黑翅土白蚁ISSR-PCR体系的建立与优化

采用单因子梯度优化的方法,对已初步建立的黑翅土白蚁ISSR-PCR的反应体系在dNTPs浓度、Mg²⁺浓度、引物浓度、模板量及TaqDNA聚合酶用量等方面进行了优化。结果表明,适用于黑翅土白蚁的ISSR-PCR反应体系中各因素的最佳浓度分别为：dNTPs 0.2 mmol·L^-1,Mg²⁺ 3.0 mmol·L^-1,引物浓度0.4 μmol·L^-1,模板用量DNA 20 ng,TaqDNA聚合酶2.5 U。     

A Simple and Reliable Assay for Detecting Specific Nucleotide Sequences in Plants Using Optical Thin-film Biosensor Chips

Here we report the adaptation and optimization of an efficient, accurate and inexpensive assay that employs custom-designed silicon-based optical thin-film biosensor chips to detect unique transgenes in genetically modified （GM） crops and SN-P markers in model plant genomes. Briefly, aldehyde-attached sequence-specific singlestranded oligonucleotide probes are arrayed and covalently attached to a hydrazine-derivatized biosensor chip surface. Unique DNA sequences （or genes） are detected by hybridizing biotinylated PCR amplicons of the DNA sequences to probes on the chip surface. In the SN-P assay, target sequences （PCR amplicons） are hybridized in the presence of a mixture of biotinylated detector probes and a thermostable DNA ligase. Only perfect matches between the probe and target sequences, but not those with even a single nucleotide mismatch, can be covalently fixed on the chip surface. In both cases, the presence of specific target sequences is siL, nified by a color change on the chip surface （gold to blue/purple） after brief incubation with an anti-biotin IgG horseradish peroxidase （HRP） to generate a precipitable product from an HRP substrate.     

2种热带珍稀果树蛋黄果和蛋黄桃榄果在粤西引种试验及其发展潜力分析

从国外引进两种珍稀果树蛋黄果和蛋黄桃榄果,在粤西地区进行引种栽培试验以各个果树品种的生长量、保存率和结果情况来评价各品种的适应性,最后对两种果树在我国的发展潜力作了分析和预测。     

从化温泉松材线虫病综合防治示范区建设及其成效

2001～2005年,在严密监测疫情的基础上,对从化温泉松材线虫病综合防治示范区采取检疫封锁、清除病死树、应用引诱剂防治和树干打孔注药等综合防治措施,取得了良好的防治效果,发病松林面积由2001年开始发病时的573.3 hm2减少到2005年底的346.7 hm2,病死树数量由2001年的3 726株降低到2005年的239株,林间松墨天牛种群数量也大幅度下降.初步形成了一套较为完整的松材线虫病防治技术方法.     

Ulva (Enteromorpha) Polysaccharides and Oligosaccharides: A Potential Functional Food Source from Green-Tide-Forming Macroalgae

The high-valued utilization of Ulva (previously known as Enteromorpha) bioresources has drawn increasing attention due to the periodic blooms of world-wide green tide. The polysaccharide is the main functional component of Ulva and exhibits various physiological activities. The Ulva oligosaccharide as the degradation product of polysaccharide not only possesses some obvious activities, but also possesses excellent solubility and bioavailability. Both Ulva polysaccharides and oligosaccharides hold promising potential in the food industry as new functional foods or food additives. Studies on Ulva polysaccharides and oligosaccharides are increasing and have been the focus of the marine bioresources field. However, the comprehensive review of this topic is still rare and do not cover the recent advances of the structure, isolation, preparation, activity and applications of Ulva polysaccharides and oligosaccharides. This review systematically summarizes and discusses the recent advances of chemical composition, extraction, purification, structure, and activity of Ulva polysaccharides as well as oligosaccharides. In addition, the potential applications as new functional food and food additives have also been considered, and these will definitely expand the applications of Ulva oligosaccharides in the food and medical fields.     

