KOは、米国心臓協会からの助成金によってサポートされています。

あなたが始める前に大人の心<ol><li>新鮮な108mMのNa +、5mMのK +、2mMのCa 2 +は 、8MMのMgCl 2、1mMののNaH 2 PO 4、4mmの飽和NaHCO 3、10mMのスクロース、5mMのトレハロース、5mMのHEPES（pHは7.1、すべての試薬 ​​からを含む人工体液（AH）溶液を調製シグマケミカル）。スクロースおよびトレハロースは、細菌汚染を防ぐために、使用直前に冷蔵保存溶液からAHに追加する必要があります。 </li><li>室温および少なくとも15分間空気バブリングによって酸素を解決するためにAH持参。 </li><li>脂肪の除去に必要ないくつかの細かい毛細血管（例えばガラス管、100ul、VWR）を引き出します。 </li></ol>幼虫の心<ol><li> Sylgardコーティングされたカバースリップ：22x22mmカバースリップの上に、Sylgard溶液を50 -70μl程度の転送を爪楊枝を使って。 ° C一晩65℃Sylgard硬化をしましょう​​。 </li><li> Broadieとベイトのバッファを準備します（135mm幅のNaCl、5mMのKClを、4mmののMgCl 2、2mMのCaCl 2で 、5mMのTES、36mmのショ糖、pHは7.15 Broadieとベイト、1993を参照してください。）。 </li><li> histoacryl接着剤を適用するために必要なツールを準備します。最初に、いくつかの細かい毛細血管（例えば、科学製品GB100T8P）引き出します。チューブに小さい方の端を挿入することにより、小さなプラスチック製のチューブ（タイゴン、1 / 32&quot;）を1.5ミリリットルのピペットチップを接続する。もう一方の端に広い開口部とキャピラリを挿入します。プラスチック製の先端に接着剤と穏やかな吸引のドロップに毛細管を浸漬することによりHistoacryl接着剤でキャピラリーをロードする。接着剤を扱うとき一キャピラリー接着剤の先端から、過剰な接着剤を除去するために手でキャピラリー番目のグラスを持っている必要があります。それは数秒内にそうなる硬化緩衝生理食塩水と接触するまで、接着剤は液体です。しかし、それは通常、試料に印加しながら接着剤キャピラリー先端からまたはに削除されるのに十分な長さのプラスチックのままです。 </li></ol>アダルトフライから半無傷ショウジョウバエのハート<ol><li>大人ショウジョウバエのハエは、2〜5分間フライナップ（キャロライナ生物サプライ株式会社）で麻酔する。ケアは、長い露光のためのフライナップでハエを状態にならないようにご注意ください。寒さへの短期暴露はまた、ハエを麻酔するために使用することができますが、それはもはや心拍数とリズムに永続的な効果を持っているとしてCO 2が推奨されていません。 </li><li>麻酔ハエは、ワセリンの薄層でコーティングされたシャーレに、背側を下に、配置されます。疎水性のゼリーの翼と体可逆的に&quot;スティック&quot;のクチクラが、必要に応じその場を再配置することができます。これは、後続の操作時に特に重要になります。 </li><li>最初のカットは、春のはさみ（Roboz＃5611）の湾曲したペアを使用して行われます。はさみブレードは、足の下に置き、首の近くに胸部の背面に向かって傾斜している。頭、腹側神経索、および脚はシングルカットで削除されます。準備をして酸素、人工血リンパ（AH）溶液中に浸漬される。 </li><li>春のはさみを使用して、腹部（腹部セグメント7と8で構成される）の後部先端は、シングルカットで削除されます。これは腹部の両エッジに沿って横方向のカットを行うためのアクセスを提供し、後腸、腹部キューティクルの間の接続を切断するのに役立つ。腹側腹部キューティクルの解放されたフラップはその後削除されます。 </li><li>腹部の臓器は今だけtracheolsによって所定の位置に保持されているように手順3と4で腸の前部と後部の接続が切断されています。腸や他の腹部臓器は通常、宝石商の鉗子（Roboz、＃55）と揺さぶる優しいを使用して単一の塊として除去することができます。