스타 기초 상 (MQZ), NIH 보조금 ES017166 (MQZ), NSF 부여 DMS0906593 (HX).

1. BCP 분석을위한 입력 파일 준비 <ol><li> 선호하는 짧은 읽기 정렬 소프트웨어를 사용하여 적절한 참조 게놈에 점을 (칩 및 입력 라이브러리) 시퀀스에서 생산 읽고 짧은 맞 춥니 다. 매핑 된 위치는 6 열 브라우저 확장 데이터 (침대) 형식 13 (UCSC 게놈 브라우저로 변환해야 <a href="http://genome.ucsc.edu/" target="_blank">http://genome.ucsc.edu/</a> 위치를 시작), 매핑 당 탭으로 구분 된 라인 읽기 매핑 된 염색체를 나타내는 (0 기반), 최종 위치 (반 개방)는, 이름, 점수 (선택 사항) 및 가닥을 읽어보십시오. </li></ol> 2A. 프로필을 읽어 무마 : 전처리 칩은 무마 데이터의 풍부한 섬의 검색에 대한 밀도를 읽고 <ol><li> 소정의 조각의 길이, 즉,에 칩과 입력 매핑 된 위치를 확장합니다. 조각의 크기는 일반적으로 200 BP 주위에, DNA의 효소 분해 또는 sonication 동안 대상. 조각 카운트는 aggrega 아르인접 용기에 테드. 기본적으로 빈의 크기는 200 BP의 예상 조각의 길이로 설정됩니다. </li><li> 모든 변경 가능성 포인트 동일한 읽을 수가있는 용기의 집합에 의지 바깥 쪽 가장 경계에서 가능성이 가장 높은 가을. 따라서, 그 변화 지점이 동일한 읽기 카운트 두 개의 용기 사이의 내부 경계에서 발생하는 것으로 황당한입니다. 따라서 동일한있는 그룹 옆에 쓰레기통이 하나의 블록, 즉에, 빈 당 읽습니다. bedGraph 형식 13. </li></ol> 2B. 작은 반점이있는 읽기 프로필 : 작은 반점이있는 데이터의 봉우리의 탐지를위한 전처리 칩 및 입력 침대 파일 <ol><li> 중복 집계가 플러스 (+) 및 마이너스 스트랜드 칩을 개별적으로 읽기에 대한 읽습니다. 스트랜드 특정 읽기 밀도가 플러스 (+) 및 마이너스 봉우리의 bimodal 프로파일을 구성해야합니다. 가장 풍부한 봉우리 플러스 / 마이너스 쌍을 선택하고 라이브러리 조각의 길이에 대한 견적 그들의 정상 사이의 거리를 사용합니다. </li><li> 칩을 이동하고 입력은 반 조각 르를 읽고이동 및 통합 플러스 (+) 및 마이너스 가닥은 읽기의 읽기 밀도 센터와 계산에 ngth. 조각 길이를 계산하는이 방법론은 장, 외. 3에서 채택되었습니다. 동일한 병합 카운트가있는 위치는 2a.2 단계와 유사한 블록으로 그룹화해야합니다. </li></ol> 3. 