recombination

重组
  • 文章类型: Journal Article
    哺乳动物细胞系稳定性是在生物制药和体外诊断(IVD)工业中建立生物制品制造工艺时的重要考虑因素。传统的中国仓鼠卵巢(CHO)细胞系开发方法使用随机整合方法,需要转染,选择,可选的放大,放映,和单细胞克隆,以选择具有可接受生产力的克隆,产品质量,和遗传稳定性。特定于站点的集成减少了这些缺点,并且已经开发了新技术来减轻与遗传不稳定相关的风险。在这项研究中,我们应用来自ATUM的Leap-In®转座酶介导的表达系统来产生稳定的CHOK1池,用于生产用于IVD免疫测定的四种重组抗体试剂。CHO细胞系稳定性由随时间一致的抗体产生来定义。三个CHOK1池保持了适合制造的生产率,抗体产量高。剩余CHOK1池的生产率随着时间的推移而下降;然而,衍生克隆显示出可接受的稳定性。1-谷氨酰胺对CHOK1细胞系或稳定的库稳定性具有可变的作用,并显着影响抗体产物的滴度。与传统的随机积分法相比,ATUMLeap-In系统可以通过使用半位点特异性集成来生成满足制造稳定性要求的高产量稳定池,从而减少开发新免疫测定所需的时间。
    Mammalian cell line stability is an important consideration when establishing a biologics manufacturing process in the biopharmaceutical and in vitro diagnostics (IVD) industries. Traditional Chinese hamster ovary (CHO) cell line development methods use a random integration approach that requires transfection, selection, optional amplification, screenings, and single-cell cloning to select clones with acceptable productivity, product quality, and genetic stability. Site-specific integration reduces these disadvantages, and new technologies have been developed to mitigate risks associated with genetic instability. In this study, we applied the Leap-In® transposase-mediated expression system from ATUM to generate stable CHOK1 pools for the production of four recombinant antibody reagents for IVD immunoassays. CHO cell line stability is defined by consistent antibody production over time. Three of the CHOK1 pools maintained productivity suitable for manufacturing, with high antibody yields. The productivity of the remaining CHOK1 pool decreased over time; however, derivative clones showed acceptable stability. l-glutamine had variable effects on CHOK1 cell line or stable pool stability and significantly affected antibody product titer. Compared with traditional random integration methods, the ATUM Leap-In system can reduce the time needed to develop new immunoassays by using semi site-specific integration to generate high-yield stable pools that meet manufacturing stability requirements.
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  • 文章类型: Journal Article
    随着非富勒烯受体(NFA)的兴起,实验室规模的有机太阳能电池(OSC)的效率达到了20%,将这些设备转换为卷对卷兼容制造仍然对研究人员提出了许多挑战。其中包括使用绿色溶剂溶解度进行大规模制造,卷对卷兼容制造,and,并非最不重要的,每个升级步骤中的电荷载流子动力学信息,进一步了解绩效差距。在这项工作中,证明了使用具有14%功率转换效率(PCE)的狭缝模具涂层的冠军设备的再现性,在保持最佳厚度的条件下。进一步显示,对于供体:受体(D:A)共混物PM6:Y12,与沉积技术相比,处理溶剂对电荷载流子动力学具有更显著的影响。发现与用CB处理的器件相比,用邻二甲苯处理的器件的双分子复合系数降低了40%,以及有效流动性增加70%。最后,强调的是,刀片涂布产生具有与狭缝模具涂布相似的载体动力学的装置,使其成为实验室规模优化的最佳选择,而在向上规模转化方面没有显着损失。
    As the rise of nonfullerene acceptors (NFA) has allowed lab-scale organic solar cells (OSC) to reach 20% efficiency, translating these devices into roll-to-roll compatible fabrication still poses many challenges for researchers. Among these are the use of green solvent solubility for large-scale manufacture, roll-to-roll compatible fabrication, and, not least, information on charge carrier dynamics in each upscaling step, to further understand the gap in performance. In this work, the reproducibility of champion devices using slot-die coating with 14% power conversion efficiency (PCE) is demonstrated, under the condition that the optimal thickness is maintained. It is further shown that for the donor:acceptor (D:A) blend PM6:Y12, the processing solvent has a more significant impact on charge carrier dynamics compared to the deposition technique. It is found that the devices processed with o-xylene feature a 40% decrease in the bimolecular recombination coefficient compared to those processed with CB, as well as a 70% increase in effective mobility. Finally, it is highlighted that blade-coating yields devices with similar carrier dynamics to slot-die coating, making it the optimal choice for lab-scale optimization with no significant loss in translation toward up-scale.