内臓を削除しても、まだ脂肪体に囲まれて背側クチクラに接続されている心臓の鼓動のチューブを明らかにする。 </li><li>脂肪体は、結果としてそれは明らかに心臓のチューブを確認するために、この脂肪の一部を削除する必要がしばしばある光学顕微鏡では非常に不透明です。これは、細かく描かれたガラスキャピラリーを用いた脂肪吸引の技術によって実現されます。毛細血管は、標準的なピペットプラー（例：サッターP - 97ピペットプラー）を使用して作られていますし、真空源に接続されているプラ​​スチック製のチューブ（タイゴン、1 / 16&quot;）に挿入されます。このシステムは、心臓の管の周りから余分な脂肪から吸引するために使用されます。直径40ミクロ​​ンよりも大きなヒントとピペットを使用するべきではありませんので、吸引力は、先端の直径に比例する。心臓の後方部分はこの地域を完全に回避する必要があることを非常に壊れやすいので細心の注意は、心臓自体に触れないように注意しておく必要があります。 </li><li>成体ショウジョウバエの心臓の管が、現在公開され、暴行されるべきである。必要に応じて、キューティクルと接続された心を穏やかにワセリンからキューティクルを持ち上げ、慎重に背部の下のそれを突き、再び心臓組織との接触を避けることによって再配置することができます。 tにおける彼のポイントは、準備の入浴ソリューションは、新鮮なAHLに置き換える必要があります。この調製物は、前の任意の操作に酸素20〜30分間平衡を許可する必要があります。準備が60分以上維持する場合、それは新鮮なAHLで灌流してください。 </li></ol>光記録のための固定化ショウジョウバエの幼虫<ol><li> Sylgardのカバーガラスの各コーナーに近いHistoacryl接着剤の滴を配置。接着剤の滴にB＆Bバッファー50μlのを追加している硬化が即座になります。 B＆Bで接着されたスポットの間にスペースを埋める - 接着剤は、スライド上にバッファを保持します。 </li><li>放浪L3の幼虫を取り、2分間氷上でウェットティッシュの紙の上に置きます。これは、その動きが遅くなります。その後、バッファと東洋背側を上に（これは歯状突起のベルトを欠いている幼虫の側面である）とそれに幼虫を移す。すぐに頭部とSylgardの間にいくつかの接着剤を適用する。接着剤は硬化が非常に速くなりますし、移動から幼虫の頭部を防ぐ。 </li><li>鉗子を使用すると、慎重に後部気門によって動物をつかみ、ゆっくりとストレッチ。後半では幼虫の両側に沿って接着剤を適用することによって、この位置で幼虫を修正。体壁の筋肉がキューティクルのさらなる動きを減らすために、動物の脇腹に多くの接着剤を追加。幼虫は、今この位置に固定されています。カバースリップは、AHLまたはPBSで満たされた小さなペトリ皿に配置することができます。心臓の拍動は、現在、体壁の動きからの干渉なしに記録することができます。 </li></ol>代表的な結果： 新鮮な、酸素AHで維持するときに半無傷の成体ショウジョウバエの心臓は（補足データを参照して、Ocorr、ら、2007）解剖以下の時間のためにリズミカルに負かす事になります。代表的な例は、ムービー1に示します。第3齢幼虫と若ハエ（1 - 3週間後に羽化）からハーツ- 3 Hzの一般的に1の間のレートでの定期的なハートビートを示す。古いより3週間ハエは、一般的に不整脈であり、それにもかかわらず、これらの心はまだ酸素AHLで何時間も自然に打ち負かすことができます。解剖の手順の結果として損傷を受けている成人ハエの心は、一般的にリラックスすることができない極端な収縮の局所領域を示しています。 1Hzよりも遅いビートのレートはほとんど3週齢未満のハエでは観察されない。従ってそのような準備が破損すると破棄されると考えられている。 <a href="http://www.jove.com/files/ftp_upload/1425/MOVIE1.avi">ムービー1をダウンロードするには、ここをクリック。</a> -露出腹部心管を示す一週間古い大人の野生型のハエ（W 1118実験室株）（左前方）。定期的な、リズミカルな収縮を注意してください。右上隅の不透明な領域が残っている腹部の脂肪体であり、心臓の両側に丸い細胞が心膜細胞である。

