ベルナール ・ Kulemaka とサム ・ コネルとブレント レッドフォード 3i ゼブラフィッシュ ケアのため画像の質問とデボラ ビッグバン カレン耳を傾ける、ケイ ・ スチュワートの守備のための有用なコメントと試薬指導、スミス研究室のメンバーに感謝しますこの作品は、ゼブラフィッシュ研究幹細胞のセンターとノートルダム大学とノートルダム大学で再生医療のノートルダム大学、エリザベスとマイケル ・ ギャラガー家族、アルフレッド ・ p. スローン財団、センターによって支えられました。大聖堂。すべての動物の研究は、博士コーディ スミスに IACUC ノートルダム大学に準拠して行われました。

すべての動物の研究は、ノートルダム大聖堂機関動物ケアおよび使用委員会の大学によって承認されました。
1. ゼブラフィッシュ標本の作製
<ol><li>標準的な手順13あたり交尾商工会議所にオス一匹と 1 つアダルト女性 Tg (転換タンパク質) を配置します。本稿では、Tg(sox10:eos) 魚9アクセスが蛍光蛋白質と他の形質転換線を同様に使用することができますを使用します。魚では、配置を行う場合に 1 つ以上の区域を設定します。一晩部屋のままに魚を許可します。</li>
	<li>次の朝は、100 mm のペトリ皿に卵を収集します。上映前に卵を成熟させ 24 時間後受精 (hpf) を許可します。</li>
	<li>上記の動物の遺伝子のヘテロ接合体なら、Tg(sox10:eos) + 488 nm 光源と GFP と胚の画面 24 hpf 料理は解剖顕微鏡のセットをフィルターします。Tg(sox10:eos) + 胚を分離でき、48 に成熟する hpf。</li>
	<li>針やピンセットを使って手動で Dechorionate 胚。</li>
	<li>準備、0.8% 低溶解点アガロース溶液の 5 mL を電子レンジします。<ol>
<li>Agarose が touch にクール、場所 3-4 麻酔 Tg (sox10:eos) +48 10 mm のガラス基板の中央に hpf 魚底シャーレ。</li>
		<li>カバーガラス、約 1 mL の表面をカバーする十分な agarose を追加します。探針を使用すると、その両側に魚を配置できます。動物の取付を確実に固めるための agarose を許可します。寒天の凝固14まで、ゼブラフィッシュを継続的に再配置する必要があります。凝固は約 2 分です。</li>
	</ol>
</li>
	<li>2 分の agarose が凝固した後、ゆっくりと胚培 0.02% アミノ安息香酸エステル (Tricaine) 寒天や皿の底面を水中まで皿を追加します。これは、約 3 mL をする必要があります。</li>
</ol>2. 顕微鏡取り付けと事前変換イメージング
<ol><li>共焦点ソフトウェアを開き、キャプチャ、フォーカス ウィンドウ [図 1] を選択します。キャプチャ ウィンドウの下には、[キャプチャ設定] タブ [図 1] ドロップダウン ラボ固有の変換イメージング設定を選択します。ここでは、ラボ固有の設定「魚イメージングします」と呼びます</li>
	<li>共焦点範囲に試験片を置き、コースと微調整ノブを使用してフォーカスに。</li>
	<li>フォーカス ウィンドウを開き、興味 (すなわち後根神経節) の目的の地域を探します。</li>
	<li>C488 レーザー フィルターを設定] メニューの [を選択します。300 ms に露出を設定、5、パワー、75 [図 2] に強化します。</li>
	<li>キャプチャの種類] セクションの [3 D] ボックスを確認します。[ 3 D キャプチャ] セクションで、現在の位置を使用してを選択し、電流のまわりの範囲をチェックします。同じセクションの範囲を 35、36、飛行機と 1 ステップ サイズの数に設定します。範囲を増加またはイメージング領域の深さに対応して縮小することができます。脊髄の間 35-40 スタック範囲の値は通常、[図 5] は。</li>
	<li>[図 5] の現在の場所を選択します。</li>
	<li>画像を取得するには、[キャプチャ] ウィンドウの下部に [開始。</li>
</ol>3. 単一セルの光電
<ol><li>共焦点ソフトウェアを開き、キャプチャ、フォーカス ウィンドウ [図 1] を選択します。キャプチャ ウィンドウの下には、[キャプチャ設定] タブ [図 1] ドロップダウン ラボ固有の変換イメージング設定を選択します。ここでは、ラボ固有の設定は「魚は全チップを切除」と呼ばれる</li>