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  • 文章类型: Journal Article
    这项工作揭示了通过研究具有染色质减少的物种来获得有关某些生物学问题的其他信息的机会。讨论了染色质减少的假设生物学意义的简要回顾。本文分析了染色质减少的生物学作用,因为它与C值谜有关。建议将染色质减少视为基因组减少的普遍机制,减少基因组中重组事件的频率,这导致了物种的专业化和适应更狭窄的环境条件。提出了一个假设,表明非编码DNA在真核生物同源重组中的作用。CyclopskolensisLilljeborg,1901年(co足类,甲壳动物)被提议作为模型物种,用于研究由于染色质减少而导致的染色体和体细胞系细胞相间核结构转化的机制。co足类中的染色质减少被认为是胚胎细胞在个体发育过程中不可逆分化的阶段。考虑了染色质减少的环状物的形态形成过程。
    This work reveals the opportunities to obtain additional information about some biological problems through studying species that possess chromatin diminution. A brief review of the hypothesized biological significance of chromatin diminution is discussed. This article analyzes the biological role of chromatin diminution as it relates to the C-value enigma. It is proposed to consider chromatin diminution as a universal mechanism of genome reduction, reducing the frequency of recombination events in the genome, which leads to specialization and adaptation of the species to more narrow environmental conditions. A hypothesis suggesting the role of non-coding DNA in homologous recombination in eukaryotes is proposed. Cyclopskolensis Lilljeborg, 1901 (Copepoda, Crustacea) is proposed as a model species for studying the mechanisms of transformation of the chromosomes and interphase nuclei structure of somatic line cells due to chromatin diminution. Chromatin diminution in copepods is considered as a stage of irreversible differentiation of embryonic cells during ontogenesis. The process of speciation in cyclopoids with chromatin diminution is considered.
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  • 文章类型: Journal Article
    重组事件使种群和物种的进化史复杂化,并对迁移隔离(IM)模型的推断产生重大影响。然而,已经开发了几种现有的方法,假设基因座内没有重组并且基因座之间自由重组。在这项研究中,我们使用基因组数据研究了重组对IM模型估计的影响.我们进行了一项模拟研究,以评估多达1,000个基因座的参数估计器的一致性,并分析真实的基因树,以检查估计IM模型参数时的误差来源。结果表明,重组的存在导致IM模型参数的有偏估计,随着基因座数量的增加,人口规模被高估,迁移率被低估。当使用100个或更多个基因座时,偏差的大小倾向于随重组速率而增加。另一方面,随着基因座数量的增加,分裂时间的估计保持一致。在没有重组的情况下,IM模型参数的估计器保持一致。
    Recombination events complicate the evolutionary history of populations and species and have a significant impact on the inference of isolation-with-migration (IM) models. However, several existing methods have been developed, assuming no recombination within a locus and free recombination between loci. In this study, we investigated the effect of recombination on the estimation of IM models using genomic data. We conducted a simulation study to evaluate the consistency of the parameter estimators with up to 1,000 loci and analyze true gene trees to examine the sources of errors in estimating the IM model parameters. The results showed that the presence of recombination led to biased estimates of the IM model parameters, with population sizes being more overestimated and migration rates being more underestimated as the number of loci increased. The magnitude of the biases tended to increase with the recombination rates when using 100 or more loci. On the other hand, the estimation of splitting times remained consistent as the number of loci increased. In the absence of recombination, the estimators of the IM model parameters remained consistent.