추정 뒤 우리 BCMIX의 근사값을 사용하여 각 블록의 밀도를 읽고 의미 <ol><li> 각 블록의 읽기 밀도는 감마 분포의 혼합에 따라 평균 매개 변수, Γ (α, β)와 (θ t) 관심, 푸 아송 분포로 모델링하고, 변화 포인트의 사전 확률은 블록 경계에서 발생 P의. G에 관심 컨디셔닝 (θ t) (α, β)는 효과적으로 모델에게 무한 상태 HMM을 렌더링합니다. 최대 뒤쪽 가능성을 사용하여 하이퍼 매개 변수 α, β, 및 P를 추정합니다. </li><li> 명시 적으로에 대한 Bayes 견적을 계산각 블록, θ t 등 E (θ t | γ Z). 앞으로 더 많은 전통적인하지만 시간이 소요되는 교체 및 뒤로 더 계산 효율적으로 경계 복잡성 혼합 근사치로 자주 HMMs에 사용되는 필터는, 뒤쪽 수단을 추정하기 위해, θ 다. 그 결과 후부 수단 동일, θ C와 블록 추가 업데이트 경계 조정과 함께 차단해야하므로 대략 piecewise 상수의 프로필에 &quot;부드럽게&quot;입니다. </li></ol> 4A. 확산 농축의 세그먼트로 포스트 프로세스 뒤쪽 방식 : 프로필을 읽어 확산 <ol><li> 입력의 수 (λ) 관심, 배경 속도로 각각의 새로운 θ C 블록 당 읽고를 사용하여 칩 뒤쪽 뜻은, θ C, 일부 임계 값 δ를 초과하는지 여부에 따라 간단한 가설 테스트를 사용하여 농축을 결정합니다. 90 일 &lt;/&gt; - quantile 기본 D이며, 대부분의 경우에 적합합니다 논의하게 될 것입니다. </li><li> 병합 인접 θ C 단일 지역과 보고서는 간단한 침대 형식의 좌표를 병합로 농축을 초과 블록 떨어져 있습니다. 또한, 하나는 읽기 밀도 추정의 고해상도 정보를 보존 bedGraph 형식의 각 블록에 대한 θ C를 신고 할 수 있습니다. </li></ol> 지하 4 층. 피크 후보로 포스트 프로세스 뒤쪽 방식 : 작은 반점이있는이 프로필을 읽어 <ol><li> 모두 읽은 횟수의 평균 (γ 2)로 (λ) 관심, 배경 속도를 정의하고 임계 값, D를 초과하는 모든 블록을 식별합니다. 작은 반점이있는 봉우리가 더 실질적으로 풍부 할 것으로 예상되기 때문에, 기본 δ는 관심의 99 일 - quantile (λ)로 설정되어 있습니다. </li><li> 후보 피크 정상 회담으로 최대 θ C로 블록을 설정하고 비슷한 읽기 서재를 공유 측면을 노릴 블록을 인접sity (± 1 작은 변화 할 수 있도록하기 위해 계산 읽어). 이 adjoined 지역은 후보 구속력 사이트로 정의됩니다. </li><li> 칩 후보 구속력 사이트 및 가설 테스트의 평균 읽기 횟수로 λ 2 계산이 대 입력 배경 null이 가설이었다, H 0, 그건 λ 한 P-값이 임계 값에 따라 ≥ λ 2, H 0을 거부합니다. 침대 형식으로 출력 후보 봉우리. </li></ol>

