The authors wish to thank Drs. Sung-wan An and Mike O&#8217;Donnell for practical advice on establishing this assay, Dr. Chih-Jen Cheng for helpful discussions on the use of ion-specific electrodes, and Dr. Chou-Long Huang for his mentorship and support. This work was supported by the National Institutes of Health (K08DK091316 to ARR) and the American Society of Nephrology Gottschalk Award to ARR.

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The authors have nothing to disclose.

一緒にイオン固有の電極を有するラムゼイアッセイの使用は、孤立した昆虫マルピーギ（腎）細管内の流体分泌速度とイオンフラックスの測定を可能にします。 20以上の細管は 、インビトロmicroperfused細管内の個々のアッセイと比較してより高いスループットを可能にする、一度にアッセイすることができます。また、イオン特異電極は、第2の装置への流体の少量の移動に導入?...

<html>腎上皮イオン輸送は、生物のiono-と浸透圧調節の下にあります。 キイロショウジョウバエマルピーギ（腎臓）細管上皮イオン輸送の分子メカニズムを研究するための比類のない機会を提供しています。これは、生理的な研究への尿細管のアクセスとペアにショウジョウバエの強力な遺伝学の組み合わせに起因するものです。技術1を開拓し 、研究者の名にちなんで名付けラムゼイアッセイは、孤立したマルピーギ細管から流体分泌速度を測定し、ダウと同僚2で 1994年にショウジョウバエに設立されました。これは、流体の分泌を調節する細胞特異的なシグナル伝達経路を定義するには、そのようなGAL4-UASシステム3,4 ショウジョウバエ遺伝的ツールを使用して、さらなる研究のために道を開きました。例は、他の多くの中で6,7-ペプチドホルモン5に対する応答におけるカルシウムシグナル伝達を含みます。 ハエは、尿細管の主なセグメントからの塩化カリウムに富む流体の分泌を介して起こるでve_content &quot;&gt;遺伝子技術と古典的な生理学的研究の組み合わせは、その尿の生成を示している。これは主に、陽イオンの並列経上皮分泌を介して行われKは+だけでなく、 の Na + は 、主細胞、およびClを通して- 。星細胞8-12を通じて分泌別途経上皮の K +およびNa +フラックスを測定する能力は、流体分泌の測定よりも輸送メカニズムのより詳細な特性評価を可能にします単独で、例えば、非刺激ショウジョウバエ細管ではNa + / K + -ATPアーゼ阻害剤ウアバインは、主細胞への取り込みは、有機アニオントランスポーター阻害剤タウロコール酸13によって阻害された場合でも、体液分泌2には影響を与えないが、リントンとオドネルは、ウアバインが脱分極することを示しました側底膜電位、およびNa +フラックス9を上昇させます 。代表的な結果に示すように、我々はこれらの結果をレプリケートし、K +フラックス14を同時に減少させることが示されました。増加の Na + フラックスおよび K +フラックスを減少させた分泌の正味の変化が生じ、流体分泌に対する反対の効果を持っています。 。このように、「ウアバインパラドックス」、すなわちへの2つの解像度があり、 ショウジョウバエの細管内の流体の分泌に影響を与えませんウアバイン初期観察は：まず、刺激細管に、流体分泌に対するウアバインの効果は明らかではないが原因有機アニオントランスポーター13によるその取り込み。そして第二に、非刺激細管に、ウアバインは（代表的な結果とrefを参照してください。9）液分泌の純変化なしで、その結果、上皮の Na + および K +フラックスへの影響に反対しています。 Na + / K + -ATPのため、主な役割非刺激細管にアーゼ基底膜を越えて輸送プロセスを共役型のNa +のための有利な濃度勾配を生成するために、細胞内のNa +濃度を低下させることです。確かに、別々 の Na + および K +フラックスを測定することにより、我々は、フライナトリウム-カリウム-2-塩化共輸送体（NKCC）を欠いている細管をさらにウアバイン添加後減少し、経上皮に変化がないがないと、経上皮K +フラックスが低下していることを実証しましたNa +が14フラックス 。これらの知見は、NKCCを通じてセルに入るの Na + をNa + / K + -ATPアーゼを介してリサイクルされ、私たちの結論を支持しました。別の例では、Ianowski ら 6mmの10 mMのからバスK +濃度の低下は、流体分泌の純変化なしで、経上皮K +フラックスとRhodniusのprolixusから尿細管における増加した上皮の Na + 流入を減少することが観察され<sup&gt; 15。幼虫細管全体での Na + フラックスおよび K +フラックスの差動効果も塩分17を飼育することに応答して変動する塩食16に二蚊の種に応じて、 ショウジョウバエの細管において観察されています。 ラムゼイアッセイ調製物における経上皮イオンフラックスの測定における最大の課題は、分泌された流体内のイオン濃度の決意です。この課題は、難photometery 18、放射性イオン19を使用すると、電子プローブ波長分散分光法20を含む様々なソリューションと満たされています。これらの技術は、イオン濃度を測定するための機器に分泌液滴の移動を必要とします。非刺激ショウジョウバエ細管により分泌される流体の体積が小さいため、通常は0.5〜NL /分で、これは技術的な課題を提起し、分泌された流体の一部である場合、エラーが導入され転送時に失わ。対照的に、イオン特異的電極の使用は、 その場での （イオン濃度を算出することが可能な）イオン活性の測定を可能にします。現在のプロトコルは、K +イオノフォア21としてバリノマイシン使用してRhodnius細管全体の経上皮K +フラックスを測定するためにMaddrellらによって使用されるものから適合し、また、4- ターシャの -butylcalix [4]アレーン四酢酸の使用が記載されましたテトラエチルエステル系NaがMesserli らによって特徴づけられる特異的イオン固有の電極を+。アル。22。イオン特定電極はまた、大人の9,23および幼虫16 キイロショウジョウバエでラムゼイアッセイにおいてマルピーギ細管により分泌液中のイオン濃度を測定するために使用されてきた、ニュージーランドアルパインウェタ（Hemideinaマオリ ）24と蚊17インチ ここでは、詳細にラムゼイとしての使用を記載ショウジョウバエからマルピーギ細管流体分泌速度を測定するだけでなく、分泌液、したがって、経上皮イオンフラックスの計算内の K +およびNa +の濃度を決定するために、イオン固有の電極を使用すると言います。アッセイの概要を図1に提供されます。 <img alt="図1" src="/files/ftp_upload/53144/53144fig1.jpg" /> マルピーギ細管の図1の回路図とイオン濃度を測定するためのイオン特定電極の使用とラムゼイアッセイ 。この図は、ラムゼイアッセイのためのセットアップを示しています。 （A）各フライは、4つの細管、前方細管一対の後部細管のペア、血リンパに囲まれた腹腔内のそのフロートを持っています。各ペアでは、二つの細管はその後、中腸とhindguの接合部に尿を空に尿管、に参加しますトン。細管は、ブラインド・エンドです。尿は（赤で示した）は、流体分泌メインセグメントによって生成され、消化管に尿管に向かって内外に流れます。解剖後、細管のペアは、尿管を横断することにより、腸から解離します。 （B）は、尿細管のペアは、その後、アッセイ皿のウェル内入浴食塩水の液滴に移しました。 2細管の一つは、「アンカー細管は、「金属ピンの周りを包み、不活性であるとしてここでいいます。他の細管は、分泌細管です。 （液体を分泌しない）最初のセグメントと分泌細管の主なセグメントは、入浴の生理食塩水の液滴内に残ります。その後、イオンと水の移動入浴生理食塩水から、主要セグメントの尿細管内腔へ、および生体内で起こるように、尿管に向かって移動します。下部セグメント（青）が入浴生理食塩水、したがって不活性外です。尿管が切断されるので、分泌液が尿管の切断端からの液滴として現れます。 T彼は、分泌が続くように、流体液滴が時間とともに拡大し、分泌され、その直径は、接眼マイクロメータを用いて測定されます。ミネラルオイルの層は、分泌液の蒸発を防止します。リファレンスとイオン特定電極が分泌液のイオン濃度を測定する。 <a href="https://www.jove.com/files/ftp_upload/53144/53144fig1large.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a>