	<li>C488 c541 レーザー フィルターを設定] メニューの [を選択します。同じ顕微鏡のソフトウェアを使用していない場合、は、別のレーザーと選択、488 nm と 541 nm のレーザーを選択するメニューを見つけます。300 ms への露出を設定、5、パワー、75 [図 2] に強化します。これらのレーザーの設定は、退色または毒性を引き起こすことがなく十分な蛍光シグナルを生成に基づいて選択されます。毒性や退色が視覚化されるレーザー パワーや露出を減らします。</li>
	<li>フォーカス ウィンドウを開き、フォーカス ウィンドウの [photomanipulation] タブをクリックします。レーザーのパラメーターを調整します。2、スタックのレーザー出力を変更しをクリックしてGo。ラスター ブロック サイズを 1 に変更し、設定をクリックします。ダブルクリックしてサイズを 4 に変更します。レーザー ラインを v405 に変更 [図 3]。</li>
	<li>キャプチャ ウィンドウの高度なキャプチャ設定を開きます。[Photomanipulation] タブを選択し、ダブルクリックして繰り返しを 2 に変更します。[図 4] [ok] をクリックします。</li>
	<li>フォーカス ウィンドウで、[XY] タブを選択します。[図 3,図 4] の [photomanipulation] タブで手順 2 からレーザーのパラメーターを再確認してください。Photoconvert なく周囲のセルの光電細胞にレーザーの設定を設定します。<ol>
<li>隣接するセルの光電が存在する場合は、レーザー出力を下げます。セルの光電が発生しない場合は、レーザーを増やすことができます。最適な photoconvert 興味のない周辺地域のみにレーザーの出力を設定します。</li>
	</ol>
</li>
	<li>タイムラプスをオンにすると、下の種類をキャプチャします。[図 6A] を開始をクリックします。</li>
	<li>ライブ タイムラプス ウィンドウが開いたら、[図 7] の上部のツールバーで、[円] ツールを選択します。</li>
	<li>セルの中央地域で円を描きます。引かれた円を右クリックして、 FRAP 地域を選択し、3 秒間待ちます。選択した領域は暗くなるべき [図 8]。キャプチャを停止をクリックします。</li>
	<li>1 つ以上の動物をイメージングする場合フォーカス メニューと選択位置 2 [XY] タブに戻ります。手順 4.1 4.6 を繰り返します。</li>
	<li>セルの人口を変換するには、手順 4.1 4.4 FRAP 関心領域は、線ツールを使用して円を描くのではなくのプロトコルおよびレーザーのパラメーターします。関心領域に直線を描くし、上記の同じパラメーターを使用して、領域を FRAP します。</li>
</ol>4. ポスト光電イメージング
<ol><li>すべてのポイントが photoconverted です。Precoversion イメージング手順 3 に記載されている設定ラボ固有の標準画像のスタックを選択します。これは、キャプチャ キャプチャ ウィンドウ [図 5] タブのドロップダウンの設定下にあります。</li>
	<li>C488 レーザーを選択し ms に露出を設定、5、パワー、75 [図 2] に強化します。</li>
	<li>C488 レーザーと同じメニューの下にある c541 レーザーを選択します。500 ms に露出を設定、レーザーの電源を 10、および 75 [図 9] を強化します。</li>
	<li>キャプチャの種類] セクションの [3 D] ボックスを確認します。[ 3 D キャプチャ] セクションで、現在の位置を使用してを選択し、電流のまわりの範囲をチェックします。同じセクションの範囲を 35、36、飛行機と 1 ステップ サイズの数に設定します。増加または [図 5] 希望のイメージング深さに合わせて減少する範囲数。</li>
	<li>XY フォーカス] タブで複数のポイントがある場合は、キャプチャ ウィンドウでマルチポイント リスト オプションを選択します。ない場合は、現在の場所を選択します。</li>
	<li>画像を取得するには、[キャプチャ] ウィンドウの下部に [開始。</li>
</ol>

