Genetic Techniques

遗传技术
  • 文章类型: Journal Article
    背景:肺孢子菌肺炎(PCP)通常影响免疫功能低下的个体,而在有免疫能力的人中,它相对很少发生,在大多数情况下,肺孢子虫感染被检测为无症状定植。本研究旨在建立不同免疫状态(免疫功能低下和免疫功能低下)的人类宿主中肺孢子虫感染的患病率。使用分子诊断方法,并将其诊断价值与经典染色方法进行比较。
    方法:我们使用了从保加利亚人群中肺孢子病患病率的前瞻性研究中收集到的数据。临床标本(包括咽喉分泌物,诱导痰,气管抽吸物,和支气管肺泡灌洗)从220名怀疑PCP的患者(153名免疫活性患者和67名免疫功能低下的患者)中收集,采用显微镜染色方法和实时PCR检测P。结果:38例(17%)标本(32例免疫功能低下患者和6例免疫功能正常受试者)中检测到病原体的DNA。从染色方法检查的所有220个临床样本中,Gomori染色仅检测到5个(2%)Jirovecii囊肿。所有PCP患者均接受甲氧苄啶-磺胺甲恶唑治疗,但是在其中十个(HIV阳性患者)中,这种疾病有致命的结果。
    结论:这项研究是保加利亚的第一项研究,包括诊断人类肺孢子虫病的主要可用实验室方法。关于PCP的病因诊断,在我们的研究中,与染色方法相比,实时PCR的灵敏度更高。样品收集和检查方法的选择对实验室诊断的效率具有重要作用。
    BACKGROUND: Pneumocystis pneumonia (PCP) commonly affects immunocompromised individuals, whereas in immunocompetent persons, it occurs relatively rarely, and in most cases, the Pneumocystis infection is detected as an asymptomatic colonization. The present study aimed to establish the prevalence of Pneumocystis jirovecii infection in human hosts with different immune status (immunocompromised and immunocompetent), using molecular diagnostic methods, and to compare their diagnostic value with that of classical staining methods.
    METHODS: We used the collected-to-this-moment data from a prospective study on the prevalence of pneumocystosis among the Bulgarian population. Clinical specimens (including throat secretions, induced sputum, tracheal aspirates, and bronchoalveolar lavage) collected from 220 patients suspected of PCP (153 immunocompetent and 67 immunocompromised patients) were examined with microscopic staining methods and real-time PCR for detection of P. jirovecii. Results: DNA of the pathogen was detected in 38 (17%) specimens (32 immunocompromised patients and 6 immunocompetent subjects). From all 220 clinical samples examined by staining methods, only five (2%) P. jirovecii cysts were detected by the Gomori stain. All patients with PCP were treated with trimethoprim-sulfamethoxazole, but in ten of them (HIV-positive patients), the disease had a fatal outcome.
    CONCLUSIONS: This study is the first in Bulgaria including the main available laboratory methods for diagnosis of human pneumocystosis. Regarding the etiological diagnosis of PCP, in our study the sensitivity of real-time PCR was higher compared to the staining methods. The choice of a method for sample collection and examination has an important role in the efficiency of the laboratory diagnostics.
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  • 文章类型: Journal Article
    非整倍体,染色体增益或丢失的存在,是癌症的标志.这里,我们描述了KaryoCreate(核型CRISPR工程非整倍体技术),该系统通过共表达靶向染色体特异性CENPA-结合α-卫星重复序列的sgRNA以及与突变体KNL1融合的dCas9,从而能够产生染色体特异性非整倍体。我们为24条染色体中的19条设计了独特且高度特异性的sgRNA。这些构建体的表达导致细胞后代中靶向染色体的错误分离和诱导获得或丢失。在10个染色体上验证了增益的平均效率为8%,损失的平均效率为12%(高达20%)。在结肠上皮细胞中使用KaryoCreate,我们显示染色体18q丢失,常见于胃肠道癌症,促进对TGF-β的抗性,可能是由于多个基因的协同半合子缺失。总之,我们描述了一种创新技术来创建和研究癌症背景下的染色体不分离和非整倍性。
    Aneuploidy, the presence of chromosome gains or losses, is a hallmark of cancer. Here, we describe KaryoCreate (karyotype CRISPR-engineered aneuploidy technology), a system that enables the generation of chromosome-specific aneuploidies by co-expression of an sgRNA targeting chromosome-specific CENPA-binding ɑ-satellite repeats together with dCas9 fused to mutant KNL1. We design unique and highly specific sgRNAs for 19 of the 24 chromosomes. Expression of these constructs leads to missegregation and induction of gains or losses of the targeted chromosome in cellular progeny, with an average efficiency of 8% for gains and 12% for losses (up to 20%) validated across 10 chromosomes. Using KaryoCreate in colon epithelial cells, we show that chromosome 18q loss, frequent in gastrointestinal cancers, promotes resistance to TGF-β, likely due to synergistic hemizygous deletion of multiple genes. Altogether, we describe an innovative technology to create and study chromosome missegregation and aneuploidy in the context of cancer and beyond.
