β淀粉样蛋白人源性抗体的制备

目的:应用噬菌体展示及抗体库技术,制备并鉴定β淀粉样蛋白(Aβ)人源性抗体。方法:应用固相筛选方法,以人工合成的Aβ1-15肽为靶标分子,在大容量全合成人源性噬菌体抗体库中筛选抗Aβ人源性抗体,并进行特异性鉴定。结果:经过3轮筛选,单克隆鉴定获得噬菌体抗体F11,竞争性ELISA表明抗体对Aβ1-42的结合位点位于1～15氨基酸残基内,ELISA结果证实抗体特异性良好。结论:以Aβ1-15肽为靶标分子获得了特异性良好的人源性抗体。     

中国内蒙古地区点池蝇属一新种(双翅目,蝇科)

记述分布于内蒙古地区的蝇科Muscidae秽蝇亚科Coenosiinae中的点池蝇属Spilogona Schnabl 1新种:鹦喙点池蝇S.psittorhamphos sp.nov..模式标本保存于军事医学科学院微生物流行病研究所医学昆虫标本馆.     

鞘磷脂酶通路与紫外线诱导的细胞凋亡

紫外线是一种重要的环境因素,对人类日常生活起着广泛的影响效应。大量的非保护的日光暴露不仅可以导致皮肤炎症、过度老化甚至皮肤癌症的发生,而且还能够诱导多种细胞凋亡。鞘磷脂酶-神经酰胺信号通路的激活与细胞凋亡关系密切,本文旨在探讨该通路在介导紫外线诱导细胞凋亡中的地位,重点描述了第二信使神经酰胺代谢的研究进展、鞘磷脂酶通路参与紫外线诱导细胞凋亡的机制。深入了解和研究紫外线诱导细胞凋亡的过程及其相关信号转导途径,有助于指导紫外线辐射的防护,开发新的治疗策略。     