<ol>
	<li>Ocorr, K., Reeves, N., Wessells, R. J., Fink, M., Chen, H. -. S. V., Akasaka, T., Yasuda, S., Metzger, J., Giles, W., Posakony, J. W., Bodmer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=KCNQ+potassium+channel+mutations+cause+cardiac+arrhythmias+in+Drosophila+that+mimic+the+effects+of+aging.">KCNQ potassium channel mutations cause cardiac arrhythmias in Drosophila that mimic the effects of aging.</a> Proc Natl Acad Sci U S A. 104, 3943-3948 (2007).</li><li>Broadie, K. S., Bate, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+embryonic+neuromuscular+synapse+of+Drosophila+melanogaster.">Development of the embryonic neuromuscular synapse of Drosophila melanogaster.</a> J Neurosci. 13, 144-166 (1993).</li></ol>

ショウジョウバエモデルでは、胎生発育から学習や記憶に至るまで、科学的なさまざまな質問に対処するために使用されている強力な遺伝学的ツールであることが証明されている。最近この多目的なモデル生物はハエの心機能の遺伝学を調査するために使用されています。成体ショウジョウバエで心臓生理学を定量化するための試行回数は、腹部のクチクラを通してそのままハエで行った観?...

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Micro Dissecting Spring Scissors (curved)</td>
<td>&nbsp;</td>
<td>Roboz</td>
<td>RS-5611</td>
<td>Good for gross cuts (Step 3)</td>
</tr>
<tr>
<td>Micro Dissecting Spring Scissors (straight)</td>
<td>&nbsp;</td>
<td>Roboz</td>
<td>RS-5620</td>
<td>&nbsp;</td>
<tr>
<td>Dumont #55 forceps</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>11295-51</td>
<td>&nbsp;</td>
<tr>
<td>Dumont #5 forceps</td>
<td>&nbsp;</td>
<td>Fine Science Tools</td>
<td>11295-10</td>
<td>&nbsp;</td>
<tr>
<td>Glass Capillaries, 100ul</td>
<td>&nbsp;</td>
<td>VWR</td>
<td>53432-921</td>
<td>&nbsp;</td>
<tr>
<td>Glass Capillaries, fine</td>
<td>&nbsp;</td>
<td>Science Products</td>
<td>GB100T8P</td>
<td>&nbsp;</td>
<tr>
<td>Pipette Puller</td>
<td>&nbsp;</td>
<td>Sutter Equipment</td>
<td>P-97</td>
<td>Both horizontal and vertical pipette pullers will work</td>
</tr>
<tr>
<td>Plastic tubing</td>
<td>&nbsp;</td>
<td>Tygon R-3603</td>
<td>1/16&#x201D; inner diameter</td>
<td>for 100&mu;l capillaries</td>
</tr>
<tr>
<td>Plastic tubing</td>
<td>&nbsp;</td>
<td>Tygon R-3603</td>
<td>1/32&#x201D; inner diameter</td>
<td>for small capillaries</td>
</tr>
<tr>
<td>Histoacryl&reg; tissue adhesive</td>
<td>&nbsp;</td>
<td>B.Braun, Melsungen</td>
<td>&nbsp;</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

visualizing the beating heart in drosophila

市販<em&gt;ショウジョウバエ</em&gt;心臓は最近、遺伝子、細胞、および筋原性心内分子メカニズムの基礎となる機能を調べるための良いモデル系として注目されています。ハエで心機能を調べる上で重要なステップは、まだ心臓の鼓動の臓器を観察し、記録されることを可能にしながら、その筋の機能を維持する方法で、心臓にアクセスする方法を見つけることです。幼虫と成人の両方で心臓の鼓動を観察し、記録するための2つの異なった方法<em&gt;ショウジョウバエ</em&gt;ここで説明されています。大人のハエを使って私たちの半無傷の準備は、色素性クチクラからの干渉と脂肪体を覆うことなく、腹部、心臓の明確な可視化が可能になります。幼虫の心臓を記録するには、それにより心筋の収縮に関連付けられていない心の動きを減らし体壁の動きを最小化する幼虫を、固定化する必要が打つ。私たちの方法論は1-3 Hzのレートでの時間のために打つことができる安定した大人と幼虫の心の準備を生成する。

