一个新的家蚕锌指蛋白基因的克隆及基因组结构分析

锌指蛋白是一类能与细胞内核酸特异结合 ,调控基因表达活性 ,对细胞分裂、分化、胚胎发育及个体生长有重要作用的转录因子。从家蚕 5龄丝腺组织cDNA文库中克隆了一个具有锌指结构的新基因 ,命名为BmZFP基因 (GenBank登录号 :AY75 36 5 9) ,其cDNA全长为 180 9bp ,编码 14 3个氨基酸 ,3′端非翻译区 (3′ untranslatedregion ;3′ UTR)达 1332bp碱基序列。BmZFP氨基酸序列推测有 6个功能结构域 ,是一种CCHC型锌指蛋白。虽然BmZFP氨基酸序列与人、大鼠和小鼠的相关锌指蛋白的氨基酸序列同源性只有 33%左右 ,但 6个功能域中的Cys(C)和His(H)却完全匹配 ,推测其功能与人、大鼠和小鼠的相关锌指蛋白有相似性。BmZFP基因序列的结构分析表明 :该基因由 2个外显子和 1个 14 86bp碱基序列的内含子组成 ,在 5′端上游 - 182～ - 2 2 2区域存在一个启动子元件 ,但不是典型的TATA盒启动子。     

A reactive pattern of ischemia-induced nestin protein in the rat brain

AIM:To explore the expressive profile of nestin protein in the focal ischemic brain and to study the recovery mechanism of brain focal infarct.METHODS:Cellular morphology,time-course and distribution pattern of nestin positive response were immunohistochemically examined in different brain regions of 36 adult male SD rats. RESULTS:Nestin positive response of different brain regions in sham operated rats was present in small- and micro-vasculartures and the third ventricle bottom and ependyma. A large number of nestin positive cells were detected in ischemic brain, and were more remarkable in the cortical areas of parietal lobe and preoptic area as well as ischemic caudoputamen. Stellate nestin positive cells were located in the deep layer of ischemic cortex, but fibrillary cells were located in the shallow layer. Nestin positive cells in the ischemic caudoputamen showed the same changes of morphology as those cells in the deep layer of ischemic cortex. Morphological and number alterations of nestin positive cells were the most remarkable at 1 weeks post-ischemia, which showed more hypertrophy and proliferation in morphology, and a marked increase in number was present in the ischemic cerebral cortex and the ischemic caudoputamen. These alterations of nestin positive cells persisted up to 6 weeks post-ischemia, and then, the nestin positive response in the ischemic brain decreased gradually.CONCLUSION:Focal cerebral ischemia induces nestin re-expression on reactive astrocytes, which may be very important to the self-recovery of cerebral infarct.     

Factors affecting the virulence of Ralstonia solanacearum and its colonization on tobacco roots

Tobacco bacterial wilt caused by Ralstonia solanacearum is a serious disease affecting tobacco cultivation in southwest China. The response surface methodology was employed to evaluate the optimal conditions of tobacco bacterial wilt, and green fluorescent protein gene (gfp) labelling was applied to monitor the location and survival dynamics of R. solanacearum (Rs::gfp) on tobacco roots and in soil under these optimal conditions. The results showed that the highest wilt incidence was 91.13%, which occurred when the population reached 6.6 × 10⁶ CFU/g soil, the temperature was 30.55 °C, and the humidity was >81.42%. The Rs::gfp densely colonized the root tips and root hairs, and cells of Rs::gfp were observed intermittently in the elongation zone or at the point of the emerging lateral roots. The Rs::gfp number in the rhizosphere soil was 10.75‐, 73.13‐ and 74.86‐times higher than that in the bulk soil at 10, 15 and 20 days after transplantation, respectively. Increased colonization by Rs::gfp was related to the population of the pathogen, the environmental temperature and the humidity in the soil. These three conditions determined whether R. solanacearum would induce tobacco wilt. This is the first study to investigate factors affecting the virulence of a tobacco wilt bacterial pathogen, which is important for conducting field diagnosis and biocontrol of tobacco bacterial wilt.     

C-reactive protein, tumor necrosis factor α, and interleukin-6 in dogs with pyometra and SIRS

Objective: To determine the frequency of the systemic inflammatory response syndrome (SIRS) in canine pyometra and to evaluate the relationship between C‐reactive protein (CRP), tumor necrosis factor α (TNFα), interleukin‐6 (IL‐6), and SIRS. Design: Prospective clinical study. Setting: Veterinary teaching hospital. Animals: Fifty‐three clinical cases of canine pyometra and 19 healthy control bitches. Interventions: Upon admission to the veterinary hospital, history and physical examination findings, including previously defined clinical SIRS parameters, were documented. Blood samples were obtained for hematology and biochemical tests and for CRP, TNFα, and IL‐6 analysis. The diagnosis of pyometra was confirmed by histopathology of the uterus after ovariohysterectomy. After surgery, clinical SIRS parameters, length of hospitalization, and mortality were recorded. Measurements and main results: Pyometra dogs were grouped as SIRS positive (30/53; 57%) or SIRS negative (23/53; 43%). Logistic regression showed that CRP was the only parameter that significantly related to SIRS apart from the clinical criteria that define this syndrome. The mortality rate was low (2/53; 3.8%), and conclusions regarding association with SIRS could not be drawn. A positive SIRS status, high plasma CRP concentration, and high body temperature were variables that related to increased morbidity reflected by the length of hospitalization. Conclusions: SIRS was seen in 57% of canine pyometra cases and a positive SIRS status showed a positive association with prolonged hospitalization. The mortality rate was low (3.3%) among SIRS positive dogs, indicating that progression to multiple organ dysfunction syndrome (MODS) rarely occurs in surgically treated cases of pyometra. CRP was associated with SIRS and with prolonged hospitalization. Further studies of plasma CRP may be warranted in canine intensive care cases susceptible to development of SIRS and MODS.     

