Core Collection Based Backcrossing: An Efficient Approach for Breeding,Germplasm Enhacement and Gene Discovery

Plant germplasm underpins much of crop development. Millions of germplasm accessions have been collected and conserved ex situ, and the major challenge is now how to exploit and utilize this abundant resource.     

Core Collection Based Backcrossing： An Efficient Approach for Breeding, Germplasm Enhacement and Gene Discovery

Plant germplasm underpins much of crop development. Millions of germplasm accessions have been collected and conserved ex situ, and the major challenge is now how to exploit and utilize this abundant resource. ＂Genoplasmics＂ is a vital cross-disciplinary research field, which seeks to apply the principles and techniques of genomics to gennplasm research. We describe in this paper the concept, strategy and approach behind genoplasmics, and summarize current progress in the areas of the definition of core collections （CC） and mini core collection （MCC） （Jia et al., 2005）. Based on wheat core collection as donor parents, 249 sets introgression lines （ILs） were developed which consisted of about 20 000 lines. As CC/MCC derived ILs （CCILs） potentially reveal many alleles at loci distributed throughout the genome, they can be reasonably described as genome wide multiple allele ILs （GMA-ILs） （Zhou et al., 2005; Liu et al., 2005）. Hundreds lines selected from the IL have been used as parents and more than 2 000 cross combination have been made in wheat breeding program of China and more than 100 lines were selected directly from the IL for yield test.     

白细胞介素18生物学作用及其在病毒感染中的表达调控

白细胞介素18（IL－18）作为一种能诱导产生IFN－γ的因子，在机体产生抗微生物免疫中起着重要作用。巨噬细胞是生物活性IL－18的主要来源，它们持续转录IL－18的mRNA并表达其前体蛋白。微生物感染可提高巨噬细胞中IL－18基因的表达水平，IL－18分泌的调节以IL－18前体蛋白翻译后的调节为主，而不是对转录活性进行调控。本文综述了IL－18的生物学特性，总结了IL－18促进炎症和免疫调节功能的最新知识，重点讨论病毒感染时巨噬细胞产生IL－18的Caspase依赖性调控。     

bcr-abl融合基因片段和mIL-7基因双表达载体的构建与表达

利用重组DNA技术构建bcr-ab l融合基因片段和m IL-7基因双表达载体pV bcr-ab l/m IL 7,转染CHO细胞,通过IFA检测bcr-ab l融合基因片段和RT-PCR检测m IL-7基因,以探讨基因的双表达情况。结果表明:成功构建了双表达载体pV bcr-ab l/m IL 7,并检测到bcr-ab l和m IL-7在真核细胞的暂态表达,这为慢性粒细胞白血病bcr-ab l融合基因疫苗的研究提供了新的工具。     

Mycoplasma hyopneumoniae-derived lipid-associated membrane proteins induce apoptosis in porcine alveolar macrophage via increasing nitric oxide production,oxidative stress,and caspase-3 activation

Mycoplasma hyopneumoniae is the primary etiological agent of enzootic pneumonia in swine. Lipid-associated membrane proteins (LAMP) of mycoplasma are the main pathogenicity factors in mycoplasma diseases. In this study, we investigated the effects of M. hyopneumoniae LAMP on porcine alveolar macrophage (PAM) 3D4/21 cell line. Apoptotic features, such as chromatin condensation and apoptotic bodies, were observed in LAMP-treated PAM 3D4/21 cells. Moreover, LAMP significantly increased the number of TUNEL positive apoptotic cells in PAM 3D4/21 cells compared with the untreated control. In addition, flow cytometric analysis using dual staining with annexin-V-FITC and propidium iodide (PI) showed that LAMP of M. hyopneumoniae induced a time-dependent apoptosis in PAM 3D4/21 cells. Moreover, increased levels of superoxide anion production and activated caspase-3 in PAM 3D4/21 cells were observed after exposure to LAMP. Increased production of nitric oxide (NO) was also confirmed in the cell supernatants. Besides, apoptotic rates increase and caspase-3 activation were suppressed by NOS inhibitor or antioxidant. It is suggested that LAMP of M. hyopneumoniae induced apoptosis in porcine alveolar macrophage via NO production, superoxide anion production, and caspase-3 activation.     

羊传染性脓疱病毒疫苗株和野毒株GIF基因比较分析

羊传染性脓疱(orf)是由羊传染性脓疱病毒(orf virus,ORFV)感染引起的绵羊和山羊的一种接触性人兽共患病。粒细胞-巨噬细胞集落刺激因子(GM-CSF)/白细胞介素(IL-2)抑制因子(GIF)基因为ORFV编码中晚期病毒基因,它能够与GM-CSF、IL-2结合并且抑制二者的活性,从而抑制宿主抗病毒作用。为了比较疫苗毒株和流行毒株间GIF的差异,本试验扩增并测定了ORFV疫苗株和野毒株的GIF基因序列,比较分析了ORFV疫苗弱毒株和野毒株GIF基因的核酸水平和氨基酸水平的差异情况,以及二、三级蛋白结构。结果表明:本次测定的ORFV疫苗株与野毒GIF基因核苷酸序列相似性为94.3%,氨基酸序列相似性为92.5%,两者的蛋白三级结构预测上也有差异。本研究结果为该病的防控提供了参考依据。     