<table>
	<tbody>
		<tr>
			<td>Sylgard 184 Silicone Elastomer Kit</td>
			<td>Ellsworth Adhesives</td>
			<td>http://www.ellsworth.com/dow-corning-sylgard-184-silicone-encapsulant-0-5kg-kit-clear/</td>
			<td>May be purchased from multiple distributors</td>
		</tr>
		<tr>
			<td>Petri dish, polystyrene, 100 mm x 15 mm</td>
			<td>Fisher</td>
			<td>FB0875712</td>
			<td>Specific brand is not important</td>
		</tr>
		<tr>
			<td>Petri dish, polystyrene, 35 mm x 10 mm</td>
			<td>Corning Life Sciences</td>
			<td>Fisher 08-757-100A</td>
			<td>Specific brand is not important</td>
		</tr>
		<tr>
			<td>Scalpel Handle #3</td>
			<td>Fine Science Tools</td>
			<td>10003-12</td>
			<td>Specific brand is not important</td>
		</tr>
		<tr>
			<td>Scalpel Blades #1</td>
			<td>Fine Science Tools</td>
			<td>10011-00</td>
			<td>Specific brand is not important; use appropriate sharps precautions</td>
		</tr>
		<tr>
			<td>Needle, 30G x 1/2</td>
			<td>Becton Dickinson</td>
			<td>305106</td>
			<td>Use appropriate sharps precautions</td>
		</tr>
		<tr>
			<td>Minutien pins, black anodized, 0.15 mm</td>
			<td>Fine Science Tools</td>
			<td>26002-15</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereomicroscope with ocular micrometer</td>
			<td>Nikon</td>
			<td>SMZ800</td>
			<td>Specific brand is not important; this is given as an example</td>
		</tr>
		<tr>
			<td>Sheet of black stained glass, 3 mm (1/8 inch) thick</td>
			<td>Hobby shop</td>
			<td></td>
			<td>Example includes Spectrum Black Opal by Spectrum Glass (http://www.delphiglass.com/spectrum-glass/opalescent/spectrum-black-opal)</td>
		</tr>
		<tr>
			<td>Glass cutting tools (glass cutter, glass cutting pliers)</td>
			<td>Hobby shop</td>
			<td></td>
			<td>Examples include the Studio Pro Lightweight Running Pliers by Diamond Tech (http://www.delphiglass.com/glass-cutters-tools/pliers-nippers/studio-pro-lightweight-running-pliers) and the Studio Pro Brass Glass Cutter by Diamond Tech (http://www.delphiglass.com/glass-cutters-tools/glass-cutters/studio-pro-brass-glass-cutter). Use appropriate safety precautions when cutting glass</td>
		</tr>
		<tr>
			<td>Borosilicate glass capillary tube, unfilamented, GC120-10, OD 1.2 mm, ID 0.69 mm, length 10 cm</td>
			<td>Warner Instruments</td>
			<td>30-0042</td>
			<td></td>
		</tr>
		<tr>
			<td>Borosilicate glass capillary tube, filamented, GC120F-10, OD 1.2 mm, ID 0.69 mm, length 10 cm</td>
			<td>Warner Instruments</td>
			<td>30-0044</td>
			<td></td>
		</tr>
		<tr>
			<td>Nitric acid, 70%</td>
			<td>Sigma</td>
			<td>438073</td>
			<td>CAUTION: see Material Data Safety Sheet for appropriate storage and handling guidelines. Specific brand is not important</td>
		</tr>
		<tr>
			<td>Cimarec 7 in x 7 in hotplate</td>
			<td>Fisher</td>
			<td>11675911Q</td>
			<td>Specific brand is not important; caution when heated</td>
		</tr>
		<tr>
			<td>Selectophore dichlorodimethylsilane</td>
			<td>Sigma</td>
			<td>40136-1ML</td>
			<td>CAUTION: see Material Data Safety Sheet for appropriate storage and handling guidelines</td>
		</tr>
		<tr>
			<td>Two-step vertical pipet puller</td>
			<td>Narishige</td>
			<td>PC-10</td>
			<td>Other pipet pullers can be used; this is given as an example</td>
		</tr>
		<tr>
			<td>Glass petri dish, 150 mm diameter x 15 mm height</td>
			<td>Fisher</td>
			<td>08-748E</td>
			<td>Specific brand is not important; only one dish needed</td>
		</tr>
		<tr>
			<td>World Precision Instruments E210 1 mm micropipette storage jar</td>
			<td>Fisher</td>
			<td>50-821-852</td>
			<td>May be available from other distributors. Useful to have two jars. Note that although this jar is specified for 1 mm pipets, and the pipets used here are 1.2 mm, in our experience the 1 mm jar works best for the 1.2 mm pipets.</td>
