新生大鼠辣椒素处理后脊髓内阿片受体的变化

本实验用受体放射自显影方法,研究了新生大鼠辣椒素皮下注射,成年后脊髓内３Ｈ－埃托菲（３Ｈ－ｅｔｏｒｐｈｉｎｅ）结合位点数的变化。发现新生鼠辣椒素处理可以引起脊髓后角浅层及中央管周围’Ｈ－ｅｔｏｒｐｈｉｎｅ结合位点明显减,其中Ⅰ、Ⅱ层自显影银粒数减少３６％左右。Ⅲ层减少２０％,中央管周围减少１１％。而前角及背外测束３Ｈ－ｅｔｏｒｐｈｉｎｅ结合位点数无显著性差异。结果表明脊髓内初级感觉传入细纤维上有阿片受体分布。本研究为探明阿片类物质在脊髓水平的痛觉调控机制提供一定的形态学依据。     

微生物群落结构探针杂交评价不同培养基从活性污泥分离优势菌群的能力

用ERICPCR （Enterobacterial Repetitive Intergenic ConsensusPCR）、苯酚羟化酶大亚基基因(LmPHs)扩增和群落结构探针分子杂交检测技术对LB、dCGY、MP和FWM 4种培养基从焦化废水处理厂2个曝气池活性污泥中分离优势功能菌群的能力进行了比较研究。LmPHs扩增显示7种回收菌群中均有以多亚基苯酚羟化酶为代谢途径的苯酚降解菌存在。用代表苯酚降解高峰期活性污泥优势菌组成的总DNA的ERICPCR产物经地高辛标记作为群落结构的混合探针M1和M8,对8种回收菌群的ERICPCR指纹图谱进行杂交检测,不同培养基回收优势菌的能力不同,以废水为基础的FWM培养基从活性污泥中回收到的优势菌种群最多(30.8%～42.9%)。本文建立了用微生物群落结构探针杂交技术对不同培养基回收分离优势菌能力进行评价的方法。     

Phylogenetic analysis of Nosema antheraeae (Microsporidia) isolated from Chinese oak silkworm, Antheraea pernyi

The microsporidian Nosema antheraeae is a pathogen that infects the Chinese oak silkworm, Antheraea pernyi. We sequenced the complete small subunit (SSU) rRNA gene and the internal transcribed spacer (ITS) of N. antheraeae, and compared the SSU rRNA sequences in other microsporidia. The results indicated that Nosema species, including N. antheraeae, formed two distinct clades, consistent with previous observations. Furthermore, N. antheraeae is clustered with N. bombycis with high bootstrap support. The organization of the rRNA gene of N. antheraeae is LSU-ITS1-SSU-ITS2-5S, also following a pattern similar to the Nosema type species, N. bombycis. Thus, N. antheraeae is a Nosema species and has a close relationship to N. bombycis.     

The plant glycosyltransferase clone collection for functional genomics

The glycosyltransferases (GTs) are an important and functionally diverse family of enzymes involved in glycan and glycoside biosynthesis. Plants have evolved large families of GTs which undertake the array of glycosylation reactions that occur during plant development and growth. Based on the Carbohydrate‐Active enZymes (CAZy) database, the genome of the reference plant Arabidopsis thaliana codes for over 450 GTs, while the rice genome (Oryza sativa) contains over 600 members. Collectively, GTs from these reference plants can be classified into over 40 distinct GT families. Although these enzymes are involved in many important plant specific processes such as cell‐wall and secondary metabolite biosynthesis, few have been functionally characterized. We have sought to develop a plant GTs clone resource that will enable functional genomic approaches to be undertaken by the plant research community. In total, 403 (88%) of CAZy defined Arabidopsis GTs have been cloned, while 96 (15%) of the GTs coded by rice have been cloned. The collection resulted in the update of a number of Arabidopsis GT gene models. The clones represent full‐length coding sequences without termination codons and are Gateway^® compatible. To demonstrate the utility of this JBEI GT Collection, a set of efficient particle bombardment plasmids (pBullet) was also constructed with markers for the endomembrane. The utility of the pBullet collection was demonstrated by localizing all members of the Arabidopsis GT14 family to the Golgi apparatus or the endoplasmic reticulum (ER). Updates to these resources are available at the JBEI GT Collection website http://www.addgene.org/ .     

Combinatorial signals of activin/nodal and bone morphogenic protein regulate the early lineage segregation of human embryonic stem cells

Cell fate commitment of pre-implantation blastocysts, to either the inner cell mass or trophoblast, is the first step in cell lineage segregation of the developing human embryo. However, the intercellular signals that control fate determination of these cells remain obscure. Human embryonic stem cells (hESCs) provide a unique model for studying human early embryonic development. We have previously shown that Activin/Nodal signaling contributes to maintaining pluripotency of hESCs, which are derivatives of the inner cell mass. Here we further demonstrate that the inhibition of Activin/Nodal signaling results in the loss of hESC pluripotency and trophoblast differentiation, similar to BMP4-induced trophoblast differentiation from hESCs. We also show that the trophoblast induction effect of BMP4 correlates with and depends on the inhibition of Activin/Nodal signaling. However, the activation of BMP signaling is still required for trophoblast differentiation when Activin/Nodal signaling is inhibited. These data reveal that the early lineage segregation of hESCs is determined by the combinatorial signals of Activin/Nodal and BMP.     