Watch this Scientific Journal Video about Visualizing the Beating Heart in Drosophila at JoVE.com

Visualizing the Beating Heart in Drosophila

幼虫および成体での心臓の鼓動を可視化するために必要なテクニック<em&gt;ショウジョウバエ</em&gt;提示されます。各ライフステージでは、異なる方法論が必要になります。

の心臓の鼓動の可視化ショウジョウバエ</em

The Drosophila heart has recently emerged as a good model system for examining the genetic, cellular, and molecular mechanisms underlying function in ...

visualizing-the-beating-heart-in-drosophila

Research

JoVE Journal

Biology

Visualizing the Beating Heart in Drosophila

18.6K ビュー.  The Sanford Burnham Institute for Medical Research. 幼虫および成体での心臓の鼓動を可視化するために必要なテクニックショウジョウバエ提示されます。各ライフステージでは、異なる方法論が必要になります。

ビデオ: Visualizing the Beating Heart in Drosophila

Visualizing the Live Drosophila Glial-neuromuscular Junction with Fluorescent Dyes

Our project identified GFP labeled glial structures at the developing larval fly neuromuscular synapse. To look at development of live glial-nerve-muscle synapses, we developed a larval tissue preparation that had features of live intact larvae, but also had good optical properties.  This new preparation also allowed for access of perfusates to the synapse.  We used fly larvae, immersed them in artificial hemolymph, and relaxed their normal rhythmic body contractions by chilling them. Next we dissected off the posterior segments of each animal and with a blunt insect pin pushed the mouth parts backward through the body cavity.  This everted the larval body wall, like turning a sock inside-out.  We completed the dissection with ultra-fine dissection scissors and thus exposed the visceral side of the body wall muscles. The glial structures at the NMJ expressed membrane targeted GFP under the control of glial specific promoters. The post-synaptic membrane, the SSR (Subsynaptic Reticula) in muscle expressed synaptically targeted dsRed. We needed to acutely label the motor neuron terminals, the third part of the synapse. To do this we applied primary antibodies to HRP, conjugated to a far-red emitting flurophore.  To test for dye diffusion properties into the perisynaptic space between the motor neuron terminals and the SSR, we applied a solution of large Dextran molecules conjugated to far-red emitting flurophore and collected images.

Visualizing the Live Drosophila Glial-neuromuscular Junction with Fluorescent Dyes

We described structural features of the Glia-neuromuscular synapses in a novel Inside-out tissue preparation of live fly larvae using fluorescent dyes with confocal microscopy. We labeled live neuron terminals with fluorescent primary antibodies to HRP, and also visualized the perisynaptic space with fluorescent Dextrans.

ライブの視覚化ショウジョウバエ</em蛍光色素で>グリア - 神経筋接合部

Our project identified GFP labeled glial structures at the developing larval fly neuromuscular synapse. To look at development of live glial-nerve-muscle ...

生物学

Fluorescent Labeling of Drosophila Heart Structures

The Drosophila melanogaster dorsal vessel, or heart, is a tubular structure comprised of a single layer of contractile cardiomyocytes, pericardial cells that align along each side of the heart wall, supportive alary muscles and, in adults, a layer of ventral longitudinal muscle cells. The contractile fibers house conserved constituents of the muscle cytoarchitecture including densely packed bundles of myofibrils and cytoskeletal/submembranous protein complexes, which interact with homologous components of the extracellular matrix. Here we describe a protocol for the fixation and the fluorescent labeling of particular myocardial elements from the hearts of dissected larvae and semi-intact adult Drosophila. Specifically, we demonstrate the labeling of sarcomeric F-actin and of &alpha;-actinin in larval hearts. Additionally, we perform labeling of F-actin and &alpha;-actinin in myosin-GFP expressing adult flies and of &alpha;-actinin and pericardin, a type IV extracellular matrix collagen, in wild type adult hearts. Particular attention is given to a mounting strategy for semi-intact adult hearts that minimizes handling and optimizes the opportunity for maintaining the integrity of the cardiac tubes and the associated tissues. These preparations are suitable for imaging via fluorescent and confocal microscopy. Overall, this procedure allows for careful and detailed analysis of the structural characteristics of the heart from a powerful genetically tractable model system.