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  • 文章类型: Journal Article
    人类肠腺病毒种类F(HAdV-F)是儿童腹泻死亡的主要原因。基因组分析将是理解传播动力学的关键,疾病严重程度的潜在驱动因素,和疫苗开发。然而,目前,全球HAdV-F基因组数据有限。这里,我们对2013年至2022年在肯尼亚沿海收集的粪便样本中的HAdV-F进行了测序和分析。样本是在肯尼亚沿海的Kilifi县医院从13岁以下的儿童中收集的,这些儿童在过去24小时内报告了三个或更多的粪便。通过系统发育分析和突变谱分析分析了基因组以及来自世界其他地区的数据。基于与先前描述的标准和命名法一致的系统发育聚类来分配类型和谱系。参与者的临床和人口统计学数据与基因型数据相关联。在使用实时聚合酶链反应确定的91例病例中,组装了88个接近完整的基因组,分别分为HAdV-F40(n=41)和HAdV-F41(n=47)。这些类型在整个研究期间共同传播。HAdV-F40(谱系1-3)和HAdV-F41(谱系1,2A,3A,3C,和3D)。在五个样品中观察到F40和F41型共感染,在一个样品中观察到F41和B7型共感染。两名F40和41合并感染的儿童也感染了轮状病毒,并患有使用Vesikari评分系统定义的中度和重度疾病,分别。在谱系1和3之间出现的四个HAdV-F40序列中发现了异型重组。HAdV-F41病例均无黄疸。这项研究提供了广泛的遗传多样性的证据,合并感染,在肯尼亚沿海农村的HAdV-F40中进行重组,这将为公共卫生政策提供信息,疫苗开发,包括局部循环谱系,和分子诊断试验的发展。我们建议未来进行全面研究,阐明HAdV-F遗传多样性和免疫力,以开发合理的疫苗。
    Human enteric adenovirus species F (HAdV-F) is a leading cause of childhood diarrhoeal deaths. The genomic analysis would be key to understanding transmission dynamics, potential drivers of disease severity, and vaccine development. However, currently, there are limited HAdV-F genomic data globally. Here, we sequenced and analysed HAdV-F from stool samples collected in coastal Kenya between 2013 and 2022. The samples were collected at Kilifi County Hospital in coastal Kenya from children <13 years of age who reported a history of three or more loose stools in the previous 24 hours. The genomes were analysed together with the data from the rest of the world by phylogenetic analysis and mutational profiling. Types and lineages were assigned based on phylogenetic clustering consistent with the previously described criteria and nomenclature. Participant clinical and demographic data were linked to genotypic data. Of ninety-one cases identified using real-time Polymerase Chain Reaction, eighty-eight near-complete genomes were assembled, and these were classified into HAdV-F40 (n = 41) and HAdV-F41 (n = 47). These types co-circulated throughout the study period. Three and four distinct lineages were observed for HAdV-F40 (Lineages 1-3) and HAdV-F41 (Lineages 1, 2A, 3A, 3C, and 3D). Types F40 and F41 coinfections were observed in five samples and F41 and B7 in one sample. Two children with F40 and 41 coinfections were also infected with rotavirus and had moderate and severe diseases as defined using the Vesikari Scoring System, respectively. Intratypic recombination was found in four HAdV-F40 sequences occurring between Lineages 1 and 3. None of the HAdV-F41 cases had jaundice. This study provides evidence of extensive genetic diversity, coinfections, and recombination within HAdV-F40 in a rural coastal Kenya that will inform public health policy, vaccine development that includes the locally circulating lineages, and molecular diagnostic assay development. We recommend future comprehensive studies elucidating on HAdV-F genetic diversity and immunity for rational vaccine development.
