我国登革4型病毒广州株基因组非编码区序列测定及分析

目的 测定和分析我国登革 4型病毒广州 (D4-B5 )株基因组非编码区 (NCR)序列 ,为探讨其结构特征与功能的关系提供依据。方法 从登革 4型病毒感染的乳鼠脑中提取总RNA ,采用RACE法扩增病毒基因组 5’和 3’端片段 ,分别将其克隆至pGEM -T载体 ,挑取阳性克隆进行序列测定 ;利用RNAdraw软件对非编码区二级结构进行预测。结果与结论 我国登革 4型病毒广州株基因组 5′和 3′非编码区长度分别为 10 1nt和 40 3nt,具有黄病毒共有的保守序列和二级结构。与登革4型病毒多米尼加分离株比较显示 ,5′NCR第 5 7和 36位核苷酸的改变对其二级结构有显著的影响 ;3′NCR多处核苷酸差异导致两者预测的二级结构差别较大 ,但均能形成相同的保守结构 ,它们可能对病毒基因组RNA的复制。

基因组非编码区在神经系统遗传病诊治中富有潜力

《中华神经科杂志》2024年第5期发表了福建医科大学附属第一医院神经内科甘世锐等的文章《从暗物质到沃土:基因组非编码区在神经系统遗传病诊断与治疗中的应用及前景》。文章聚焦基因组非编码区相关的各种诊断分析及干预技术,及其在神经系统单基因病和多基因病发病机制、诊断及治疗中的应用,旨在为神经系统遗传病的研究提供更全面的视角。

1999年新分离的登革病毒福建株基因组非编码区的结构特征

目的 :测定和分析我国登革 2型病毒福建株 (FJ 11)基因组非编码区 (NCR)序列 ,为探讨其结构特征与功能的关系提供依据。方法 :从登革 2型病毒感染的C6/36细胞中提取总RNA ,采用RACE法扩增病毒基因组 5′和 3′端片段 ,分别将其克隆至pGEM T载体 ,挑取阳性克隆进行序列测定 ;利用RNAdraw软件对非编码区二级结构进行预测。结果与结论 :我国登革 2型病毒FJ 11株基因组 5′和 3′非编码区长度分别为 96nt和 4 5 4nt,具有黄病毒共有的保守序列和二级结构。与登革 2型病毒美洲基因型比较显示 ,5′NCR第 69位核苷酸的改变对其二级结构有影响 ;3′NCR端约 70nt能形成相同的保守结构 ,而前 380nt呈现多处核苷酸的差异而导致两者预测的二级结构差别较大 。

丙肝病毒(HCV)基因库构建、cDNA克隆化及合成肽应用的系列研究

对我国部分地区丙肝高危人群进行了较大规模的调查,证明了我国丙肝感染的严重性及丙肝抗体的应答规律;建立了HCV基因组RNA的反转录PCR方法,开展了HCV的基因检测工作。利用PCR扩增及λgt11噬菌体系统,首次构建成功我国人群HCV cDNA基因库,共获约8×10~6个噬菌斑。对此基因库进行筛选、鉴定、亚克隆及DNA测序等一系列工作,获得了我国人HCV基因组非编码区、结构区和非结构区的克隆,比较了其与国外序列的同源性和差异性。

DNA sequences homologous to hepatitis C virus(HCV) in the extrachromosomal circular DNA in peripheral blood mononuclear cells of HCV-negative subjects

Objective: This study aimed to investigate DNA sequences that are substantially homologous to the corresponding RNA sequence sections of the hepatitis C virus (HCV). These DNA sequences are present in the whole DNA extracted from peripheral blood mononuclear cells (PBMCs) of HCV-negative subjects. We presumed that these experimentally proven 5'-noncoding region (5'-NCR) homologous DNA sequences could be contained in the extrachromosomal circular DNA (eccDNA) fraction as part of the whole cellular DNA. Methods: Home-made polymerase chain reaction (PCR) with whole cellular and isolated eccDNA, nucleotide basic local alignment search tool (BLASTn) alignments, and tests for patterns of methylation in selected sequence sections were performed. Results: The PCR tests revealed DNA sequences of up to 320 bp that broadly matched the corresponding sequence sections of known HCV genotypes. In contrast, BLASTn alignment searches of published HCV 5'-NCR sequences with human genome databases revealed only sequence segments of up to 36 bp of the 5'-NCR. The composition of these sequences shows missing base pairs, base pair mismatches as well as complete homology with HCV reference sequences. These short sequence sections are present in numerous copies on both the same and different chromosomes. The selected sequence region within the DNA sequences of the 5'-NCR revealed a broad diversity of individual patterns of methylation. Conclusions: The experimental results confirm our assumption that parts of the HCV 5'-NCR genomic RNA sequences are present at the DNA level in the eccDNA fraction of PBMCs. The tests for methylation patterns therein revealed individual methylomes which could represent an epigenetic feature. The respective sequence section might be subject to genetic regulation.

Non-coding regions of the Ebola virus genome contain indispensable phylogenetic and evolutionary information

We compared the numbers of nucleotide substitutions occurring in the non-coding regions and coding regions of Ebola virus genomes and found that non-coding regions contain indispensable phylogenetic and evolutionary information. The omission of genetic data from non-coding regions can lead to unreliable phylogenies and inaccurate estimates of evolutionary parameters.