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複雑な組織の種類セルは特定のドメインに整理します。最近の技術はこれらの大規模な組織の構造の1,2,の3の内で個々 のセルをラベルに利用されています。単一細胞の相互作用および複雑な組織内で細胞人口の相互作用を視覚化する同様に利用できる 2 つの手法を示します。光電技術の利点は、科学者はセルをはっきりと...

複数の異なる細胞が複雑な動物や植物の組織の維持・構築に対話します。これらの細胞は、インターカ レートとティッシュの固定を必要とする高分解能顕微鏡なしの単一セルのレベルで近所の人から区別することは困難。しかし、どのようにこれらの組織フォームを理解、維持、病気になるには、組織内の単一のセルを調べることが不可欠がされて時間をかけて相互作用しています。理想的には、これらの実験は、固定する必要がなく非侵襲的な方法で組織内の単一セルのラベルを必要とします。科学者は今この作業1,2,3、4を達成するために多数の技術を開発しました。
発見とクラ ゲの緑色蛍光タンパク質 (GFP) の実装は、組織環境1の異なるセルのラベルの 1 つの刺激的なアプローチだった。細胞特異的発現プロモーターを使用して、それは遺伝子1のラベルが付いているセルのサブセットを選択することが可能です。また、GFP3,4のユーザー選択式の GFP の発現するウイルスを利用できます。GFP 発現の遺伝的媒介が; 組織における細胞のサブセットの内でユーザーが選択した式を許可しませんが、非常に便利でき、GFP のウイルス発現が有利な侵襲的です。単一細胞および複雑な組織2,でそれらの間の相互作用を視覚化することが可能なっている GFP 誘導体および Brainbow 組織内よりまばら異なる蛍光蛋白質を表現するような巧妙な技術の出現で、5します。 ただし、これらのアプローチがランダムな方法で細胞をラベルします。目的の実験には、単一細胞の可視化や実験者によって定義されているセルの人口が必要とする場合そのため制限されます。そのような実験と区別する単一のセル方式で操作できる遺伝子発現蛍光タンパク質を持っているに有利であろう他の蛍光・非蛍光性の細胞から。
この目標を達成するため、複雑な生体組織内の単一セルの細胞生物学を視覚化は、科学的なコミュニティは、異なる蛍光タンパク質6,7,8の単一セルの光電を使用します。緑から赤の蛍光状態紫外線にさらされたときに移行蛍光蛋白質 (すなわち、eos、楓等) の表現を制御する遺伝子を使用して (488 nm) 光、我々 は蛍光に分類されたからの単一のセルを区別できます。隣人6,7,8。このアプローチは、回折限界領域にレーザー スタックからライトを指示することができます私たちの共焦点の顕微鏡に接続されている装置を利用しています。この手法により、我々 はどちらか単一セルまたはユーザー定義の方法9,10,11より大きい人口ラベルできます。手法は、ウイルス ・ GFP の単一細胞注射に比べて低侵襲です。Photoconvert 末梢神経系と脊髄9,10の腹側に位置する細胞のようなより大きい人口を photoconvert 神経節内の単一細胞ことを示して我々 の概念の証拠として 11,12。彼らの動きや開発中に分化に洞察力を得るためにこれら photoconverted のセル人口 24 h 後、視覚化できます。

