RNA特异性腺苷脱氨酶(Adenosine deaminases acting on RNA,ADAR)蛋白家族广泛分布于脊椎动物与无脊椎动物中。目前,脊椎动物ADAR的功能研究已较为系统和深入,诸多研究指出了其在免疫调控、病毒防御、癌症治疗以及神经发育等多个领域发...RNA特异性腺苷脱氨酶(Adenosine deaminases acting on RNA,ADAR)蛋白家族广泛分布于脊椎动物与无脊椎动物中。目前,脊椎动物ADAR的功能研究已较为系统和深入,诸多研究指出了其在免疫调控、病毒防御、癌症治疗以及神经发育等多个领域发挥的关键作用。本文归纳了无脊椎动物ADAR研究中的关键问题,重点聚焦于其结构特征、表达模式、RNA编辑情况,以及在免疫和神经发育方面的功能。分析表明,无脊椎动物ADAR与脊椎动物ADAR具有相似的功能,这充分体现了ADAR在无脊椎与脊椎动物之间功能的高度保守性。在此基础上,本文对无脊椎动物ADAR的系统演化规律及其在跨物种适应性中的分子机制研究前景进行了展望,以期为深入解析ADAR家族的进化保守性与功能多样性提供理论参考。展开更多
Background:Tandem gene repeats naturally occur as important genomic features and determine many traits in living organisms,like human diseases and microbial productivities of target bioproducts.Methods:Here,we develop...Background:Tandem gene repeats naturally occur as important genomic features and determine many traits in living organisms,like human diseases and microbial productivities of target bioproducts.Methods:Here,we developed a bacterial type-II toxin-antitoxin-mediated method to manipulate genomic integration of tandem gene repeats in Saccharomyces cerevisiae and further visualised the evolutionary trajectories of gene repeats.We designed a tri-vector system to introduce toxin-antitoxin-driven gene amplification modules.Results:This system delivered multi-copy gene integration in the form of tandem gene repeats spontaneously and independently from toxin-antitoxin-mediated selection.Inducing the toxin(RelE)expressing via a copper(II)-inducible CUP1 promoter successfully drove the in-situ gene amplification of the antitoxin(RelB)module,resulting in~40 copies of a green fluorescence reporter gene per copy of genome.Copy-number changes,copy-number increase and copy-number decrease,and stable maintenance were visualised using the green fluorescence protein and blue chromoprotein AeBlue as reporters.Copy-number increases happened spontaneously and independent on a selection pressure.Increased copy number was quickly enriched through toxin-antitoxin-mediated selection.Conclusion:In summary,the bacterial toxin-antitoxin systems provide a flexible mechanism to manipulate gene copy number in eukaryotic cells and can be exploited for synthetic biology and metabolic engineering applications.展开更多
翻白叶树是中国南方的常绿树种,具有重要的经济和药用价值。通过Illumina HiSeq X ten高通量测序平台,对翻白叶树叶绿体基因组进行测序、组装和注释,分析翻白叶树的叶绿体基因组特征及系统发育关系。结果表明,翻白叶树叶绿体全基因组具...翻白叶树是中国南方的常绿树种,具有重要的经济和药用价值。通过Illumina HiSeq X ten高通量测序平台,对翻白叶树叶绿体基因组进行测序、组装和注释,分析翻白叶树的叶绿体基因组特征及系统发育关系。结果表明,翻白叶树叶绿体全基因组具有典型的四分体结构,全长为162843 bp,共注释126个基因,其中包括81个蛋白编码基因、37个tRNA和8个rRNA。密码子偏好性分析表明,翻白叶树的密码子使用模式偏向以A或U结尾,亮氨酸(Leu)密码子使用频率最高,半胱氨酸(Cys)使用率最低。重复序列分析共检测到284个SSR位点,其中单碱基重复的SSR位点最多,有171个,6碱基重复最少,仅有2个。翅子树属叶绿体基因组比较分析显示,反向重复区域的位置和边界区域的基因分布存在收缩与扩张的现象。系统发育分析表明,翻白叶树与景东翅子树、勐仑翅子树、截裂翅子树和蚬木亲缘关系较近。该研究为翻白叶树的分子标记开发、物种鉴定以及遗传多样性评估等研究提供重要的理论依据。展开更多
