Stability of the Sarcin/Ricin domain of 28S RNA in rat ribosome under hydrostatic pressure

Under 2 100 bar of hydrostatic pressure, KNA N-glycosidase can still cleave the N-C bond of adenosine at position 4324 in R/S domain of 28S RNA in rat ribosome, demonstrating that high pressure has no effect on the tertiary structure of S/R domain.     

尖塘鳢属鱼类线粒体16SrRNA基因序列变异及分子系统进化

为探讨尖塘鳢属鱼类的系统发育关系,笔者通过PCR法得到云斑尖塘鳢、线纹尖塘鳢和尖头塘鳢的线粒体16SrRNA基因部分序列（569bp）,并结合从GenBank中下载的平头沙塘鳢、溪鳢及刺盖塘鳢的16SrRNA基因部分同源序列,分析了6种塘鳢科鱼类的系统发育关系．运用MAGA4．0软件分析可知,塘鳢鱼类6个种之间存在142个变异位点,其中简约信息位点57个,转换／颠换之比为1．6,表明塘鳢科鱼类16SrRNA基因序列转换／颠换未达饱和;6种塘鳢科鱼类之间的序列差异在0．054～0．147之间,其中平头沙塘鳢和刺盖塘鳢的序列差异最大（0．147）,线纹尖塘鳢与云斑尖塘鳢的序列差异最小（0．054）,且种间序列差异不大．通过NJ,ME,MP系统树的建立,表明线纹尖塘鳢与云斑尖塘鳢的亲缘关系最近,且尖塘鳢属与塘鳢属鱼类的同源性不高,验证了传统分类学把尖塘鳢独立成属的科学性．     

基于16S rRNA和POMC基因序列的中国北方林蛙属动物系统发生关系

基于16S rRNA和POMC基因部分序列研究了中国北方林蛙属动物的系统发生关系.利用ClustalX软件对序列进行对位排列后,长度为1148bp,内群变异位点259,简约位点110.利用MP法、ML法和BI法构建系统进化树,结果显示林蛙属物种构成单系群,其中东北种群聚为一支,中国林蛙聚为一支,支持东北林蛙为有效物种.桓仁林蛙和核型为2n=26的林蛙属物种聚为一支,因此不支持核型为2n=24的林蛙形成单系群.桓仁林蛙、昆嵛林蛙、黑龙江林蛙单独聚为一支,表明三者之间的亲缘关系较近.     

鲟形目线粒体16S rRNA的部分序列变异及系统发生

采用通用引物对3种鲟形目（Acipenseriformes）鱼类,中华鲟（Acipenser sinensis）、俄罗斯鲟（Acipenser gueldenstaedtii）和匙吻鲟（Polyodon spathula）的16S rRNA基因部分片段进行扩增,并与NCBI数据库中获得另外6种鲟形目鱼类相应的16S rRNA序列部分进行比较,探讨鲟形目2个科5个属共9个种之间的遗传变异和亲缘关系.数据合并后用于分析的序列共514 bp,变异位点29个,含简约信息位点16个,单一信息位点13个.以多鳍鱼目（Polypteriformes）多鳍鱼属Polypterus ornatipinnis为外群,采用部分16S rRNA序列基于Kimura双参数模型构建其系统发育关系,结果表明：MP法和NJ法得到系统树基本相同,其科、亚科和属的分化上基本与传统形态学分类相吻合,另外,欧鳇与鲟属鱼类的分化也并不明显.值得注意的是,鲟亚科6个种所划分出的3个分支恰恰分别归属于3个地理区域,欧鳇、闪光鲟和俄罗斯鲟主要集中于黑海和里海流域等地区;中华鲟和达氏鲟分布在西北太平洋,中国长江流域以及朝鲜;而高首鲟则分布于东太平洋.     