		</tr>
		<tr>
			<td>Silica Gel, Tel-Tale Desiccant, indicating, 10-18 mesh</td>
			<td>Fisher</td>
			<td>S161-500</td>
			<td>Indicating silica useful for determining whether silica gel retains desiccating ability</td>
		</tr>
		<tr>
			<td>World Precision Instruments MicroFil, 34G</td>
			<td>Fisher</td>
			<td>50-821-914</td>
			<td>May be available from other distributors.</td>
		</tr>
		<tr>
			<td>1 ml syringe with luer lock</td>
			<td>Becton Dickinson</td>
			<td>309659</td>
			<td>May be available from other distributors.</td>
		</tr>
		<tr>
			<td>3 ml syringe with luer lock</td>
			<td>Becton Dickinson</td>
			<td>309657</td>
			<td>May be available from other distributors.</td>
		</tr>
		<tr>
			<td>D300 3-way stopcock with female luer lock inlet port, male luer outlet port with rotating collar and guard</td>
			<td>Cole-Parmer</td>
			<td>UX-30600-02</td>
			<td>Specific brand is not important</td>
		</tr>
		<tr>
			<td>Female Luer Locking Connector</td>
			<td>4 Medical Solutions</td>
			<td>ADC 9873-10</td>
			<td>Specific brand is not important; barbed end is ~4 mm at narrowest point and ~7 mm at widest point.</td>
		</tr>
		<tr>
			<td>Silicone Tubing I.D. x O.D. x Wall: 1/16 x 1/8 x 1/32 in. (1.59 x 3.18 x 0.79 mm)</td>
			<td>Fisher</td>
			<td>14-179-110</td>
			<td>Specific brand is not important</td>
		</tr>
		<tr>
			<td>E-3603 tubing, I.D. x O.D.: 1/32 x 3/32 in</td>
			<td>Fisher</td>
			<td>14171208</td>
			<td>Specific brand is not important</td>
		</tr>
		<tr>
			<td>Modeling clay</td>
			<td></td>
			<td></td>
			<td>Specific brand is not important</td>
		</tr>
		<tr>
			<td>Selectophore potassium ionophore I, cocktail B</td>
			<td>Sigma</td>
			<td>99373</td>
			<td>CAUTION: see Material Data Safety Sheet for appropriate storage and handling guidelines</td>
		</tr>
		<tr>
			<td>Selectophore sodium ionophore X</td>
			<td>Sigma</td>
			<td>71747</td>
			<td>Sodium ionphore X = 4-tert-butylcalix[4]arene-tetraacetic acid tetraethylester</td>
		</tr>
		<tr>
			<td>Selectophore 2-nitrophenyl octyl ether</td>
			<td>Sigma</td>
			<td>73732</td>
			<td></td>
		</tr>
		<tr>
			<td>Selectophore sodium tetraphenylborate</td>
			<td>Sigma</td>
			<td>72018</td>
			<td></td>
		</tr>
		<tr>
			<td>Schneider&#39;s Drosophila medium</td>
			<td>Life Technologies</td>
			<td>21720024</td>
			<td></td>
		</tr>
		<tr>
			<td>High impedance electrometer</td>
			<td>World Precision Instruments</td>
			<td>FD223a</td>
			<td></td>
		</tr>
		<tr>
			<td>Microelectrode holder 1 mm with 45&#176; body, vented, with handle</td>
			<td>Warner Instruments</td>
			<td>64-1051</td>
			<td></td>
		</tr>
		<tr>
			<td>Microelectrode holder 1 mm with straight body, vented</td>
			<td>Warner Instruments</td>
			<td>64-1007</td>
			<td></td>
		</tr>
		<tr>
			<td>Silver wire</td>
			<td>Warner Instruments</td>
			<td>64-1318</td>
			<td></td>
		</tr>
		<tr>
			<td>Micromanipulators, pair</td>
			<td>Leitz</td>
			<td></td>
			<td>Various brands/models will work; this is an example</td>
		</tr>
		<tr>
			<td>Faraday cage</td>
			<td>Technical Manufacturing Corporation</td>
			<td>81-334-03</td>
			<td>This is an example; any Faraday cage will work</td>
		</tr>
		<tr>
			<td>Single gooseneck fiberoptic light</td>
			<td>Nikon</td>
			<td></td>
			<td>Specific brand is not important</td>
		</tr>
		<tr>
			<td>mineral oil</td>
			<td>Fisher</td>
			<td>BP-2629</td>
			<td>Specific brand is not important</td>
		</tr>
		<tr>
			<td>forceps, Dumont #5 with Biologie tip</td>
			<td>Fine Science Tool</td>
			<td>11295-10</td>
			<td>May be available from other distributors.</td>
		</tr>
	</tbody>
</table>

