Development of microsatellite markers in white birch (Betula platyphylla var. japonica)

Betula platyphylla var. japonica is a typical pioneer tree species in the secondary succession in northern Japan. We describe the cloning and characterization of 13 polymorphic, codominant microsatellite loci isolated from this species. These polymorphic loci had 2–8 alleles per locus and a range of expected heterozygosities from 0.050 to 0.808.     

Regulation of synaptophysin degradation by mammalian homologues of seven in absentia.

Synaptophysin is an integral membrane protein of synaptic vesicles characterized by four transmembrane domains with both termini facing the cytoplasm. Although synaptophysin has been implicated in neurotransmitter release, and decreased synaptophysin levels have been associated with several neurodegenerative diseases, the molecular mechanism that regulates the degradation of synaptophysin remains unsolved. Using the cytoplasmic C terminus of synaptophysin as bait in a yeast two-hybrid screen, we identified two synaptophysin-binding proteins, Siah-1A and Siah-2, which are rat homologues of Drosophila Seven in Absentia. We demonstrated that Siah-1A and Siah-2 associate with synaptophysin both in vitro and in vivo and defined the binding domains of synaptophysin and Siah that mediate their association. Siah proteins exist in both cytosolic and membrane-associated pools and co-localize with synaptophysin on synaptic vesicles and early endosomes. In addition, Siah proteins interact specifically with the brain-enriched E2 ubiquitin-conjugating enzyme UbcH8 and facilitate the ubiquitination of synaptophysin. Furthermore, overexpression of Siah proteins promotes the degradation of synaptophysin via the ubiquitin-proteasome pathway. Our findings indicate that Siah proteins function as E3 ubiquitin-protein ligases to regulate the ubiquitination and degradation of synaptophysin.     

类黄酮化合物在植物胁迫反应中作用的研究进展

植物胁迫发生时,一个明显的特征是在植物器官中积累红色与紫色类黄酮化合物。文章讨论了类黄酮化合物在植物胁迫保护中作用,如类黄酮化合物在抗植物UV—B辐射、抗病性以及铝毒害耐性等多方面的作用,也讨论了植物受胁迫时类黄酮积累的分子基础。     

Ion‐Exchange and Adsorption of Fe(III) by Sepia Melanin

Sepia eumelanin is associated with many metal ions, yet little is known about its metal binding capacity and the chemical nature of the binding site(s). Herein, the natural concentrations of metal ions are presented and the ability to remove metals by exposure of the melanin granules to EDTA is quantified. The results reveal that the binding constants of melanin at pH 5.8 for Mg(II), Ca(II), Sr(II) and Cu(II) are, respectively, 5, 4, 14 and 34 times greater than the corresponding binding constants of these ions with EDTA. By exposing Sepia eumelanin to aqueous solutions of FeCl₃, the content of bound Fe(III) can be increased from a natural concentration of ～180 ppm to a saturation limit of ～80 000 ppm or 1.43 mmol/g of melanin. Similar saturation limits are found for Mg(II) and Ca(II). Exposure of Sepia melanin granules to aqueous solutions containing Ca(II) results in the stoichiometric replacement of the initially bound Mg(II), arguing that these two ions occupy the same binding site(s) in the pigment. The pH‐dependent binding of Mg(II) and Ca(II) suggests coordination of these ions to carboxylic acid groups in the pigment. Mg(II) and Ca(II) can be added to a Fe(III)‐saturated melanin sample without affecting the amount of Fe(III) pre‐adsorbed, clearly establishing Fe(III) and Mg(II)/Ca(II) occupy different binding sites. Taking recent Raman spectroscopic data into account, the binding of Fe(III) is concluded to involve coordination to o‐dihydroxyl groups. The effects of metal ion content on the surface morphology were analyzed. No significant changes were found over the full range of Fe(III) concentration studied, which is supported by the Brunauer–Emmett–Teller surface area analysis. These observations imply the existence of channels within the melanin granules that can serve to transport metal ions.     

黄色潜蝇茧蜂发育起点温度与有效积温的研究

在15-30℃温度范围内,观察了不同梯度温度下黄色潜蝇茧蜂Opius flavus Weng etChen生长发育的历期,并对实验数据采用直线性回归的方法处理。结果表明：黄色潜蝇茧蜂卵、幼虫、蛹的发育起点温度分别为8.518℃、9.909℃和8.656℃,其有效积温分别为60.27日度、65.75日度和87.78日度;卵——成虫的发育起点温度是9.631℃,有效积温为203.04日度。     

