この仕事は a. b. に NIH GM117446 助成金によって支えられました。

1 のセルの準備の流れ Cytometry の並べ替え
<ol><li>文化一晩成長後 5 x 106 1.5 mL あたり7セルを 10 倍の密度に達するような YEPD 液 8 mL を含む 15 mL の試験管を接種する (注 1 の議論」を参照)。</li>
	<li>酵母 (1,400 × g、室温、4 ° C で) 5 分 15 mL スクリュー キャップ遠心管でスピンダウン、1.5 mL 70% エタノールで 1.6 の mL および microfuge の管に転送この座っている部屋の温度で 1 時間または氷 (少なくとも 3 h をさせる細胞を再懸濁します4 ° C で不明確に保存されることができます) (議論点 (2) を参照)。</li>
	<li>1 分の microfuge (14,000 x g、4 ° C) で酵母をスピン、1 分の 1 mL 50 mM クエン酸ナトリウム、pH 7.2、スピン ・ ダウン (14,000 x g, 4 ° C) で再懸濁します、上清を吸引、1 mL 50 mM クエン酸ナトリウム、pH 7.2 で再懸濁します、0.25 mg/mL 50 ° c または一晩熱ブロックまたは水浴で 37 ° C で 1 h RNAse ソリューションを含みます。</li>
	<li>50 μ L, プロテイナーゼ K 溶液 (20 mg/mL 10 mM Tris pH 7.5、2 mM CaCl2、ボリューム グリセリン 50% の重量で再停止される) を追加し、50 ° C で 1 時間インキュベート</li>
	<li>Cells (14,000 × g, 4 ° C) スピンダウン、1 mL 50 mM クエン酸ナトリウム、pH 7.2 細胞を再懸濁します、スピン ・ ダウン (14,000 x g、4 ° C)、真空上清を吸引、クエン酸ナトリウム 50 mM で再停止される 1 mL 1 μ M 緑核酸ひずみで再懸濁します、pH 7.2 室温で 1 時間暗闇の中で孵化、2 x 2 の超音波 s 各 (出力 2 ワット)。</li>
</ol>2. 細胞選別
<ol><li>図 1のように各細胞周期の段階から、少なくとも 160 万単相細胞を収集フェーズ G1、S、"初期 G2 は、"、「後半 G2」は、DNA 内容に従ってセルを並べ替えるセルの並べ替えアイコンを使用して、(議論点 (3) を参照)。</li>
	<li>Microfuge の管にセルを転送およびスピン ・ ダウンで 4 ° C、および microfuge 14,000 x g で 20 分間細胞と真空上清を吸引 (ペレットは、無期限に-20 ° C で凍結保存ことができます; ポイント (4) の議論を参照)。</li>
</ol>3. DNA の抽出とシーケンシング ライブラリの準備
注: 次の手順に基づいて酵母ゲノム DNA 抽出キットで「議定書 I」(材料の表を参照してください).
<ol><li>酵母細胞壁溶解酵素細胞壁や酵母細胞壁溶解酵素の 5 μ L を消化、ボルテックス、によって再懸濁します、37 ° C、40-60 分インキュベートすることができる独自のバッファー「消化バッファー」の 120 μ L を追加します。</li>
	<li>「換散バッファー、」洗剤と渦 10-20 s ハードを含む独自のバッファーの 120 μ L を追加します。</li>
	<li>250 μ L のクロロホルムを追加 - 徹底的にミックス 1 分。</li>
	<li>2 分間および microfuge の最高速度で回転します。</li>
	<li>DNA 結合列と、および microfuge の最高速度で 1 分間遠心上清をロードします。</li>
	<li>「DNA 洗浄バッファーの「エタノール、および、および microfuge の最大の速度で 1 分間遠心を含む独自バッファー 300 μ l を追加します。流れを破棄 DNA 洗浄バッファーの 300 μ L を追加し、洗浄プロセスを繰り返します。</li>
	<li>新鮮なおよび microfuge の管にスピン列を転送、水 (ない TE) の 60 μ L を追加 - 1-3 分待って、10 の遠心分離機、DNA を溶出します。</li>
	<li>された dsDNA 高感度バッファーで希釈 1: 200 と、指定された規格の 10 μ L を用いた校正、蛍光光度計で測定蛍光 dsDNA 高感度試薬の 195 μ L DNA の 5 μ L を追加することによって濃度を測定します。10 と 50 ng の DNA 収量の間期待します。</li>
	<li>超音波 (ピーク事件電源 450、デューティー比 30%、サイクル/バースト 200、治療時間 60 秒、水レベル 6) 250-350 bp の断片を DNA を破壊します。</li>
	<li>DNA サンプル調製キットを使用してライブラリを準備し、高速モードで DNA シーケンス楽器でシーケンス処理するそれ (少なくとも 1000 万 50 bp シングル エンド ヒット) (議論注 (5) を参照)。</li>
</ol>4. データ ・ レプリケーションの世代シーケンスの解析のプロファイルします。
<ol><li>Gsnap12を用いた出芽酵母sacCer3 ゲノム シーケンスを配置 (ディスカッション注 (6) を参照)。</li>
	<li>塩基あたりを読む Bedtools の"genomeCoverageBed"ソフトウェア13を使用して深さを決定します。</li>
	<li>存在する場合、読み取りの深さで artefactual スパイクを削除 (ディスカッション注 (7) を参照)。</li>
	<li>滑らかな読む深さ r"runMean"関数を使用してウィンドウをスライド 20 kb で中央分離帯を用いた染色体によってパッケージ"caTools"(ディスカッション注 (8) 参照)。</li>
	<li>プロットは完全にレプリケートされた読み取りの深さ (ディスカッション注 (9) を参照) の割合として S 段階、初期 G2 後半 G2 で深さを読みます。</li>
</ol>