use of the ramsay assay to measure fluid secretion and ion flux rates in the drosophila melanogaster malpighian tubule

腎上皮イオン輸送の調節は、生物が外部条件の変化の顔にイオン性および浸透圧の恒常性を維持することができます。 キイロショウジョウバエマルピーギ（腎臓）細管が原因でこの生物の強力な遺伝学と生理学的研究への尿細管のアクセスに、上皮のイオン輸送の分子メカニズムを研究するための比類のない機会を提供しています。ここで、我々は、分泌液中のナトリウム及びカリウムの濃度を測定するために、イオン特異的電極を使用して、単離されたフライ尿細管からの流体の分泌速度を測定するためラムゼイアッセイの使用を記載しています。このアッセイは、イオン濃度を測定するための別の装置に分泌液を転送する必要なく、一度に20〜細管の上皮の流体及びイオンフラックスの研究を可能にします。遺伝的に異なる細管は、輸送プロセスにおける特定の遺伝子の役割を評価するために分析することができます。また、Bathing生理食塩水を添加し、その化学的性質、または薬物またはホルモンの影響を調べるために改変することができます。要約すると、この技術は、基本的なショウジョウバエの細管上皮イオン輸送機構、ならびにこれらの輸送メカニズムの規制の分子特徴づけを可能にします。

図7、図8、K +およびNa +濃度を測定するために、イオン特定電極とラムゼイアッセイの使用を示す遺伝的および薬理学的に異なるK +およびNa +フラックス 、単独の流体分泌速度を測定することにより、捕捉されない情報を区別することができます。 図 Na +フラックスが（ 図7B）に変更されていない間NKCCにおけるホ?...

Watch this Scientific Journal Video about Use of the Ramsay Assay to Measure Fluid Secretion and Ion Flux Rates in the Drosophila melanogaster Malpighian Tubule at JoVE.com

Use of the Ramsay Assay to Measure Fluid Secretion and Ion Flux Rates in the Drosophila melanogaster Malpighian Tubule

このプロトコルは、 キイロショウジョウバエから単離しマルピーギ（腎）細管からの流体分泌速度を測定するためのラムゼイアッセイの使用を記載しています。また、イオン特異的電極の使用は、経上皮イオンフラックスの計算を可能にする、分泌液中のナトリウム及びカリウムの濃度を測定するために、記載されています。

で液分泌とイオンフラックス速度を測定するためのラムゼイアッセイの使用<em&gt;キイロショウジョウバエ</em&gt;マルピーギ管

Modulation of renal epithelial ion transport allows organisms to maintain ionic and osmotic homeostasis in the face of varying external conditions. The ...

