third-generation sequencing

  • 文章类型: Journal Article
    背景:结构变体(SV)在遗传研究和精准医学中起着重要作用。由于现有的SV检测方法通常包含大量的假阳性呼叫,需要对检测结果进行过滤的方法。
    结果:我们开发了一种新颖的基于深度学习的SV过滤工具,CSV-Filter,对于短期和长期阅读。CSV-Filter采用一种新颖的基于CIGAR串对齐结果的多级灰度图像编码方法,并采用图像增强技术来改善SV特征提取。CSV-Filter还利用自监督学习网络作为分类模型进行传输,并采用混合精密操作来加速训练。实验表明,CSV-Filter与流行的SV检测工具的集成可以大大减少短读取和长读取的假阳性SV,同时保持真正的正SV几乎不变。与DeepSVFilter相比,用于短读取的SV过滤工具,CSV-Filter可以识别更多的误报呼叫,并支持长读取作为附加功能。
    方法:https://github.com/xzyschumacher/CSV-Filter。
    BACKGROUND: Structural variants (SVs) play an important role in genetic research and precision medicine. As existing SV detection methods usually contain a substantial number of false positive calls, approaches to filter the detection results are needed.
    RESULTS: We developed a novel deep learning-based SV filtering tool, CSV-Filter, for both short and long reads. CSV-Filter uses a novel multi-level grayscale image encoding method based on CIGAR strings of the alignment results and employs image augmentation techniques to improve SV feature extraction. CSV-Filter also utilizes self-supervised learning networks for transfer as classification models, and employs mixed-precision operations to accelerate training. The experiments showed that the integration of CSV-Filter with popular SV detection tools could considerably reduce false positive SVs for short and long reads, while maintaining true positive SVs almost unchanged. Compared with DeepSVFilter, a SV filtering tool for short reads, CSV-Filter could recognize more false positive calls and support long reads as an additional feature.
    METHODS: https://github.com/xzyschumacher/CSV-Filter.
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  • 文章类型: Journal Article
    杂交狼尾草,顶级生物质能源,由于其稀缺的乳酸菌和高纤维含量,面临使用限制。本研究评估了瘤胃液预处理对杂交狼尾草青贮的影响,重点研究了青贮饲料的持续时间和瘤胃液对品质和纤维分解的影响。先进的第三代测序用于跟踪微生物多样性的变化,并显示瘤胃液显着增强了干物质,粗蛋白,和水溶性碳水化合物,从而将发酵质量提高到令人满意的pH水平(3.40-3.67)。理想的结果,包括最高的纤维分解和酶效率(47.23%),用5%瘤胃液在60天内获得。瘤胃液的添加改变了优势种,包括牛尾芽孢杆菌(0.00%vs.18.21%)和植物乳杆菌(21.03%vs.47.02%),在高浓度处理中未检测到肠杆菌。此外,发现特定乳酸菌与发酵指标之间存在很强的相关性,揭示了实现高效和经济有益的杂交狼尾草生产的潜力。
    Hybrid Pennisetum, a top biomass energy source, faces usage limitations because of its scarce lactic acid bacteria and high fiber content. This study assessed the influence of rumen fluid pretreatment on hybrid Pennisetum\'s silage, with focus on silage duration and rumen fluid effects on quality and fiber decomposition. Advanced third-generation sequencing was used to track microbial diversity changes and revealed that rumen fluid considerably enhanced dry matter, crude protein, and water-soluble carbohydrates, thus improving fermentation quality to satisfactory pH levels (3.40-3.67). Ideal results, including the highest fiber breakdown and enzymatic efficiency (47.23 %), were obtained with 5 % rumen fluid in 60 days. The addition of rumen fluid changed the dominant species, including Paucilactobacillus vaccinostercus (0.00 % vs. 18.21 %) and Lactiplantibacillus plantarum (21.03 % vs. 47.02 %), and no Enterobacter was detected in the high-concentration treatments. Moreover, strong correlations were found between specific lactic acid bacteria and fermentation indicators, revealing the potential of achieving efficient and economically beneficial hybrid Pennisetum production.