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著者が明らかに何もありません。

一方、この手法は堅牢で、比較的まっすぐな前方、特に注意は次に捧げられるべき。
(1) 以来、文化は接種後必要な密度だけ 4 h に到達した後収穫される場合細胞周期の分布に相違が顕在ログ段階に達する前に少なくとも 12 時間の文化が成長するを推奨します。我々 の仮定では比較的安定した平衡に達した細胞周期の分布はより飽和させた文化は、最近では新鮮な媒体に...

真核生物ゲノムのレプリケーションは、レプリケーションでは、レプリケーションからフォーク (Fragkosら2015年1文献) 両方の方向で進むの起源と呼ばれる複数の個別サイトで開始されます。起源が異なるタイミングと、焼成の効率とレプリケーション元のアクティビティを監視し、この変化の原因を解明するいくつかの手法が開発されました。個々 の原点の活動は、単一座礁させた DNA2、アクティブな起源の周りのフォームのレベルから推論できるまたは特定の複製中間体3を監視する第 2 ゲルの電気泳動を使用して、どちらで検出できます。放射性プローブ。起源は、前者の特定の知られていたシーケンスに制限され、これらの手法の両方はより簡単に出芽酵母よりも哺乳類セルので適用されます。マイクロ アレイの出現により、世界的に焼成の起源を評価することが可能になりました。これは最初重い同位体と DNA の分類、中含まれている軽い同位体に G1 ブロックから細胞を放出、重・軽ハイブリッド DNA ゲノム4の形成を監視によって行われました。高スループット シーケンスの導入許可同様ゲノムは、高価な同位体ラベリングの要件なしで活動を起源の監視します。細胞は、DNA の内容によると流れの cytometer のディープ シーケンスを受ける DNA ソートされます。シーケンスのカバレッジが S 期にわたって 2 倍に 1 x から進むにつれて、ので相対的なレプリケーションのタイミングは G1 あるいは G25,6S 期細胞の読み取りの深さを比較することによって評価できます。特に酵母に適用これらのテクニックは、dna 塩基配列、クロマチン構造と DNA 複製タンパク質起源タイミングと効率の規制方法のより深い理解につながった。
細胞増殖の中に遺伝情報の忠実な伝達には、DNA の複製の起源で行われるの唯一の成功の開始だけでなく、複製フォークが満たすために発生するレプリケーションが正常に完了が必要です。レプリケーションの開始のようなレプリケーションの完了のタイミングは、残りの細胞周期の後半でもレプリケートされていない特定の領域にゲノム間で異なります。このような領域は特にアクティブな複製の起源から遠いかシーケンスやクロマチン構造の DNA ポリメラーゼを阻害する場合があります。後期地域をレプリケートする染色体の破損および高い突然変異率と関連付けられ、がんと老化7,8,9に関与している壊れやすいサイトとして自分自身のマニフェストことができます。しかし、ゲノムの安定性の維持に DNA の複製が正しく完了の重要性にもかかわらずこれが起こる場所と方法の理解が遅れてレプリケーション開始。後半レプリケーションは病気に関連付けられている個々 の遺伝子の中で、たとえば、qPCR10場所の解明と後半のレプリケーションを欠けている原因の基礎となるグローバル研究検討されています。ここで我々 は"G2 seq"高スループット シーケンスのゲノム複製の完了に光を当てるとフローサイトメトリーを組み合わせる我々 として酵母の11を参照手法について述べる。軽微な変更は、このプロトコルは DNA 量順の流れをすることができます任意のセルに合わせることができます。