Fluorescent Labeling of Drosophila Heart Structures

Here we describe a basic protocol for fluorescent labeling of different elements of heart tubes from larva and adult Drosophila melanogaster. These specimens are well-suited for imaging via fluorescent or confocal microscopy. This technique permits detailed structural analysis of the features of the hearts from a powerful model organism.

の蛍光標識ショウジョウバエハートの構造

The Drosophila melanogaster dorsal vessel, or heart, is a tubular structure comprised of a single layer of contractile cardiomyocytes, pericardial cells ...

Monitoring Heart Function in Larval Drosophila melanogaster for Physiological Studies

We present various methods to record cardiac function in the larval Drosophila. The approaches allow heart rate to be measured in unrestrained and restrained whole larvae. For direct control of the environment around the heart another approach utilizes the dissected larvae and removal of the internal organs in order to bathe the heart in desired compounds. The exposed heart also allows membrane potentials to be monitored which can give insight of the ionic currents generated by the myocytes and for electrical conduction along the heart tube. These approaches have various advantages and disadvantages for future experiments that are discussed. The larval heart preparation provides an additional model besides the Drosophila skeletal NMJ to investigate the role of intracellular calcium regulation on cellular function. Learning more about the underlying ionic currents that shape the action potentials in myocytes in various species, one can hope to get a handle on the known ionic dysfunctions associated to specific genes responsible for various diseases in mammals.

Monitoring Heart Function in Larval Drosophila melanogaster for Physiological Studies

We present various ways to monitor heart function in the larva of Drosophila for assessing questions dealing with the function of gap junctions, ion channel mutations, modulation of pacemaker activity and pharmacological studies.

幼虫のモニタリングの心機能キイロショウジョウバエ生理学的研究のための

We present various methods to record cardiac function in the larval Drosophila. The approaches allow heart rate to be measured in unrestrained  and  ...

Preparation of embryos for Electron Microscopy of the Drosophila embryonic heart tube

The morphogenesis of the Drosophila embryonic heart tube has emerged as a valuable model system for studying cell migration, cell-cell adhesion and cell shape changes during embryonic development. One of the challenges faced in studying this structure is that the lumen of the heart tube, as well as the membrane features that are crucial to heart tube formation, are difficult to visualize in whole mount embryos, due to the small size of the heart tube and intra-lumenal space relative to the embryo. The use of transmission electron microscopy allows for higher magnification of these structures and gives the advantage of examining the embryos in cross section, which easily reveals the size and shape of the lumen. In this video, we detail the process for reliable fixation, embedding, and sectioning of late stage Drosophila embryos in order to visualize the heart tube lumen as well as important cellular structures including cell-cell junctions and the basement membrane.

Preparation of embryos for Electron Microscopy of the Drosophila embryonic heart tube

We describe a process for fixation, embedding, sectioning, and imaging of late stage Drosophila embryos for Trasmission Electron Microscopy of the embryonic heart tube. This technique allows for the visualization of the heart tube lumen as well as the basement membrane, which lines the lumen of the heart.

の電子顕微鏡のための胚の調製ショウジョウバエ胎児心臓の管

The morphogenesis of the Drosophila  embryonic heart tube has emerged as a valuable model system for studying cell migration, cell-cell adhesion and cell ...