<table border="0" cellpadding="0" cellspacing="0" width="1846">
	<tbody>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt;width:320pt" width="427">Tg(sox10:eos) zebrafish animals</td>
			<td style="width:125pt" width="167"></td>
			<td style="width:85pt" width="113"></td>
			<td style="width:854pt" width="1139">Fish were obtained and crossed from the fish facility at the University of Notre Dame</td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">100 X 15 mm petri dish</td>
			<td>VWR</td>
			<td>25384-302</td>
			<td></td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">Embryo medium</td>
			<td></td>
			<td></td>
			<td>Embryo medium is made weekly and provided by the fish facility at the University of Notre Dame containing 5L RO water, 30uL methylene blue, and 200mL salt stock.</td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">0.8% Low Melting Point Agarose</td>
			<td>dot scientific inc</td>
			<td>9012-36-6</td>
			<td></td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">35 X 10 mm glass-coverslip bottom petri dish</td>
			<td>Ted Pella Inc.</td>
			<td>14021-20</td>
			<td></td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">Needle dissecting probe</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">0.002% 3-aminobenzoic acid ester (Tricaine)</td>
			<td>Fluka analytical</td>
			<td>A5040-250G</td>
			<td></td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">Fluorescent Dissecting Microscope with GFP filters</td>
			<td>Zeiss Axiozoom</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">Confocal microscope with lasers to excite GFP and RFP filter sets</td>
			<td>3i spinning disk confocal</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">UV light source (laser) for photoconversion</td>
			<td>405 nm laser</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">Slidebook software</td>
			<td>3i</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21" style="height:15.75pt">
			<td height="21" style="height:15.75pt">Methylene blue</td>
			<td>Kordon</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

single-cell photoconversion in living intact zebrafish

動物や植物の組織細胞の異なる集団で構成されます。これらの細胞と組織を維持・構築に時間をかけて対話中断されるとき病気を引き起こすことができます。科学者は、細胞のサブセットに蛍光蛋白質を表現することによって特徴とそのまま組織内でこれらの細胞の自然動態を調査するためのテクニックを開発しました。しかし、時は、実験は時単一細胞または細胞の人口のように、組織内の細胞より選択した可視化する必要があります。科学者はこれを実現し、セルの人口内の単一のセルを可視化する蛍光タンパク質の単一セルの光電を活用しています。このテクニックを示すためには、方法を示しますここをそのまま、興味の Eos を表現する細胞に UV ライトを指示するゼブラフィッシュの生活します。私たちは、どのように彼らは組織の変更を確認するそれらの photoconverted Eos+セル 24 時間後をイメージします。二つの手法: 単一セルの光電とセルの人口の photoconversions。これらの技術は、細胞間相互作用、細胞運命と分化、細胞移動、作りそれ多数の生物的質問に適用する技術を視覚化する使用できます。

組織6内の個別のセルにラベルを付けるには、蛍光タンパク質の光変換を使用できます。これを示すには、 Tg(sox10:eos)魚9 sox10の規制のシーケンス下の蛍光蛋白質 Eos を表現する使用されました。48 Tg(sox10:eos)動物 hpf が最初にマウントされていると、可能性があります任意の非特異的光電検出イメージを作成します?...

Watch this Scientific Journal Video about Single-cell Photoconversion in Living Intact Zebrafish at JoVE.com

Single-cell Photoconversion in Living Intact Zebrafish

ここでは、蛍光蛋白質、Eos、生きている動物の表現する特定の領域に紫外線暴露により光電セルを達成する方法を表示するためのプロトコルを提案する.

生活そのままゼブラフィッシュの単一セルの光電

Animal and plant tissue is composed of distinct populations of cells. These cells interact over time to build and maintain the tissue and can cause ...

single-cell-photoconversion-in-living-intact-zebrafish

Research

JoVE Journal

Developmental Biology

5.9K ビュー.  University of Notre Dame. ここでは、蛍光蛋白質、Eos、生きている動物の表現する特定の領域に紫外線暴露により光電セルを達成する方法を表示するためのプロトコルを提案する.

ビデオ: Single-cell Photoconversion in Living Intact Zebrafish

Measuring Protein Stability in Living Zebrafish Embryos Using Fluorescence Decay After Photoconversion (FDAP)

Protein stability influences many aspects of biology, and measuring the clearance kinetics of proteins can provide important insights into biological systems. In FDAP experiments, the clearance of proteins within living organisms can be measured. A protein of interest is tagged with a photoconvertible fluorescent protein, expressed in vivo and photoconverted, and the decrease in the photoconverted signal over time is monitored. The data is then fitted with an appropriate clearance model to determine the protein half-life. Importantly, the clearance kinetics of protein populations in different compartments of the organism can be examined separately by applying compartmental masks. This approach has been used to determine the intra- and extracellular half-lives of secreted signaling proteins during zebrafish development. Here, we describe a protocol for FDAP experiments in zebrafish embryos. It should be possible to use FDAP to determine the clearance kinetics of any taggable protein in any optically accessible organism.