Complete Genome Sequence of Bifidobacterium longum JDM301

Bifidobacteria, known as probiotic bacteria, are high-G+C Gram-positive bacteria which naturally inhabit the human gastrointestinal tract and vagina. Recently, we completely sequenced Bifidobacterium longum JDM301, which is a widely used Chinese commercial strain with several probiotic properties.Bifidobacterium spp., which are considered model probiotic bacteria like Lactobacillus spp., play an important role in the stability of the intestinal microflora, the modulation of the immune response, and so on (6, 8). We determined the complete genome sequence of B. longum JDM301, which is commercially used in China as a probiotic strain, using the GS 20 system (454 Life Science Corporation) (7). A total of 192,888 reads with an average length of 210 bp were assembled into 112 contigs by the 454 assembly tool. Among these, 92 large contigs were larger than 500 bp. We determined the order of the largest contigs through BLAST analysis with the reference strain B. longum ATCC 15697 (GenBank accession number {"type":"entrez-nucleotide","attrs":{"text":"CP001095","term_id":"213522389","term_text":"CP001095"}}CP001095) (10) and arranged the others by multiplex PCR. Gaps were closed by sequencing gap-spanning PCR products or clones using ABI 3730 xl DNA sequencers. Primer design and sequence assembly were performed with the Phred/Phrap/Consed software package (2, 3).The complete genome of B. longum JDM301 is composed of a 59.8% G+C circular chromosome of 2,477,838 bp without any plasmid. The genome of JDM301 (2.48 Mb) is smaller than that of B. longum ATCC 15697 (2.83 Mb) and slightly larger than the complete genomes of B. longum NCC2705 (2.26 Mb; GenBank accession number {"type":"entrez-nucleotide","attrs":{"text":"AE014295","term_id":"58012118","term_text":"AE014295"}}AE014295) and DJO10A (2.38 Mb; GenBank accession number {"type":"entrez-nucleotide","attrs":{"text":"CP000605","term_id":"189427298","term_text":"CP000605"}}CP000605). The JDM301 genome contains 1,959 protein-coding genes, three rRNA operons, and 55 tRNA genes. There are four rRNA operons with two cascaded in the three reference B. longum strains, while there are three in JDM301. We resequenced the three regions containing rRNA operons in the genome of JDM301 and found no cascaded rRNA operon. However, the locations of the three rRNA operons in JDM301 are the same as in the other three B. longum strains. No complete prophages were found in the genome sequence, but 12 phage-related fragments were identified. The genome also contains 15 pseudogenes, which is evidence of the recent and ongoing genome reduction of lactic acid bacilli (9). In addition, 15 complete or disrupted insertion sequence (IS) elements were found in the entire genome, which were identified as 5 derivatives of ISBlo5, 3 complete copies of ISBlo3, and 7 other ISs or derivatives belonging to the IS256, IS3, IS21, and IS30 family elements, respectively. One of them, named ISBad1, was 98.08% identical to that of B. adolescentis, and the others have been reported in the B. longum NCC2705 genome (8).Genome analysis revealed 14 response regulators and 14 sensor histidine kinases throughout the JDM301 chromosome, which may suggest a less complex regulatory network in JDM301 than that in ATCC 15697 (10). JDM301 has been grown as a commercial strain in stable and rich nutritional medium for such a long time that the regulatory networks in the genome may degenerate slowly, which is required for responses to dynamic environmental cues in the gastrointestinal tract.A gene (for BLJ_1359) encoding a serpin (serine protease inhibitor) with 92.69% identity to that of NCC2705 (4) was found in the genome sequence. The serpin is a potential probiotic effector molecule, and it may contribute to the immunomodulation of this B. longum strain. As we know, modulation of the immune system is one of probiotic functions of lactic acid bacteria (5).As model probiotic bacteria, Bifidobacterium spp. attract more and more interest since the molecular mechanisms of their probiotic activities remain unclear to a large degree (11). On the other hand, the biosafety of probiotics has attracted more attention with their enlarged and wide applications in food and drug products (1). We believe that this work will bring us deeper insight into the probiotic activities and safety of the strain widely used in China.     

猪CuZnSOD基因的克隆、表达及功能分析

为了进一步了解和认识CuZnSOD基因的结构和功能,揭示CuZnSOD对猪抗氧化机能的影响,寻找与肉质性状相关联的分子标记,文章采用RACE(Rapid amplification of cDNA end)方法,对莱芜猪CuZnSOD基因cDNA进行克隆测序,分析其结构和功能,并用Real-timePCR检测CuZnSOD基因的表达.结果表明,CuZnSOD基因cDNA序列全长658 bp(GenBank登录号:GU944822),包含76 bp的5'UTR和120 bp的3'UTR序列.全部CDS序列462 bp,编码153个氨基酸,分子量为15.9 kDa,等电点为6.03.CuZnSOD基因编码的氨基酸序列中,第3氨基酸残基处存在1个O-糖基化位点,第86氨基酸残基处存在1个N-糖基化位点.二级结构中α螺旋仅占1.31%.在进化过程中高度保守,与人、牛、小鼠和褐鼠的编码区同源性分别为87.74%、87.66%、83.44%和83.23%;氨基酸序列同源性分别为90.26%、94.12%、92.21%和91.50%.CuZnSOD存在典型的金属结合配体结构域(GFHVHQFGDNT).基于蛋白序列所构建的分子进化树表明猪与牛的亲缘关系最近.在mRNA水平上,CuZnSOD是一个广谱表达基因,在大脑、心脏、脾脏、肝脏、肾脏、肺、大肠、小肠、脊髓,肌肉、背膘和胃中都能检测到,其在肾脏,小肠和肺中表达量较高,在心脏和肌肉组织中表达量较低.     

