微卫星是基因组上的特殊短重复序列,微卫星不稳定的程度与一些肿瘤的分型、治疗和预后相关。目前,微卫星长度变化的检测往往是基于大量细胞,检测灵敏度低。本文整合激光显微切割技术,基于多次退火环状循环扩增(multiple annealing and l...微卫星是基因组上的特殊短重复序列,微卫星不稳定的程度与一些肿瘤的分型、治疗和预后相关。目前,微卫星长度变化的检测往往是基于大量细胞,检测灵敏度低。本文整合激光显微切割技术,基于多次退火环状循环扩增(multiple annealing and looping-based amplification cycles,MALBAC)的单细胞全基因组放大技术和毛细管电泳长度测量方法,经过关键技术点的改进,建立了一套针对组织中少量细胞的多微卫星位点检测方法。研究结果表明,基于技术改进,HE染色的组织细胞经激光显微切割分选后,可成功用MALBAC技术进行全基因组放大,并在多微卫星位点的检测上,获得了高度的准确性和重复性。利用所建立的方法,发现肠型胃癌早期病变组织-肠上皮化生(intestinal metaplasia,IM)的单个腺体内部出现多种长度变化的微卫星改变,说明该癌前病变组织中DNA错配修复系统已经出现问题。本方法所获得的全基因组放大产物,也可以用于外显子组测序和全基因组测序。另外,该方法适用于任何组织的少量细胞,甚至单细胞的多微卫星位点检测,以及全基因组的研究,为精细研究少量病变细胞的基因组特征以及组织异质性提供了有效的方法。展开更多
The low biomass in environmental samples is a major challenge for microbial metagenomic studies. The amplification of a genomic DNA was frequently applied to meeting the minimum requirement of the DNA for a high-throu...The low biomass in environmental samples is a major challenge for microbial metagenomic studies. The amplification of a genomic DNA was frequently applied to meeting the minimum requirement of the DNA for a high-throughput next-generation-sequencing technology. Using a synthetic bacterial community, the amplification efficiency of the Multiple Annealing and Looping Based Amplification Cycles（MALBAC） kit that is originally developed to amplify the single-cell genomic DNA of mammalian organisms is examined. The DNA template of 10 pg in each reaction of the MALBAC amplification may generate enough DNA for Illumina sequencing. Using 10 pg and 100 pg templates for each reaction set, the MALBAC kit shows a stable and homogeneous amplification as indicated by the highly consistent coverage of the reads from the two amplified samples on the contigs assembled by the original unamplified sample. Although Genome Plex whole genome amplification kit allows one to generate enough DNA using 100 pg of template in each reaction, the minority of the mixed bacterial species is not linearly amplified. For both of the kits, the GC-rich regions of the genomic DNA are not efficiently amplified as suggested by the low coverage of the contigs with the high GC content. The high efficiency of the MALBAC kit is supported for the amplification of environmental microbial DNA samples, and the concerns on its application are also raised to bacterial species with the high GC content.展开更多
目的:探讨最适的β地中海贫血疾病HBB基因单细胞全基因组扩增方法。方法:60份β地中海贫血成纤维细胞(HBB基因变异位点CD17和IVSⅡ654)和48份废弃胚胎单个卵裂球进行多次退火环状循环扩增法(MALBAC)和多重置换扩增法(MDA)扩增及高通量测...目的:探讨最适的β地中海贫血疾病HBB基因单细胞全基因组扩增方法。方法:60份β地中海贫血成纤维细胞(HBB基因变异位点CD17和IVSⅡ654)和48份废弃胚胎单个卵裂球进行多次退火环状循环扩增法(MALBAC)和多重置换扩增法(MDA)扩增及高通量测序,比较位点检测率、等位基因脱扣(ADO)率及扩增均一度等。结果:β地中海贫血疾病HBB基因MALBAC技术位点检测率(100%)高于MDA技术(96.3%);CD17和IVSⅡ654的ADO率MALBAC技术为9.09%和0.00%,MDA技术为23.08%和19.23%;对编码人β-珠蛋白的HBB基因附近60个SNP位点检测显示MALBAC技术ADO率为12.04%,MDA技术为21.25%;MALBAC技术拷贝数变异检测变异系数为0.13,MDA技术为0.15。结论:β地中海贫血单细胞诊断MALBAC法优于M D A法。展开更多
基金The Strategic Priority Research Program of the Chinese Academy of Sciences (CAS) under contract Nos XDB06010100 and XDB06010200the National Basic Research Program (973 Program) of China under contract No.2012CB417304+2 种基金the National Natural Science Foundation of China under contract No.U1301232the Sanya Institute of Deep Sea Science and Engineering under contract Nos SIDSSE-201206,SIDSSE-BR-201303 and SIDSSE-201305the award from King Abdullah University of Science and Technology under contract No.SAC0040/UK-C0016
文摘The low biomass in environmental samples is a major challenge for microbial metagenomic studies. The amplification of a genomic DNA was frequently applied to meeting the minimum requirement of the DNA for a high-throughput next-generation-sequencing technology. Using a synthetic bacterial community, the amplification efficiency of the Multiple Annealing and Looping Based Amplification Cycles（MALBAC） kit that is originally developed to amplify the single-cell genomic DNA of mammalian organisms is examined. The DNA template of 10 pg in each reaction of the MALBAC amplification may generate enough DNA for Illumina sequencing. Using 10 pg and 100 pg templates for each reaction set, the MALBAC kit shows a stable and homogeneous amplification as indicated by the highly consistent coverage of the reads from the two amplified samples on the contigs assembled by the original unamplified sample. Although Genome Plex whole genome amplification kit allows one to generate enough DNA using 100 pg of template in each reaction, the minority of the mixed bacterial species is not linearly amplified. For both of the kits, the GC-rich regions of the genomic DNA are not efficiently amplified as suggested by the low coverage of the contigs with the high GC content. The high efficiency of the MALBAC kit is supported for the amplification of environmental microbial DNA samples, and the concerns on its application are also raised to bacterial species with the high GC content.
文摘目的:探讨最适的β地中海贫血疾病HBB基因单细胞全基因组扩增方法。方法:60份β地中海贫血成纤维细胞(HBB基因变异位点CD17和IVSⅡ654)和48份废弃胚胎单个卵裂球进行多次退火环状循环扩增法(MALBAC)和多重置换扩增法(MDA)扩增及高通量测序,比较位点检测率、等位基因脱扣(ADO)率及扩增均一度等。结果:β地中海贫血疾病HBB基因MALBAC技术位点检测率(100%)高于MDA技术(96.3%);CD17和IVSⅡ654的ADO率MALBAC技术为9.09%和0.00%,MDA技术为23.08%和19.23%;对编码人β-珠蛋白的HBB基因附近60个SNP位点检测显示MALBAC技术ADO率为12.04%,MDA技术为21.25%;MALBAC技术拷贝数变异检测变异系数为0.13,MDA技术为0.15。结论:β地中海贫血单细胞诊断MALBAC法优于M D A法。