use-ramsay-assay-to-measure-fluid-secretion-ion-flux-rates-drosophila

Research

JoVE Journal

Biology

Use of the Ramsay Assay to Measure Fluid Secretion and Ion Flux Rates in the Drosophila melanogaster Malpighian Tubule

11.7K ビュー.  University of Texas Southwestern Medical Center. このプロトコルは、 キイロショウジョウバエから単離しマルピーギ（腎）細管からの流体分泌速度を測定するためのラムゼイアッセイの使用を記載しています。また、イオン特異的電極の使用は、経上皮イオンフラックスの計算を可能にする、分泌液中のナトリウム及びカリウムの濃度を測定するために、記載されています。 

ビデオ: Use of the Ramsay Assay to Measure Fluid Secretion and Ion Flux Rates in the Drosophila melanogaster Malpighian Tubule

Microinjection Techniques for Studying Mitosis in the Drosophila melanogaster Syncytial Embryo

This protocol describes the use of the Drosophila melanogaster syncytial embryo for studying mitosis1. Drosophila has useful genetics with a sequenced genome, and it can be easily maintained and manipulated. Many mitotic mutants exist, and transgenic flies expressing functional fluorescently (e.g. GFP) - tagged mitotic proteins have been and are being generated. Targeted gene expression is possible using the GAL4/UAS system2. 

The Drosophila early embryo carries out multiple mitoses very rapidly (cell cycle duration, &asymp;10 min). It is well suited for imaging mitosis, because during cycles 10-13, nuclei divide rapidly and synchronously without intervening cytokinesis at the surface of the embryo in a single monolayer just underneath the cortex. These rapidly dividing nuclei probably use the same mitotic machinery as other cells, but they are optimized for speed; the checkpoint is generally believed to not be stringent, allowing the study of mitotic proteins whose absence would cause cell cycle arrest in cells with a strong checkpoint. Embryos expressing GFP labeled proteins or microinjected with fluorescently labeled proteins can be easily imaged to follow live dynamics (Fig. 1). In addition, embryos can be microinjected with function-blocking antibodies or inhibitors of specific proteins to study the effect of the loss or perturbation of their function3. These reagents can diffuse throughout the embryo, reaching many spindles to produce a gradient of concentration of inhibitor, which in turn results in a gradient of defects comparable to an allelic series of mutants. Ideally, if the target protein is fluorescently labeled, the gradient of inhibition can be directly visualized4. It is assumed that the strongest phenotype is comparable to the null phenotype, although it is hard to formally exclude the possibility that the antibodies may have dominant effects in rare instances, so rigorous controls and cautious interpretation must be applied. Further away from the injection site, protein function is only partially lost allowing other functions of the target protein to become evident.

Microinjection Techniques for Studying Mitosis in the Drosophila melanogaster Syncytial Embryo

This protocol describes the use of microinjection and high resolution imaging in the Drosophila melanogaster syncytial embryo to study mitosis.

に有糸分裂研究のためのマイクロインジェクション技術キイロショウジョウバエ合胞体胚

This protocol describes the use of the Drosophila melanogaster syncytial embryo  for studying mitosis1.  Drosophila has useful genetics with a sequenced ...

生物学

Photobleaching Assays (FRAP &amp; FLIP) to Measure Chromatin Protein Dynamics in Living Embryonic Stem Cells

Fluorescence Recovery After Photobleaching (FRAP) and Fluorescence Loss In Photobleaching (FLIP) enable the study of protein dynamics in living cells with good spatial and temporal resolution. Here we describe how to perform FRAP and FLIP assays of chromatin proteins, including H1 and HP1, in mouse embryonic stem (ES) cells. In a FRAP experiment, cells are transfected, either transiently or stably, with a protein of interest fused with the green fluorescent protein (GFP) or derivatives thereof (YFP, CFP, Cherry, etc.). In the transfected, fluorescing cells, an intense focused laser beam bleaches a relatively small region of interest (ROI). The laser wavelength is selected according to the fluorescent protein used for fusion. The laser light irreversibly bleaches the fluorescent signal of molecules in the ROI and, immediately following bleaching, the recovery of the fluorescent signal in the bleached area - mediated by the replacement of the bleached molecules with the unbleached molecules - is monitored using time lapse imaging. The generated fluorescence recovery curves provide information on the protein's mobility. If the fluorescent molecules are immobile, no fluorescence recovery will be observed. In a complementary approach, Fluorescence Loss in Photobleaching (FLIP), the laser beam bleaches the same spot repeatedly and the signal intensity is measured elsewhere in the fluorescing cell. FLIP experiments therefore measure signal decay rather than fluorescence recovery and are useful to determine protein mobility as well as protein shuttling between cellular compartments. Transient binding is a common property of chromatin-associated proteins. Although the major fraction of each chromatin protein is bound to chromatin at any given moment at steady state, the binding is transient and most chromatin proteins have a high turnover on chromatin, with a residence time in the order of seconds. These properties are crucial for generating high plasticity in genome expression1. Photobleaching experiments are therefore particularly useful to determine chromatin plasticity using GFP-fusion versions of chromatin structural proteins, especially in ES cells, where the dynamic exchange of chromatin proteins (including heterochromatin protein 1 (HP1), linker histone H1 and core histones) is higher than in differentiated cells2,3.