假俭草抗寒性与体内碳水化合物、脯氨酸、可溶性蛋白含量的关系

为了阐述假俭草(Eremochloa ophiuroides(Munro.)Hack.)的抗寒性与碳水化合物、脯氨酸、可溶性蛋白含量季节动态变化之间的关系,于2008年10月-2009年5月,研究了在自然温度变化过程中,假俭草E126匍匐茎中碳水化合物、脯氨酸、可溶性蛋白的季节性动态变化及其与半致死温度(LT₅₀)变化的关系。结果表明:在越冬前后假俭草E126匍匐茎LT₅₀呈现先降低后升高的季节变化趋势,可溶性总糖、蔗糖、果糖含量,可溶性总糖淀粉比率以及脯氨酸含量伴随田间气温变化均呈现先升高后降低的趋势,可溶性蛋白、淀粉含量则呈现出先降低又升高的趋势。假俭草E126匍匐茎LT₅₀季节变化与可溶性总糖、蔗糖、果糖含量,可溶性总糖淀粉比率季节变化之间存在极显著负相关(P<0.01),而与淀粉含量、脯氨酸含量、可溶性蛋白含量的季节变化间相关性不显著。因此,可溶性总糖含量、蔗糖含量、果糖含量、可溶性总糖淀粉比率对其冬季抗寒性增强有重要作用。     

蛋白结晶技术在病毒学中的应用

病毒及其亚单位蛋白的三维结构 (3 D)解析是认识病毒蛋白功能的有力手段。对病毒结构的认识正经历着病毒粒子电镜结构、纳米水平的精细结构及病毒组成蛋白原子水平 3 D结构的变化。晶体的 X射线衍射技术可在原子水平上认识病毒蛋白的结构。这为从结构生物学的角度认识病毒复制、病毒粒子的装配、病毒的致病与免疫机理及抗病毒药物设计提供了技术平台     

Effects of water‐misting sprays with forced ventilation on post mortem glycolysis,AMP‐activated protein kinase and meat quality of broilers after transport during summer

Effects of water‐misting sprays with forced ventilation on post mortem glycolysis, adenosine monophosphate‐activated protein kinase (AMPK) and meat quality of broilers after transport during summer were investigated in the present paper. A total of 105 mixed‐sex Arbor Acres broilers were divided into three treatment groups: (i) 45 min transport without rest (T); (ii) 45 min transport with 1 h rest (TR); and (iii) 45 min transport with 15 min water‐misting sprays with forced ventilation and 45 min rest (TWFR). Each treatment consisted of five replicates with seven birds each. The results indicated that the water‐misting sprays with forced ventilation could mitigate the stress caused by transport under high temperature conditions during summer, which reduced the energy depletion in post mortem Pectoralis major (PM) muscle. This resulted in a higher energy status compared to the T group, which would decrease the expression of phosphorylation of AMPK (p‐AMPK). Furthermore, decreased the expression of p‐AMPK then slowed down the rate of glycolysis in post mortem PM muscle during the early post mortem period, which in turn lessened the negative effects caused by transport on meat quality. In conclusion, water‐misting sprays with forced ventilation may be a better method to control the incidence of the pale, soft and exudative meat in broilers.     