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  • 文章类型: Journal Article
    Mucoralean真菌生理学的研究是一个被忽视的领域,过去缺乏有效的遗传工具阻碍了这一领域。然而,由这些真菌引起的新出现的真菌感染,被称为毛霉菌病,促使许多研究人员研究了Mucorales的致病潜力。目前这种吸引人研究毛霉菌病的主要原因是其高杀伤力,缺乏有效的抗真菌药物,以及最近增加的发病率。毛霉菌病出现特征的最当代的例子是几个亚洲国家宣布的流行病,这是COVID-19大流行的直接后果。幸运的是,了解毛霉菌病和开发新治疗策略的压力促使新的遗传技术和方法的兴起。这篇综述描述了Mucorales基因操作的历史,强调方法的发展以及它们如何允许这些真菌的主要遗传研究。此外,我们强调了最近研究毛霉菌病的新遗传模型的发展,这是该领域的一个里程碑,将配置与这种疾病有关的未来研究。
    The study of the Mucoralean fungi physiology is a neglected field that the lack of effective genetic tools has hampered in the past. However, the emerging fungal infection caused by these fungi, known as mucormycosis, has prompted many researchers to study the pathogenic potential of Mucorales. The main reasons for this current attraction to study mucormycosis are its high lethality, the lack of effective antifungal drugs, and its recent increased incidence. The most contemporary example of the emergence character of mucormycosis is the epidemics declared in several Asian countries as a direct consequence of the COVID-19 pandemic. Fortunately, this pressure to understand mucormycosis and develop new treatment strategies has encouraged the blossoming of new genetic techniques and methodologies. This review describes the history of genetic manipulation in Mucorales, highlighting the development of methods and how they allowed the main genetic studies in these fungi. Moreover, we have emphasized the recent development of new genetic models to study mucormycosis, a landmark in the field that will configure future research related to this disease.
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  • 文章类型: Journal Article
    RNA结合蛋白(RBP)调节细胞内几乎所有的转录后过程。为了充分理解RBP函数,确定它们的体内靶标至关重要。分析RBP目标的标准技术,如交联免疫沉淀(CLIP)及其变体,在某些情况下是有限的或次优的,例如,当相容的抗体不可用时以及当处理小细胞群体如神经元亚型和原代干细胞时。这篇综述总结并比较了最近设计用于在这种情况下鉴定RBP靶标的几种遗传方法。TRIBE(通过编辑鉴定的RNA结合蛋白的靶标),RNA标记,和STAMP(通过APOBEC介导的谱分析调查靶标)是可用于研究转录后调控和RBP鉴定的新遗传工具。我们描述了潜在的RNA碱基编辑技术,最近的应用,和治疗意义。
    RNA binding proteins (RBPs) regulate nearly all post-transcriptional processes within cells. To fully understand RBP function, it is essential to identify their in vivo targets. Standard techniques for profiling RBP targets, such as crosslinking immunoprecipitation (CLIP) and its variants, are limited or suboptimal in some situations, e.g. when compatible antibodies are not available and when dealing with small cell populations such as neuronal subtypes and primary stem cells. This review summarizes and compares several genetic approaches recently designed to identify RBP targets in such circumstances. TRIBE (targets of RNA binding proteins identified by editing), RNA tagging, and STAMP (surveying targets by APOBEC-mediated profiling) are new genetic tools useful for the study of post-transcriptional regulation and RBP identification. We describe the underlying RNA base editing technology, recent applications, and therapeutic implications.
