量最高,堇薇、红薇、银薇3个品种群亚油酸含量分别为71.62％、70.91％、72.87％;从紫薇籽油中检测出奇数碳脂肪酸类二十三烷酸,该脂肪酸具有抗癌活性,表明紫薇籽油是一种值得开发的保健油脂。     

牛MYOZ1基因启动子活性分析

【目的】鉴定牛MYOZ1基因转录起始位点,确定牛MYOZ1基因核心启动子区域,为进一步研究牛MYOZ1基因的转录调控机制奠定基础。【方法】以秦川牛肌肉5′RACE准备cDNA为模板,设计5′RACE扩增试验,确定牛MYOZ1基因转录起始位点。以秦川牛外周血基因组DNA为模板,通过PCR克隆获得牛MYOZ1基因转录调控区-1 628/+61目的片段。通过生物信息学分析软件预测可能包含的转录因子结合位点,设计逐段缺失引物,获得7个亚克隆,将其分别与pGL3-Basic载体连接,得到牛MYOZ1基因启动子双荧光素酶报告基因重组质粒,通过脂质体法转染C2C12细胞系,检测7个重组质粒的荧光素酶活性,分析启动子活性。【结果】确定了牛MYOZ1基因的转录起始位点,成功克隆获得7个系列缺失的牛MYOZ1基因启动子双荧光素酶报告基因重组质粒:pMYOZ1-1 628/+61、pMYOZ1-1 430/+61、pMYOZ1-1 179/+61、pMYOZ1-932/+61、pMYOZ1-676/+61、pMYOZ1-437/+61和pMYOZ1-116/+61,其中重组质粒pMYOZ1-116/+61启动子活性极显著高于pGL3-Basic,推测牛MYOZ1基因-116/+61区域可能包含核心启动子;重组质粒pMYOZ1-1 628/+61启动子活性极显著高于pMYOZ1-1 430/+61片段活性(P0.01),表明牛MYOZ1基因启动子区域-1 628/-1 430片段可能包含启动子活性增强元件。生物信息学分析发现,牛MYOZ1基因启动子-116/+61片段可能包含SP1、GC Box、CAAT等多个重要转录因子结合位点;-1 628/-1 430片段可能包含SP1、MyoD等多个重要转录因子结合位点。【结论】成功构建了7个系列缺失的牛MYOZ1基因启动子双荧光素酶报告基因重组质粒,且初步确定了牛MYOZ1基因的核心启动子区域位于-116/+61。     

菲莱氏温扬球虫(Wenyonella philiplevinei)的裂殖体、裂殖子及大配子体在杯状细胞中发育的超微结构研究

本文描述了寄生于北京鸭小肠上皮杯状细胞中的菲莱氏温扬球虫滋养体、裂殖体、裂殖子、大配子体的超微结构,并与寄生干吸收上皮细胞的同种虫体以及鸡十二指肠杯状细胞中的Eimeria acervulina 作了比较。整个裂殖生殖(包括成熟裂殖子的形成)可在杯状细胞中进行。发育中的大配子体(早、中期大配子体),可在杯状细胞内生长,但未见小配子体在其中发育。裂殖生殖时期虫体常寄生于杯状细胞的胞质内,而大配子体多见于杯状细胞的粘液颗粒之中,此与 E.acervulina 不同。所见各期虫体在杯状细胞内发育正常,其结构与在吸收上皮寄生者相同。