离子交换法精制丙氨酸的研究

合成法生产的丙氨酸,产品中Ｃｌ￣－,含量过高,仅为工业级。我们采用多柱串联的离子交换系统,对工业级丙氨酸进行了脱ＣＬ￣－,脱试验,交换后丙氨酸产品中的Ｃｌ￣－、含量分别小于０．０２％和０．０３％,符合食品添加剂的标准。     

芒果APl同源基因的克隆及其生物信息学分析

我们采用RT-PCR方法克隆了2个APl同源基因全长cDNA,分别命名为MAPl-1(GenBank accession No.FJ529206)和MAPl-2(GenBank accession No.FJ529207).MAPl-1编码247个氨基酸,开放阅读框长度为741 bp,蛋白质分子量为28.54kD,等电点为8.31;MAPl-2编码248个氨基酸,开放阅读框长度为744 bp,蛋白质分子量为28.78 kD,等电点为8.70.同源性分析表明,它们的核苷酸序列与其它木本植物APl同源基因的一致性为72%～81%.实验分析表明,MAPl-1和MAPl-2第1至第61个氨基酸含有一个MADS盒结构域,第88至第178个为K盒结构域;两个基因均定位于细胞核,且功能位点分布存在着不同,推测这两个基因在花器官发育过程中的功能存在差异.蛋白二级结构预测显示,MAPl-1蛋白有12个a-螺旋,4个β折叠区,14个β-转角;而MAPl-2蛋白有11个a-螺旋,5个β折叠区,15个β-转角:其大多数氨基酸具有亲水性.本研究有助于进一步了解芒果的开花分子机理及成花的生物学发育阶段.     

含铬重组液激活部分缺失金属原子簇的钼铁蛋白的研究

棕色固氮菌（Ａｚｏｔｏｂａｃｔｅｒ ｖｉｎｅｌａｎｄｉｉ）固氮酶钼铁蛋白经邻菲口罗啉和Ｏ２ 处理后,变为部分缺失ＦｅＭｏｃｏ 和Ｐ－ｃｌｕｓｔｅｒ的失活蛋白。与由Ｋ２ＣｒＯ４、高柠檬酸铁、Ｎａ２Ｓ和二硫苏糖醇组成的重组液保温后,处理蛋白对乙炔和质子还原的活性都得以显著恢复;然而,它的吸收光谱和圆二色谱虽有明显恢复,但仍与还原钼铁蛋白有所不同。这表明,激活蛋白中也许存在功能与钼铁蛋白相似,而结构则有所差异的含铬（ＣｒＦｅ）蛋白     

Coating and selective deposition of nanofilm on silicone rubber for cell adhesion and growth

A recently developed method for surface modification, layer-by-layer (LbL) assembly, has been applied to silicone, and its ability to encourage endothelial cell growth and control cell growth patterns has been examined. The surfaces studied consisted of a precursor, with alternating cationic polyethyleneimine (PEI) and anionic sodium polystyrene sulfonate (PSS) layers followed by alternating gelatin and poly-d-lysine (PDL) layers. Film growth increased linearly with the number of layers. Each PSS/PEI bilayer was 3 nm thick, and each gelatin/PDL bilayer was 5 nm thick. All layers were more hydrophilic than the unmodified silicone rubber surface, as determined from contact angle measurements. The contact angle was primarily dictated by the outermost layer. Of the coatings studied, gelatin was the most hydrophilic. A film of (PSS/PEI)₄/(gelatin/PDL)₄/ gelatin was highly favorable for cell adhesion and growth, in contrast to films of (PSS/PEI)₈ or (PSS/PEI)₈/PSS. Cell growth patterns were successfully controlled by selective deposition of microspheres on silicone rubber, using microcontact printing with a silicone stamp. Cell adhesion was confined to the region of microsphere deposition. These results demonstrate that the LbL self-assembly technique provides a general approach to coat and selectively deposit films with nanometer thickness on silicone rubber. Furthermore, they show that this method is a viable technique for controlling cellular adhesion and growth.     

奇异果甜蛋白及其基因工程

奇异果甜蛋白(thaumatin)是迄今为止最甜的物质之一,对其研究具有很重要的意义。奇异果甜蛋白的生化性质基本清楚,基因序列和氨基酸序列都已测定。它的甜味可能是由奇异果甜蛋白上特定基团和受体结合引起的。对奇异果甜蛋白的生理功能知之甚少。近二十年来,在奇异果甜蛋白的基因工程上取得了一定进展,但仍然存在许多困难。 Abstract:Thaumatin is one of the sweetest substances known to date,it is important to study the thaumatin.The biochemical properties of thaumatin have been clarified clearly.Thaumatin had been isolated and sequenced.The mechanism of the sweetness of thaumatin may be due to the combination of some special groups and the receptors.The exact function of thaumatin is still not clear.Although gene engineering of thaumatin has been carried out for 20 years,there are still some difficulties to be solved for using in the market.