Measuring Protein Stability in Living Zebrafish Embryos Using Fluorescence Decay After Photoconversion FDAP

Protein levels in cells and tissues are often tightly regulated by the balance of protein production and clearance. Using Fluorescence Decay After Photoconversion (FDAP), the clearance kinetics of proteins can be experimentally measured in vivo.

光変換後の蛍光減衰を使用して生活ゼブラフィッシュ胚におけるタンパク質の安定性の測定（FDAP）

Protein stability influences many aspects of biology, and measuring the clearance kinetics of proteins can provide important insights into biological ...

発生生物学

Analysis of Zebrafish Larvae Skeletal Muscle Integrity with Evans Blue Dye

The zebrafish model is an emerging system for the study of neuromuscular disorders. In the study of neuromuscular diseases, the integrity of the muscle membrane is a critical disease determinant. To date, numerous neuromuscular conditions display degenerating muscle fibers with abnormal membrane integrity; this is most commonly observed in muscular dystrophies. Evans Blue Dye (EBD) is a vital, cell permeable dye that is rapidly taken into degenerating, damaged, or apoptotic cells; in contrast, it is not taken up by cells with an intact membrane. EBD injection is commonly employed to ascertain muscle integrity in mouse models of neuromuscular diseases. However, such EBD experiments require muscle dissection and/or sectioning prior to analysis. In contrast, EBD uptake in zebrafish is visualized in live, intact preparations. Here, we demonstrate a simple and straightforward methodology for performing EBD injections and analysis in live zebrafish. In addition, we demonstrate a co-injection strategy to increase efficacy of EBD analysis. Overall, this video article provides an outline to perform EBD injection and characterization in zebrafish models of neuromuscular disease.

In this study, we describe a straightforward method to perform Evans Blue Dye (EBD) analysis on zebrafish larvae. This technique is a powerful tool for the characterization of skeletal muscle integrity and delineation of zebrafish models of muscular dystrophy, and is a valuable method for the development of novel therapeutics.

エバンスブルー色素でゼブラフィッシュ幼生骨格筋の整合性の分析

The zebrafish model is an emerging system for the study of neuromuscular disorders.  In the study of neuromuscular diseases, the integrity of the muscle ...

Imaging Subcellular Structures in the Living Zebrafish Embryo

In vivo imaging provides unprecedented access to the dynamic behavior of cellular and subcellular structures in their natural context. Performing such imaging experiments in higher vertebrates such as mammals generally requires surgical access to the system under study. The optical accessibility of embryonic and larval zebrafish allows such invasive procedures to be circumvented and permits imaging in the intact organism. Indeed the zebrafish is now a well-established model to visualize dynamic cellular behaviors using in vivo microscopy in a wide range of developmental contexts from proliferation to migration and differentiation. A more recent development is the increasing use of zebrafish to study subcellular events including mitochondrial trafficking and centrosome dynamics. The relative ease with which these subcellular structures can be genetically labeled by fluorescent proteins and the use of light microscopy techniques to image them is transforming the zebrafish into an in vivo model of cell biology. Here we describe methods to generate genetic constructs that fluorescently label organelles, highlighting mitochondria and centrosomes as specific examples. We use the bipartite Gal4-UAS system in multiple configurations to restrict expression to specific cell-types and provide protocols to generate transiently expressing and stable transgenic fish. Finally, we provide guidelines for choosing light microscopy methods that are most suitable for imaging subcellular dynamics.

Imaging the dynamic behavior of organelles and other subcellular structures in vivo can shed light on their function in physiological and disease conditions. Here, we present methods for genetically tagging two organelles, centrosomes and mitochondria, and imaging their dynamics in living zebrafish embryos using wide-field and confocal microscopy.

