细叶百合休眠与解除SSH文库构建及其调控基因的初步筛选

 为了验证百合鳞茎休眠解除过程中基因表达的差异性，以细叶百合休眠鳞茎和休眠解除鳞 茎为材料，利用抑制消减杂交技术构建了百合鳞茎休眠及解除正、反向抑制消减文库。文库富集了差异 基因，消减效率符合要求，插入片段集中于250 ~ 1 000 bp 之间。对正、反向文库随机挑选阳性克隆测序， 各获得100 个表达序列标签（EST），在NCBI 上进行BLASTx 分析，并用KOBAS 系统将获得的unigene 定位到Pathways 中。分析结果表明，休眠文库ESTs 功能主要涉及胁迫响应方面，如苯丙氨酸代谢途径、 促分裂素原活化蛋白激酶途径等与休眠有关。休眠解除文库在糖代谢、激素响应及信号转导方面表达量 较高，如亚油酸代谢途径、淀粉及蔗糖代谢途径等参与了休眠解除过程。     

Identification and Functional Analysis of Differentially Expressed Genes of Ascaris suum Goeze, 1782 from Ascaris lumbricoides Linnaeus, 1758

In order to provide further evidence to prove that Ascaris suum Goeze,1782 and Ascaris lumbricoides Linnaeus,1758 are really different species in taxonomy,and to identity A.suum larval migrans-related genes for diagnosis and prevention use,A.suum genes that were differentialy expressed from the same gender of A.lumbricoides were enriched by subtracting the same expressed genes using suppression subtractive hybridization （SSH） assay.Specificity of the selectively enriched cDNA was verified by Southern blot analysis.The female A.suum specific cDNA library was then constructed and sequenced.Basic local alignment search tool （BLAST） analysis of female A.suum specific cDNA identified 6 specific ESTs with tentative functions related to larva migrans.This study provided further evidence for differentiating A.suum from A.lumbricoides.Mining for the detailed information and application of the 6 ESTs are worth being done in the future studies.     

外源性谷氨酰胺对肉仔鸡空肠发育的影响

进一步研究谷氨酰胺(Gln)在促进肠道发育、免疫功能,提高机体对创伤、感染等应激状态下的适应性方面的作用机理,本试验选择1日龄艾维因肉仔鸡160只,按公母均分的原则随机分成4组,各处理组环磷酰胺注射剂量为4mg/kg,免疫抑制于试验第三周进行。Ⅰ组为对照组饲喂基础日粮,Ⅱ、Ⅲ、Ⅳ组为试验组分别在基础日粮的基础上添加质量分数为0.1%、0.2%、0.4%的Gln进行饲喂,建立谷氨酰胺对环磷酰胺免疫抑制艾维因肉仔鸡调节作用的动物模型,测定机体空肠指数、绒毛直径和固有膜厚度,为Gln在生产上促进肉仔鸡肠道发育、预防免疫抑制及抵抗应激损伤作用提供依据。     

Sources of resistance to bacterial blight of stock (Matthiola incana R. Br.)

Summary Accessions ofM. tricuspidata (L.) R. Br.,M. aspera Boiss. andMatthiola longipetala (Vent.) DC. were tested for their reaction to bacterial blight of stock (M. incana R. Br.), caused byXanthomonas campestris pv.incanae. Potted plants were sprayed with bacterial cell suspension, adjusted to 10⁸ cells/ml. The tested accessions of the three species were found highly resistant, while control plants ofM. incana were severely infected. InterspecificF ₁ hybrid plants betweenM. incana andM. tricuspidata also exhibited high resistance to the disease. The implications and the expected difficulties in breeding stock for bacterial blight resistance are discussed. Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No 1235-E, 1993 series.     

抑制性消减杂交技术及其在动物基因研究中的应用

抑制性消减杂交(SSH)是结合抑制性PCR和消减杂交技术发展起来的一种高效分离差异表达基因的方法,具有特异性高、假阳性率低、操作简便、灵敏度高等特点.在两种状态下基因的表达变化、差异基因的克隆和鉴定对基因表达调控有着重要意义.SSH在动物抗病、抗应激及药物的靶基因等方面的研究中取得了重要的进展.     