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  • 文章类型: Journal Article
    背景:使用第三代测序数据的结构变异(SV)检测方法被广泛采用,然而准确检测SV仍然具有挑战性。对于某些SV类型,不同的方法通常会产生不一致的结果,复杂的工具选择和揭示偏见的检测。
    结果:本研究使用来自PacBio的模拟和真实数据(CLR:连续长读,CCS:循环共有测序)和纳米孔(ONT)平台。我们评估它们在检测各种大小和类型的SV时的性能,断点偏差,和不同测序深度的基因分型准确性。值得注意的是,管道,如Minimap2-cuteSV2、NGMLR-SVIM、PBMM2-pbsv,Winnowmap-Sniffles2和Winnowmap-SVision表现出相对较高的召回率和精确度。我们的发现还表明,将多个管道与相同的对准器组合在一起,像pbmm2或winnowmap,可以显著提高性能。可以在动态表中查看各个管道的详细排名和性能指标:http://pmglab。top/SVPipelinesRanking。
    结论:这项研究全面描述了众多管道的优缺点,提供有价值的见解,可以改善第三代测序数据中的SV检测,并为SV注释和功能预测提供信息。
    BACKGROUND: Structural variation (SV) detection methods using third-generation sequencing data are widely employed, yet accurately detecting SVs remains challenging. Different methods often yield inconsistent results for certain SV types, complicating tool selection and revealing biases in detection.
    RESULTS: This study comprehensively evaluates 53 SV detection pipelines using simulated and real data from PacBio (CLR: Continuous Long Read, CCS: Circular Consensus Sequencing) and Nanopore (ONT) platforms. We assess their performance in detecting various sizes and types of SVs, breakpoint biases, and genotyping accuracy with various sequencing depths. Notably, pipelines such as Minimap2-cuteSV2, NGMLR-SVIM, PBMM2-pbsv, Winnowmap-Sniffles2, and Winnowmap-SVision exhibit comparatively higher recall and precision. Our findings also show that combining multiple pipelines with the same aligner, like pbmm2 or winnowmap, can significantly enhance performance. The individual pipelines\' detailed ranking and performance metrics can be viewed in a dynamic table: http://pmglab.top/SVPipelinesRanking .
    CONCLUSIONS: This study comprehensively characterizes the strengths and weaknesses of numerous pipelines, providing valuable insights that can improve SV detection in third-generation sequencing data and inform SV annotation and function prediction.
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  • 文章类型: Journal Article
    重型α-地中海贫血(α-TM)常引起HbBart(c4)胎儿水肿和母亲严重的产科并发症。逐步筛查具有受α-TM影响的后代风险的夫妇是有效的预防方法,但无法检测到某些罕见的地中海贫血基因型。一名32岁的男性低HbA2(2.4%)和轻度贫血进行了基于实时PCR的多色熔解曲线分析(MMCA),因为他的妻子是-SEA缺失携带者。多重连接依赖性探针扩增(MLPA)的结果表明在先证中存在-SEA缺失。使用自行设计的MLPA探针结合较长的PCR发现了α-珠蛋白基因簇的新缺失,第三代测序进一步准确描述为16.8Kb(hg38,Chr16:1,65,236-1,82,113)缺失。鉴定了范围从1,53,226至1,54,538(GRch38/hg38)的片段,其表明同源重组事件的存在。第三代测序在获得复杂结构变异的准确信息方面是准确和有效的。
    α-thalassemia major (α-TM) often causes Hb Bart\'s (c4) hydrops fetalis and severe obstetric complications in the mother. Step-wise screening for couples at risk of having offspring(s) affected by α-TM is the efficient prevention method but some rare genotypes of thalassemia cannot be detected. A 32-year-old male with low HbA2 (2.4%) and mild anemia was performed real-time PCR-based multicolor melting curve analysis (MMCA) because his wife was -SEA deletion carrier. The result of multiplex ligation-dependent probe amplification (MLPA) suggested the existence of -SEA deletion in the proband. A novel deletion of the α-globin gene cluster was found using self-designed MLPA probes combined with longer PCR, which was further accurately described to be 16.8Kb (hg38, Chr16:1,65,236-1,82,113) deletion by the third-generation sequencing. A fragment ranging from 1,53,226 to 1,54,538(GRch38/hg38) was identified which suggested the existence of the homologous recombination event. The third-generation sequencing is accurate and efficient in obtaining accurate information for complex structural variations.