Photobleaching Assays FRAP &amp; FLIP to Measure Chromatin Protein Dynamics in Living Embryonic Stem Cells

We describe photobleaching methods including Fluorescence Recovery After Photobleaching (FRAP) and Fluorescence Loss In Photobleaching (FLIP) to monitor chromatin protein dynamics in embryonic stem (ES) cells. Chromatin protein dynamics, which is considered to be one of the means to study chromatin plasticity, is enhanced in pluripotent cells.

胚性幹細胞を生体内でクロマチン蛋白質のダイナミクスを測定するアッセイ（FRAP＆FLIP）を光退色

Fluorescence Recovery After Photobleaching (FRAP) and Fluorescence Loss In Photobleaching (FLIP) enable the study of protein dynamics in living cells with ...

Insulin Injection and Hemolymph Extraction to Measure Insulin Sensitivity in Adult Drosophila melanogaster

Conserved nutrient sensing mechanisms exist between mammal and fruit fly where peptides resembling mammalian insulin and glucagon, respectively function to maintain glucose homeostasis during developmental larval stages 1,2. Studies on largely post-mitotic adult flies have revealed perturbation of glucose homeostasis as the result of genetic ablation of insulin-like peptide (ILP) producing cells (IPCs) 3. Thus, adult fruit flies hold great promise as a suitable genetic model system for metabolic disorders including type II diabetes. To further develop the fruit fly system, comparable physiological assays used to measure glucose tolerance and insulin sensitivity in mammals must be established. To this end, we have recently described a novel procedure for measuring oral glucose tolerance response in the adult fly and demonstrated the importance of adult IPCs in maintaining glucose homeostasis 4,5. Here, we have modified a previously described procedure for insulin injection 6 and combined it with a novel hemolymph extraction method to measure peripheral insulin sensitivity in the adult fly. Uniquely, our protocol allows direct physiological measurements of the adult fly's ability to dispose of a peripheral glucose load upon insulin injection, a methodology that makes it feasible to characterize insulin signaling mutants and potential interventions affecting glucose tolerance and insulin sensitivity in the adult fly.

Insulin Injection and Hemolymph Extraction to Measure Insulin Sensitivity in Adult Drosophila melanogaster

Conserved insulin signaling pathways found in the fruit fly Drosophila melanogaster make this organism a potential tool for modeling metabolic disorders including type II diabetes. To this end, it is critical to establish physiological assays to effectively measure systemic insulin action in peripheral glucose disposal in the adult fly.

インスリン注射と成人のインスリン感受性を測定する血リンパの抽出キイロショウジョウバエ</em

Conserved nutrient sensing mechanisms exist between mammal and fruit fly where peptides resembling mammalian insulin and glucagon, respectively function ...

Measurement of Lifespan in Drosophila melanogaster

Aging is a phenomenon that results in steady physiological deterioration in nearly all organisms in which it has been examined, leading to reduced physical performance and increased risk of disease. Individual aging is manifest at the population level as an increase in age-dependent mortality, which is often measured in the laboratory by observing lifespan in large cohorts of age-matched individuals. Experiments that seek to quantify the extent to which genetic or environmental manipulations impact lifespan in simple model organisms have been remarkably successful for understanding the aspects of aging that are conserved across taxa and for inspiring new strategies for extending lifespan and preventing age-associated disease in mammals.
The vinegar fly, Drosophila melanogaster, is an attractive model organism for studying the mechanisms of aging due to its relatively short lifespan, convenient husbandry, and facile genetics. However, demographic measures of aging, including age-specific survival and mortality, are extraordinarily susceptible to even minor variations in experimental design and environment, and the maintenance of strict laboratory practices for the duration of aging experiments is required. These considerations, together with the need to practice careful control of genetic background, are essential for generating robust measurements. Indeed, there are many notable controversies surrounding inference from longevity experiments in yeast, worms, flies and mice that have been traced to environmental or genetic artifacts1-4. In this protocol, we describe a set of procedures that have been optimized over many years of measuring longevity in Drosophila using laboratory vials. We also describe the use of the dLife software, which was developed by our laboratory and is available for download (<a href="http://sitemaker.umich.edu/pletcherlab/software">http://sitemaker.umich.edu/pletcherlab/software</a>). dLife accelerates throughput and promotes good practices by incorporating optimal experimental design, simplifying fly handling and data collection, and standardizing data analysis. We will also discuss the many potential pitfalls in the design, collection, and interpretation of lifespan data, and we provide steps to avoid these dangers.

Measurement of Lifespan in Drosophila melanogaster

Drosophila melanogaster is a powerful model organism for exploring the molecular basis of longevity regulation. This protocol will discuss the steps involved in generating a reproducible, population-based measurement of longevity as well as potential pitfalls and how to avoid them.

における寿命の測定<em&gt;キイロショウジョウバエ</em

Aging is a phenomenon that results in steady physiological deterioration in nearly all organisms in which it has been examined, leading to reduced ...