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  • 文章类型: Journal Article
    由LSD病毒(LSDV)引起的块状皮肤病(LSD),是痘病毒属Capropoxvirus的成员。根据其快速传播和全球经济影响的潜力,它被世界动物卫生组织(WOAH)列为应报告的疾病。由于这些特点,LSDV传输模式促使人们进行了深入的研究。先前使用强毒疫苗衍生的重组LSDV菌株Saratov/2017的实验研究表明,该菌株具有在抗载体环境中传播的能力。这项研究表明,第二种新型重组疫苗衍生的LSDV菌株Udmurtiya/2019,可以感染与患病动物接触的公牛,在没有昆虫媒介的情况下。公牛被安置在防虫动物生物安全3级设施中,其中一半的动物静脉注射重组LSDV(Udmurtiya/2019),其余五只动物进行模拟接种,但与接种组保持接触。感染/接种组(IN)和未感染/未接触组(IC),监测41天,连续记录体温,观察临床症状,收集血液样本和鼻拭子,使用实时PCR检测LSDV的存在。结果表明,两组动物的同居足以将病毒从IN传播到IC组,临床体征包括发热(〜41°C)和典型的LSD结节性皮肤病变的发作,IN组开始于10dpi,IC组开始于16dpi。此外,在拭子中检测到LSDV基因组以及抗LSDV抗体的存在,两组动物的血液和血清样本。这些结果提供了LSDV在受控环境中传播的额外证据,而患病和健康动物之间没有直接接触,然而在没有载体的情况下。基于这些观察,关于病毒基因组中的突变与其传播方式之间的假设关系的问题变得更加重要,需要在经典和新型重组LSDV毒株之间进行直接比较的进一步研究.
    Lumpy skin disease (LSD) caused by LSD virus (LSDV), is a member of the poxvirus genus Capripoxvirus. It is classified as a notifiable disease by the World Organization for Animal Health (WOAH) based on its potential for rapid spread and global economic impact. Due to these characteristics, the mode of LSDV transmission has prompted intensive research efforts. Previous experimental studies using the virulent vaccine-derived recombinant LSDV strain Saratov/2017, demonstrated that this strain has the capacity for transmission in a vector-proof environment. This study demonstrated that a second novel recombinant vaccine-derived LSDV strain Udmurtiya/2019, can infect bulls in contact with diseased animals, in the absence of insect vectors. Bulls were housed in an insect proof animal biosafety level 3 facility, where half the animals were inoculated intravenously with the recombinant LSDV (Udmurtiya/2019), whilst the remaining five animals were mock-inoculated but kept in contact with the inoculated group. Both the infected / inoculated group (IN) and uninfected / incontact group (IC), were monitored for 41 days with continuous registration of body temperature, observations for clinical signs and collection of blood samples and nasal swabs for testing of LSDV presence using real-time PCR. Results indicated that cohabitation of animals from both groups was sufficient to transmit the virus from the IN to the IC-group, with the onset of clinical signs including pyrexia (~41°C) and classical LSD nodular skin lesions starting at 10 dpi for the IN group and 16 dpi for the IC-group. Additionally, the presence of LSDV genomes as well as anti-LSDV antibodies were detected in swabs, blood and serum samples from animals belonging to both groups. These results provides additional evidence of LSDV transmission in a controlled environment without direct contact between diseased and healthy animals, yet in the absence of vectors. Based on these observations, the question concerning a hypothetical relation between mutations in the virus genome and its mode of transmission gains more importance and requires additional investigations with direct comparisons between classical and novel recombinant LSDV strains.
