The Phylogeny Tree Reconstruction Based on the Usage Frequencyof Codons and Corresponding Complementary Codons

为了更深入地了解密码子与互补密码子使用相关的内涵,70个单细胞和多细胞生物被更进一步的分析。结果得到70种细胞生物具有较高的相关系数平均值(0.5101,标准差是0.1389),表明密码子与其互补密码子使用间确实存在正的使用相关联系,进一步地支持了以前的结果。此外,通过对70个单细胞和多细胞生物在基于密码子与互补密码子使用频率差异,以及配对频率的高低信息的分析基础上,绘制进化树,得到的进化树与传统的进化树非常接近。The hypothesis that a codon bias usage is identical to its complementary codon usage preference has been investigated by using the relationship analysis of codons vs their complementary ones among 70 organisms. Significantly positive usage correlations between codons and their complementary ones were found and its implication in biology was also analyzed. The codoncomplementary codon tree was further built, which fairly exhibited the evolutionary relationship of these organisms. The results not only demonstrated the validity of our hypothesis,but also manifested the usefulness of correlation analysis in studying on codon usage pattern and molecular evolutionary mechanisms of organism.ThisworkwassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina(No.60305001)andagrantfromtheScienceandTechnologyMinistryofChina(PreliminaryStudyonFunctionalGenomeSystematics)(No.2001CCA01400)

Correlation Analyses of Codons and Corresponding Complementary Codons Usage

遗传密码是基因与蛋白质进行信息对接的桥梁,研究不同进化阶层生物的密码子与互补密码子的使用规律是揭示物种进化的一种重要途径。为了阐明不同生物和细胞器基因密码子与互补密码子使用之间的内在联系及其在进化中的意义,作者选取了44种细胞生物、16种病毒、40种线粒体和20种叶绿体的基因密码子与互补密码子数据,并进行关联分析。结果显示:(1)无论是古细菌,真细菌,病毒,真核生物还是两类细胞器,它们的密码子与互补密码子的使用频率大多表现为显著或极显著正相关;(2)不同生物和细胞器基因密码子与互补密码子使用频率之间相关程度也存在明显的异质性。细胞生物和两类细胞器基因密码子与互补密码子使用的高度一致性反映了它们可能具有共同的起源,显著的异质性则反映了它们分别经历了不同的进化选择压力。密码子与互补密码子的使用相关程度不仅能被用作为测量物种进化过程中所经历选择压力的指标,而且也能被用作为碱基摆动和修饰的指示器。此外,文中还对生物进化早期存在DNA双链同时具有编码基因功能的可能性进行了讨论。To reveal the relationship between codons and corresponding complementary codons usage, the data of codon and corresponding complementary codon usage from 44 cellular organisms, 16 viruses, 40 mitochondria and 20 chloroplasts were analyzed. Significant correlations between codons and corresponding complementary codons usage were found in the majority of the studied subjects except viruses, albeit there was also significant heterogeneity among them. The degree of correlation between codons and corresponding complementary codons usage may be used as an index not only for measuring the degree of selection force during organism evolution, but also for exploring the degree of anticodons' modification and wobbling-pairing with corresponding codons within organisms. In addition, it is also discussed that the two strands of DNA may have simultaneous coding function in the early stage of organism evolution.国家自然科学基金项目((No 60305001)资助

处理油基钻屑的微生物复合菌剂、其制备方法及应用

本发明涉及一种处理油基钻屑的微生物复合菌剂、其制备方法及其应用。发明提供了一种处理油基钻屑的微生物复合菌剂，该复合菌剂包含保藏号为CGMCC NO：8983的铜绿假单胞菌和保藏号为CGMCC NO：8984的鲍曼不动杆菌。本发明还公开了上述微生物复合菌剂的制备方法，包括液态和固态菌剂的制备方法，以及所述复合菌剂在油基钻屑处理中的应用

一种制备聚甲基三氟丙基硅氧烷固相微萃取涂层的方法

本发明涉及固相微萃取相涂层的制备，具体地说是一种制备聚甲基三氟丙基硅氧烷固相微萃取涂层的方法，1)取羟基封端的聚甲基三氟丙基硅氧烷，加入甲基三甲氧基硅烷溶胶-凝胶反应前驱物；2)于前驱物中加入三氟乙酸作为溶胶-凝胶反应的催化剂；3)振荡混匀上述所获得的溶胶-凝胶反应液，离心，得溶胶清液；4)将纤维针、搅拌棒或吸附棒放入溶胶清液中10－30分钟后取出，室温下成胶，即得涂渍有涂层的纤维针、搅拌棒或吸附棒。本发明的优点为：方法简单、产品质量好和涂层选择性高。带填