Molecular assembly of recombinant chicken type II collagen in the yeast <Emphasis Type="Italic">Pichia pastoris</Emphasis>

Effective treatment of rheumatoid arthritis can be mediated by native chicken type II collagen (nCCII), recombinant peptide containing nCCII tolerogenic epitopes (CTEs), or a therapeutic DNA vaccine encoding the full-length CCOL2A1 cDNA. As recombinant CCII (rCCII) might avoid potential pathogenic virus contamination during nCCII preparation or chromosomal integration and oncogene activation associated with DNA vaccines, here we evaluated the importance of propeptide and telopeptide domains on rCCII triple helix molecular assembly. We constructed pC- and pN-procollagen (without N- or C-propeptides, respectively) as well as CTEs located in the triple helical domain lacking both propeptides and telopeptides, and expressed these in yeast Pichia pastoris host strain GS115 (his4, Mut⁺) simultaneously with recombinant chicken prolyl-4-hydroxylase α and β subunits. Both pC- and pN-procollagen monomers accumulated inside P. pastoris cells, whereas CTE was assembled into homotrimers with stable conformation and secreted into the supernatants, suggesting that the large molecular weight pC-or pN-procollagens were retained within the endoplasmic reticulum whereas the smaller CTEs proceeded through the secretory pathway. Furthermore, resulting recombinant chicken type II collagen pCα1(II) can induced collagen-induced arthritis (CIA) rat model, which seems to be as effective as the current standard nCCII. Notably, protease digestion assays showed that rCCII could assemble in the absence of C- and N-propeptides or telopeptides. These findings provide new insights into the minimal structural requirements for rCCII expression and folding.     

细枝木麻黄气生瘤的人工形成

细枝木麻黄气生瘤的人工形成邹铧,张忠泽,张成刚,丁鉴,王育英,付莉（中国科学院沈阳应用生态研究所,沈阳１１００１５）ＡｒｔｉｆｉｃｉａｌｆｏｒｍａｔｉｏｎｏｆａｅｒｉａｌｎｏｄｕｌｅｓｏｎＣａｓｕａｒｉｎａｃｕｎｎｉｎｇｈａｍｉａｎａ￥ＺｏｕＨｕａ;...     

Genetic diversity of Guangxi chicken breeds assessed with microsatellites and the mitochondrial DNA D-loop region

The domestic chicken (Gallus gallus domesticus) is an excellent model for genetic studies of phenotypic diversity. The Guangxi Region of China possesses several native chicken breeds displaying a broad range of phenotypes well adapted to the extreme hot-and-wet environments in the region. We thus evaluated the genetic diversity and relationships among six native chicken populations of the Guangxi region and also evaluated two commercial breeds (Arbor Acres and Roman chickens). We analyzed the sequences of the D-loop region of the mitochondrial DNA (mtDNA) and 18 microsatellite loci of 280 blood samples from six Guangxi native chicken breeds and from Arbor Acres and Roman chickens, and used the neighbor-joining method to construct the phylogenetic tree of these eight breeds. Our results showed that the genetic diversity of Guangxi native breeds was relatively rich. The phylogenetic tree using the unweighed pair-group method with arithmetic means (UPGAM) on microsatellite marks revealed two main clusters. Arbor Acres chicken and Roman chicken were in one cluster, while the Guangxi breeds were in the other cluster. Moreover, the UPGAM tree of Guangxi native breeds based on microsatellite loci was more consistent with the genesis, breeding history, differentiation and location than the mtDNA D-loop region. STRUCTURE analysis further confirmed the genetic structure of Guangxi native breeds in the Neighbor-Net dendrogram. The nomenclature of mtDNA sequence polymorphisms suggests that the Guangxi native chickens are distributed across four clades, but most of them are clustered in two main clades (B and E), with the other haplotypes within the clades A and C. The Guangxi native breeds revealed abundant genetic diversity not only on microsatellite loci but also on mtDNA D-loop region, and contained multiple maternal lineages, including one from China and another from Europe or the Middle East.     