リビングゼブラフィッシュ胚における細胞内構造のイメージング

In vivo imaging provides unprecedented access to the dynamic behavior of cellular and subcellular structures in their natural context. Performing such ...

Biosensing Motor Neuron Membrane Potential in Live Zebrafish Embryos

The protocols described here are designed to allow researchers to study cell communication without altering the integrity of the environment in which the cells are located. Specifically, they have been developed to analyze the electrical activity of excitable cells, such as spinal neurons. In such a scenario, it is crucial to preserve the integrity of the spinal cell, but it is also important to preserve the anatomy and physiological shape of the systems involved. Indeed, the comprehension of the manner in which the nervous system-and other complex systems-works must be based on a systemic approach. For this reason, the live zebrafish embryo was chosen as a model system, and the spinal neuron membrane voltage changes were evaluated without interfering with the physiological conditions of the embryos. 
Here, an approach combining the employment of zebrafish embryos with a FRET-based biosensor is described. Zebrafish embryos are characterized by a very simplified nervous system and are particularly suited for imaging applications thanks to their transparency, allowing for the employment of fluorescence-based voltage indicators at the plasma membrane during zebrafish development. The synergy between these two components makes it possible to analyze the electrical activity of the cells in intact living organisms, without perturbing the physiological state. Finally, this non-invasive approach can co-exist with other analyses (e.g., spontaneous movement recordings, as shown here).

Protocols described here allow for the study of the electrical properties of excitable cells in the most non-invasive physiological conditions by employing zebrafish embryos in an in vivo system together with a fluorescence resonance energy transfer (FRET)-based genetically encoded voltage indicator (GEVI) selectively expressed in the cell type of interest.

生きたゼブラフィッシュ胚における運動ニューロン膜電位のバイオセンシング

The protocols described here are designed to allow researchers to study cell communication without altering the integrity of the environment in which the ...

Induction of Hypoxia in Living Frog and Zebrafish Embryos

Here, we introduce a novel system for hypoxia induction, which we developed to study the effects of hypoxia in aquatic organisms such as frog and zebrafish embryos. Our system comprises a chamber featuring a simple setup that is nevertheless robust to induce and maintain a specific oxygen concentration and temperature in any experimental solution of choice. The presented system is very cost-effective but highly functional, it allows induction and sustainment of hypoxia for direct experiments in vivo and for various time periods up to 48 h.
To monitor and study the effects of hypoxia, we have employed two methods - measurement of levels of hypoxia-inducible factor 1alpha (HIF-1&#945;) in whole embryos or specific tissues and determination of retinal stem cell proliferation by 5-ethynyl-2&#8242;-deoxyuridine (EdU) incorporation into the DNA. HIF-1&#945; levels can serve as a general hypoxia marker in the whole embryo or tissue of choice, here embryonic retina. EdU incorporation into the proliferating cells of embryonic retina is a specific output of hypoxia induction. Thus, we have shown that hypoxic embryonic retinal progenitors decrease proliferation within 1 h of incubation under 5% oxygen of both frog and zebrafish embryos.
Once mastered, our setup can be employed for use with small aquatic model organisms, for direct in vivo experiments, any given time period and under normal, hypoxic or hyperoxic oxygen concentration or under any other given gas mixture.

We introduce a novel hypoxic chamber system for use with aquatic organisms such as frog and zebrafish embryos. Our system is simple, robust, cost-effective and allows the induction and sustainment of hypoxia in vivo and for up to 48 h. We present 2 reproducible methods to monitor the effectiveness of hypoxia.

生きた蛙およびゼブラフィッシュの胚における低酸素の誘導

Here, we introduce a novel system for hypoxia induction, which we developed to study the effects of hypoxia in aquatic organisms such as frog and ...