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  • 文章类型: Journal Article
    诊断骨和软组织肿瘤仍然具有挑战性,因为有大量的亚型,其中许多缺乏诊断生物标志物。DNA甲基化谱已被证明是脑肿瘤分类的可靠基础,在这个成功之后,已开发出一种基于DNA甲基化的肉瘤分类工具,该工具来自海德堡的DeutschesKrebsforschunchszentrum(DKFZ)。在这项研究中,我们评估了他们的分类器对986例骨和软组织肿瘤和对照的独立数据集DNA甲基化谱的表现.我们发现,“DKFZ肉瘤分类器”能够对986个样本中的55%进行诊断预测,83%的预测与组织学诊断一致。在对DKFZ分类器进行训练的820例组织学诊断病例进行验证时,61%的病例得到了预测,在88%的病例中,组织学诊断与预测的甲基化类型一致,结果与DKFZ分类器论文中报道的结果相当。分类器在诊断间充质软骨肉瘤(CHSs,88%灵敏度),脊索瘤(敏感性为85%),和纤维发育不良(83%的敏感性)。在最不经常正确分类的亚型中,透明细胞CHSs(14%灵敏度),恶性周围神经鞘瘤(27%的敏感性),和多形性脂肪肉瘤(29%的敏感性)。分类器预测导致在我们的六个病例中修改了组织学诊断。我们观察到,尽管更高的肿瘤纯度导致了更大的预测可能性,它与分类器准确度无关.我们的结果表明,DKFZ分类器代表了探索肉瘤发病机理的强大研究工具;它有可能成为有价值的诊断工具。
    Diagnosing bone and soft tissue neoplasms remains challenging because of the large number of subtypes, many of which lack diagnostic biomarkers. DNA methylation profiles have proven to be a reliable basis for the classification of brain tumours and, following this success, a DNA methylation-based sarcoma classification tool from the Deutsches Krebsforschungszentrum (DKFZ) in Heidelberg has been developed. In this study, we assessed the performance of their classifier on DNA methylation profiles of an independent data set of 986 bone and soft tissue tumours and controls. We found that the \'DKFZ Sarcoma Classifier\' was able to produce a diagnostic prediction for 55% of the 986 samples, with 83% of these predictions concordant with the histological diagnosis. On limiting the validation to the 820 cases with histological diagnoses for which the DKFZ Classifier was trained, 61% of cases received a prediction, and the histological diagnosis was concordant with the predicted methylation class in 88% of these cases, findings comparable to those reported in the DKFZ Classifier paper. The classifier performed best when diagnosing mesenchymal chondrosarcomas (CHSs, 88% sensitivity), chordomas (85% sensitivity), and fibrous dysplasia (83% sensitivity). Amongst the subtypes least often classified correctly were clear cell CHSs (14% sensitivity), malignant peripheral nerve sheath tumours (27% sensitivity), and pleomorphic liposarcomas (29% sensitivity). The classifier predictions resulted in revision of the histological diagnosis in six of our cases. We observed that, although a higher tumour purity resulted in a greater likelihood of a prediction being made, it did not correlate with classifier accuracy. Our results show that the DKFZ Classifier represents a powerful research tool for exploring the pathogenesis of sarcoma; with refinement, it has the potential to be a valuable diagnostic tool.