不同品种类型玉米不同器官和全株生物产量比较

本试验旨在比较不同品种类型玉米(Zea mays)不同器官和全株的生物产量,以提高玉米定向培育的选择效率。选择32种具有代表性的玉米优良品种为试验材料,根据淀粉性质、籽实外形、成熟性质和用途4种分类方法,分别对完熟期玉米的籽实、玉米芯、苞叶、叶片、叶鞘、茎秆及全株的鲜物质、风干物质、干物质以及粗蛋白质和总能产量进行比较。每个品种选择5个地块,每个地块选取10株玉米。结果表明:玉米的籽实、玉米芯、苞叶、叶片、叶鞘、茎秆和全株的鲜物质、风干物质、干物质、粗蛋白质和总能产量不同品种类型间差异均显著(P0.05)。根据淀粉性质、籽实外形和成熟性质分类不足以区别不同品种类型玉米的不同器官和全株生物产量(P0.05)。按用途分类,不同品种类型玉米不同器官和全株生物产量(玉米籽实的风干物质、干物质和总能产量除外)均差异显著(P0.05),表现为饲用玉米红粒玉米普通玉米糯玉米。对广泛种植的普通玉米和饲用玉米进行比较,设定普通玉米产量为100.0%,则饲用玉米籽实、玉米芯、苞叶、叶片、叶鞘、茎秆和全株的鲜物质产量分别为121.9%、164.2%、175.5%、149.0%、151.7%、168.8%和149.9%;风干物质产量分别为107.9%、143.7%、155.1%、139.4%、126.1%、162.0%和129.1%;干物质产量分别为107.5%、143.4%、155.0%、139.5%、125.7%、162.0%和129.21%;粗蛋白质产量分别为119.0%、142.9%、181.5%、161.6%、122.0%、137.4%和131.7%;总能产量分别为107.7%、143.8%、155.0%、139.4%、126.1%、162.0%和129.1%。玉米籽实干物质、粗蛋白质和总能产量占玉米全株的比例,普通玉米分别为47.75%、57.87%和48.49%,饲用玉米分别为39.72%、52.36%和40.48%。由此得出,普通玉米全株饲喂是"粮改饲"的最基本的策略,而饲用玉米籽实和全株生物产量都高于普通玉米,种植饲用玉米可以增加30%左右的土地利用。     

饲粮蛋白质水平对空怀期云南半细毛羊氮沉积和养分排放的影响

本试验旨在研究饲粮蛋白质水平对空怀期云南半细毛羊氮沉积和养分排放的影响,以期为空怀期云南半细毛羊饲粮配比和减少环境负荷研究提供理论参考。试验选用50只体况良好、体重相近、38月龄的空怀期云南半细毛羊,随机分成5个组(每组10只),分别饲喂蛋白质水平为7.60%(组1)、9.49%(组2)、11.29%(组3)、11.56%(组4)和14.96%(组5)的饲粮,饲粮其他营养水平保持一致。试验羊进行19d的饲养试验,其中预试期14d,正试期5d。正试期从每组选择5只试验羊进行消化代谢试验,试验羊在代谢笼中单笼饲养,采用全收粪尿法连续收集5d粪便,并采集饲粮样品。结果表明:1)饲粮蛋白质水平对空怀期云南半细毛羊的干物质采食量和粪干物质排放量无显著影响(P>0.05)。2)随着饲粮蛋白质水平的升高,氮摄入量呈显著或极显著增加(P<0.05或P<0.01);组3的氮沉积率极显著高于组1(P<0.01),其他组间差异不显著(P>0.05)。3)粪氮排放量随饲粮蛋白质水平的升高逐渐增加,组2与组1、组3差异不显著(P>0.05),其他组间差异极显著(P<0.01);粪钙排放量以组3最低(5.04g/d),且极显著低于组5(P<0.01);粪磷排放量随饲粮蛋白质水平的升高逐渐增加,组1、组2、组3极显著低于组5(P<0.01),组4显著低于组5(P<0.05)。4)尿氮排放量随着饲粮蛋白质水平的升高逐渐增加,组2与组1、组3差异不显著(P>0.05),其他组间差异极显著(P<0.01);尿钙排放量以组3最低,为1.18g/d,比组1、组5分别降低0.53和0.78g/d;尿磷排放量组1显著低于组5(P<0.05),其他各组间差异不显著(P>0.05)。5)粪尿氮排放总量组5极显著高于其他组(P<0.01),粪尿钙排放总量组3极显著低于其他组(P<0.01),粪尿磷排放总量组1、组2极显著低于组5(P<0.01)。6)粪氮占比为72.44%~42.06%,随着饲粮蛋白质水平的升高逐渐降低,尿氮占比为27.56%~57.94%,随着饲粮蛋白质水平的升高逐渐升高;粪、尿钙和磷占比各组间差异不显著(P>0.05)。综合各项指标,在本试验条件下,当饲粮蛋白质水平为11.29%时,空怀期云南半细毛羊的氮沉积最佳,粪尿钙排放总量最低;饲粮蛋白质水平在一定范围(7.06%~11.56%)时对空怀期云南半细毛羊粪尿磷排放总量无显著影响;空怀期云南半细毛羊对钙、磷的排放以从粪中排放为主,多余的氮则主要从尿中以尿氮的形式排出。     

口蹄疫病毒3C蛋白多克隆抗体的制备与鉴定

扩增口蹄疫病毒(FMDV) 3C蛋白编码基因,将其克隆到原核表达载体,并转化至大肠杆菌BL21中进行诱导表达; 3C重组蛋白纯化后免疫新西兰大白兔,制备多克隆抗体,通过ELISA和Western blot检测多克隆抗体的效价和特异性,并将该抗体通过间接免疫荧光(IFA)和Western blot应用于3C的检测。ELISA结果显示,制备的3C蛋白多克隆抗体效价达1∶256 000; IFA结果显示,该抗体能够检测到3C蛋白在细胞中的定位; Western blot结果显示,该多克隆抗体能够检测到在细胞中过表达的3C蛋白。本研究制备的FMDV 3C蛋白多克隆抗体为FMDV及其3C蛋白的相关研究提供了重要的物质基础。