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  • 文章类型: Journal Article
    植物病毒是全球豆类生产的主要威胁。近年来,在各种豆类种植系统中,新的病毒株的出现频率越来越高,这就需要发展尖端的病毒监测技术。在这项研究中,我们使用从不同地点收集的140份有症状和无症状的叶片样本,调查了克什米尔山谷常见豆田的病毒感染情况.通过高通量测序(HTS)检查了病毒的遗传多样性,并鉴定了三种病毒,即,豆普通花叶病毒(BCMV),豆类普通花叶病病毒(BCMNV),三叶草黄脉病毒(ClYVV)。BCMNV和ClYVV是来自印度的新报告。转录组的从头组装构建了这些病毒的几乎完整的基因组。RT-PCR成果证实这些病毒的存在具有56的涌现发病率。4%的BCMV,山谷中BCMNV为27.1%,ClYVV为16.4%。发现一些样品含有多种病毒感染,其中BCMV是最主要的。在BCMV和ClYVV的基因组中检测到重组事件,但不是BCMNV.系统发育和配对身份矩阵证据表明病毒来自多个国家。我们的结果表明,HTS随后的多重PCR检测是一个简单的,快速,同时诊断植物病毒的可靠方法。
    Plant viruses are a major threat to legume production worldwide. In recent years, new virus strains have emerged with increasing frequencies in various legume cropping systems, which demands the development of cutting-edge virus surveillance techniques. In this study, we surveyed the common bean fields of Kashmir valley for virus infection using a total of 140 symptomatic and non-symptomatic leaf samples collected from different locations. The genetic diversity of viruses was examined by high-throughput sequencing (HTS) with three viruses being identified, namely, Bean Common Mosaic Virus (BCMV), Bean Common Mosaic Necrosis Virus (BCMNV), and Clover Yellow Vein Virus (ClYVV). BCMNV and ClYVV are new reports from India. De novo assembly of transcriptome constructed near-complete genomes of these viruses. RT-PCR results confirmed the presence of these viruses with an emerge incidence of 56. 4% for BCMV, 27.1% for BCMNV and 16.4 for ClYVV in the valley. Several samples were found to contain multiple virus infections with BCMV being the most predominant. Recombination events were detected in the genomes of BCMV and ClYVV, but not BCMNV. Phylogenetic and pairwise identity matrix evidence suggests viral import from multiple countries. Our results demonstrate that HTS followed by multiplex PCR assay is a simple, rapid, and reliable approach for simultaneous diagnosis of plant viruses.
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  • 文章类型: Journal Article
    自1996年猪繁殖与呼吸综合征病毒(PRRSV)在中国首次被发现以来,已经出现了几种遗传上不同的PRRSV毒株,其致病性和严重程度各不相同。从而加大了我国和世界范围内PRRS防控的难度。在2017年至2021年之间,中国NADC34样菌株的检出率有所提高。迄今为止,NADC34样菌株已传播到中国10个省,因此产生了不同程度的致病性和死亡率。在这次审查中,我们总结了NADC34样菌株在中国的历史和流行,基因组特征,限制性片段长度多态性,重组,致病性,以及该菌株在中国的疫苗状况。这样做,本研究旨在为进一步制定针对NADC34样菌株的防控措施提供依据。
    Since porcine reproductive and respiratory syndrome virus (PRRSV) was first described in China in 1996, several genetically distinct strains of PRRSV have emerged with varying pathogenicity and severity, thereby making the prevention and control of PRRS more difficult in China and worldwide. Between 2017 and 2021, the detection rate of NADC34-like strain in China increased. To date, NADC34-like strains have spread to 10 Chinese provinces and have thus developed different degrees of pathogenicity and mortality. In this review, we summarize the history of NADC34-like strains in China and clarify the prevalence, genomic characteristics, restriction fragment length polymorphisms, recombination, pathogenicity, and vaccine status of this strain in China. In so doing, this study aims to provide a basis for the further development of prevention and control measures targeting the NADC34-like strain.