<table width="722">
	<tbody>
		<tr height="21">
			<td height="21" style="width:301px;height:21px;">YeaStar Genomic DNA kit</td>
			<td style="width:135px;">Genesee Scientific</td>
			<td style="width:119px;">11-323</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:301px;height:21px;">1 &#181;M SYTOX Green</td>
			<td style="width:135px;">ThermoFisher</td>
			<td style="width:119px;">57020</td>
			<td>resuspend in 50 mM sodium citrate, pH 7.2</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:301px;height:21px;">50 mM sodium citrate, pH 7.2</td>
			<td style="width:135px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="147">
			<td height="147" style="width:301px;height:147px;">RNase solution (0.25 mg / mL)</td>
			<td style="width:135px;">Sigma</td>
			<td style="width:119px;">R6513</td>
			<td style="width:167px;">0.25 mg / mL RNaseA resuspended in 50 mM sodium citrate, pH 7.2, boil RNase solution for 10 minutes before the first use only, and from then on store at -20&#176;</td>
		</tr>
		<tr height="42">
			<td height="42" style="width:301px;height:42px;">proteinase K solution (20 mg / mL)</td>
			<td style="width:135px;">ThermoFisher / Invitrogen</td>
			<td style="width:119px;">25530-015</td>
			<td>resuspend in 10 mM Tris, pH 7.5, 2 mM CaCl2, 50% glycerol, store at -20&#176;C</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Model 50 Sonic Dismembrator</td>
			<td style="width:135px;">Fisher Scientific</td>
			<td>FB50A220</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:301px;height:21px;">BD Biosciences FACSAria II</td>
			<td style="width:135px;">BD Biosciences</td>
			<td>644832</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:301px;height:21px;">Zymo-spin III columns</td>
			<td style="width:135px;">Zymo Research</td>
			<td style="width:119px;">C1005</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:301px;height:21px;">Qubit dsDNA HS Assay Kit</td>
			<td style="width:135px;">ThermoFisher</td>
			<td style="width:119px;">Q32851</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:301px;height:21px;">Qubit 3.0 Fluorometer</td>
			<td style="width:135px;">ThermoFisher</td>
			<td style="width:119px;">Q33216</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Covaris Model LE220 Focused-Ultrasonicator</td>
			<td style="width:135px;">Covaris</td>
			<td style="width:119px;">500219</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:301px;height:21px;">Illumina TruSeq DNA LT Sample Prep Kit</td>
			<td style="width:135px;">Illumina</td>
			<td>15026486</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:301px;height:21px;">Illumina HiSeq 2500 instrument</td>
			<td style="width:135px;">Illumina</td>
			<td>SY&#8211;401&#8211;2501&#160;</td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="width:301px;height:63px;">gsnap alignment software</td>
			<td style="width:135px;">open source software / Genentech</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">http://research-pub.gene.com/gmap</td>
		</tr>
	</tbody>
</table>

g2-seq: a high throughput sequencing-based technique for identifying late replicating regions of the genome