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관심 없음 충돌이 선언 없습니다.

우리는 동일하게 모두 작은 반점이있는 및 확산 데이터 구조를 식별 할 수 ChIPseq 데이터를 분석하기위한 모델을 개발하기 시작했다. 지금까지 농축의 지역, 대형 섬 크기의 presupposed 기대를 반영 특히 확산 지역, 식별하기 어려운되었습니다. 이러한 문제를 해결하기 위해, 우리는 기존의 경험적 모델과 적은 혁신적인 HMMs 이상의 많은 장점을 가지고 HMM 기술의 가장 최근의 진보를 활용. <p class="j...

a novel bayesian change-point algorithm for genome-wide analysis of diverse chipseq data types

ChIPseq은 단백질 DNA의 상호 작용을 조사에 널리 사용되는 기술이다. 읽기 밀도 프로파일은 단백질 바인딩 된 DNA의 차세대 시퀀싱을 사용하고 참조 게놈을 읽어 짧은 정렬에 의해 생성됩니다. 강화 지역은 종종 대상 단백질 하나에 따라, 모양에 크게 차이가 봉우리로 공개되어 있습니다. 예를 들어, 전사 인자는 종종 사이트 및 시퀀스 특정 방식으로 바인딩하고 히스톤 수정이 더 퍼질 수 있으며 농축 2 확장, 확산 섬을 특징으로하는 동안, 작은 반점이있는 봉우리를 생산하는 경향이 있습니다. 안정적으로이 지역을 식별하는 것은 우리의 일의 초점이었다. ChIPseq 데이터를 분석 알고리즘은 휴리스틱 3-5에서 더 엄격한 통계 모델에 대한 다양한 방법론, 예를 들어 숨겨진 마르코프 모델 (HMMs) 6-8을 고용하고 있습니다. 우리는 어려운 - 투 - 정의, 특별 매개 변수 그렇게 자주의 필요성을 최소화 솔루션을 추구해상도를 손상시키고 도구의 직관적 인 사용성을 줄일. HMM 기반의 방법과 관련하여, 우리는 매개 변수 추정 절차 및 자주 이용되는 단순한, 유한 상태 분류를 절감 할 목적으로. 또한, 기존의 ChIPseq 데이터 분석의 범주를 포함하여 해당 도구의 후속 응용 프로그램에 의해 다음에 작은 반점이있는 또는 확산 중 하나로 밀도 프로파일을 읽어 예상. 우리는 더 유능하게 데이터 유형의 전체 스펙트럼을 해결 할 수있는 하나의 더 다양한 모델과 함께 두 개의 모델에 대한 필요성을 대체 할 목적으로. 이러한 목표를 달성하기 위해, 우리는 먼저 통계 프레임 워크를 구축 만 명시 적으로 활용 HMMs 9 최첨단 사전, 수식을 성능의 이점에 중요한 혁신을 사용하여 자연스럽게 모델 ChIPseq 데이터 구조. 보다 정교한 그리고 경험적 모델, 우리 HMM는 무한을 통해 숨겨진 상태를 수용베이스 모델입니다. 우리는 더 농축의 세그먼트를 정의 읽어 밀도에 적절한 변경 사항을 식별에 적용. 우리의 분석은 우리의 베이지안 변경 포인트 (BCP) 알고리즘은 감소 계산 복잡성-입증 요약 실행 시간과 메모리 사용량에 의해를 가지고 방법을 공개했다. BCP 알고리즘이 성공적으로 강력한 정확성과 제한된 사용자 정의 매개 변수 작은 반점이있는 산봉우리와 확산 섬 식별에 모두 적용되었습니다. 이 도시의 다양한 기능과 사용의 용이성 모두. 따라서, 우리는이 그것을 연구 그룹 간의 협력과 확증에 도움이 수 ChIPseq 데이터 분석을위한 훌륭한 도구 만들기, 쉽게 비교하고 대조하는 방법으로 데이터 유형 및 최종 사용자의 광범위한 범위에 걸쳐 쉽게 구현 될 수있다 생각합니다. 여기, 우리는 유용성을 설명하기 위해 기존의 전사 인자 10,11 및 epigenetic 데이터를 12 BCP의 응용 프로그램을 보여줍니다.

BCP는 히스톤 수정 데이터에 광범위 농축의 영역을 식별에 탁월한. 참조 점으로서, 우리는 이전에 SICER 3, 강력한 성능을 입증 기존 도구의 사람들에게 우리의 결과를 비교했다. 가장 BCP의 장점을 설명하기 위해, 우리는 잘 성공 속도를 평가하기위한 기반을 구축하기 위해 연구 된 히스톤 수정을 살펴 보았다. 이 적극적으로 베꼈 유전자기구 (그림 1)과 강력하게 연관 게재 된 이...

Watch this Scientific Journal Video about A Novel Bayesian Change-point Algorithm for Genome-wide Analysis of Diverse ChIPseq Data Types at JoVE.com

A Novel Bayesian Change-point Algorithm for Genome-wide Analysis of Diverse ChIPseq Data Types

우리 베이지안 변경 포인트 (BCP)이 알고리즘은 숨겨진 마르코프 모델을 통해 모델링 변화 포인트의 최신 발전을 토대로와 염색질 immunoprecipitation 시퀀싱 (ChIPseq) 데이터 분석에 적용됩니다. BCP는 광범위하고 작은 반점이있는 두 데이터 유형에서 잘 수행하지만, 정확하게 확산 히스톤 농축의 강력한 재현 섬을 식별하는 탁월한.

다양한 ChIPseq 데이터 유형의 게놈 차원의 분석을위한 소설 베이지안 변경 - 포인트 알고리즘

ChIPseq is a widely used technique for investigating protein-DNA interactions. Read density profiles are generated by using next-sequencing of ...

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JoVE Journal

Biology

11.2K 조회수.  Stony Brook University. 우리 베이지안 변경 포인트 (BCP)이 알고리즘은 숨겨진 마르코프 모델을 통해 모델링 변화 포인트의 최신 발전을 토대로와 염색질 immunoprecipitation 시퀀싱 (ChIPseq) 데이터 분석에 적용됩니다. BCP는 광범위하고 작은 반점이있는 두 데이터 유형에서 잘 수행하지만, 정확하게 확산 히스톤 농축의 강력한 재현 섬을 식별하는 탁월한.