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  • 文章类型: Journal Article
    虽然聚(3-羟基丁酸酯)(PHB)有望成为生物塑料,由于原材料的高成本,其商业利用受到了阻碍。然而,甘油成为PHB生产的可行原料,提供可持续的生产方法和大幅降低成本的潜力。甘油是PHB生产的有前途的原料,为可持续制造和可观的成本节约提供了途径。能够将甘油转化为PHB的菌株的鉴定和表征代表了推进PHB生产研究的关键策略。在这项研究中,我们分离了一个菌株,Ralstoniasp.RRA(RRA)。该菌株在从甘油合成PHB方面表现出显著的熟练程度。以甘油为碳源,RRA实现了0.19h-1的特定生长速率,在30小时内达到了约50%的PHB含量。通过第三代基因组和转录组测序,我们阐明了基因组组成,并鉴定了总共八个基因(glpR,glpD,glpS,glpT,glpP,glpQ,glpV,和glpK)参与甘油代谢途径。利用这些发现,菌株RRA在从低成本可再生碳源生产PHB方面显示出显著的前景。
    While poly (3-hydroxybutyrate) (PHB) holds promise as a bioplastic, its commercial utilization has been hampered by the high cost of raw materials. However, glycerol emerges as a viable feedstock for PHB production, offering a sustainable production approach and substantial cost reduction potential. Glycerol stands out as a promising feedstock for PHB production, offering a pathway toward sustainable manufacturing and considerable cost savings. The identification and characterization of strains capable of converting glycerol into PHB represent a pivotal strategy in advancing PHB production research. In this study, we isolated a strain, Ralstonia sp. RRA (RRA). The strain exhibits remarkable proficiency in synthesizing PHB from glycerol. With glycerol as the carbon source, RRA achieved a specific growth rate of 0.19 h-1, attaining a PHB content of approximately 50% within 30 h. Through third-generation genome and transcriptome sequencing, we elucidated the genome composition and identified a total of eight genes (glpR, glpD, glpS, glpT, glpP, glpQ, glpV, and glpK) involved in the glycerol metabolism pathway. Leveraging these findings, the strain RRA demonstrates significant promise in producing PHB from low-cost renewable carbon sources.
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  • 文章类型: Journal Article
    蜜蜂是自然界中不可或缺的传粉媒介,具有举足轻重的生态,经济,和科学价值。然而,Apismellifera的全长转录组,采用先进的第三代纳米孔测序技术,尚未报告。这里,对未接种和Nosemaceranae接种的A.mellifera工人的中肠组织进行了纳米孔测序,然后基于高质量的长读数构建和注释全长转录组。接下来是A.mellifera的当前参考基因组的序列和注释的改进。在接种N.ceranae和10dpi后7天,从工人的腹部产生了总共5,942,745和6,664,923个原始读数,而7,100,161和6,506,665个原始读数是从相应的未接种工人的肠道生成的。经过严格的质量控制,获得了6,928,170、6,353,066、5,745,048和6,416,987个清洁读数,长度分布范围从1kb到10kb。此外,分别检测到16,824,17,708,15,744和18,246个全长转录本,包括28,019个非冗余的。其中,43,666、30,945、41,771、26,442和24,532个全长转录本可以注释到Nr,KOG,eggNOG,GO,和KEGG数据库,分别。此外,首次鉴定出501个新基因(20,326个新转录本),其中401(20,255),193(13,365),414(19,186),228(12,093),和202(11,703)分别注释到上述五个数据库中的每一个。通过RT-PCR和Sanger测序证实了三种随机选择的新转录物的表达和序列。2082个基因的5个UTR,2029个基因的3个UTR,730个基因的5'和3'UTR均被扩展。此外,17,345SSR,14,789个完整的ORF,1224长非编码RNA(lncRNAs),检测到37个家族的650个转录因子(TFs)。这项工作的发现不仅完善了A.mellifera参考基因组的注释,而且为相关的分子和组学研究提供了宝贵的资源和基础。