1A6/DRIM,the human UTP20 functions in 28S and 5.8S rRNA processing

1A6/DRIM has been identified as UTP20, a small subunit processome component, functioning in 18S rRNA processing. In the present study, the maturation of 28S rRNA and 5.8S rRNA was inhibited when 1A6/DRIM was silenced in HeLa cells; and coin-cidently, an accumulation of 32S rRNA precursor was observed. Immunoprecipitation was performed with the anti-1A6/DRIM antibody, followed by Northern blot with the ITS2 probe. The results showed that 1A6/DRIM was associated with both 32S and 12S rRNA precursors in vivo. The expression profile of 1A6/DRIM during rRNA processing was investigated by sucrose density gradient fractionation in combination with Western blot analysis. The results demonstrated that 1A6/DRIM was involved in the pre-60S particles in addition to the pre-40S particles and co-sediment with the 32S and 12S rRNA precursors in the nucleolus. Furthermore, the interaction of U8 snoRNA with 1A6/DRIM was revealed by immunoprecipitation. These results demonstrated that 1A6/DRIM interacted with both 32S rRNA and U8 snoRNA, being involved in 28S rRNA and 5.8S rRNA processing.     

灰黄霉素高产变株与出发菌株18S rRNA基因序列的比较分析

根据真菌18S rDNA的保守序列设计引物,对灰黄霉素高产突变菌Penicillium griseofulvum F208与出发菌株Penicillium griseofulvum 3.5190的18S rRNA进行克隆测序及对比分析,并登录GenBank(序列号为EF608151和EF607282).依据18S rDNA建立的系统进化树表明突变株F208与出发菌株3.5190的遗传距离较远,而与Penicillium urticae亲缘关系最近.出发菌株3.5190与Penicillium commune亲缘关系最近.18SrDNA作为分子标记可有效地鉴别灰黄霉素产生菌(Penicillium griseofulvum)高产与低产菌株.     

Analysis of RAPD and mitochondrial 16S rRNA gene sequences from Trichiurus lepturus and Eupleurogrammus muticus in the Yellow Sea

Random amplified polymorphic DNA (RAPD) technique is applied to 12 individuals from each species of the hairtail fishes Trichiurus lepturus and Eupleurogrammus muticus in the Yellow Sea. The percentage of polymorphic sites, degree of genetic polymorphism and genetic distance are compared and the phylogenetic tree is constructed by Neighbor-joining method. The partial mitochondrial 16S rRNA gene is amplified by polymerase chain reaction (PCR) and the PCR products are directly sequenced after being purified. These sequences, together with the homologous sequences of another Trichiuridae species Lepidopus caudatus obtained from GenBank, are used to analyze nucleotide difference and to construct a UPGMA phylogenetic tree by means of biological informatics. Analysis shows: (1) the RAPD technique is a highly sensitive method for investigating genetic diversity in T. lepturus, and E. muticus. T. lepturus exhibits a lower polymorphism and genetic diversity than E. muticus; (2) according to the analysis of the partial mitochondrial 16S rRNA gene sequences, a very low intraspecific variation and considerably high divergence among species were found, which reveals a dual nature of conservatism and variability in mitochondrial 16S rRNA gene; (3) five primers generate the species-specific RAPD sites and these sites can be served as the molecular markers for species identification and (4) it can be proved at DNA variation level that T. lepturus and E. muticus are of two species respectively pertaining to different genera, which supports the Nelson taxonomic conclusion.     

巍山某锑冶炼厂周围植物中锑含量测定和分析

目的:了解大理巍山某地锑冶炼厂周围植物中锑污染情况.方法:在严格的质量控制下,用AA-6200型火焰原子吸收光谱法测定锑冶炼厂周围各种植物中锑的含量(包括吸附在植物表面的锑).结果:不同距离不同植物和同一距离同种植物中存在着不同程度的锑污染,其中草的污染最严重.结论:植物中存在锑污染,应加强综合治理,减少环境污染.     

植物SOD和类SOD活性物质研究进展

本文就近年来迅速发展的植物超氧化物歧化酶的纯化工艺、性质及结构研究进行概述。并介绍类SOD活性物质及其在抗衰老中的应用。