双歧杆菌对迁延性及慢性腹泻患儿部分胃肠激素的影响

目的：探讨双歧杆菌对迁延性及慢性腹泻患儿血清胃泌素(GAS)、血浆胃动素(MOT)和血浆生长抑素(SS)水平的影响。方法：应用放免法测定20例用双歧杆菌和19例未用微生态制剂治疗的迁延性及慢性腹泻患儿治疗前和治疗7d后空腹及餐后1h的血清GAS、血浆MOT和血浆SS水平,结果与20例正常儿童比较,并分析三种胃肠激素间的相关性。结果：治疗前两组病例空腹和餐后的血清GAS、血浆MOT和血浆SS水平高于正常儿童。除空腹未用微生态制剂病例的血清GAS水平外,治疗前两组病例血中的三种胃肠激素水平高于治疗7d后。治疗7d后双歧杆菌治疗病例空腹和餐后的血清GAS和血浆MOT水平低于未用微生态制剂病例,且血清GAS水平与正常儿童差异无显著性。治疗7d后血浆SS水平三组间差异无显著性。另两组病例治疗前空腹和餐后三种胃肠激素间均无关联,治疗7d后的双歧杆菌治疗病例和正常儿童GAS与SS和MOT与SS则呈正相关。结论：双歧杆菌制剂对迁延性及慢性腹泻儿童胃肠激素的分泌有调理作用,应用双歧杆菌治疗的患儿血清GAS、血浆MOT和血浆SS水平较未用微生态制剂的患儿更快恢复正常。     

rhTNF α表达条件的优化与中试发酵

为了确定出rhTNFα最佳表达条件,实验利用正交试验设计方法,对rhTNFα工程菌的进行发酵培养和42℃热诱导,此后借助蛋白凝胶电泳分析软件对各组样品的凝胶电泳图片定量分析,利用方差分析对影响TNF基因工程菌对目的产物表达的几个重要的条件进行了优化,并最终确定出pH7．5、培养温度27℃、培养时间4．5h、诱导时间5h的最佳表达条件。在该条件下进行中试发酵TNF的表达产物占到了菌体总蛋白的60％左右,且大部分以可溶形式存在。说明在大肠杆菌生长正常的前提下适度低温培养有利于rhTNFα的表达和减少包涵体的形成。     

GFP为报告基因的酵母哺乳动物细胞穿梭载体的构建及其在人血管内皮细胞中的表达

为研究酵母作为载体在口服基因治疗及免疫中的作用 ,需要一种能够在酵母中复制而在哺乳动物细胞中表达的穿梭载体 .利用通用载体质粒融合系统 (UPS)构建了一种以GFP为报告基因的新载体 ,以常规的氯化锂法对酿酒酵母进行转化 ,证明该载体能够在酵母中复制 ;以脂质体介导向人血管内皮细胞进行了转染 ,有绿色荧光 ,证明该载体能够在哺乳动物细胞中表达 .所获得的新型的穿梭载体为口服酵母在基因治疗中的应用提供了物质准备     

云南保山猪线粒体DNA D-loop区序列初步分析 Primary Analysis of Mitochondrial DNA D-loop Region Sequence in Baoshan Pig

摘要：为了解云南保山猪(Baoshan pig)的遗传多样性及其遗传背景,我们测定了19个个体线粒体DNA D-loop高变区I 15 363～15 801片段序列438 bp。检测到10种单倍型,包括8个多态位点,其中5次T/C转换、1次G/A转换、1次G/C颠换和1次A/T颠换,其A、T、G、C碱基的平均含量分别为35.4%、26.9%、13.2%和24.5%,A+T含量(62.3%)明显高于G+C含量(37.7%)。对于保山猪的保种及其持续利用有着重要的理论指导意义。 Abstract:To investigate the genetic diversity and genetic data of Baoshan pig in Yunnan province,the mitochondrial DNA D-loop hypervariable segment I sequences 15 363～15 801 (438 bp) in 19 individuals of Baoshan pig were sequenced.Ten mitochondrial haplotypes were identified in the samples,with 8 sites showing polymorphism,which were 5 T/C and 1 G/A transitions,1 G/C and 1 A/T transversions.The contents of A,T,G and C were 35.4%,269%,13.2% and 24.5%,respectively.The content of A+T (62.3%) was significantly higher than that of G+C (37.3%).It will be of importance to conservation and sustainable utilization in Baoshan pig.     

中国的红索藻属植物

记述了中国产红索藻属Thtorea Bory emend．Necchi的2种2变种,即棘刺红索藻T．hispida(Thorea)Desvaux emend,Sheath,Vis et Cole,棘刺红索藻小孢变种T．hispida var,microspora S．L．Xie et Z．X．Shi,蓝色红索藻T．vio—lacea Bory emend．Sheath,Vis et Cole和蓝色红索藻长毛变种T．violacea var．longipilosa S．L．Xie et Z．X．Shi．其中,蓝色红索藻T．violacea Bor yemend．Sheath,Vis et Cole为中国新记录,棘刺红索藻小孢变种T．hispida var．microspora S．L．Xie et Z．X．Shi和蓝色红索藻长毛变种T．violacea var,longipilosa S．L Xie et Z．X．Shi为新变种。