两份太空诱变玉米雄性不育突变体的遗传研究

从搭载神舟4号飞船的4份玉米自交系后代中选育出两份雄性不育突变体, 对其进行育性鉴定, 并分析不育性状的稳定性及遗传特点。以不育材料的不育株为母本, 同群体的可育株和其他自交系为父本进行杂交, 结合自交、回交分析其后代的育性表现; 同时, 以具有正常细胞质的自交系为母本, 育性完全恢复的测交F1植株为父本进行反交, 对其反交的F1及F2进行育性观察分析。结果表明：这两份不育材料不育株的花药内无花粉或含少量畸形花粉, 败育彻底, 花粉败育表现为典败型。不育性状在不同年份、不同季节、不同地点下稳定遗传, 属可遗传的单基因控制的隐性核不育类型。     

柠条重要害虫四线奇尺蛾天津亚种幼虫的空间分布研究

四线奇尺蛾天津亚种是近几年新发现的危害柠条的重要害虫,研究四线奇尺蛾种群的空间格局和抽样技术,可为该害虫的危害调查与防治提供理论依据。本文应用6个聚集指标和Taylor幂法则及Iwao的m~*-m回归分析法,对四线奇尺蛾天津亚种幼虫的空间分布型和抽样技术进行了研究,并做了影响因素分析。结果表明:四线奇尺蛾天津亚种幼虫在6个样地均呈聚集分布,分布的基本成分是个体群,通过分布型参数,采用Iwao法计算出了在不同精度下幼虫抽样数公式和序贯抽样模型,该模型可为四线奇尺蛾天津亚种的预测预报及防治提供理论依据。     

两种肿腿蜂对锈色粒肩天牛虫粪及其寄主植物气味的学习行为

经研究,白蜡吉丁肿腿蜂Sclerodermus pupariae Yang et Yao与哈氏肿腿蜂Sclerodermus harmandi(Buysson)均可寄生锈色粒肩天牛Apriona swainsoni (Hope)的低龄幼虫,可用于该害虫的生物防治.为了探讨其学习行为,采用Y-型嗅觉仪、培养皿两种方法,测...     

背角无齿蚌摄食率及对水中叶绿素a清除能力的研究

椭圆背角无齿蚌是云南滇池的一种主要贝类物种。为探索该物种应用于滇池水体生物操纵的可行性,采用半野外模拟和原位围隔的方法,文章研究了背角无齿蚌的摄食率及对水中Chla的清除能力。结果表明:在23-28℃的温度范围内,背角无齿蚌的摄食率(IR)和湿重(W)呈现显著的相关冪指数关系:IR=aWb,1龄蚌和3龄蚌符合下列关系式:IR=6.2283X0.45,(R2=0.94);IR=0.0002X2.2,(R2=0.93)。3龄蚌的摄食率高于1龄蚌,且随生物量的增加摄食率有所减少。实验同时证明,背角无齿蚌有良好的清除水体中Chla的效果,对降低CODMn、TP含量同样具有较好的效果,且3龄蚌优于1龄蚌。通过方差分析综合分析得出,在生物量为4.17只/m3时,清除水体Chla的效果最优。       

Three Neolignan Glycosides from the Root of Nothopanax davidii

Three neolignan glycosides, including a new compound (7S,8R)-dihydro-3′-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-1′-benzofuranpropanol-9-O-β-D-xylopyranoside ( 1 ), were isolated from the root of Nothopanax davidii. Their structures were determined by extensive spectroscopic analyses, particularly NMR, HR-ESI-MS, and ECD experiments, and the absolute configuration of 2 was first definitively determined. The anti-tumor activity was assessed on four tumor cells by MTT assay, the anti-inflammatory activity was determined by inhibition of NO production in LPS reduced RAW264.7 cells, and the interaction with iNOS was predicted by molecular docking. At the dose of 100 μM, the three neolignan glycosides showed no cytotoxic activity against HepG2, HCT116, HeLa and A549 human tumor cells, but significantly inhibited LPS induced NO generation in RAW264.7 cells with inhibition rates of 31.53 %, 23.95 %, and 20.79 %, respectively, showing weak anti-inflammatory activity, possibly due to their binding to key residues of iNOs involved in inhibitor binding.