비디오: A Novel Bayesian Change-point Algorithm for Genome-wide Analysis of Diverse ChIPseq Data Types

A Neuronal and Astrocyte Co-Culture Assay for High Content Analysis of Neurotoxicity

High Content Analysis (HCA) assays combine cells and detection reagents with automated imaging and powerful image analysis algorithms, allowing measurement of multiple cellular phenotypes within a single assay. In this study, we utilized HCA to develop a novel assay for neurotoxicity. Neurotoxicity assessment represents an important part of drug safety evaluation, as well as being a significant focus of environmental protection efforts. Additionally, neurotoxicity is also a well-accepted in vitro marker of the development of neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Recently, the application of HCA to neuronal screening has been reported. By labeling neuronal cells with &beta;III-tubulin, HCA assays can provide high-throughput, non-subjective, quantitative measurements of parameters such as neuronal number, neurite count and neurite length, all of which can indicate neurotoxic effects. However, the role of astrocytes remains unexplored in these models. Astrocytes have an integral role in the maintenance of central nervous system (CNS) homeostasis, and are associated with both neuroprotection and neurodegradation when they are activated in response to toxic substances or disease states. GFAP is an intermediate filament protein expressed predominantly in the astrocytes of the CNS. Astrocytic activation (gliosis) leads to the upregulation of GFAP, commonly accompanied by astrocyte proliferation and hypertrophy. This process of reactive gliosis has been proposed as an early marker of damage to the nervous system. The traditional method for GFAP quantitation is by immunoassay. This approach is limited by an inability to provide information on cellular localization, morphology and cell number. We determined that HCA could be used to overcome these limitations and to simultaneously measure multiple features associated with gliosis - changes in GFAP expression, astrocyte hypertrophy, and astrocyte proliferation - within a single assay. In co-culture studies, astrocytes have been shown to protect neurons against several types of toxic insult and to critically influence neuronal survival. Recent studies have suggested that the use of astrocytes in an in vitro neurotoxicity test system may prove more relevant to human CNS structure and function than neuronal cells alone. Accordingly, we have developed an HCA assay for co-culture of neurons and astrocytes, comprised of protocols and validated, target-specific detection reagents for profiling &beta;III-tubulin and glial fibrillary acidic protein (GFAP). This assay enables simultaneous analysis of neurotoxicity, neurite outgrowth, gliosis, neuronal and astrocytic morphology and neuronal and astrocytic development in a wide variety of cellular models, representing a novel, non-subjective, high-throughput assay for neurotoxicity assessment. The assay holds great potential for enhanced detection of neurotoxicity and improved productivity in neuroscience research and drug discovery.

This article describes a novel protocol and reagent set designed for sensitive measurement of neurotoxic effects of compounds and treatments on co-cultures of neurons and astrocytes using high content analysis. Results demonstrate that high content analysis represents an exciting novel technology for neurotoxicity assessment.

Neurotoxicity 높은 컨텐츠 분석의 연결 및 Astrocyte 공동 문화 분석

High Content Analysis (HCA) assays combine cells and detection reagents with automated imaging and powerful image analysis algorithms, allowing ...

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생물학

Genome-wide Analysis of Aminoacylation (Charging) Levels of tRNA Using Microarrays

tRNA aminoacylation, or charging, levels can rapidly change within a cell in response to the environment[1]. Changes in tRNA charging levels in both prokaryotic and eukaryotic cells lead to translational regulation which is a major cellular mechanism of stress response. Familiar examples are the stringent response in E. coli and the Gcn2 stress response pathway in yeast ([2-6]). Recent work in E. coli and S. cerevisiae have shown that tRNA charging patterns are highly dynamic and depends on the type of stress experienced by cells [1, 6, 7]. The highly dynamic, variable nature of tRNA charging makes it essential to determine changes in tRNA charging levels at the genomic scale, in order to fully elucidate cellular response to environmental variations. In this review we present a method for simultaneously measuring the relative charging levels of all tRNAs in S. cerevisiae . While the protocol presented here is for yeast, this protocol has been successfully applied for determining relative charging levels in a wide variety of organisms including E. coli and human cell cultures[7, 8].