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  ...

Imaging Through the Pupal Case of Drosophila melanogaster

The longstanding use of Drosophila as a model for cell and developmental biology has yielded an array of tools. Together, these techniques have enabled analysis of cell and developmental biology from a variety of methodological angles. Live imaging is an emerging method for observing dynamic cell processes, such as cell division or cell motility. Having isolated mutations in uncharacterized putative cell cycle proteins it became essential to observe mitosis in situ using live imaging. Most live imaging studies in Drosophila have focused on the embryonic stages that are accessible to manipulation and observation because of their small size and optical clarity. However, in these stages the cell cycle is unusual in that it lacks one or both of the gap phases. By contrast, cells of the pupal wing of Drosophila have a typical cell cycle and undergo a period of rapid mitosis spanning about 20 hr of pupal development. It is easy to identify and isolate pupae of the appropriate stage to catch mitosis in situ. Mounting intact pupae provided the best combination of tractability and durability during imaging, allowing experiments to run for several hours with minimal impact on cell and animal viability. The method allows observation of features as small as, or smaller than, fly chromosomes. Adjustment of microscope settings and the details of mounting, allowed extension of the preparation to visualize membrane dynamics of adjacent cells and fluorescently labeled proteins such as tubulin. This method works for all tested fluorescent proteins and can capture submicron scale features over a variety of time scales. While limited to the outer 20 &#181;m of the pupa with a conventional confocal microscope, this approach to observing protein and cellular dynamics in pupal tissues in vivo may be generally useful in the study of cell and developmental biology in these tissues.

Imaging Through the Pupal Case of Drosophila melanogaster

This paper demonstrates the use of a fast scanning confocal microscope to image cell behavior directly through the puparium. By leaving the pupal case intact, this method allows observation and measurement of dynamic cell processes at a stage of Drosophila development that is difficult to study directly.

の蛹ケースを画像化<em&gt;キイロショウジョウバエ</em

The longstanding use of Drosophila as a model for cell and developmental biology has yielded an array of tools. Together, these techniques have enabled ...

Quantitative Immunofluorescence Assay to Measure the Variation in Protein Levels at Centrosomes

Centrosomes are small but important organelles that serve as the poles of mitotic spindle to maintain genomic integrity or assemble primary cilia to facilitate sensory functions in cells. The level of a protein may be regulated differently at centrosomes than at other .cellular locations, and the variation in the centrosomal level of several proteins at different points of the cell cycle appears to be crucial for the proper regulation of centriole assembly. We developed a quantitative fluorescence microscopy assay that measures relative changes in the level of a protein at centrosomes in fixed cells from different samples, such as at different phases of the cell cycle or after treatment with various reagents. The principle of this assay lies in measuring the background corrected fluorescent intensity corresponding to a protein at a small region, and normalize that measurement against the same for another protein that does not vary under the chosen experimental condition. Utilizing this assay in combination with BrdU pulse and chase strategy to study unperturbed cell cycles, we have quantitatively validated our recent observation that the centrosomal pool of VDAC3 is regulated at centrosomes during the cell cycle, likely by proteasome-mediated degradation specifically at centrosomes.

Here, a novel quantitative fluorescence assay is developed to measure changes in the level of a protein specifically at centrosomes by normalizing that protein&#8217;s fluorescence intensity to that of an appropriate internal standard.

中心体におけるタンパク質レベルの変化を測定するための定量的免疫蛍光アッセイ

Centrosomes are small but important organelles that serve as the poles of mitotic spindle to maintain genomic integrity or assemble primary cilia to ...

Optical Quantification of Intracellular pH in Drosophila melanogaster Malpighian Tubule Epithelia with a Fluorescent Genetically-encoded pH Indicator

Epithelial ion transport is vital to systemic ion homeostasis as well as maintenance of essential cellular electrochemical gradients. Intracellular pH (pHi) is influenced by many ion transporters and thus monitoring pHi is a useful tool for assessing transporter activity. Modern Genetically Encoded pH-Indicators (GEpHIs) provide optical quantification of pHi in intact cells on a cellular and subcellular scale. This protocol describes real-time quantification of cellular pHi regulation in Malpighian Tubules (MTs) of Drosophila melanogaster through ex vivo live-imaging of pHerry, a pseudo-ratiometric GEpHI with a pKa well-suited to track pH changes in the cytosol. Extracted adult fly MTs are composed of morphologically and functionally distinct sections of single-cell layer epithelia, and can serve as an accessible and genetically tractable model for investigation of epithelial transport. GEpHIs offer several advantages over conventional pH-sensitive fluorescent dyes and ion-selective electrodes. GEpHIs can label distinct cell populations provided appropriate promoter elements are available. This labeling is particularly useful in ex vivo, in vivo, and in situ preparations, which are inherently heterogeneous. GEpHIs also permit quantification of pHi in intact tissues over time without need for repeated dye treatment or tissue externalization. The primary drawback of current GEpHIs is the tendency to aggregate in cytosolic inclusions in response to tissue damage and construct over-expression. These shortcomings, their solutions, and the inherent advantages of GEpHIs are demonstrated in this protocol through assessment of basolateral proton (H+) transport in functionally distinct principal and stellate cells of extracted fly MTs. The techniques and analysis described are readily adaptable to a wide variety of vertebrate and invertebrate preparations, and the sophistication of the assay can be scaled from teaching labs to intricate determination of ion flux via specific transporters.