多数の技術は、細胞周期の S 期で DNA 複製の進行状況を追跡する開発されています。これらの技術のほとんどは、場所の解明とゲノム重複ではなく、その完了の開始時期に向かって指示されています。しかし、我々 はこれらの地域の染色体の破損や、突然変異レベルが上昇に苦しむので、レプリケーションを完了する最後はゲノムの領域を理解し、彼らは病気と高齢化に関連付けられていることが重要です。ここで我々 は我々 が代わりにレプリケーションを完了する最後のゲノムのこれらの領域を識別するために複製開始反応を監視するために使用されている技術を拡張する方法について説明します。このアプローチは、フローサイトメトリーと高スループット シーケンスの組み合わせに基づいています。このレポートは、この手法の酵母への応用に焦点を当て、アプローチは DNA の内容によると流れの cytometer で並べ替えることができます任意のセルで使用できます。

我々 は出芽酵母における後半の複製サイトを識別するために上記の手順を使用しています。人工染色体の知られている遅い複製領域を使用してこの方法をテストを正確かつ信頼性の高い技術を証明しました。我々 の結果も示しているレプリケーションのタイムリーな完了の生物学的重要性染色体 7、我々 は G2 seq 結果に基づいて後期複製として識別、後期複製領域が...

Watch this Scientific Journal Video about G2-seq: A High Throughput Sequencing-based Technique for Identifying Late Replicating Regions of the Genome at JoVE.com

G2-seq: A High Throughput Sequencing-based Technique for Identifying Late Replicating Regions of the Genome

G2-seq: 高スループット シーケンス ベースを識別する方法後半ゲノムの領域を複製します。

フローサイトメトリーとゲノムの後半の複製領域を識別する高スループット シーケンスを結合する手法について述べる。

Numerous techniques have been developed to follow the progress of DNA replication through the S phase of the cell cycle. Most of these techniques have ...

g2-seq-high-throughput-sequencing-based-technique-for-identifying

Research

JoVE Journal

Genetics

5.7K ビュー.  Fred Hutchinson Cancer Research Center. フローサイトメトリーとゲノムの後半の複製領域を識別する高スループット シーケンスを結合する手法について述べる。

ビデオ: G2-seq: A High Throughput Sequencing-based Technique for Identifying Late Replicating Regions of the Genome

A Robotic Platform for High-throughput Protoplast Isolation and Transformation

Over the last decade there has been a resurgence in the use of plant protoplasts that range from model species to crop species, for analysis of signal transduction pathways, transcriptional regulatory networks, gene expression, genome-editing, and gene-silencing. Furthermore, significant progress has been made in the regeneration of plants from protoplasts, which has generated even more interest in the use of these systems for plant genomics. In this work, a protocol has been developed for automation of protoplast isolation and transformation from a &#39;Bright Yellow&#39; 2 (BY-2) tobacco suspension culture using a robotic platform. The transformation procedures were validated using an orange fluorescent protein (OFP) reporter gene (pporRFP) under the control of the Cauliflower mosaic virus 35S promoter (35S). OFP expression in protoplasts was confirmed by epifluorescence microscopy. Analyses also included protoplast production efficiency methods using propidium iodide. Finally, low-cost food-grade enzymes were used for the protoplast isolation procedure, circumventing the need for lab-grade enzymes that are cost-prohibitive in high-throughput automated protoplast isolation and analysis. Based on the protocol developed in this work, the complete procedure from protoplast isolation to transformation can be conducted in under 4 hr, without any input from the operator. While the protocol developed in this work was validated with the BY-2 cell culture, the procedures and methods should be translatable to any plant suspension culture/protoplast system, which should enable acceleration of crop genomics research.

A high-throughput, automated, tobacco protoplast production and transformation methodology is described. The robotic system enables massively parallel gene expression and discovery in the model BY-2 system that should be translatable to non-model crops.