热应激对家禽HPG轴结构和繁殖功能的影响及HSPs的作用

高温环境容易引起家禽热应激,造成家禽下丘脑-垂体-性腺(hypothalamic-pituitary-gonadal,HPG)轴各组织结构不同程度的损伤,进而影响家禽正常繁殖功能,给集约化饲养管理模式下家禽养殖业造成一定的损失。热休克蛋白(HSPs)是一类保护性蛋白,它能在家禽遭受高温应激时发挥分子伴侣作用,一定程度上保护机体免受高温刺激的损伤。文章对热应激条件下家禽的HPG轴各组织结构、繁殖功能的影响及HSPs的作用进行综述,为家禽生产提供相关资料。     

Study on Secretory Expression and Immunogenicity of PPRV F Gene in Insect Cells

This study was aimed to explore the use of baculovirus expression system to secrete peste des petits ruminants virus (PPRV) F gene protein and use it as subunit vaccine. The gene fragment encoding F protein of PPRV was cloned into the baculovirus pFastBac Ⅰ transfer vector with a honeybee melittin signal peptide.The constructed F-pFastBac was transformed into Escherichia coli DH10Bac,resulting the recombinant baculovirus DNA (F-Bacmid) which was confirmed by blue-white plaque assay and antibiotic resistance selection.The F-Bacmid was then transfected into Sf9 insect cells by the cellfectin transfection reagent.The recombinant F protein was expressed in High Five cells in the serum-free medium.The SDS-PAGE and Western blotting analysis of recombinant protein showed that the protein could be expressed in insect cells and secreted into the culture medium. For the immunogenicity study,the recombinant protein was then inoculated into BALB/c mice, the results showed that the recombinant protein was able to stimulate B cells to produce special antibodies. In conclusions,the recombinant baculovirus expressing F protein of PPRV were successfully constructed.This study applied a basis for the development of PPRV subunit vaccine.     

Oxalate-degrading capacities of lactic acid bacteria in canine feces

In this study, lactic acid bacteria in canine feces were isolated and identified, and their oxalate-degrading capacities were evaluated. The oxalate-degrading capacities were determined for 24 of 47 (51.06%) lactic acid bacteria isolates. Of these, 8 isolates [Leuconostoc mesenteroides (RL75), Lactococcus garvieae (CD2), Lactococcus subsp. lactis (CS21), Enterococcus faecium (CL71 and CL72), and Enterococcus faecalis (CD14, CS62, and CD12)] degraded more than 5% of the oxalate present, while the others degraded less than 5% of the oxalate in vitro. Isolates that degraded more than 5% of the oxalate present were selected for further examination. The oxalate-degrading capacities of individual isolates, a mixture of Enterococcus, a mixture of Lactococcus, and a mixture of the eight isolates were evaluated in media containing different concentrations of glucose (sufficient, insufficient, or no glucose). In comparison with the control medium, all of the individual isolates and mixtures of isolates could degrade oxalate in all three groups (P<0.05). In most cases, the isolates growing in medium with 20 g/L of glucose had higher oxalate-degrading capacities than those growing in medium with 2.5 g/L of glucose or no glucose. The mixture of all isolates showed higher oxalate-degrading capacity than the individual isolates and other mixtures. The oxalate-degrading capacities of the isolates were isolate dependent.     

表达猪生长激素基因的重组腺病毒的构建及对猪生长的促进效果观察

利用复制缺陷型重组腺病毒作为基因表达载体,将猪生长激素（pGH）基因直接转导到猪体内细胞,研究猪生长激素基因在猪体内的促生长作用.用同源重组的方法,构建含pGH基因的重组腺病毒（Ad-pGH）.将其感染293细胞和PK-15细胞,均可检测到pGH.用1 mL此重组腺病毒（1010TCID50）一次性肌肉注射60日龄的杂交长白猪.结果表明,试验组的猪平均增重比对照组的猪增加37%（注射后第4周）和19%（注射后第6周）;饲料报酬提高28%（注射后第4周）和18%（注射后第6周）.试验结果证明,由重组腺病毒表达的pGH具有生物学活性,在猪体内起到明显的促进生长的作用.重组腺病毒介导的pGH基因在猪体内的表达可维持约4周.     

从尼日利亚进境的芋头中截获最短尾短体线虫

广东检验检疫技术中心植检实验室于2008年4月从尼日利亚进境的芋头中分离到数条短体线虫,经纯培养、形态观察、测量,以及对rDNA-ITS、D2D3区序列的扩增、克隆、测序分析,鉴定为最短尾短体线虫(Pratylenchus brachyurus(Godfrey,1929)Filipjev & Schuurmans Stekhoven,1941)。该线虫在国内局部分布,属于检疫性线虫,在系统内首次截获。