Following Endocardial Tissue Movements via Cell Photoconversion in the Zebrafish Embryo

During embryogenesis, cells undergo dynamic changes in cell behavior, and deciphering the cellular logic behind these changes is a fundamental goal in the field of developmental biology. The discovery and development of photoconvertible proteins have greatly aided our understanding of these dynamic changes by providing a method to optically highlight cells and tissues. However, while photoconversion, time-lapse microscopy, and subsequent image analysis have proven to be very successful in uncovering cellular dynamics in organs such as the brain or the eye, this approach is generally not used in the developing heart due to challenges posed by the rapid movement of the heart during the cardiac cycle. This protocol consists of two parts. The first part describes a method for photoconverting and subsequently tracking endocardial cells (EdCs) during zebrafish atrioventricular canal (AVC) and atrioventricular heart valve development. The method involves temporally stopping the heart with a drug in order for accurate photoconversion to take place. Hearts are allowed to resume beating upon removal of the drug and embryonic development continues normally until the heart is stopped again for high-resolution imaging of photoconverted EdCs at a later developmental time point. The second part of the protocol describes an image analysis method to quantify the length of a photoconverted or non-photoconverted region in the AVC in young embryos by mapping the fluorescent signal from the three-dimensional structure onto a two-dimensional map. Together, the two parts of the protocol allows one to examine the origin and behavior of cells that make up the zebrafish AVC and atrioventricular heart valve, and can potentially be applied for studying mutants, morphants, or embryos that have been treated with reagents that disrupt AVC and/or valve development.

This protocol describes a method for the photoconversion of Kaede fluorescent protein in endocardial cells of the living zebrafish embryo that enables the tracking of endocardial cells during atrioventricular canal and atrioventricular heart valve development.

ゼブラフィッシュ胚における細胞光電を介して次の心内膜組織運動

During embryogenesis, cells undergo dynamic changes in cell behavior, and deciphering the cellular logic behind these changes is a fundamental goal in the ...

Single-cell Transcriptomic Analyses of Mouse Pancreatic Endocrine Cells

Pancreatic endocrine cells, which are clustered in islets, regulate blood glucose stability and energy metabolism. The distinct cell types in islets, including insulin-secreting &#946; cells, are differentiated from common endocrine progenitors during the embryonic stage. Immature endocrine cells expand via cell proliferation and mature during a long postnatal developmental period. However, the mechanisms underlying these processes are not clearly defined. Single-cell RNA-sequencing is a promising approach for the characterization of distinct cell populations and tracing cell lineage differentiation pathways. Here, we describe a method for the single-cell RNA-sequencing of isolated pancreatic &#946; cells from embryonic, neonatal and postnatal pancreases.

We describe a method for the isolation of endocrine cells from embryonic, neonatal and postnatal pancreases followed by single-cell RNA sequencing. This method allows analyses of pancreatic endocrine lineage development, cell heterogeneity and transcriptomic dynamics.

マウス膵臓内分泌細胞の単一細胞トランスクリプトーム解析

Pancreatic endocrine cells, which are clustered in islets, regulate blood glucose stability and energy metabolism. The distinct cell types in islets, ...

Microinjection of DNA into Eyebuds in Xenopus laevis Embryos and Imaging of GFP Expressing Optic Axonal Arbors in Intact, Living Xenopus Tadpoles

The primary visual projection of tadpoles of the aquatic frog Xenopus laevis serves as an excellent model system for studying mechanisms that regulate the development of neuronal connectivity. During establishment of the retino-tectal projection, optic axons extend from the eye and navigate through distinct regions of the brain to reach their target tissue, the optic tectum. Once optic axons enter the tectum, they elaborate terminal arbors that function to increase the number of synaptic connections they can make with target interneurons in the tectum. Here, we describe a method to express DNA encoding green fluorescent protein (GFP), and gain- and loss-of-function gene constructs, in optic neurons (retinal ganglion cells) in Xenopus embryos. We explain how to microinject a combined DNA/lipofection reagent into eyebuds of one day old embryos such that exogenous genes are expressed in single or small numbers of optic neurons. By tagging genes with GFP or co-injecting with a GFP plasmid, terminal axonal arbors of individual optic neurons with altered molecular signaling can be imaged directly in brains of intact, living Xenopus tadpoles several days later, and their morphology can be quantified. This protocol allows for determination of cell-autonomous molecular mechanisms that underlie the development of optic axon arborization in vivo.

