青枯菌Ⅲ型分泌系统HrcN原核表达与亚细胞定位

为探究青枯菌Ⅲ型分泌系统（type Ⅲ secretion system,T3SS）HrcN在致病过程中的功能,分别克隆青枯菌CBM613菌株的hrcN基因并连接至pET30a和pRI-eGFP载体,转化寄主细胞,开展原核表达及亚细胞定位研究。结果显示,HrcN蛋白是T3SS的结构组分之一,具有ATP酶活性,可在胞内水解ATP酶为效应蛋白的分泌过程提供能量。蛋白亚细胞定位预测表明,青枯菌HrcN蛋白定位于细胞内膜和细胞质,激光共聚焦定位结果显示,HrcN蛋白部分在叶绿体表达,部分在细胞内膜和细胞质表达,与蛋白亚细胞定位预测结果基本一致。据此推测HrcN是一种定位于细胞内膜上的外周蛋白,该结论为后续研究青枯菌T3SS的功能及其致病机制奠定基础。     

表达禽流感病毒核蛋白重组噬菌体的构建

摘要：利用PCR技术，扩增去除部分序列、长度为1320 bp、编码440个氨基酸的禽流感病毒(AIV)NP基因片段，将其克隆至pR质粒的T4噬菌体SOC基因C末端获得重组质粒pR-NP，以此重组载体转化大肠杆菌E2，用溶菌酶缺陷噬菌体T4-Z1感染重组E2菌，重组载体与缺陷噬菌体T4-Z1基因发生同源重组，将NP基因整合到噬菌体基因组中，用PCR方法筛选重组噬菌体并命名为T4-Z1-NP。经Western blot检测证实，T4-Z1-NP表达的NP融合蛋白具有免疫学活性。成功构建了表达禽流感病毒核蛋白的重组噬菌体。     

中国农史学科百年历史之溯源

1955年7月,中国农业遗产研究室在南京农学院正式成立,标志着我国农史研究事业受到党和国家的重视,进入了一个较快的发展阶段。然而,少有人知的是,作为中国农业遗产研究室的前身——金陵大学农业图书合作部,早在1920年代就开始初步的农史研究工作。金陵大学农业图书合作部自成立之初就与美国农业部和国会图书馆合作,由美国农业部官员施永高和金陵大学农林科长芮思娄主导,美方派遣图书馆专业人员卫德女士来华,任金陵大学农业图书合作部主任,协助编制古农书索引。这场合作为中国的农史学科发展提示了方向,金陵大学农业图书合作部历经战乱改组而不改初心,广泛收集地理方志,加以校勘编纂,为中国农史学科发展做了人员、资料和方法上的准备,为后世农史研究留下了宝贵的资料,同时也奠定了中国农业遗产研究室的雏形。     

鸡包涵体肝炎过程中IFN-γ的mRNA原位杂交

FAV-Ⅷ型禽腺病毒口服接种感染2日龄SPF雏鸡,攻毒后取不同日龄的肝脏于福尔马林溶液中固定,并进行石蜡包埋,石蜡切片进行原位杂交染色.结果表明,着染部位主要出现在坏死灶或血管周围的成团或散在的淋巴细胞的胞浆内,在病情严重时的5 dpi开始增多,至20 dpi表达量也很高,以后开始减少,直到30 dpi基本消失.说明鸡包涵体肝炎过程中肝脏IFN-γ的mRNA大量上调,可能与T淋巴细胞的增多有关;而且IFN-γ作为免疫增强剂与抗病毒感染和病症恢复也有关.     

赛里木湖新疆高原鳅生物学研究

本文对赛里木湖新疆高原鳅的形态特性、生长、食性及繁殖习性等生物学进行了观察研究。经观测赛里木湖新疆高原鳅雌性体长7.8cm(6.0g)，雄性体长9.0cm(8.2g)达性成熟。繁殖时间5-7月，平均绝对怀卵量20096粒/尾。食性以钩虾为主，其次是摇蚊幼虫。本文还对新疆不同水域新疆高原鳅形态特征进行了比较，并就赛里木湖水域环境对新疆高原鳅的影响进行了探讨。     

二斑叶螨与朱砂叶螨在棉花上的种间竞争力

通过比较二斑叶螨(Tetraychus urticae Koch)和朱砂叶螨(T.cinnabarinus Boisduval)以棉花为寄主时,单种种群和混合种群数量动态及内禀增长力(rm)值来确定2种叶螨竞争力的大小.结果表明:2种叶螨试验单种种群的活动虫态数量动态曲线均在第38天达到峰值,两者的单种种群达到峰值时活...     