    Honeybees are an indispensable pollinator in nature with pivotal ecological, economic, and scientific value. However, a full-length transcriptome for Apis mellifera, assembled with the advanced third-generation nanopore sequencing technology, has yet to be reported. Here, nanopore sequencing of the midgut tissues of uninoculated and Nosema ceranae-inoculated A. mellifera workers was conducted, and the full-length transcriptome was then constructed and annotated based on high-quality long reads. Next followed improvement of sequences and annotations of the current reference genome of A. mellifera. A total of 5,942,745 and 6,664,923 raw reads were produced from midguts of workers at 7 days post-inoculation (dpi) with N. ceranae and 10 dpi, while 7,100,161 and 6,506,665 raw reads were generated from the midguts of corresponding uninoculated workers. After strict quality control, 6,928,170, 6,353,066, 5,745,048, and 6,416,987 clean reads were obtained, with a length distribution ranging from 1 kb to 10 kb. Additionally, 16,824, 17,708, 15,744, and 18,246 full-length transcripts were respectively detected, including 28,019 nonredundant ones. Among these, 43,666, 30,945, 41,771, 26,442, and 24,532 full-length transcripts could be annotated to the Nr, KOG, eggNOG, GO, and KEGG databases, respectively. Additionally, 501 novel genes (20,326 novel transcripts) were identified for the first time, among which 401 (20,255), 193 (13,365), 414 (19,186), 228 (12,093), and 202 (11,703) were respectively annotated to each of the aforementioned five databases. The expression and sequences of three randomly selected novel transcripts were confirmed by RT-PCR and Sanger sequencing. The 5\' UTR of 2082 genes, the 3\' UTR of 2029 genes, and both the 5\' and 3\' UTRs of 730 genes were extended. Moreover, 17,345 SSRs, 14,789 complete ORFs, 1224 long non-coding RNAs (lncRNAs), and 650 transcription factors (TFs) from 37 families were detected. Findings from this work not only refine the annotation of the A. mellifera reference genome, but also provide a valuable resource and basis for relevant molecular and -omics studies.
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  • 文章类型: Journal Article
    目的:探讨第三代纳米孔测序技术在糖尿病合并疑似肺结核患者中的诊断价值。
    方法:样品,包括痰和支气管肺泡灌洗液(BALF),从2021年10月至2023年8月收治的疑似肺结核的糖尿病患者中收集。纳米孔测序,抗酸杆菌(AFB)涂片,分枝杆菌固体培养,XpertMTB/RIF,并进行DNA检测,并比较其诊断效能。
    结果:第三代纳米孔测序技术在糖尿病患者肺结核诊断中具有很高的准确性。与传统方法相比,纳米孔测序显示灵敏度显著提高(76.80%),阴性预测值(30.40%),巧合(77.92%),和诊断准确性(AUC=0.822)。结合Xpert检测实现了最高的诊断性能,灵敏度提高(81.20%),阳性预测值(98.20%),阴性预测值(35.00%),巧合(81.82%),和AUC(0.843)。尽管抗酸染色有局限性,其与纳米孔测序的结合提高了筛查的有效性。
    结论:与已建立的诊断方法如耐酸染色相比,分枝杆菌固体培养,XpertMTB/RIF,和DNA检测,第三代纳米孔测序技术显示,在糖尿病患者中检测疑似肺结核的敏感性显著提高.值得注意的是,纳米孔测序与Xpert检测的联合应用进一步提高了诊断准确性.
