Construction of ice nucleation active <Emphasis Type="Italic">Enterobacter cloacae</Emphasis> for control of insect pests

Ice nucleation active(INA)bacteria are the most potent heterogeneous ice nuclei in nature,which have become an important biological resource for diverse applications.Many researches have proved that INA bacteria can raise the supercooling points(SCPs)of insect pests,then reduce their cold hardiness.However,INA bacteria‘s inefficient colonization on the surface or in the guts of insects,and the high incidence of frost injury induced by their release hampered the application of INA bacteria in controlling insect pests in agricultural fields.In this study,we constructed a recombinant plasmid mob-Tn5-iceA with the ability of broad-host-range conjugal mobilization and integration of the ina gene of icaA into chromosomal DNA of many gram-negative bacteria by Tn5 transposition.In addition,Ent.cloacae strains stably carrying iceA and expressing high ice nucleation activity(INA),even in the absence of antibiotic pressure,were constructed through conjugal mobilization and Tn5 transposition.Ent,cloacae strains have benn reported to be able to efficently colonize in the guts of insects,but have weak plant epiphytic ability.Therefore,these transgenic Ent.Cloacae may be promising candidates for control of insect pests in agricultural fields.     

Expression of recombinant human lysozyme in the milk of transgenic mice

Human lysozyme is a 130-aa (amino acid) alkaline polypeptide, and has both anti-bacterial and anti-viral properties which make it an important component of human natural immunity system. As a first step toward the ultimate goal of improving the anti-bacterial properties of bovine and ovine milk, a transgenic mouse that contains the genomic DNA sequence of the human lysozme gene has been generated for the first time. From 83 mice generated by microinjection, a total of 6 positive transgenic mice were identified by PCR and Southern blot. F1 mice positive for transgene in lines were also detected by PCR. This shows that transgene could be transmitted from founder transgenic mice to their offspring. Recombinant human lysozyme (rHlys) was found in the whey of 3 female positive transgenic mice by Western blot. The highest concentration of rHlys for transgenic mice was 0.2mg/mL. The antibacterial activity of the whey for transgenic mice was highly enhanced up to 0.4 times as much as that of human, while that of non-transgenic mouse was very low. Although the lysozyme activity of transgenic mice is still lower than that of human, the rHlys exhibits the same specific activity as that of human lysozyme. It provides a strong basis for further studies into the possible application of rHlys express in mammary gland.     

简便实用的转抗除草剂基因后代植株鉴定方法--种子萌发测定法

种子萌发法是检测外源抗性基因在转基因植物中的表达和分析外源抗性基因在转基因植物中遗传行为的简单而直接的方法,以转ｂａｒ基因燕麦后代Ｒ２种子为材料,用不同体积分数的除草剂Ｃｈａｌｌｅｎｇｅ处理种子,萌发的幼苗经ＰＣＲ和Ｓｏｕｔｈｅｒｎ ｄｏｔ ｂｌｏｔ鉴定,发现在０．０３％的除草剂上萌发的幼苗,部分不含ｂａｒ基因,而在０．０７％和０．０９％的除草剂上萌发的幼苗,均含ｂａｒ基因。用０．０７％的除草剂测     

水稻花培育种技术操作和无性系变异体选择

概述了水稻花培育种的技术操作程序和细胞无性系变异的选择方法。选择合适的水稻花培起始材料,选用适宜的培养基配方,对于水稻花培中愈伤组织诱导和分化至关重要。某些增效因子（例如水解乳蛋白、单核苷酸、ＡｇＮＯ３等）可提高灿稻花培的绿苗分化率。无性系变异为农作物细胞工程育种提供丰富的选择材料。通过对细胞变异的研究,建立了裸米选择－测米培胚的技术方法,并选育出多个高蛋白量的水稻优质品种（品系）。     

庆大霉素高产菌株的抗性方法选育

以生产菌株绛红小单孢菌为出发株,应用N 离子注入及紫外线诱变技术,利用高浓度的庆大霉素梯度平板筛选,或配合含有高浓度庆大霉素的液体培养基的生态驯化,筛选到摇瓶效价分别比出发株提高75.2%和70.1%的N08和Wt63两个高产菌株,10 L发酵罐发酵产量分别达2 118 u/mL和1 843 u/mL,C组分含量符合中国药典2000版的规定.     