文摘RNA特异性腺苷脱氨酶(Adenosine deaminases acting on RNA,ADAR)蛋白家族广泛分布于脊椎动物与无脊椎动物中。目前,脊椎动物ADAR的功能研究已较为系统和深入,诸多研究指出了其在免疫调控、病毒防御、癌症治疗以及神经发育等多个领域发挥的关键作用。本文归纳了无脊椎动物ADAR研究中的关键问题,重点聚焦于其结构特征、表达模式、RNA编辑情况,以及在免疫和神经发育方面的功能。分析表明,无脊椎动物ADAR与脊椎动物ADAR具有相似的功能,这充分体现了ADAR在无脊椎与脊椎动物之间功能的高度保守性。在此基础上,本文对无脊椎动物ADAR的系统演化规律及其在跨物种适应性中的分子机制研究前景进行了展望,以期为深入解析ADAR家族的进化保守性与功能多样性提供理论参考。
基金supported partially by the Australian Government through the Australian Research Council Centres of Excellence funding scheme(project CE200100029)。
文摘Background:Tandem gene repeats naturally occur as important genomic features and determine many traits in living organisms,like human diseases and microbial productivities of target bioproducts.Methods:Here,we developed a bacterial type-II toxin-antitoxin-mediated method to manipulate genomic integration of tandem gene repeats in Saccharomyces cerevisiae and further visualised the evolutionary trajectories of gene repeats.We designed a tri-vector system to introduce toxin-antitoxin-driven gene amplification modules.Results:This system delivered multi-copy gene integration in the form of tandem gene repeats spontaneously and independently from toxin-antitoxin-mediated selection.Inducing the toxin(RelE)expressing via a copper(II)-inducible CUP1 promoter successfully drove the in-situ gene amplification of the antitoxin(RelB)module,resulting in~40 copies of a green fluorescence reporter gene per copy of genome.Copy-number changes,copy-number increase and copy-number decrease,and stable maintenance were visualised using the green fluorescence protein and blue chromoprotein AeBlue as reporters.Copy-number increases happened spontaneously and independent on a selection pressure.Increased copy number was quickly enriched through toxin-antitoxin-mediated selection.Conclusion:In summary,the bacterial toxin-antitoxin systems provide a flexible mechanism to manipulate gene copy number in eukaryotic cells and can be exploited for synthetic biology and metabolic engineering applications.
文摘翻白叶树是中国南方的常绿树种,具有重要的经济和药用价值。通过Illumina HiSeq X ten高通量测序平台,对翻白叶树叶绿体基因组进行测序、组装和注释,分析翻白叶树的叶绿体基因组特征及系统发育关系。结果表明,翻白叶树叶绿体全基因组具有典型的四分体结构,全长为162843 bp,共注释126个基因,其中包括81个蛋白编码基因、37个tRNA和8个rRNA。密码子偏好性分析表明,翻白叶树的密码子使用模式偏向以A或U结尾,亮氨酸(Leu)密码子使用频率最高,半胱氨酸(Cys)使用率最低。重复序列分析共检测到284个SSR位点,其中单碱基重复的SSR位点最多,有171个,6碱基重复最少,仅有2个。翅子树属叶绿体基因组比较分析显示,反向重复区域的位置和边界区域的基因分布存在收缩与扩张的现象。系统发育分析表明,翻白叶树与景东翅子树、勐仑翅子树、截裂翅子树和蚬木亲缘关系较近。该研究为翻白叶树的分子标记开发、物种鉴定以及遗传多样性评估等研究提供重要的理论依据。