ハイスループットプロトプラスト単離と変革のためのロボットプラットフォーム

Over the last decade there has been a resurgence in the use of plant protoplasts that range from model species to crop species, for analysis of signal ...

遺伝学

Mapping RNA-RNA Interactions Globally Using Biotinylated Psoralen

Knowing how RNAs interact with themselves and with others is key to understanding RNA based gene regulation in the cell. While examples of RNA-RNA interactions such as microRNA-mRNA interactions have been shown to regulate gene expression, the full extent to which RNA interactions occur in the cell is still unknown. Previous methods to study RNA interactions have primarily focused on subsets of RNAs that are interacting with a particular protein or RNA species. Here, we detail a method named Sequencing of Psoralen crosslinked, Ligated, and Selected Hybrids (SPLASH) that allows genome-wide capture of RNA interactions in vivo in an unbiased manner. SPLASH utilizes in vivo crosslinking, proximity ligation, and high throughput sequencing to identify intramolecular and intermolecular RNA base-pairing partners globally. SPLASH can be applied to different organisms including bacteria, yeast and human cells, as well as diverse cellular conditions to facilitate the understanding of the dynamics of RNA organization under diverse cellular contexts. The entire experimental SPLASH protocol takes about 5 days to complete and the computational workflow takes about 7 days to complete.

Here, we detail the method of Sequencing of Psoralen crosslinked, Ligated, and Selected Hybrids (SPLASH), which enables genome-wide mapping of intramolecular and intermolecular RNA-RNA interactions in vivo. SPLASH can be applied to study RNA interactomes of organisms including yeast, bacteria and humans.

ビオチン化ソラレンを用いたRNA-RNA相互作用のマッピング

Knowing how RNAs interact with themselves and with others is key to understanding RNA based gene regulation in the cell. While examples of RNA-RNA ...

Retroviral Scanning: Mapping MLV Integration Sites to Define Cell-specific Regulatory Regions

Moloney murine leukemia (MLV) virus-based retroviral vectors integrate predominantly in acetylated enhancers and promoters. For this reason, mLV integration sites can be used as functional markers of active regulatory elements. Here, we present a retroviral scanning tool, which allows the genome-wide identification of cell-specific enhancers and promoters. Briefly, the target cell population is transduced with an mLV-derived vector and genomic DNA is digested with a frequently cutting restriction enzyme. After ligation of genomic fragments with a compatible DNA linker, linker-mediated polymerase chain reaction (LM-PCR) allows the amplification of the virus-host genome junctions. Massive sequencing of the amplicons is used to define the mLV integration profile genome-wide. Finally, clusters of recurrent integrations are defined to identify cell-specific regulatory regions, responsible for the activation of cell-type specific transcriptional programs.
The retroviral scanning tool allows the genome-wide identification of cell-specific promoters and enhancers in prospectively isolated target cell populations. Notably, retroviral scanning represents an instrumental technique for the retrospective identification of rare populations (e.g. somatic stem cells) that lack robust markers for prospective isolation.

Here, we describe a protocol for genome-wide mapping of the integration sites of Moloney murine leukemia virus-based retroviral vectors in human cells.

レトロウイルススキャン：細胞特異的調節領域を定義するためのMLV統合サイトのマッピング

Moloney murine leukemia (MLV) virus-based retroviral vectors integrate predominantly in acetylated enhancers and promoters. For this reason, mLV ...

Generation of Native Chromatin Immunoprecipitation Sequencing Libraries for Nucleosome Density Analysis

We present a modified native chromatin immunoprecipitation sequencing (ChIP-seq) experimental protocol compatible with a Gaussian mixture distribution based analysis methodology (nucleosome density ChIP-seq; ndChIP-seq) that enables the generation of combined measurements of micrococcal nuclease (MNase) accessibility with histone modification genome-wide. Nucleosome position and local density, and the posttranslational modification of their histone subunits, act in concert to regulate local transcription states. Combinatorial measurements of nucleosome accessibility with histone modification generated by ndChIP-seq allows for the simultaneous interrogation of these features. The ndChIP-seq methodology is applicable to small numbers of primary cells inaccessible to cross-linking based ChIP-seq protocols. Taken together, ndChIP-seq enables the measurement of histone modification in combination with local nucleosome density to obtain new insights into shared mechanisms that regulate RNA transcription within rare primary cell populations.