天然落葵红色素研究初报

落葵紅色素系以成熟的落葵果实为原料,经由物理方法提取获得的一种水溶性天然食用红色素。该色素在酸性至中性的介质中呈鲜艳的紫红色;经毒理学实验和卫生学检验,证明它是一种安全无毒,符合一般食品添加剂卫生学要求的良好的食品着色剂。据实验结果分析,落葵红色素中主要化学成分是甜菜花青素(betacyanines):甜菜苷(betanin)。     

抗HPV16 E7-ribozyme在CV-1细胞中的稳定表达

构建了由RSV—LTR启动子带动并能在细胞内稳定复制的Ribozyme的自身修剪表达质粒pRSV—Rz523、Ribozyme反义对照质粒pRSV—AE7及人增殖细胞核抗原基因(PCNA)启动子带动的HPVl6 E7片段(+554～+686)的真核表达质粒pPCNA—E7。经G418抗性筛选获得了稳定表达Ribozyme的CV-1细胞克隆,其表达水平约为9．Opmol／lO6个细胞,其中活性Ribozyme的量大于50fmol／lO6个细胞,分离得到的Ribozyme可在体外特异切割E7靶RNA片段。通过共转染Ribozyme(或反义对照)和底物表达质粒并筛选出细胞克隆．研究了Ribozyme在细胞中对底物表达水平的影响。初步结果显示．Rihozyme的导人可使细胞内底物E7的RNA表达水平降低了90％(反义对照使E7 RNA表达降低20％)。上述结果提示：在CV-1细胞中表达的Ribozyme不仅在体外,同时在细胞内具有一定的生物学活性,有可能应用于逆转官颈癌细胞的恶性表型。     

黄土高原苜蓿-冬小麦轮作系统土壤水分时空动态及产量响应

2 0 0 1～ 2 0 0 3年在甘肃庆阳黄土高原连续 3 a研究了紫花苜蓿 -冬小麦轮作系统中土壤 0～ 3 0 0 cm剖面水分动态特征 ,作物产量及其含 N量。处理包括 4龄苜蓿草地 (L C)、4龄苜蓿草地后茬持续休闲 (L F)、4龄苜蓿草地休闲 4个月后种植冬小麦(L Fl W) ,和 4龄苜蓿草地休闲 1个月后种植冬小麦 (L Fs W)。结果表明 ,种植 4a苜蓿后春季翻挖实施休闲至冬小麦播种(L Fl W)的 4个月期间 ,降雨的入渗深度为 150 cm,而苜蓿秋季翻挖休闲至小麦播种 (L Fs W)的一个月间 ,降雨在土壤内的入渗深度为 90 cm,不同休闲长度对头茬冬小麦土壤 0～ 90 cm水分贮存量无显著影响 ,亦不影响头茬冬小麦的出苗和出苗数。苜蓿后茬完全休闲 (L F)一个生长季后 ,60～ 90 cm土壤水分含量达田间最大重力持水量 (Drainage U pper L imit DU L )的 93 % ,0～ 3 0 0cm剖面土壤贮水量达 670 mm ,是剖面田间最大重力持水量 (DUL )的 78% ;L Fl W和 L Fs W处理下头茬小麦籽粒产量之间差异显著 (P<0 .0 5) ,收获指数和千粒重等指数无显著差异 ;L Fl W和 L Fs W处理中获得的二茬小麦产量无显著差异 ;连续种植苜蓿与种植小麦有接近的生物量 ,但苜蓿地植物总 N的输出量较小麦田高 2～ 3倍。由于黄土高原降雨变率大 ,因此预测土壤含水量动态有     

不结球白菜新种质P70-203雄性不育细胞质类型的鉴定

本研究根据OguraCMS、PolimaCMS的不育性状相关的线粒体基因序列设计特异引物,对不结球白菜雄性不育系新种质P70-203及其保持系P60-27-1进行PCR分析.研究结果表明,Polima引物P3/P4,P5/P6在不育系与可育系中均无扩增条带;Ogura引物P1/P2在不育系中扩增出750 bp的特异片段,但可育系中无扩增条带.将扩增的特异条带回收并测序,将得到的测序结果在NCBI中进行Blastn同源性比较,结果与青花菜Ogura(登录号:EU604643)和萝卜Ogura(登录号:AB055438)细胞质雄性不育同源性均达到99%.从分子角度初步推测:该雄性不育系新种质P70-203具有Ogura细胞质.     

seRNA PAM controls skeletal muscle satellite cell proliferation and aging through trans regulation of Timp2 expression synergistically with Ddx5

Muscle satellite cells (SCs) are responsible for muscle homeostasis and regeneration and lncRNAs play important roles in regulating SC activities. Here, in this study, we identify PAM (Pax7 Associated Muscle lncRNA) that is induced in activated/proliferating SCs upon injury to promote SC proliferation as myoblast cells. PAM is generated from a myoblast‐specific super‐enhancer (SE); as a seRNA it binds with a number of target genomic loci predominantly in trans. Further studies demonstrate that it interacts with Ddx5 to tether PAM SE to its inter‐chromosomal targets Timp2 and Vim to activate the gene expression. Lastly, we show that PAM expression is increased in aging SCs, which leads to enhanced inter‐chromosomal interaction and target genes upregulation. Altogether, our findings identify PAM as a previously unknown lncRNA that regulates both SC proliferation and aging through its trans gene regulatory activity.