    OBJECTIVE: To explore the diagnostic value of third-generation nanopore sequencing technology in patients with diabetes mellitus suspected of pulmonary tuberculosis.
    METHODS: Samples, including sputum and bronchoalveolar lavage fluid(BALF), were collected from patients with diabetes mellitus suspected of pulmonary tuberculosis who were admitted from October 2021 to August 2023. Nanopore sequencing, acid-fast bacilli (AFB) smear, mycobacterial solid culture, Xpert MTB/RIF, and DNA detection were performed, and their diagnostic efficacy was compared.
    RESULTS: Third-generation nanopore sequencing technology exhibited high accuracy in diagnosing pulmonary tuberculosis in patients with diabetes mellitus. Compared to traditional methods, nanopore sequencing showed significantly improved sensitivity (76.80 %), negative predictive value (30.40 %), coincidence (77.92 %), and diagnostic accuracy (AUC = 0.822). Combined detection with Xpert achieved the highest diagnostic performance, with increased sensitivity (81.20 %), positive predictive value (98.20 %), negative predictive value (35.00 %), coincidence (81.82 %), and AUC (0.843). Although acid-fast staining had limitations, its combination with nanopore sequencing improved screening effectiveness.
    CONCLUSIONS: Compared to established diagnostic modalities such as acid-fast staining, mycobacterial solid culture, Xpert MTB/RIF, and DNA detection, third-generation nanopore sequencing technology demonstrates a significant improvement in sensitivity for detecting suspected pulmonary tuberculosis in diabetic patients. Notably, the combined application of nanopore sequencing with Xpert testing offers a further enhancement in diagnostic accuracy.
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  • 文章类型: Journal Article
    缺失是基因组结构变异的关键类型,与许多遗传疾病有关。第三代测序技术的出现促进了复杂基因组结构的分析,并阐明了基因组变异导致的表型变化和疾病发作的潜在机制。重要的是,它为删除变体调用引入了创新的观点。在这里,我们提出了一种名为双注意力结构变异(DASV)的方法来分析测序数据中的缺失结构变异。DASV将基因比对信息转换为图像,并通过双重注意机制将其与基因组测序数据整合。随后,它采用多尺度网络来精确识别缺失区域。与四种广泛使用的基因组结构变异调用工具相比:cuteSV,SVIM,鼻烟和PBSV,结果表明,DASV始终在准确率和召回率之间取得平衡,增强各种数据集的F1分数。源代码可在https://github.com/deconvolution-w/DASV获得。
    Deletion is a crucial type of genomic structural variation and is associated with numerous genetic diseases. The advent of third-generation sequencing technology has facilitated the analysis of complex genomic structures and the elucidation of the mechanisms underlying phenotypic changes and disease onset due to genomic variants. Importantly, it has introduced innovative perspectives for deletion variants calling. Here we propose a method named Dual Attention Structural Variation (DASV) to analyze deletion structural variations in sequencing data. DASV converts gene alignment information into images and integrates them with genomic sequencing data through a dual attention mechanism. Subsequently, it employs a multi-scale network to precisely identify deletion regions. Compared with four widely used genome structural variation calling tools: cuteSV, SVIM, Sniffles and PBSV, the results demonstrate that DASV consistently achieves a balance between precision and recall, enhancing the F1 score across various datasets. The source code is available at https://github.com/deconvolution-w/DASV.
