响应面法优化太白贝母粗多糖超声波提取工艺研究

对太白贝母粗多糖提取工艺的研究,为太白贝母的深入综合利用提供依据。采用超声波提取太白贝母粗多糖,在单因素试验基础上,利用响应面法对提取工艺参数进行优化研究。建立料液比、时间、超声温度之间的数学模型,通过典型性分析得出最优工艺条件为:提取时间为16 min,提取温度75℃,料液比为1∶15,总糖的含量为0.461%。试验表明,响应面法对太白贝母粗多糖提取条件的优化是可行的,可用于实际预测。     

水稻糯性相关基因的全基因组关联分析

利用1 090 071个SNP标记, 对419份广西地方稻种资源核心种质的糯性进行全基因组关联分析。结果表明, 运用混合线性模型, 在P<4.72×10^-8 (4.72E-8)水平下, 检测到45个与糯性显著关联的SNP位点, 均位于第6号染色体上。通过筛选显著关联位点上、下游各150 kb区域内的基因, 共找到305个候选基因, 其中包含2个与淀粉合成酶相关的Wx和SSIIa基因; 同时在第6号染色体5.69-5.89 Mb区域发现4个与糯性显著关联的SNP位点, 该区域可能是影响水稻(Oryza sativa)糯性的重要候选区域。     

Narbonin,a novel 2S protein from Vicia narbonensis L. seeds: cDNA,gene structure and developmentally regulated formation

cDNA and genomic clones encoding narbonin, a 2S globulin from the seed of narbon bean (Vicia narbonensis L.), were obtained using the polymerase chain reaction (PCR) and sequenced. The full-length cDNA as well as genomic clones contain a single open reading frame (ORF) of 873 bp that encodes a protein with 291 amino acids comprising the mature narbonin polypeptide (M _r ca. 33 100) and an initiation methionine. The deduced amino acid sequence lacks a transient N-terminal signal peptide. The genomic clones do not contain any intron. No homology was found to nucleic acid and protein sequences so far registered in sequence data libraries. The biosynthesis of narbonin during embryogenesis is developmentally-regulated and its pattern of synthesis closely resembles that of typical seed storage globulins. However, during seed germination narbonin was degraded very slowly, indicating that it may have other function than storage protein. Southern analysis suggests the existence of a small narbonin gene family. Narbonin genes were also found in four different species of the genus Vicia as well as in other legumes such as Canavalia ensiformis and Glycine max. In Escherichia coli a recombinant narbonin was produced which yielded crystals like those prepared from narbonin purified from seeds.     

脊髓提取液对培养脊髓神经细胞中GABA能及DYN能神经元突起生长的影响

本文以体外培养的小鼠脊髓神经元为模型研究了人胚脊髓提取液对Ｅ１２－１５小鼠脊髓中ＧＡＢＡ能神经元和ＤＮＹ能神经元的突起生长的营养作用,结果发现人胚脊髓提取液在蛋白浓度为２５０μｇ／ｍｌ时对ＧＡＢＡ能神经元的突起生长无营养作用,但对ＤＮＹ能神经元的突起生长有显著的促进作用。提示了人胚脊髓提取液中有促进神经元突起生长的营养物质,且对特定胎龄的不同的神经元有不同的作用。     

p21基因的克隆及其对肺癌细胞生长的抑制

用反转录ＰＣＲ从正常人胚胎肺细胞中获得了ｐ２１基因ｃＤＮＡ,将其插入真核表达载体ｐＭＳＣＶｎｅｏ,构建成重组质粒,ｐＭＳ２１,并将其转染至肺癌细胞株Ａ５４９．通过集落形成观察到ｐ２１对肺癌细胞具有明显的抑制作用,经ＲＮＡ狭缝杂交、Ｗｅｓｔ－ｅｒｎｂｌｏｔ分析和免疫细胞化学实验证实这是ｐ２１表达的结果．荷瘤裸鼠实验也进一步证实了ｐ２１对肺癌细胞具有明显的抑制作用．为ｐ２１的深入研究提供了基础．     

Studies on the methods for the determination of phosphorylation sites in highly phosphorylated peptides or proteins: phosphorylation sites of hen egg white riboflavin binding protein

To determine the phosphate binding sites in hen egg white riboflavin binding protein (RBP), a highly phosphorylated peptide, which consisted of 23 amino acid residues including eight phosphoserines, was isolated from the tryptic digest of reduced and carboxymethylated RBP. The conditions of the beta-elimination-addition reaction to convert phosphoserine residues in the peptide to cysteic acids, S-methylcysteines, alanines, and beta-methylaminoalanines (DL-alpha-amino-beta-methylamino propionic acid) were examined. These converted peptides were purified by HPLC and subjected to Edman degradation. The results of Edman degradation indicated that the S-methylcysteine derivative of the peptide gave the most satisfactory result for determining the phosphate binding sites in the peptide. The phosphorylation sites of the peptide determined by the method mentioned above are as follows: His182-Leu-Leu-Ser185-Glu-Ser(P)-Ser(P)-Glu-Glu190-Ser (P)-Ser(P)-Ser(P)-Met-Ser195(P)-Ser(P)-Ser(P)-Glu-Glu-. These studies indicated that the conversion of phosphoserines in phosphoproteins to S-methylcysteines followed by Edman analysis was a useful method for the elucidation of the phosphorylation sites in phosphopeptides.     

利用PEG法对GUS基因在几种杨树原生质体中瞬间表达的研究(简报)

建立合适的外源基因转移系统是植物基因工程的一个至关重要的方面。外源基因的瞬间表达能够在短时间内确定外源基因是否转移到植物细胞中,从而确定重组质粒DNA上的启动子对于某一受体系统是否有效。利用PEG(聚乙二醇)法或电激法进行直接基因转移在火     

A Method for 3D Histopathology Reconstruction Supporting Mouse Microvasculature Analysis

Structural abnormalities of the microvasculature can impair perfusion and function. Conventional histology provides good spatial resolution with which to evaluate the microvascular structure but affords no 3-dimensional information; this limitation could lead to misinterpretations of the complex microvessel network in health and disease. The objective of this study was to develop and evaluate an accurate, fully automated 3D histology reconstruction method to visualize the arterioles and venules within the mouse hind-limb. Sections of the tibialis anterior muscle from C57BL/J6 mice (both normal and subjected to femoral artery excision) were reconstructed using pairwise rigid and affine registrations of 5 µm-thick, paraffin-embedded serial sections digitized at 0.25 µm/pixel. Low-resolution intensity-based rigid registration was used to initialize the nucleus landmark-based registration, and conventional high-resolution intensity-based registration method. The affine nucleus landmark-based registration was developed in this work and was compared to the conventional affine high-resolution intensity-based registration method. Target registration errors were measured between adjacent tissue sections (pairwise error), as well as with respect to a 3D reference reconstruction (accumulated error, to capture propagation of error through the stack of sections). Accumulated error measures were lower (p<0.01) for the nucleus landmark technique and superior vasculature continuity was observed. These findings indicate that registration based on automatic extraction and correspondence of small, homologous landmarks may support accurate 3D histology reconstruction. This technique avoids the otherwise problematic “banana-into-cylinder” effect observed using conventional methods that optimize the pairwise alignment of salient structures, forcing them to be section-orthogonal. This approach will provide a valuable tool for high-accuracy 3D histology tissue reconstructions for analysis of diseased microvasculature.