We present a modified native chromatin immunoprecipitation sequencing (ChIP-seq) methodology for the generation of sequence datasets suitable for a nucleosome density ChIP-seq analytical framework integrating micrococcal nuclease (MNase) accessibility with histone modification measurements.

ネイティブのクロマチン免疫沈降のヌクレオソーム密度解析ライブラリをシーケンスの生成

We present a modified native chromatin immunoprecipitation sequencing (ChIP-seq) experimental protocol compatible with a Gaussian mixture distribution ...

Robust DNA Isolation and High-throughput Sequencing Library Construction for Herbarium Specimens

Herbaria are an invaluable source of plant material that can be used in a variety of biological studies. The use of herbarium specimens is associated with a number of challenges including sample preservation quality, degraded DNA, and destructive sampling of rare specimens. In order to more effectively use herbarium material in large sequencing projects, a dependable and scalable method of DNA isolation and library preparation is needed. This paper demonstrates a robust, beginning-to-end protocol for DNA isolation and high-throughput library construction from herbarium specimens that does not require modification for individual samples. This protocol is tailored for low quality dried plant material and takes advantage of existing methods by optimizing tissue grinding, modifying library size selection, and introducing an optional reamplification step for low yield libraries. Reamplification of low yield DNA libraries can rescue samples derived from irreplaceable and potentially valuable herbarium specimens, negating the need for additional destructive sampling and without introducing discernible sequencing bias for common phylogenetic applications. The protocol has been tested on hundreds of grass species, but is expected to be adaptable for use in other plant lineages after verification. This protocol can be limited by extremely degraded DNA, where fragments do not exist in the desired size range, and by secondary metabolites present in some plant material that inhibit clean DNA isolation. Overall, this protocol introduces a fast and comprehensive method that allows for DNA isolation and library preparation of 24 samples in less than 13 h, with only 8 h of active hands-on time with minimal modifications.

This article demonstrates a detailed protocol for DNA isolation and high-throughput sequencing library construction from herbarium material including rescue of exceptionally poor-quality DNA.

堅牢な DNA の隔離および標本の高スループット シーケンス ライブラリーの構築

Herbaria are an invaluable source of plant material that can be used in a variety of biological studies. The use of herbarium specimens is associated with ...

Embryo Microinjection and Transplantation Technique for Nasonia vitripennis Genome Manipulation

The jewel wasp Nasonia vitripennis has emerged as an effective model system for the study of processes including sex determination, haplo-diploid sex determination, venom synthesis, and host-symbiont interactions, among others. A major limitation of working with this organism is the lack of effective protocols to perform directed genome modifications. An important part of genome modification is delivery of editing reagents, including CRISPR/Cas9 molecules, into embryos through microinjection. While microinjection is well established in many model organisms, this technique is particularly challenging to perform in N. vitripennis primarily due to its small embryo size, and the fact that embryonic development occurs entirely within a parasitized blowfly pupa. The following procedure overcomes these significant challenges while demonstrating a streamlined, visual procedure for effectively removing wasp embryos from parasitized host pupae, microinjecting them, and carefully transplanting them back into the host for continuation and completion of development. This protocol will strongly enhance the capability of research groups to perform advanced genome modifications in this organism.

Embryo Microinjection and Transplantation Technique for Nasonia vitripennis Genome Manipulation

Microinjection of Nasonia vitripennis embryos is an essential method for generating heritable genome modifications. Described here is a detailed procedure for microinjection and transplantation of Nasonia vitripennis embryos, which will greatly facilitate future genome manipulation in this organism.

胚のインジェクションと移植キョウソヤドリコバチゲノム操作手法

The jewel wasp Nasonia vitripennis has emerged as an effective model system for the study of processes including sex determination, haplo-diploid sex ...