抑制性差减杂交技术及其在柑橘上的应用

抑制性差减杂交技术是一种高效分离和鉴定差异表达基因的生物学手段。介绍了抑制性差减杂交技术的基本原理、技术方法以及在柑橘中的应用。     

Isolation and expression analysis of differentially expressed genes in stem tissue of the Greek lemon cv. Adamopoulou

Lemon (Citrus limon (L.) Burm. f.) is susceptible to mal secco, a serious vascular disease caused by the fungus Phoma tracheiphila (Petri) Kant. and Gik., as well as low temperatures. The greek lemon cultivar Adamopoulou, thought to be derived from the Portuguese cultivar Lisbon, exhibits enhanced resistance to mal secco and cold as opposed to cv. Lisbon. Suppression subtractive hybridization (SSH) was employed for the isolation of differentially expressed genes in lemon stem tissue. A subtractive cDNA library was constructed and a total of 296 clones were sequenced. The obtained sequences were edited, resulting in 56 non-redundant ESTs. Sequence analysis revealed homology to previously identified genes involved in defense mechanisms against biotic and abiotic stresses, as well as sequences with no significant similarity in the GenBank. Selected ESTs were analyzed by real-time PCR for confirmation purposes. This analysis revealed significant expression differences between the two cultivars for genes expressing allantoinase, ultraviolet-B-repressible protein, 4-coumarate:CoA ligase and other proteins that are known to be upregulated under biotic and abiotic stress conditions.     

樱桃谷鸭人工感染鸭疫里默杆菌肝脏差异基因的筛选与鉴定

鸭疫里默杆菌病给全世界养鸭业带来了严重的经济损失,但人们对其毒力因子以及致病的分子机理,尤其是宿主对感染的应答反应还缺乏深入认识.本研究利用抑制消减杂交技术(SSH)构建了鸭疫里默杆菌感染过程中鸭肝脏组织差减cDNA文库,通过PCR和斑点杂交筛选到45个在鸭疫里默杆菌感染过程中鸭肝脏组织差异表达的基因,这些基因的功能分为急性期反应、炎症反应、免疫和防御应答、损伤修复以及其他功能.利用real-time RT-PCR对其中20个基因的在感染过程中不同时间段(8、24和48 h)表达水平进行了验证,结果表明这些基因在鸭疫里默杆菌感染过程中表达水平都有不同程度的上调或下调(P＜0.05或P＜0.01).试验结果表明,鸭疫里默杆菌感染引起鸭肝脏的一系列反应,包括急性期反应、炎症反应、免疫应答以及损伤修复等,通过对这些基因的差异调节,一方面维持机体的内环境平衡状态,另一方面启动机体的免疫系统识别和抵抗病原菌的侵袭.     

Methods of detection of Chlamydia psittaci in domesticated and wild birds

OBJECTIVE: To study the occurrence of Chlamydia psittaci in domesticated and wild birds and compare the sensitivity of molecular detection with cell culture isolation. DESIGN: Study of cell culture isolation and PCR detection of C psittaci in avian samples. PROCEDURE: Samples were obtained from 485 birds. Domesticated birds were selected at random from pet shops, private aviaries and zoos, while wild birds were captured locally, sampled, and immediately released. Swabs were collected from choanal slit, conjunctiva and cloaca of each bird and pooled. Samples were divided into equal portions for use in PCR dot-blot and cell culture detection. PCR and dot-blot detection was based on the ompB gene. RESULTS: Prevalence of infection varied markedly between flocks of captive birds. It was highest where there were frequent changes in the flock members or where there were many birds confined in small areas. C psittaci was not detected in wild birds or water birds. The sensitivity of cell culture compared to PCR dot-blot detection was 68%. All samples positive by cell culture were also positive by PCR. CONCLUSIONS: PCR-dot blot detection of C psittaci in birds appears to be more sensitive than cell culture isolation in this study. C psittaci infection of birds may occur in clinically normal captive birds.