玉屏风多糖对草鱼肠黏膜形态结构及主要免疫与吸收相关基因表达的影响

本试验旨在探讨不同比例玉屏风多糖对草鱼肠黏膜形态结构及主要免疫与吸收相关基因表达的影响。试验选择750尾平均体重为(74.50±2.50)g的健康草鱼,随机分为5组,每组6个重复,每个重复25尾。对照组(Ⅰ组)投喂基础饲料,试验组(Ⅱ~Ⅴ组)投喂在基础饲料基础上分别添加0.8、1.2、1.6、2.0 g/kg玉屏风多糖的试验饲料。预试期7 d,正试期28 d。结果表明:1)与对照组相比,在试验第14天时,Ⅴ组的隐窝深度显著降低(P0.05),而绒腺比则显著提高(P0.05)。2)对照组相比,在试验第7天时,Ⅲ和Ⅳ组头肾中白介素-2(IL-2)mRNA相对表达量显著或极显著提高(P0.05或P0.01),Ⅱ、Ⅲ、Ⅳ和Ⅴ组头肾中干扰素γ(IFN-γ)mRNA相对表达量均极显著提高(P0.01),Ⅲ、Ⅳ和Ⅴ组肠道中钠葡萄糖转运蛋白1(SG LT-1)和葡萄糖转运蛋白2(GLUT-2)mRNA相对表达量显著或极显著提高(P0.05或P0.01))。3)与对照组相比,在试验第14天时,Ⅳ和Ⅴ组头肾中IL-2 mRNA相对表达量极显著提高(P0.01),Ⅱ、Ⅲ、Ⅳ和Ⅴ组头肾中IFN-γmRNA相对表达量显著或极显著提高(P0.05或P0.01),Ⅲ、Ⅳ和Ⅴ组肠道中SG LT-1和G LUT-2 mRNA相对表达量极显著提高(P0.01)。4)与对照组相比,在试验第21天时,Ⅳ组头肾中IL-2 mRNA相对表达量显著提高(P0.05),Ⅱ、Ⅲ、Ⅳ和Ⅴ组头肾中IFN-γmRNA相对表达量极显著提高(P0.01),Ⅱ、Ⅲ、Ⅳ和Ⅴ组肠道中SG LT-1和G LUT-2 mRNA相对表达量显著或极显著提高(P0.05或P0.01)。5)与对照组相比,在试验第28天时,Ⅳ和Ⅴ组头肾中IL-2 mRNA相对表达量极显著提高(P0.01),Ⅲ、Ⅳ和Ⅴ组头肾中IFN-γmRNA相对表达量显著或极显著提高(P0.05或P0.01),Ⅱ、Ⅲ、Ⅳ和Ⅴ组肠道中SGLT-1 mRNA相对表达量显著或极显著提高(P0.05或P0.01)。综上所述,在草鱼饲料中添加一定量的玉屏风多糖能够改善肠黏膜形态结构,促进肠道中SGLT-1和GLUT-2基因的表达,调控头肾中IL-2和IFN-γ基因的表达,从而提高肠道吸收功能、增强机体免疫力。从节约饲养成本出发,草鱼饲料中玉屏风多糖最适添加量为1.6 g/kg。     

IL-2在自然感染兔脑炎原虫獭兔体内免疫作用的研究

为观察 IL-2在自然感染兔脑炎原虫獭兔体内的免疫作用 ,用双抗体夹心 EL ISA试剂盒对 8只自然感染兔脑炎原虫的獭兔和 4只健康长耳白对照兔的血清及培养 3 d和 4d的脾和淋巴结的细胞培养上清中的 IL-2进行了检测。检测结果为病兔与对照兔 IL -2平均含量差异不显著 (P >0 .0 5) ,但病兔 IL -2平均含量高于对照兔。提示 IL -2对病兔产生了一定的免疫作用 ,但可能不扮演主要角色     

间歇光照对肉鸡腹水征及生产性能的影响

４００只７日龄艾维茵肉鸡,随机均分为１,２,３和４组,４个小组垫料平养。１组和３组采用２３Ｌ∶１Ｄ的连续光照程序（ＣＬ）,２组和４组为１Ｌ∶３Ｄ的间歇光照程序（ＩＬ）。１组和２组空气中氨气浓度≤１０ｐｐｍ,３组和４组空气中氨气浓度控制在２５～３５ｐｐｍ。结果表明,间歇光照可显著降低由氨气浓度过高引起的肉仔鸡腹水征和心肺功能异常造成的死亡率,与连续光照相比,间歇光照不影响肉鸡出栏时的体重,但能改善饲料报酬。要想充分发挥间歇光照对肉鸡的有利作用,必须为其提供良好的饲养条件。     

IL15/PAP融合蛋白基因克隆及其原核与植物表达载体的构建

将IL15和PAP基因通过一甘氨酸接头(Gly4Ser)3连接在一起,构建原核和植物表达载体,以期表达具有导向杀伤活性的融合蛋白.在引物设计中,通过引物在IL15基因下游引入(Gly4Ser)3的编码序列和BamHI位点,然后采取分步克隆及PCR、酶切、连接等一系列分子克隆方法,将IL15和PAP基因融合在一起,构建融合蛋白的原核与植物表达载体.经PCR和NcoI/SalI双酶切鉴定及测序,证实原核表达载体pET32a-IL15/PAP及植物表达载体pB-I P中均插入了正确的融合基因序列.