Genome-wide Analysis of Aminoacylation Charging Levels of tRNA Using Microarrays

We describe a method for microarray analysis to determine relative aminoacylation levels of all tRNAs from S. cerivisiae.

Microarrays을 사용하여 tRNA의 Aminoacylation (충전) 레벨의 게놈 - 와이드 분석

tRNA aminoacylation, or charging, levels can rapidly change within a cell in response to the environment[1]. Changes in tRNA charging levels in both ...

Genome-wide Analysis using ChIP to Identify Isoform-specific Gene Targets

Recruitment of transcriptional and epigenetic factors to their targets is a key step in their regulation. Prominently featured in recruitment are the protein domains that bind to specific histone modifications. One such domain is the plant homeodomain (PHD), found in several chromatin-binding proteins. The epigenetic factor RBP2 has multiple PHD domains, however, they have different functions (Figure 4). In particular, the C-terminal PHD domain, found in a RBP2 oncogenic fusion in human leukemia, binds to trimethylated lysine 4 in histone H3 (H3K4me3)1. The transcript corresponding to the RBP2 isoform containing the C-terminal PHD accumulates during differentiation of promonocytic, lymphoma-derived, U937 cells into monocytes2. Consistent with both sets of data, genome-wide analysis showed that in differentiated U937 cells, the RBP2 protein gets localized to genomic regions highly enriched for H3K4me33. Localization of RBP2 to its targets correlates with a decrease in H3K4me3 due to RBP2 histone demethylase activity and a decrease in transcriptional activity. In contrast, two other PHDs of RBP2 are unable to bind H3K4me3. Notably, the C-terminal domain PHD of RBP2 is absent in the smaller RBP2 isoform4. It is conceivable that the small isoform of RBP2, which lacks interaction with H3K4me3, differs from the larger isoform in genomic location. The difference in genomic location of RBP2 isoforms may account for the observed diversity in RBP2 function. Specifically, RBP2 is a critical player in cellular differentiation mediated by the retinoblastoma protein (pRB). Consistent with these data, previous genome-wide analysis, without distinction between isoforms, identified two distinct groups of RBP2 target genes: 1) genes bound by RBP2 in a manner that is independent of differentiation; 2) genes bound by RBP2 in a differentiation-dependent manner.
To identify differences in localization between the isoforms we performed genome-wide location analysis by ChIP-Seq. Using antibodies that detect both RBP2 isoforms we have located all RBP2 targets. Additionally we have antibodies that only bind large, and not small RBP2 isoform (Figure 4). After identifying the large isoform targets, one can then subtract them from all RBP2 targets to reveal the targets of small isoform. These data show the contribution of chromatin-interacting domain in protein recruitment to its binding sites in the genome.

Here we are presenting a chromatin immunoprecipitation (ChIP) procedure for genome-wide location analysis of protein isoforms that differ in a histone-binding domain. We are applying it to ChIP-Seq analysis to identify the targets of the KDM5A/JARID1A/RBP2 histone demethylase.

이소형 특정 유전자 목표를 식별 칩을 사용하여 게놈 차원의 분석

Recruitment of transcriptional and epigenetic factors to their targets is a key step in their regulation. Prominently featured in recruitment are the ...

Genome-wide Screen for miRNA Targets Using the MISSION Target ID Library

The Target ID Library is designed to assist in discovery and identification of microRNA (miRNA) targets. The Target ID Library is a plasmid-based, genome-wide cDNA library cloned into the 3'UTR downstream from the dual-selection fusion protein, thymidine kinase-zeocin (TKzeo). The first round of selection is for stable transformants, followed with introduction of a miRNA of interest, and finally, selecting for cDNAs containing the miRNA's target. Selected cDNAs are identified by sequencing (see Figure 1-3 for Target ID Library Workflow and details).
To ensure broad coverage of the human transcriptome, Target ID Library cDNAs were generated via oligo-dT priming using a pool of total RNA prepared from multiple human tissues and cell lines. Resulting cDNA range from 0.5 to 4 kb, with an average size of 1.2 kb, and were cloned into the p3&#900;TKzeo dual-selection plasmid (see Figure 4 for plasmid map). The gene targets represented in the library can be found on the Sigma-Aldrich webpage. Results from Illumina sequencing (Table 3), show that the library includes 16,922 of the 21,518 unique genes in UCSC RefGene (79%), or 14,000 genes with 10 or more reads (66%).