Microinjection of DNA into Eyebuds in Xenopus laevis Embryos and Imaging of GFP Expressing Optic Axonal Arbors in Intact, Living Xenopus Tadpoles

This protocol aims to demonstrate how to microinject a DNA/DOTAP mixture into eyebuds of one day old Xenopus laevis embryos, and how to image and reconstruct individual green fluorescent protein (GFP) expressing optic axonal arbors in tectal midbrains of intact, living Xenopus tadpoles.

キセノプス・レービス胚における眼芽へのDNAのマイクロインジェクションとGFPのイメージングは、無傷で光学軸軸樹園を発現し、生きているキセノプス・タマジャクシ

The primary visual projection of tadpoles of the aquatic frog Xenopus laevis serves as an excellent model system for studying mechanisms that regulate the ...

Visualizing the Developing Brain in Living Zebrafish using Brainbow and Time-lapse Confocal Imaging

Development of the vertebrate nervous system requires a precise coordination of complex cellular behaviors and interactions. The use of high resolution in vivo imaging techniques can provide a clear window into these processes in the living organism. For example, dividing cells and their progeny can be followed in real time as the nervous system forms. In recent years, technical advances in multicolor techniques have expanded the types of questions that can be investigated. The multicolor Brainbow approach can be used to not only distinguish among like cells, but also to color-code multiple different clones of related cells that each derive from one progenitor cell. This allows for a multiplex lineage analysis of many different clones and their behaviors simultaneously during development. Here we describe a technique for using time-lapse confocal microscopy to visualize large numbers of multicolor Brainbow-labeled cells over real time within the developing zebrafish nervous system. This is particularly useful for following cellular interactions among like cells, which are difficult to label differentially using traditional promoter-driven colors. Our approach can be used for tracking lineage relationships among multiple different clones simultaneously. The large datasets generated using this technique provide rich information that can be compared quantitatively across genetic or pharmacological manipulations. Ultimately the results generated can help to answer systematic questions about how the nervous system develops.

In vivo imaging is a powerful tool that can be used to investigate the cellular mechanisms underlying nervous system development. Here we describe a technique for using time-lapse confocal microscopy to visualize large numbers of multicolor Brainbow-labeled cells in real time within the developing zebrafish nervous system.

Brainbowとタイムラプス共焦点イメージングを用いた生きているゼブラフィッシュの発達脳の可視化

Development of the vertebrate nervous system requires a precise coordination of complex cellular behaviors and interactions. The use of high resolution in ...

Eye Removal in Living Zebrafish Larvae to Examine Innervation-dependent Growth and Development of the Visual System

Zebrafish exhibit remarkable life-long growth and regenerative abilities. For example, specialized stem cell niches established during embryogenesis support continuous growth of the entire visual system, both in the eye and the brain. Coordinated growth between the retinae and the optic tectum ensures accurate retinotopic mapping as new neurons are added in the eyes and brain. To address whether retinal axons provide crucial information for regulating tectal stem and progenitor cell behaviors such as survival, proliferation, and/or differentiation, it is necessary to be able to compare innervated and denervated tectal lobes within the same animal and across animals. 
Surgical removal of one eye from living larval zebrafish followed by observation of the optic tectum achieves this goal. The accompanying video demonstrates how to anesthetize larvae, electrolytically sharpen tungsten needles, and use them to remove one eye. It next shows how to dissect brains from fixed zebrafish larvae. Finally, the video provides an overview of the protocol for immunohistochemistry and a demonstration of how to mount stained embryos in low-melting-point agarose for microscopy.

The article explains how to surgically remove eyes from living zebrafish larvae as the first step toward investigating how retinal input influences optic tectum growth and development. In addition, the article provides information about larval anesthetization, fixation, and brain dissection, followed by immunohistochemistry and confocal imaging.

生きているゼブラフィッシュ幼虫の眼球除去による神経支配依存性の成長と視覚系の発達を調べる

Zebrafish exhibit remarkable life-long growth and regenerative abilities. For example, specialized stem cell niches established during embryogenesis ...