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  • 文章类型: Journal Article
    在基因组规模数据集的分析中,系统发育结果之间的不一致已成为普遍现象。不一致源于潜在进化过程的不确定性(例如,不完整的谱系排序),以及为每种情况确定最佳分析方法的困难。为了克服这些困难,需要更多的研究来识别不一致,并展示自信地解决它们的实用方法。这里,我们基于197个分类单元和2,526个超保守元件(UCE)基因座的分析,提供了系统基因组学研究的结果。我们研究了Eucerinae的进化关系,蜜蜂(蜜蜂和大黄蜂的亲戚)的多样化亚科,>1,200种。我们对群体中所有部落的代表和>80%的属进行了抽样,包括两个神秘的南美属,辣椒属和长柄。对UCE数据的初步分析揭示了部落之间关系的两个相互矛盾的假设。为了解决不一致,我们测试了串联和物种树方法,并使用了各种额外的策略,包括基因座过滤,分区基因树搜索,和基于基因的拓扑测试。我们表明,基因座内划分改善了基因树和随后的物种树估计,这种方法,自信地解决了我们数据集中观察到的不一致。在探索了我们提出的对桉树蜜蜂的分析策略之后,我们通过在已发布的Adephaga(昆虫纲:鞘翅目)的UCE数据集上实施该方法,验证了其解决硬系统发育问题的功效。我们的结果为Eucerinae提供了可靠的系统发育假设,并证明了解决其他系统发育数据集中不一致的实用策略。
    Incongruence among phylogenetic results has become a common occurrence in analyses of genome-scale data sets. Incongruence originates from uncertainty in underlying evolutionary processes (e.g., incomplete lineage sorting) and from difficulties in determining the best analytical approaches for each situation. To overcome these difficulties, more studies are needed that identify incongruences and demonstrate practical ways to confidently resolve them. Here, we present results of a phylogenomic study based on the analysis 197 taxa and 2,526 ultraconserved element (UCE) loci. We investigate evolutionary relationships of Eucerinae, a diverse subfamily of apid bees (relatives of honey bees and bumble bees) with >1,200 species. We sampled representatives of all tribes within the group and >80% of genera, including two mysterious South American genera, Chilimalopsis and Teratognatha. Initial analysis of the UCE data revealed two conflicting hypotheses for relationships among tribes. To resolve the incongruence, we tested concatenation and species tree approaches and used a variety of additional strategies including locus filtering, partitioned gene-trees searches, and gene-based topological tests. We show that within-locus partitioning improves gene tree and subsequent species-tree estimation, and that this approach, confidently resolves the incongruence observed in our data set. After exploring our proposed analytical strategy on eucerine bees, we validated its efficacy to resolve hard phylogenetic problems by implementing it on a published UCE data set of Adephaga (Insecta: Coleoptera). Our results provide a robust phylogenetic hypothesis for Eucerinae and demonstrate a practical strategy for resolving incongruence in other phylogenomic data sets.
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  • 文章类型: Journal Article
    Strategies for enhancing protein degradation have been proposed for treating neurological diseases associated with a decline in proteasome activity. A proteasomal deubiquitinating enzyme that controls substrate entry into proteasomes, ubiquitin-specific protease 14 (USP14), is an attractive candidate for therapies that modulate proteasome activity. This report tests the validity of genetic and pharmacological tools to study USP14\'s role in regulating protein abundance. Although previous studies implicated USP14 in the degradation of microtubule associate protein tau, tar DNA binding protein, and prion protein, the levels of these proteins were similar in our neurons cultured from wild type and USP14-deficient mice. Neither loss nor over-expression of USP14 affected the levels of these proteins in mice, implying that modifying the amount of USP14 is not sufficient to alter their steady-state levels. However, neuronal over-expression of a catalytic mutant of USP14 showed that manipulating USP14\'s ubiquitin-hydrolase activity altered the levels of specific proteins in vivo. Although pharmacological inhibitors of USP14\'s ubiquitin-hydrolase activity reduced microtubule associate protein tau, tar DNA binding protein, and prion protein in culture, the effect was similar in wild type and USP14-deficient neurons, thus impacting their use for specifically evaluating USP14 in a therapeutic manner. While examining how targeting USP14 may affect other proteins in vivo, this report showed that fatty acid synthase, v-rel reticuloendotheliosis viral oncogene homolog, CTNNB1, and synaptosome associated protein 23 are reduced in USP14-deficient mice; however, loss of USP14 differentially altered the levels of these proteins in the liver and brain. As such, it is critical to more thoroughly examine how inhibiting USP14 alters protein abundance to determine if targeting USP14 will be a beneficial strategy for treating neurodegenerative diseases.
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  • UBC9 (E2) small ubiquitin-like modifier conjugating enzyme plays a key role in the post-translational modification of proteins named sumoylation. Defects in small ubiquitin-like modifier modification may contribute to breast carcinogenesis. In the present work, we examined UBC9 genetic variation.