High-throughput Identification of Synergistic Drug Combinations by the Overlap2 Method

Although antimicrobial drugs have dramatically increased the lifespan and quality of life in the 20th century, antimicrobial resistance threatens our entire society's ability to treat systemic infections. In the United States alone, antibiotic-resistant infections kill approximately 23,000 people a year and cost around 20 billion USD in additional healthcare. One approach to combat antimicrobial resistance is combination therapy, which is particularly useful in the critical early stage of infection, before the infecting organism and its drug resistance profile have been identified. Many antimicrobial treatments use combination therapies. However, most of these combinations are additive, meaning that the combined efficacy is the same as the sum of the individual antibiotic efficacy. Some combination therapies are synergistic: the combined efficacy is much greater than additive. Synergistic combinations are particularly useful because they can inhibit the growth of antimicrobial drug resistant strains. However, these combinations are rare and difficult to identify. This is due to the sheer number of molecules needed to be tested in a pairwise manner: a library of 1,000 molecules has 1 million potential combinations. Thus, efforts have been made to predict molecules for synergy. This article describes our high-throughput method for predicting synergistic small molecule pairs known as the Overlap2 Method (O2M). O2M uses patterns from chemical-genetic datasets to identify mutants that are hypersensitive to each molecule in a synergistic pair but not to other molecules. The Brown lab exploits this growth difference by performing a high-throughput screen for molecules that inhibit the growth of mutant but not wild-type cells. The lab's work previously identified molecules that synergize with the antibiotic trimethoprim and the antifungal drug fluconazole using this strategy. Here, the authors present a method to screen for novel synergistic combinations, which can be altered for multiple microorganisms.

High-throughput Identification of Synergistic Drug Combinations by the Overlap2 Method

Synergistic drug combinations are difficult and time-consuming to identify empirically. Here, we describe a method for identifying and validating synergistic small molecules.

重複2法による相乗効果の薬剤の組合せの高スループット識別

Although antimicrobial drugs have dramatically increased the lifespan and quality of life in the 20th century, antimicrobial resistance threatens our ...

Promoter Capture Hi-C: High-resolution, Genome-wide Profiling of Promoter Interactions

The three-dimensional organization of the genome is linked to its function. For example, regulatory elements such as transcriptional enhancers control the spatio-temporal expression of their target genes through physical contact, often bridging considerable (in some cases hundreds of kilobases) genomic distances and bypassing nearby genes. The human genome harbors an estimated one million enhancers, the vast majority of which have unknown gene targets. Assigning distal regulatory regions to their target genes is thus crucial to understand gene expression control. We developed Promoter Capture Hi-C (PCHi-C) to enable the genome-wide detection of distal promoter-interacting regions (PIRs), for all promoters in a single experiment. In PCHi-C, highly complex Hi-C libraries are specifically enriched for promoter sequences through in-solution hybrid selection with thousands of biotinylated RNA baits complementary to the ends of all promoter-containing restriction fragments. The aim is to then pull-down promoter sequences and their frequent interaction partners such as enhancers and other potential regulatory elements. After high-throughput paired-end sequencing, a statistical test is applied to each promoter-ligated restriction fragment to identify significant PIRs at the restriction fragment level. We have used PCHi-C to generate an atlas of long-range promoter interactions in dozens of human and mouse cell types. These promoter interactome maps have contributed to a greater understanding of mammalian gene expression control by assigning putative regulatory regions to their target genes and revealing preferential spatial promoter-promoter interaction networks. This information also has high relevance to understanding human genetic disease and the identification of potential disease genes, by linking non-coding disease-associated sequence variants in or near control sequences to their target genes.

DNA regulatory elements, such as enhancers, control gene expression by physically contacting target gene promoters, often through long-range chromosomal interactions spanning large genomic distances. Promoter Capture Hi-C (PCHi-C) identifies significant interactions between promoters and distal regions, enabling the assignment of potential regulatory sequences to their target genes.

プロモーター キャプチャこんにちは-c: 高解像度, ゲノム プロモーターの相互作用のプロファイリング

The three-dimensional organization of the genome is linked to its function. For example, regulatory elements such as transcriptional enhancers control the ...