Quantification of &gamma;H2AX Foci in Response to Ionising Radiation

DNA double-strand breaks (DSBs), which are induced by either endogenous metabolic processes or by exogenous sources, are one of the most critical DNA lesions with respect to survival and preservation of genomic integrity. An early response to the induction of DSBs is phosphorylation of the H2A histone variant, H2AX, at the serine-139 residue, in the highly conserved C-terminal SQEY motif, forming &gamma;H2AX1. Following induction of DSBs, H2AX is rapidly phosphorylated by the phosphatidyl-inosito 3-kinase (PIKK) family of proteins, ataxia telangiectasia mutated (ATM), DNA-protein kinase catalytic subunit and ATM and RAD3-related (ATR)2. Typically, only a few base-pairs (bp) are implicated in a DSB, however, there is significant signal amplification, given the importance of chromatin modifications in DNA damage signalling and repair. Phosphorylation of H2AX mediated predominantly by ATM spreads to adjacent areas of chromatin, affecting approximately 0.03% of total cellular H2AX per DSB2,3. This corresponds to phosphorylation of approximately 2000 H2AX molecules spanning ~2 Mbp regions of chromatin surrounding the site of the DSB and results in the formation of discrete &gamma;H2AX foci which can be easily visualized and quantitated by immunofluorescence microscopy2. The loss of &gamma;H2AX at DSB reflects repair, however, there is some controversy as to what defines complete repair of DSBs; it has been proposed that rejoining of both strands of DNA is adequate however, it has also been suggested that re-instatement of the original chromatin state of compaction is necessary4-8. The disappearence of &gamma;H2AX involves at least in part, dephosphorylation by phosphatases, phosphatase 2A and phosphatase 4C5,6. Further, removal of &gamma;H2AX by redistribution involving histone exchange with H2A.Z has been implicated7,8. Importantly, the quantitative analysis of &gamma;H2AX foci has led to a wide range of applications in medical and nuclear research. Here, we demonstrate the most commonly used immunofluorescence method for evaluation of initial DNA damage by detection and quantitation of &gamma;H2AX foci in &gamma;-irradiated adherent human keratinocytes9.

Quantification of &#947;H2AX Foci in Response to Ionising Radiation

Quantification of DNA double-strand streaks using &gamma;H2AX formation as a molecular marker has become an invaluable tool in radiation biology. Here we demonstrate the use of an immunofluorescence assay for quantification of &gamma;H2AX foci after exposure of cells to radiation.

電離放射線への応答でγH2AX病巣の定量化

DNA double-strand breaks (DSBs), which are induced by either endogenous metabolic processes or by exogenous sources, are one of the most critical DNA ...

Quantitation of &gamma;H2AX Foci in Tissue Samples

DNA double-strand breaks (DSBs) are particularly lethal and genotoxic lesions, that can arise either by endogenous (physiological or pathological) processes or by exogenous factors, particularly ionizing radiation and radiomimetic compounds. Phosphorylation of the H2A histone variant, H2AX, at the serine-139 residue, in the highly conserved C-terminal SQEY motif, forming &gamma;H2AX, is an early response to DNA double-strand breaks1. This phosphorylation event is mediated by the phosphatidyl-inosito 3-kinase (PI3K) family of proteins, ataxia telangiectasia mutated (ATM), DNA-protein kinase catalytic subunit and ATM and RAD3-related (ATR)2. Overall, DSB induction results in the formation of discrete nuclear &gamma;H2AX foci which can be easily detected and quantitated by immunofluorescence microscopy2. Given the unique specificity and sensitivity of this marker, analysis of &gamma;H2AX foci has led to a wide range of applications in biomedical research, particularly in radiation biology and nuclear medicine. The quantitation of &gamma;H2AX foci has been most widely investigated in cell culture systems in the context of ionizing radiation-induced DSBs. Apart from cellular radiosensitivity, immunofluorescence based assays have also been used to evaluate the efficacy of radiation-modifying compounds. In addition, &gamma;H2AX has been used as a molecular marker to examine the efficacy of various DSB-inducing compounds and is recently being heralded as important marker of ageing and disease, particularly cancer3. Further, immunofluorescence-based methods have been adapted to suit detection and quantitation of &gamma;H2AX foci ex vivo and in vivo4,5. Here, we demonstrate a typical immunofluorescence method for detection and quantitation of &gamma;H2AX foci in mouse tissues.

Quantitation of &#947;H2AX Foci in Tissue Samples

Quantitation of DNA double-strand breaks on the basis of &gamma;H2AX foci has become an invaluable tool, particularly in radiation biology, for the evaluation of tissue radiosensitivity and effects of radiation modifying compounds. Here we demonstrate the use of an immunofluorescence assay for quantitation of &gamma;H2AX foci in tissue samples.

組織サンプルのγH2AX病巣の定量

DNA double-strand breaks (DSBs) are particularly lethal and genotoxic lesions, that can arise either by endogenous (physiological or pathological) ...