2种植物多糖对PRRSV灭活苗免疫猪抗体及T淋巴细胞亚群的影响

将24头35日龄断奶仔猪随机分为6组,2种多糖(山药多糖和黄芪多糖)分别以高、低2个剂量(山药多糖剂量17.10、8.55mg/kg,黄芪多糖剂量为11.50、5.75mg/kg)和猪PRRSV灭活苗同时注射,于免疫后不同时间点采血,监测PRRSV抗体水平和外周血中T淋巴细胞亚群的变化.结果表明,2种多糖均能增强免疫猪的体液免疫,其中以高剂量的黄芪多糖效果较好;2种多糖均能促进猪CD3+细胞的增殖,其中以山药多糖效果较好,提示2种多糖对PRRSV灭活苗免疫效果均有较好的增强作用.     

Widespread distribution of Xanthomonas perforans and limited presence of X. gardneri in Brazil

Tomato bacterial spot is caused by Xanthomonas euvesicatoria, X. vesicatoria, X. perforans and X. gardneri. In order to determine the distribution, frequency of occurrence, and diversity of these species in the Brazilian commercial tomato fields, a survey was conducted between 2009 and 2012. In this period, 204 strains were obtained from 33 counties (22 with processing tomatoes and 11 with fresh‐market tomatoes). Pathogenicity tests, BOX‐PCR, PCR with species‐specific primers, and sequence analysis of the avirulence gene avrXv3 were performed in order to identify the strains at species and race level. Xanthomonas perforans predominated among the strains (92%) and was present in most counties. In addition, this species was prevalent in most areas of both fresh‐market tomatoes (63.6% of counties surveyed) and processing tomatoes (95.4% of counties surveyed). Fifteen strains (7.5%) were identified as X. gardneri, which was found mostly in fresh‐market fields located at regions with altitude higher than 900 m, and only one strain of X. euvesicatoria (0.5%) was found in a processing tomato field. High genetic diversity was observed within X. perforans, with 137 BOX‐PCR haplotypes. Race T3 prevailed (97.5%), but reported here for the first time is the occurrence of five strains identified as race T4 in fresh‐market fields in the state of São Paulo. The race T4 phenotype of these strains resulted from the presence of an 859 bp insertion in the avirulence gene avrXv3. This insertion is related to amino acid sequences of a transposase found in X. gardneri, and to amino acid sequences of X. campestris.     

转运真核表达盒的重组T7噬菌体构建

为了构建转运真核表达盒的重组T7噬菌体,并分别在体外、体内条件下检测其标签蛋白质EGFP的表达。以T7噬菌体基因组左侧578 bp处为插入位点,取上游400 bp和下游200 bp片段作为左右同源臂,并在其中插入表达EGFP基因的真核表达盒(EEB),构建同源重组质粒p UC-L-EEB-R。将该质粒载体转化T7噬菌体宿主细菌BL21,在噬菌体繁殖过程中完成同源重组,PCR筛选重组T7-EEB噬菌体。提取该重组噬菌体基因组转染Vero细胞后体外检测EGFP蛋白质表达,纯化的噬菌体免疫小鼠后体内检测EGFP蛋白质表达。结果显示,通过同源重组方法成功构建了携带真核表达盒的重组T7噬菌体,PCR检测和酶切鉴定均证明表达盒已正确插入。T7-EEB基因组转染真核细胞可见明显的EGFP蛋白质表达,免疫小鼠后活体荧光检测到EGFP蛋白质信号,在小鼠肝脏、脾脏组织中RT-PCR检测到EGFP基因的mRNA转录。表明同源重组方法可以用于构建重组T7噬菌体,噬菌体能够转运真核表达盒并实现蛋白质表达。     

Peripheral blood lymphocyte subsets in fleece rot-resistant and -susceptible sheep

Objective To compare haematological values and lymphocyte phenotypes in the peripheral blood of fleece rot-resistant and -susceptible sheep.
Procedure Experiments were conducted on 2- and 3-year-old Merino rams, flock 1 (17 rams) and flock 2 (32 rams), respectively. Within each flock, individual rams were classified as fleece rot-resistant or -susceptible, based on established criteria. Total and differential white cell counts, and indirect fluorescent antibody tests specific for B cells and T cells were performed on all sheep. The concentration of various subsets of circulating lymphocytes was then determined in each sheep.
Results There were no significant differences between fleece rot-resistant and -susceptible sheep from either flock in the mean total or differential white cell counts. However, fleece rot-resistant rams in flock 1 did have a significantly higher concentration of circulating SBU-T1⁺ cells than fleece rot-susceptible rams from the same flock. No such difference was noted in the rams from flock 2. While all rams in flock 1 were free of clinical fleece rot, 24 rams in flock 2 (comprising all 17 fleece rot-susceptible and 7 of 15 fleece rot-resistant animals) had clinical signs of the disease. Fleece rot-free rams in this flock (irrespective of their classification as fleece rot-resistant or -susceptible) had significantly higher concentrations of circulating SBU-T1⁺ cells compared with fleece rot-affected animals. They also had significantly higher concentrations of circulating B cells, and total lymphocytes.
Conclusions An examination of peripheral blood lymphocyte subsets in fleece rot-resistant and -susceptible sheep revealed a possible association between resistance to fleece rot and the concentration of circulating SBU-T1⁺ cells.