The Target ID Library is a plasmid-based, genome-wide collection of cloned cDNA used to identify miRNA targets. Here we demonstrate its use and application.

선교 대상 아이디 라이브러리를 사용하여 miRNA 목표를위한 게놈 - 와이드 스크린

The Target ID Library is designed to assist in discovery and identification of microRNA (miRNA) targets. The Target ID Library is a plasmid-based, ...

Quantitative and Automated High-throughput Genome-wide RNAi Screens in C. elegans

RNA interference is a powerful method to understand gene function, especially when conducted at a whole-genome scale and in a quantitative context. In C. elegans, gene function can be knocked down simply and efficiently by feeding worms with bacteria expressing a dsRNA corresponding to a specific gene 1. While the creation of libraries of RNAi clones covering most of the C. elegans genome 2,3 opened the way for true functional genomic studies (see for example 4-7), most established methods are laborious. Moy and colleagues have developed semi-automated protocols that facilitate genome-wide screens 8. The approach relies on microscopic imaging and image analysis. 
	Here we describe an alternative protocol for a high-throughput genome-wide screen, based on robotic handling of bacterial RNAi clones, quantitative analysis using the COPAS Biosort (Union Biometrica (UBI)), and an integrated software: the MBioLIMS (Laboratory Information Management System from Modul-Bio) a technology that provides increased throughput for data management and sample tracking. The method allows screens to be conducted on solid medium plates. This is particularly important for some studies, such as those addressing host-pathogen interactions in C. elegans, since certain microbes do not efficiently infect worms in liquid culture.
	We show how the method can be used to quantify the importance of genes in anti-fungal innate immunity in C. elegans. In this case, the approach relies on the use of a transgenic strain carrying an epidermal infection-inducible fluorescent reporter gene, with GFP under the control of the promoter of the antimicrobial peptide gene nlp 29 and a red fluorescent reporter that is expressed constitutively in the epidermis. The latter provides an internal control for the functional integrity of the epidermis and nonspecific transgene silencing9. When control worms are infected by the fungus they fluoresce green. Knocking down by RNAi a gene required for nlp 29 expression results in diminished fluorescence after infection. Currently, this protocol allows more than 3,000 RNAi clones to be tested and analyzed per week, opening the possibility of screening the entire genome in less than 2 months.

Quantitative and Automated High-throughput Genome-wide RNAi Screens in C. elegans

We describe a protocol using C. elegans and RNAi feeding libraries that allows automated measurement of multiple parameters such as fluorescence, size and opacity of individual worms in a population. We give one example of a screen to identify genes involved in anti-fungal innate immunity in C. elegans.

의 정량 및 자동화된 고속 처리량 게놈 전체의 RNAi 화면 C. elegans</em

RNA interference is a powerful method to understand gene function, especially when conducted at a whole-genome scale and in a quantitative context. In C. ...

Genome-wide Gene Deletions in Streptococcus sanguinis by High Throughput PCR

Transposon mutagenesis and single-gene deletion are two methods applied in genome-wide gene knockout in bacteria 1,2. Although transposon mutagenesis is less time consuming, less costly, and does not require completed genome information, there are two weaknesses in this method: (1) the possibility of a disparate mutants in the mixed mutant library that counter-selects mutants with decreased competition; and (2) the possibility of partial gene inactivation whereby genes do not entirely lose their function following the insertion of a transposon. Single-gene deletion analysis may compensate for the drawbacks associated with transposon mutagenesis. To improve the efficiency of genome-wide single gene deletion, we attempt to establish a high-throughput technique for genome-wide single gene deletion using Streptococcus sanguinis as a model organism. Each gene deletion construct in S. sanguinis genome is designed to comprise 1-kb upstream of the targeted gene, the aphA-3 gene, encoding kanamycin resistance protein, and 1-kb downstream of the targeted gene. Three sets of primers F1/R1, F2/R2, and F3/R3, respectively, are designed and synthesized in a 96-well plate format for PCR-amplifications of those three components of each deletion construct. Primers R1 and F3 contain 25-bp sequences that are complementary to regions of the aphA-3 gene at their 5' end. A large scale PCR amplification of the aphA-3 gene is performed once for creating all single-gene deletion constructs. The promoter of aphA-3 gene is initially excluded to minimize the potential polar effect of kanamycin cassette. To create the gene deletion constructs, high-throughput PCR amplification and purification are performed in a 96-well plate format. A linear recombinant PCR amplicon for each gene deletion will be made up through four PCR reactions using high-fidelity DNA polymerase. The initial exponential growth phase of S. sanguinis cultured in Todd Hewitt broth supplemented with 2.5% inactivated horse serum is used to increase competence for the transformation of PCR-recombinant constructs. Under this condition, up to 20% of S. sanguinis cells can be transformed using ~50 ng of DNA. Based on this approach, 2,048 mutants with single-gene deletion were ultimately obtained from the 2,270 genes in S. sanguinis excluding four gene ORFs contained entirely within other ORFs in S. sanguinis SK36 and 218 potential essential genes. The technique on creating gene deletion constructs is high throughput and could be easy to use in genome-wide single gene deletions for any transformable bacteria.