Evaluation of the Spatial Distribution of &gamma;H2AX following Ionizing Radiation

An early molecular response to DNA double-strand breaks (DSBs) is phosphorylation of the Ser-139 residue within the terminal SQEY motif of the histone H2AX1,2. This phosphorylation of H2AX is mediated by the phosphatidyl-inosito 3-kinase (PI3K) family of proteins, ataxia telangiectasia mutated (ATM), DNA-protein kinase catalytic subunit and ATM and RAD3-related (ATR)3. The phosphorylated form of H2AX, referred to as &gamma;H2AX, spreads to adjacent regions of chromatin from the site of the DSB, forming discrete foci, which are easily visualized by immunofluorecence microscopy3. Analysis and quantitation of &gamma;H2AX foci has been widely used to evaluate DSB formation and repair, particularly in response to ionizing radiation and for evaluating the efficacy of various radiation modifying compounds and cytotoxic compounds4.
Given the exquisite specificity and sensitivity of this de novo marker of DSBs, it has provided new insights into the processes of DNA damage and repair in the context of chromatin. For example, in radiation biology the central paradigm is that the nuclear DNA is the critical target with respect to radiation sensitivity. Indeed, the general consensus in the field has largely been to view chromatin as a homogeneous template for DNA damage and repair. However, with the use of &gamma;H2AX as molecular marker of DSBs, a disparity in &gamma;-irradiation-induced &gamma;H2AX foci formation in euchromatin and heterochromatin has been observed5-7. Recently, we used a panel of antibodies to either mono-, di- or tri- methylated histone H3 at lysine 9 (H3K9me1, H3K9me2, H3K9me3) which are epigenetic imprints of constitutive heterochromatin and transcriptional silencing and lysine 4 (H3K4me1, H3K4me2, H3K4me3), which are tightly correlated actively transcribing euchromatic regions, to investigate the spatial distribution of &gamma;H2AX following ionizing radiation8. In accordance with the prevailing ideas regarding chromatin biology, our findings indicated a close correlation between &gamma;H2AX formation and active transcription9. Here we demonstrate our immunofluorescence method for detection and quantitation of &gamma;H2AX foci in non-adherent cells, with a particular focus on co-localization with other epigenetic markers, image analysis and 3D-modeling.

Evaluation of the Spatial Distribution of &#947;H2AX following Ionizing Radiation

Microscopic analysis of &gamma;H2AX foci, which form following the phosphorylation of H2AX at Ser-139 in response to DNA double-strand breaks, has become an invaluable tool in radiation biology. Here we used an antibody to mono-methylated histone H3 at lysine 4 as an epigenetic marker of actively transcribing euchromatin, to evaluate the spatial distribution of radiation-induced &gamma;H2AX formation within the nucleus.

電離放射線は、次のγH2AXの空間分布の評価

An early molecular response to DNA double-strand breaks (DSBs) is phosphorylation of the Ser-139 residue within the terminal SQEY motif of the histone ...

Clonogenic Assay: Adherent Cells

The clonogenic (or colony forming) assay has been established for more than 50 years; the original paper describing the technique was published in 19561. Apart from documenting the method, the initial landmark study generated the first radiation-dose response curve for X-ray irradiated mammalian (HeLa) cells in culture1. Basically, the clonogenic assay enables an assessment of the differences in reproductive viability (capacity of cells to produce progeny; i.e. a single cell to form a colony of 50 or more cells) between control untreated cells and cells that have undergone various treatments such as exposure to ionising radiation, various chemical compounds (e.g. cytotoxic agents) or in other cases genetic manipulation. The assay has become the most widely accepted technique in radiation biology and has been widely used for evaluating the radiation sensitivity of different cell lines. Further, the clonogenic assay is commonly used for monitoring the efficacy of radiation modifying compounds and for determining the effects of cytotoxic agents and other anti-cancer therapeutics on colony forming ability, in different cell lines. A typical clonogenic survival experiment using adherent cells lines involves three distinct components, 1) treatment of the cell monolayer in tissue culture flasks, 2) preparation of single cell suspensions and plating an appropriate number of cells in petri dishes and 3) fixing and staining colonies following a relevant incubation period, which could range from 1-3 weeks, depending on the cell line. Here we demonstrate the general procedure for performing the clonogenic assay with adherent cell lines with the use of an immortalized human keratinocyte cell line (FEP-1811)2. Also, our aims are to describe common features of clonogenic assays including calculation of the plating efficiency and survival fractions after exposure of cells to radiation, and to exemplify modification of radiation-response with the use of a natural antioxidant formulation.