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  • 文章类型: Journal Article
    地中海贫血是世界上最常见和最具破坏性的单基因疾病之一。它是由α-和/或β-珠蛋白基因的致病变体引起的,破坏这两个蛋白质链的平衡,导致α-地中海贫血或β-地中海贫血,分别。患有α-地中海贫血或β-地中海贫血的患者可能表现出严重的表型,没有简单有效的治疗方法。载体筛查的三层策略,中国已经建立了产前诊断和新生儿筛查,以预防和控制地中海贫血,其中的前两部分已经过深入研究。新生儿地中海贫血筛查实施滞后,各种筛查方案的有效性尚未得到证实。在这项研究中,血红蛋白毛细管电泳(CE),热点测试方法,和第三代测序(TGS)用于2000个新生儿样本的变异检测,评估这些方法在新生儿地中海贫血筛查中的功效。与CE(249,12.45%)和热点分析(424,21.2%)相比,CATSA检测到的地中海贫血变异体数量最多(535,26.75%),其中包括24个热点变体,α-珠蛋白基因拷贝数增加,罕见的致病变异,和三个未报告的潜在致病变异。更重要的是,CATSA直接测定了三个新生儿中变异体的顺反关系,大大缩短了地中海贫血的临床诊断时间。CATSA相对于其他基因检测显示出巨大的优势,可能成为地中海贫血三级防控策略最有力的技术支持。
    Thalassemia is one of the most common and damaging monogenic diseases in the world. It is caused by pathogenic variants of α- and/or β-globin genes, which disrupt the balance of these two protein chains and leads to α-thalassemia or β-thalassemia, respectively. Patients with α-thalassemia or β-thalassemia could exhibit a severe phenotype, with no simple and effective treatment. A three-tiered strategy of carrier screening, prenatal diagnosis and newborn screening has been established in China for the prevention and control of thalassemia, of which the first two parts have been studied thoroughly. The implementation of neonatal thalassemia screening is lagging, and the effectiveness of various screening programs has not yet been demonstrated. In this study, hemoglobin capillary electrophoresis (CE), hotspot testing method, and third-generation sequencing (TGS) were used in the variant detection of 2000 newborn samples, to assess the efficacy of these methods in neonatal thalassemia screening. Compared with CE (249, 12.45 %) and hotspot analysis (424, 21.2 %), CATSA detected the largest number of thalassemia variants (535, 26.75 %), which included 24 hotspot variants, increased copy number of α-globin gene, rare pathogenic variants, and three unreported potentially disease-causing variants. More importantly, CATSA directly determined the cis-trans relationship of variants in three newborns, which greatly shortens the clinical diagnosis time of thalassemia. CATSA showed a great advantage over other genetic tests and could become the most powerful technical support for the three-tiered prevention and control strategy of thalassemia.
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  • 文章类型: Journal Article
    常规的地中海贫血筛查采取逐步的方法,并且在全面识别所有突变谱方面具有局限性。本研究旨在探讨第三代测序(TGS)与传统分子检测相比的性能。
    TGS用于验证通过常规测试检测到的所有已知变体,并检测未诊断病例中的缺失变体。该研究于2021年12月至2022年4月在清迈MaharajNakorn医院进行。
    总共,本研究纳入19例,其中52.6%(10/19)有已知的地中海贫血变异,47.7%(9/19)的病例未通过常规方法诊断。先前检测到的所有16种变体均通过TGS验证,TGS在36.8%(7/19)的病例中还检测到43.8%(7/16)的地中海贫血变异。
    与传统方法相比,TGS可以提供额外的遗传诊断。需要更大样本量的进一步成本效益研究来探索TGS在临床实践中的作用。
    UNASSIGNED: Conventional thalassemia screening takes a stepwise approach and has limitations in comprehensively identifying all spectrums of mutations. This study aimed to investigate the performance of third-generation sequencing (TGS) compared to conventional molecular testing.
    UNASSIGNED: TGS was applied to validate all known variants detected by conventional testing and to detect missing variants in undiagnosed cases. The study was conducted at Maharaj Nakorn Chiang Mai Hospital between December 2021 and April 2022.
    UNASSIGNED: In total, 19 cases were included in this study, among which 52.6% (10/19) had known thalassemia variants, while 47.7% (9/19) cases were undiagnosed by conventional methods. All 16 variants previously detected were validated by TGS, and TGS additionally detected 43.8% (7/16) thalassemia variants for 36.8% (7/19) cases.
    UNASSIGNED: TGS could provide additional genetic diagnoses compared with conventional methods. Further cost-effectiveness studies with a larger sample size are needed to explore the role of TGS in clinical practices.
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