Genome-wide Gene Deletions in Streptococcus sanguinis by High Throughput PCR

An efficient genome-wide single gene mutation method has been established using Streptococcus sanguinis as a model organism. This method has achieved via high throughput recombinant PCRs and transformations.

게놈 전체 유전자 삭제할에<em&gt; 연쇄상 구균 sanguinis</em&gt; 높은 처리량 PCR에 의한

Transposon  mutagenesis and single-gene deletion are two methods applied in genome-wide  gene knockout in bacteria 1,2. Although transposon mutagenesis is ...

Polysome Fractionation and Analysis of Mammalian Translatomes on a Genome-wide Scale

mRNA translation plays a central role in the regulation of gene expression and represents the most energy consuming process in mammalian cells. Accordingly, dysregulation of mRNA translation is considered to play a major role in a variety of pathological states including cancer. Ribosomes also host chaperones, which facilitate folding of nascent polypeptides, thereby modulating function and stability of newly synthesized polypeptides. In addition, emerging data indicate that ribosomes serve as a platform for a repertoire of signaling molecules, which are implicated in a variety of post-translational modifications of newly synthesized polypeptides as they emerge from the ribosome, and/or components of translational machinery. Herein, a well-established method of ribosome fractionation using sucrose density gradient centrifugation is described. In conjunction with the in-house developed &#8220;anota&#8221; algorithm this method allows direct determination of differential translation of individual mRNAs on a genome-wide scale. Moreover, this versatile protocol can be used for a variety of biochemical studies aiming to dissect the function of ribosome-associated protein complexes, including those that play a central role in folding and degradation of newly synthesized polypeptides.

Ribosomes play a central role in protein synthesis. Polyribosome (polysome) fractionation by sucrose density gradient centrifugation allows direct determination of translation efficiencies of individual mRNAs on a genome-wide scale. In addition, this method can be used for biochemical analysis of ribosome- and polysome-associated factors such as chaperones and signaling molecules.

게놈 전체 규모에 Polysom​​e 분별과 포유류 Translatomes 분석

mRNA translation plays a central role in the regulation of gene expression and represents the most energy consuming process in mammalian cells. ...

Genome-wide Mapping of Drug-DNA Interactions in Cells with COSMIC (Crosslinking of Small Molecules to Isolate Chromatin)

The genome is the target of some of the most effective chemotherapeutics, but most of these drugs lack DNA sequence specificity, which leads to dose-limiting toxicity and many adverse side effects. Targeting the genome with sequence-specific small molecules may enable molecules with increased therapeutic index and fewer off-target effects. N-methylpyrrole/N-methylimidazole polyamides are molecules that can be rationally designed to target specific DNA sequences with exquisite precision. And unlike most natural transcription factors, polyamides can bind to methylated and chromatinized DNA without a loss in affinity. The sequence specificity of polyamides has been extensively studied in vitro with cognate site identification (CSI) and with traditional biochemical and biophysical approaches, but the study of polyamide binding to genomic targets in cells remains elusive. Here we report a method, the crosslinking of small molecules to isolate chromatin (COSMIC), that identifies polyamide binding sites across the genome. COSMIC is similar to chromatin immunoprecipitation (ChIP), but differs in two important ways: (1) a photocrosslinker is employed to enable selective, temporally-controlled capture of polyamide binding events, and (2) the biotin affinity handle is used to purify polyamide&#8211;DNA conjugates under semi-denaturing conditions to decrease DNA that is non-covalently bound. COSMIC is a general strategy that can be used to reveal the genome-wide binding events of polyamides and other genome-targeting chemotherapeutic agents.