The applicability of the clonogenic assay for evaluating reproductive viability has been established for more than 50 years. Here we demonstrate the general procedure for performing the clonogenic assay with adherent cells.

クローン原性アッセイ：付着細胞

The clonogenic (or colony forming) assay has been established for more than 50 years; the original paper describing the technique was published in 19561. ...

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

The proper elimination of unwanted or aberrant cells through apoptosis and subsequent phagocytosis (apoptotic cell clearance) is crucial for normal development in all metazoan organisms. Apoptotic cell clearance is a highly dynamic process intimately associated with cell death; unengulfed apoptotic cells are barely seen in vivo under normal conditions. In order to understand the different steps of apoptotic cell clearance and to compare 'professional' phagocytes - macrophages and dendritic cells to 'non-professional' - tissue-resident neighboring cells, in vivo live imaging of the process is extremely valuable. Here we describe a protocol for studying apoptotic cell clearance in live Drosophila embryos. To follow the dynamics of different steps in phagocytosis we use specific markers for apoptotic cells and phagocytes. In addition, we can monitor two phagocyte systems in parallel: 'professional' macrophages and 'semi-professional' glia in the developing central nervous system (CNS). The method described here employs the Drosophila embryo as an excellent model for real time studies of apoptotic cell clearance.

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

Here we describe an effective method for studying dynamics of apoptotic cell clearance in vivo. This method employs live Drosophila embryos as a powerful model for monitoring phagocytosis of apoptotic cells using specific labeling of apoptotic cells and phagocytes.

アポトーシス細胞のクリアランスのイメージング中に生きる<em&gt;ショウジョウバエ</em&gt;胚

The  proper elimination of unwanted or aberrant cells through apoptosis and  subsequent phagocytosis (apoptotic cell clearance) is crucial for normal  ...

Assessment of Calcium Sparks in Intact Skeletal Muscle Fibers

Maintaining homeostatic Ca2+ signaling is a fundamental physiological process in living cells. Ca2+ sparks are the elementary units of Ca2+ signaling in the striated muscle fibers that appear as highly localized Ca2+ release events mediated by ryanodine receptor (RyR) Ca2+ release channels on the sarcoplasmic reticulum (SR) membrane. Proper assessment of muscle Ca2+ sparks could provide information on the intracellular Ca2+&#160;handling properties of healthy and diseased striated muscles. Although Ca2+ sparks events are commonly seen in resting cardiomyocytes, they are rarely observed in resting skeletal muscle fibers; thus there is a need for methods to generate and analyze sparks in skeletal muscle fibers.
Detailed here is an experimental protocol for measuring Ca2+ sparks in isolated flexor digitorm brevis (FDB) muscle fibers using fluorescent Ca2+ indictors and laser scanning confocal microscopy. In this approach, isolated FDB fibers are exposed to transient hypoosmotic stress followed by a return to isotonic physiological solution. Under these conditions, a robust Ca2+ sparks response is detected adjacent to the sarcolemmal membrane in young healthy FDB muscle fibers. Altered Ca2+ sparks response is detected in dystrophic or aged skeletal muscle fibers. This approach has recently demonstrated that membrane-delimited signaling involving cross-talk between inositol (1,4,5)-triphosphate receptor (IP3R) and RyR contributes to Ca2+ spark activation in skeletal muscle. In summary, our studies using osmotic stress induced Ca2+ sparks showed that this intracellular response reflects a muscle signaling mechanism in physiology and aging/disease states, including mouse models of muscle dystrophy (mdx mice) or amyotrophic lateral sclerosis (ALS model).

Described here is a method to directly measure calcium sparks, the elementary units of Ca2+ release from sarcoplasmic reticulum&#160;in intact skeletal muscle fibers. This method utilizes osmotic-stress-mediated triggering of Ca2+ release from ryanodine receptor in isolated muscle fibers. The dynamics and homeostatic capacity of intracellular Ca2+ signaling can be employed to assess muscle function in health and disease.

無傷骨格筋線維内のカルシウムスパークスの評価

Maintaining homeostatic Ca2+ signaling is a fundamental physiological process in living cells. Ca2+ sparks are the elementary units of Ca2+ signaling in ...