High-throughput Identification of Gene Regulatory Sequences Using Next-generation Sequencing of Circular Chromosome Conformation Capture (4C-seq)

The identification of regulatory elements for a given target gene poses a significant technical challenge owing to the variability in the positioning and effect sizes of regulatory elements to a target gene. Some progress has been made with the bioinformatic prediction of the existence and function of proximal epigenetic modifications associated with activated gene expression using conserved transcription factor binding sites. Chromatin conformation capture studies have revolutionized our ability to discover physical chromatin contacts between sequences and even within an entire genome. Circular chromatin conformation capture coupled with next-generation sequencing (4C-seq), in particular, is designed to discover all possible physical chromatin interactions for a given sequence of interest (viewpoint), such as a target gene or a regulatory enhancer. Current 4C-seq strategies directly sequence from within the viewpoint but require numerous and diverse viewpoints to be simultaneously sequenced to avoid the technical challenges of uniform base calling (imaging) with next generation sequencing platforms. This volume of experiments may not be practical for many laboratories. Here, we report a modified approach to the 4C-seq protocol that incorporates both an additional restriction enzyme digest and qPCR-based amplification steps that are designed to facilitate a greater capture of diverse sequence reads and mitigate the potential for PCR bias, respectively. Our modified 4C method is amenable to the standard molecular biology lab for assessing chromatin architecture.

High-throughput Identification of Gene Regulatory Sequences Using Next-generation Sequencing of Circular Chromosome Conformation Capture 4C-seq

The identification of physical interactions between genes and regulatory elements is challenging but has been facilitated by chromosome conformation capture methods. This modification to the 4C-seq protocol mitigates PCR bias by minimizing over-amplification of PCR templates and maximizes the mappability of reads by incorporating an addition restriction enzyme digest step.

円の染色体構造の次世代シーケンシングによる遺伝子制御配列の高スループット識別キャプチャ (4 C seq)

The identification of regulatory elements for a given target gene poses a significant technical challenge owing to the variability in the positioning and ...

CRISPR-mediated Genome Editing of the Human Fungal Pathogen Candida albicans

This method describes the efficient CRISPR mediated genome editing of the diploid human fungal pathogen Candida albicans. CRISPR-mediated genome editing in C. albicans requires Cas9, guide RNA, and repair template. A plasmid expressing a yeast codon optimized Cas9 (CaCas9) has been generated. Guide sequences directly upstream from a PAM site (NGG) are cloned into the Cas9 expression vector. A repair template is then made by primer extension in vitro. Cotransformation of the repair template and vector into C. albicans leads to genome editing. Depending on the repair template used, the investigator can introduce nucleotide changes, insertions, or deletions. As C. albicans is a diploid, mutations are made in both alleles of a gene, provided that the A and B alleles do not harbor SNPs that interfere with guide targeting or repair template incorporation. Multimember gene families can be edited in parallel if suitable conserved sequences exist in all family members. The C. albicans CRISPR system described is flanked by FRT sites and encodes flippase. Upon induction of flippase, the antibiotic marker (CaCas9) and guide RNA are removed from the genome. This allows the investigator to perform subsequent edits to the genome. C. albicans CRISPR is a powerful fungal genetic engineering tool, and minor alterations to the described protocols permit the modification of other fungal species including C. glabrata, N. castellii, and S. cerevisiae.

CRISPR-mediated Genome Editing of the Human Fungal Pathogen Candida albicans

Efficient genome engineering of Candida albicans is critical to understanding the pathogenesis and development of therapeutics. Here, we described a protocol to quickly and accurately edit the C. albicans genome using CRISPR. The protocol allows investigators to introduce a wide variety of genetic modifications including point mutations, insertions, and deletions.

CRISPR を介したゲノム人間病原菌カンジダの編集

This method describes the efficient CRISPR mediated genome editing of the diploid human fungal pathogen Candida albicans. CRISPR-mediated genome editing ...

G2-seq: 高スループット シーケンス ベースを識別する方法後半ゲノムの領域を複製します。

G2-seq: 高スループットシーケンスベースを識別する方法後半ゲノムの領域を複製します。