Optical Quantification of Intracellular pH in Drosophila melanogaster Malpighian Tubule Epithelia with a Fluorescent Genetically-encoded pH Indicator

Cellular ion transport can often be assessed by monitoring intracellular pH (pHi). Genetically Encoded pH-Indicators (GEpHIs)&#160;provide optical quantification of intracellular pH in intact cells. This protocol details the quantification of intracellular pH through cellular ex vivo live-imaging of Malpighian tubules of Drosophila melanogaster with pHerry, a pseudo-ratiometric genetically encoded pH-indicator.

蛍光遺伝子にコードされた pH インジケーターとキイロショウジョウバエのマルピギー氏管の上皮細胞で光の定量化の細胞内 pH

Epithelial ion transport is vital to systemic ion homeostasis as well as maintenance of essential cellular electrochemical gradients. Intracellular pH ...

Oral Bacterial Infection and Shedding in Drosophila melanogaster

The fruit fly Drosophila melanogaster is one of the best developed model systems of infection and innate immunity. While most work has focused on systemic infections, there has been a recent increase of interest in the mechanisms of gut immunocompetence to pathogens, which require methods to orally infect flies. Here we present a protocol to orally expose individual flies to an opportunistic bacterial pathogen (Pseudomonas aeruginosa) and a natural bacterial pathogen of D. melanogaster (Pseudomonas entomophila). The goal of this protocol is to provide a robust method to expose male and female flies to these pathogens. We provide representative results showing survival phenotypes, microbe loads, and bacterial shedding, which is relevant for the study of heterogeneity in pathogen transmission. Finally, we confirm that Dcy mutants (lacking the protective peritrophic matrix in the gut epithelium) and Relish mutants (lacking a functional immune deficiency (IMD) pathway), show increased susceptibility to bacterial oral infection. This protocol, therefore, describes a robust method to infect flies using the oral route of infection, which can be extended to the study of a variety genetic and environmental sources of variation in gut infection outcomes and bacterial transmission.

Oral Bacterial Infection and Shedding in Drosophila melanogaster

This protocol describes methods to orally expose and infect the fruit fly Drosophila melanogaster with bacterial pathogens, and to measure the number of infectious bacteria shed following gut infection. We further describe the effect of immune mutants on fly survival following oral bacterial infection.

口腔の細菌感染とキイロショウジョウバエの開口

The fruit fly Drosophila melanogaster is one of the best developed model systems of infection and innate immunity. While most work has focused on systemic ...

Visualizing and Tracking Endogenous mRNAs in Live Drosophila melanogaster Egg Chambers

Fluorescence-based imaging techniques, in combination with developments in light microscopy, have revolutionized how cell biologists conduct live cell imaging studies. Methods for detecting RNAs have expanded greatly since seminal studies linked site-specific mRNA localization to gene expression regulation. Dynamic mRNA processes can now be visualized via approaches that detect mRNAs, coupled with microscopy set-ups that are fast enough to capture the dynamic range of molecular behavior. The molecular beacon technology is a hybridization-based approach capable of direct detection of endogenous transcripts in living cells. Molecular beacons are hairpin-shaped, internally quenched, single-nucleotide discriminating nucleic acid probes, which fluoresce only upon hybridization to a unique target sequence. When coupled with advanced fluorescence microscopy and high-resolution imaging, they enable one to perform spatial and temporal tracking of intracellular movement of mRNAs. Although this technology is the only method capable of detecting endogenous transcripts, cell biologists have not yet fully embraced this technology due to difficulties in designing such probes for live cell imaging. A new software application, PinMol, allows for enhanced and rapid design of probes best suited to efficiently hybridize to mRNA target regions within a living cell. In addition, high-resolution, real-time image acquisition and current, open source image analysis software allow for a refined data output, leading to a finer evaluation of the complexity underlying the dynamic processes involved in the mRNA&#39;s life cycle.
Here we present a comprehensive protocol for designing and delivering molecular beacons into Drosophila melanogaster egg chambers. Direct and highly specific detection and visualization of endogenous maternal mRNAs is performed via spinning disc confocal microscopy. Imaging data is processed and analyzed using object detection and tracking in Icy software to obtain details about the dynamic movement of mRNAs, which are transported and localized to specialized regions within the oocyte.

Visualizing and Tracking Endogenous mRNAs in Live Drosophila melanogaster Egg Chambers

Here, we present a protocol for the visualization, detection, analysis and tracking of endogenous mRNA trafficking in live Drosophila melanogaster egg chamber using molecular beacons, spinning disc confocal microscopy, and open-source analysis software.

ライブショウジョウバエメラノガスター卵室における内因性mRNAの可視化と追跡

Fluorescence-based imaging techniques, in combination with developments in light microscopy, have revolutionized how cell biologists conduct live cell ...