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  • 文章类型: Journal Article
    犬冠状病毒(CCoV)和猫冠状病毒(FCoV)在伴侣动物中流行。由于它们的高突变率和基因组重组的趋势,它们对公众健康构成潜在威胁。对CCoV和FCoV的分子特征和遗传变异进行了深入研究,但是它们的起源和进化动态仍需要进一步评估。在本研究中,我们应用了一种综合的方法,分析了S,M,和不同CCoV/FCoV分离株的N基因。主成分判别分析(DAPC)和系统发育分析表明,中国分离株的FCoV序列与荷兰的FCoV簇密切相关,重组分析表明,SN末端结构域(NTD)是最易发生突变的区域,该区域的重组是新谱系出现的重要原因。自然选择表明,CCoV和FCoV亚型处于选择限制,和CCoV-IIb处于强阳性选择。系统动力学表明,CCoV和FCoV的S1基因的平均进化速率为1.281×10-3和1.244×10-3子/站点/年,分别,CCoV和FCoV的tMRCA分别约为1901年和1822年。一起来看,我们的研究集中在追踪CCoV/FCoV的起源,并为犬和猫冠状病毒的系统发育和进化提供了充分的见解。
    Canine coronavirus (CCoV) and feline coronavirus (FCoV) are endemic in companion animals. Due to their high mutation rates and tendencies of genome recombination, they pose potential threats to public health. The molecular characteristics and genetic variation of both CCoV and FCoV have been thoroughly studied, but their origin and evolutionary dynamics still require further assessment. In the present study, we applied a comprehensive approach and analyzed the S, M, and N genes of different CCoV/FCoV isolates. Discriminant analysis of principal components (DAPC) and phylogenetic analysis showed that the FCoV sequences from Chinese isolates were closely related to the FCoV clusters in Netherlands, while recombination analysis indicated that of S N-terminal domain (NTD) was the most susceptible region of mutation, and recombination of this region is an important cause of the emergence of new lineages. Natural selection showed that CCoV and FCoV subgenotypes were in selection constraints, and CCoV-IIb was in strong positive selection. Phylodynamics showed that the mean evolution rate of S1 genes of CCoV and FCoV was 1.281 × 10-3 and 1.244 × 10-3 subs/site/year, respectively, and the tMRCA of CCoV and FCoV was about 1901 and 1822, respectively. Taken together, our study centered on tracing the origin of CCoV/FCoV and provided ample insights into the phylogeny and evolution of canine and feline coronaviruses.
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  • 文章类型: Journal Article
    在多物种合并模型下的系统发育分析假设基因座内没有重组,并且基因座之间没有自由重组。然而,在真实数据集中,病灶内重组导致同一基因座的不同位点具有不同的家谱历史,从而使模型被错误指定。尚未系统地检查重组对各种基于聚结的系统基因组分析的影响。这里,我们进行了计算机模拟,以检查重组对多位点序列数据的几种贝叶斯分析的影响,包括树种估计,物种定界(通过贝叶斯选择定界模型)和进化参数的估计,如物种发散和渗入时间,现代和灭绝物种的种群规模,和跨物种渗入概率。我们发现重组,以与人类估计相当的速度,对基于合并的树种估计影响不大,物种划界和种群参数估计。比率比人类高10倍,重组可能会影响参数估计,导致基因渗入时间和祖先人口规模的正偏差,尽管物种发散时间和跨物种渗入概率的估计几乎没有偏差。总的来说,模拟表明,在多物种合并模型下的系统发育推断对现实的球内重组量是稳健的。
    Phylogenomic analyses under the multispecies coalescent model assume no recombination within locus and free recombination among loci. Yet, in real data sets intralocus recombination causes different sites of the same locus to have different genealogical histories so that the model is misspecified. The impact of recombination on various coalescent-based phylogenomic analyses has not been systematically examined. Here, we conduct a computer simulation to examine the impact of recombination on several Bayesian analyses of multilocus sequence data, including species tree estimation, species delimitation (by Bayesian selection of delimitation models) and estimation of evolutionary parameters such as species divergence and introgression times, population sizes for modern and extinct species, and cross-species introgression probabilities. We found that recombination, at rates comparable to estimates from the human being, has little impact on coalescent-based species tree estimation, species delimitation and estimation of population parameters. At rates 10 times higher than the human rate, recombination may affect parameter estimation, causing positive biases in introgression times and ancestral population sizes, although species divergence times and cross-species introgression probabilities are estimated with little bias. Overall, the simulation suggests that phylogenomic inferences under the multispecies coalescent model are robust to realistic amounts of intralocus recombination.
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