Genome-wide Mapping of Drug-DNA Interactions in Cells with COSMIC Crosslinking of Small Molecules to Isolate Chromatin

Identifying the direct targets of genome-targeting molecules remains a major challenge. To understand how DNA-binding molecules engage the genome, we developed a method that relies on crosslinking of small molecules to isolate chromatin (COSMIC).

COSMIC와 세포의 약물-DNA 상호 작용의 게놈 넓은 매핑 (작은 분자의 가교는 염색질을 분리)

The genome is the target of some of the most effective chemotherapeutics, but most of these drugs lack DNA sequence specificity, which leads to ...

Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells

Extrachromosomal circular DNAs (eccDNAs) are common genetic elements in Saccharomyces cerevisiae and are reported in other eukaryotes as well. EccDNAs contribute to genetic variation among somatic cells in multicellular organisms and to evolution of unicellular eukaryotes. Sensitive methods for detecting eccDNA are needed to clarify how these elements affect genome stability and how environmental and biological factors&#160;induce their formation in eukaryotic cells. This video presents a sensitive eccDNA-purification method called Circle-Seq. The method encompasses column purification of circular DNA, removal of remaining linear chromosomal DNA, rolling-circle amplification of eccDNA, deep sequencing, and mapping. Extensive exonuclease treatment&#160;was&#160;required for sufficient linear chromosomal DNA degradation. The rolling-circle amplification step by &#966;29 polymerase enriched for circular DNA over linear DNA. Validation of the Circle-Seq method on three S. cerevisiae CEN.PK populations of 1010 cells detected hundreds of eccDNA profiles in sizes larger than 1 kilobase. Repeated findings of ASP3-1, COS111, CUP1, RSC30,&#160;HXT6, HXT7 genes on circular DNA in both S288c and CEN.PK suggests that DNA circularization is conserved between strains at these loci. In sum, the Circle-Seq method has broad applicability for genome-scale screening for eccDNA in eukaryotes as well as for detecting specific eccDNA types.

This paper presents a sensitive method called Circle-Seq for purifying extrachromosomal circular DNA (eccDNA). The method encompasses column purification, removal of remaining linear chromosomal DNA, rolling-circle amplification and high-throughput sequencing. Circle-Seq is applicable to genome-scale screening of eukaryotic eccDNA and studying genome instability and copy-number variation.

진핵 세포에서 염색체 외 원형 DNA의 게놈 차원의 정화

Extrachromosomal circular DNAs (eccDNAs) are common genetic elements in Saccharomyces cerevisiae and are reported in other eukaryotes as well. EccDNAs ...

Comprehensive Workflow for the Genome-wide Identification and Expression Meta-analysis of the ATL E3 Ubiquitin Ligase Gene Family in Grapevine

Classification and nomenclature of genes in a family can significantly contribute to the description of the diversity of encoded proteins and to the prediction of family functions based on several features, such as the presence of sequence motifs or of particular sites for post-translational modification and the expression profile of family members in different conditions. This work describes a detailed protocol for gene family characterization. Here, the procedure is applied to the characterization of the Arabidopsis T&#243;xicos in Levadura (ATL) E3 ubiquitin ligase family in grapevine. The methods include the genome-wide identification of family members, the characterization of gene localization, structure, and duplication, the analysis of conserved protein motifs, the prediction of protein localization and phosphorylation sites as well as gene expression profiling across the family in different datasets. Such procedure, which could be extended to further analyses depending on experimental purposes, could be applied to any gene family in any plant species for which genomic data are available, and it provides valuable information to identify interesting candidates for functional studies, giving insights into the molecular mechanisms of plant adaptation to their environment.

This article describes the procedure for the identification and characterization of a gene family in grapevine applied to the family of Arabidopsis T&#243;xicos in Levadura (ATL) E3 ubiquitin ligases.

게놈 넓은 식별 및 소문의 ATL E3 유비퀴틴 리가 유전자 가족의 식 메타 분석을 위한 포괄적인 워크플로

Classification and nomenclature of genes in a family can significantly contribute to the description of the diversity of encoded proteins and to the ...