    UBC9 genetic variation was analyzed by using the high resolution melting (HRM) method. HRM study was conducted on 173-182 healthy women and 188-190 women with breast cancer.
    During HRM screening, we analysed three known single-nucleotide polymorphisms in introns: rs4984806, rs909916 and rs909917, and one known single nucleotide polymorphism rs8063 in exon 7, in a non-coding region. The genotype frequencies for all polymorphisms were in accordance with Hardy - Weinberg equilibrium among the control subjects and breast cancer patients. The linkage disequilibrium analysis displayed that there was one polymorphism block, which consisted of three single nucleotide polymorphisms: rs909916, rs909917 and rs4984806. We identified two common haplotypes CCG and TTC, but we did not find significant differences in the distribution of these haplotypes between cases and controls.
    Our study showed no differences in the occurrence of indicated polymorphisms in the UBC9 gene in a group of healthy women compared to women with breast cancer. These results suggest that the polymorphisms of the UBC9 gene - rs4984806, rs909916, rs909917 and rs8063 can be not associated with breast cancer risk.
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  • 文章类型: Comparative Study
    BACKGROUND: Group B Streptococcal (GBS) infections in the United States are a leading cause of meningitis and sepsis in newborns. The CDC therefore recommends GBS screening for all pregnant women at 35-37 weeks of gestation and administration of intrapartum prophylaxis (in those that tested positive) as an effective means of controlling disease transmission. Several FDA approved molecular diagnostic tests are available for rapid and accurate detection of GBS in antepartum women.
    METHODS: In this study, we report a clinical comparison of the Xpert GBS LB assay and a novel FDA-cleared test, Revogene GBS LB assay. A total of 250 vaginal-rectal swabs from women undergoing prenatal screening were submitted to the University of Wisconsin\'s clinical microbiology laboratory for GBS testing.
    RESULTS: We found 96.8% of samples were concordant between the two tests, while 3.2% were discordant with a positive percent agreement of 98.0% and a negative percent agreement of 96.5% between the Revogene GBS LB assay and the GeneXpert GBS LB assay.
    CONCLUSIONS: Overall, we report that both assays perform well for the detection of GBS colonization in pregnant women.
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  • 文章类型: Journal Article
    脊柱结核是肺外结核和骨关节结核的常见表现。常见的临床表现包括全身症状,背痛,脊髓压痛,截瘫,和脊柱畸形。它们是瘫痪的常见原因,并可能增加患者的死亡率。大多数脊柱结核病例仍未确诊,早期临床症状和影像学表现缺乏特异性,这解释了为什么很难从非典型脊柱转移瘤中识别出来,布鲁氏菌病和其他疾病。脊柱结核的漏诊和误诊率较高。如果能够早期发现脊柱结核诊断目标,治疗靶点可以得到有效治疗,这不仅可以控制疾病的进展,缩短疗程,还能减轻经济压力,避免脊柱畸形。因此,早期诊断应该是我们的重点。综合运用多种诊断目标可进步脊柱结核的早期诊断率。这里,我们回顾了实验室的进展,影像学和基因检测在脊柱结核诊断中的应用。
    Spinal tuberculosis is a common manifestation of extrapulmonary tuberculosis and osteoarticular tuberculosis. Common clinical manifestations include constitutional symptoms, back pain, spinal tenderness, paraplegia, and spinal deformities. They are the common causes of paralysis and could increase the mortality in patients. Most cases of spinal tuberculosis remaining undiagnosed, and early clinical symptoms and imaging manifestations lack specificity, which explained the reason why it is difficult to identify from atypical spinal metastases, brucellosis and other diseases. The rate of missed diagnosis and misdiagnosis for spinal tuberculosis is high. If spinal tuberculosis diagnostic targets could be early detected, the therapeutic targets can be effectively treated, which can not only control the progress of the disease and shorten the course of treatment, but also reduce the economic pressure and avoid spinal deformity. Therefore, early diagnosis should be our focus. Comprehensive use of a variety of diagnostic targets can improve the early diagnosis rate of spinal tuberculosis. Here, we review the progress of laboratory, imaging and gene detection in the diagnosis of spinal tuberculosis in recent years.
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