黑龙港流域小麦育种研究现状、问题及对策

黑龙港麦区水资源严重不足,要实现该区小麦的丰产稳产,必须要求小麦品种具备多种抗逆性状。通过对黑龙港流域小麦的育种现状和育种中存在的问题进行研究,来重新确定育种目标。     

Carboxymethytl Pachymaram Up-Regulates Dendritic Cell＇s Function in Hepatitis B Virus Transgenic Mice

The effect of carboxymethytl pachymaram (CMP) on the function of dendritic cells(DCs) derived from spleens of hepatitis B virus transgenic mice are studied in vitro. The phenotypes of DCs are tested by flow cytometry (FCM), cytokines measured by ELISA. The expression of DCs’ phenotypes in HBV transgenic mice are low (CD80⁺CD11c⁺:59.12±11.53 vs 9.60±4.53, p<0.01; CD80⁺ MHC-II⁺: 44.86±12.31 vs 9.80±5.72, p<0.01, normal mice vs HBV transgenic mice), the ability of DCs stimulating T lymphocytes proliferation decreases (0.37±0.11 vs 0.20±0.11, p<0.05, normal mice vs HBV transgenic mice), levels of IL-12 and IFN-γ decrease whereas the level of IL-10 increases; CMP can enhance DCs’ ability of stimulating T lymphocytes proliferation, facilitate the secretion of IL-12 and IFN-γ, inhibit the secretion of IL-10, thus up regulates DCs function. The results show a good prospective use of CMP on the treatment of chronic hepatitis B. Biography: HOU Anji (1963–), male, Ph.D. candidate, Associate professor, research direction: clinical virology.     

转基因工程抗虫杂交稻大米的食品安全性评价

为评价转基因工程抗虫杂交稻大米的食品安全性,以转crylAc/sck双价基因抗虫杂交稻Ⅱ-32A/MSB,KF6-304大米为材料,进行了大鼠30 d喂养试验,检测转基因杂交稻大米对大鼠表观体症、脏器系数、血常规与血生化指标值的影响.结果显示:转基因抗虫杂交稻Ⅱ-32A/MSB,KF6-304大米各剂量组喂养大鼠,大鼠的行为、呼吸、毛色均正常.以Ⅱ-32A/MSB饲喂大鼠,除雌鼠低剂量组的胃体比、血清总蛋白与中剂量组的球蛋白明显高于对照组,雌鼠低剂量组的萄葡糖与中剂量组的白球比例、雄鼠低剂量组与高剂量组的嗜中性粒细胞百分比显著低于对照组外,其余重要检测指标值均与对照无显著差异.以KF6-304饲喂大鼠,除低剂量组雌鼠的甘油三酯与中剂量组雄鼠的萄葡糖显著低于对照组,其余重要检测指标值则与对照均无显著差异.以上结果提示转基因工程抗虫杂交稻Ⅱ-32A/MSB,KF6-304大米的30 d喂养试验对大鼠表现体症及生理生化无明显不良影响.表5,参12.     

慢病毒载体研究进展

慢病毒作为一种特殊的逆转录病毒,与通常使用的逆转录病毒载体和腺病毒载体比较,具有可感染分裂细胞及非分裂细胞、转移基因片段容量较大、目的基因表达时间长、不易诱发宿主免疫反应等优点,已成为当前基因治疗和转基因动物中载体研究的热点。近年来对其基础生物学特性、载体改造及其应用等研究均取得了较大进展。本文就慢病毒载体及应用方面的研究进展作一综述。     

祖辈们吃过的食物才最安全?

<正>长久试吃,从来就不是食品安全的检验方法。近来,一篇名叫《灭绝人性的×××(某商业品牌),太坑人了!太恐怖了!》的文章,在微信的朋友圈里广为传播,引起了不少朋友的高度关注。不过细读之下,也令人大跌眼镜。全文充满了阴谋论(发达国家用转基因作物来消灭"垃圾人口")、想当然("按美国标准,这些公司要赔10亿美金以上,如果上面没有标明转基因食物")和胡编