The authors thank Gilberto Morales for fish care and maintenance, and Drs. Claudia Rivera and Hector Malag&#242;n (IFC-UNAM Animal Facility) for their help in rabbit immunization. This work was supported by grants from CONACYT 131226 and PAPIIT-DGAPA-UNAM IN204916.

FLC40-14：動物で行わ全ての実験はCICUAL-プロトコル番号の下、メキシコ自治大学（UNAM）の実験動物管理使用委員会によって承認されました。 （CICUAL：「ComitéInstitucionalパラエルCuidado yの嘘・デ・ロス・Animales・デ・ラボラトリ・デル・研究所・デ・FisiologìaCELULAR、ナショナル大学自治・デ・メキシコ」）。 胚のタンパク質抽出物の調製<ol><li>各条件は、例えば72時間後に受精（HPF）のために、所望の段階で（モルファント対野生型）を比較するための200の胚 - 100を収集します。 </li><li>先の細いピンセットを使用して場所の魚の水を含むペトリ皿中の胚（ 表1参照）、手動dechorionate胚。それは、標的受容体を消化することができるように、この段階（またはプロトコルを通じて、他のプロテアーゼ）中にプロナーゼを使用しないでください。 </li><li> 1.5mlマイクロチューブに入れ胚と胚TWを洗います1×リン酸緩衝溶液（PBS）と氷（ 表1参照）。 </li><li> （ 表1を参照）deyolk用緩衝液500μlを追加します。 </li><li> （ - 40倍、約30）溶液中で胚を優しく上下にピペッティングにより卵黄のほとんどをリリース。 72 HPFと48 HPFの胚については、それぞれ、青と黄色のピペットチップを使用します。黄色のヒントが少し胚を壊さないようにカットする必要があるかもしれません。成功した卵黄の放出は、顕微鏡下で胚を観察することによって確認することができます。 </li><li> 15秒間600×gで遠心分離することによって胚を収集します。 </li><li>ピペットを使用して、慎重に上清を捨てます。 </li><li>洗浄胚は二回500μlの洗浄バッファーで穏やかに最低速でボルテックスすることによって（ 表1参照します）。 </li><li> 15秒間600×gで遠心分離することによって胚を収集します。 </li><li>ここから出発し、4°Cで手順を続行します。 </li><li>ピペットを使用して、慎重に上清を捨てます。 </li><li>溶解バッファー350μlの再懸濁胚（表1を参照）、プラスチック製乳棒を用いて均質化します。 </li><li> 4°Cで試験管ロッカーに溶解させた胚を攪拌しながら30分間インキュベート。 </li><li>遠心分離機は、不溶性の破片を除去するために15分間、11,000×gで胚を溶解しました。 </li><li>転送が新しいチューブにピペットを用いて上清をクリア。 </li><li> Bradfordタンパク質アッセイ4、または他の適切な手順により総タンパク質を決定します。 Bradfordアッセイを使用している場合、彼らは4標準タンパク質の過小評価を引き起こすように、溶解緩衝液中の界面活性剤の提示の等価な濃度の存在下で較正曲線を実行します。 </li></ol> 2.検出内因性受容体タンパク質の<ol><li> 親和性標識および免疫沈降（すべての手順4 O Cで） <ol><li> 1.5mlマイクロチューブに総胚タンパク質の500μgのバッファ1（ 表1を参照）を1μg/μlに希釈する- 400を置きます。 注：総胚タンパク質500μgのを得るためには、約100から200胚が最初に処理されなければなりません。 72 HPFの胚は、日常的にβグリカンの検出のために十分である総胚タンパク質、の〜5μgのをもたらします。 </li><li>試験管ロッカーに150 PMの最終濃度に達すると攪拌しながらインキュベートし、4℃で2時間標識TGF-β2株式の十分なボリュームを追加します。 AFLIPが開始される前にCheifetz ら 5によって説明したように、TGF-β2は、クロラミンT法によって125 Iで標識されなければなりません。 注意：使用して私は、リガンドを標識した125の処理中に露出を最小限にするためにシールド。 </li><li> 100希釈および（インキュベーションは、O / Nであってもよい）4℃でさらに2時間インキュベーションを継続：1に到達するために、目的の受容体に対する希釈していない抗体の十分なボリュームを追加します。これは、この研究で使用され、他の場所3を説明するが、ANの品質に応じて、抗血清＃31の最適希釈でありますtibody、より大きいまたはより小さい希釈が最適であってもよいです。 </li><li>適切な免疫グロブリン結合ビーズの50μlを添加（例えば、以前にTNTEで平衡化し、1再懸濁させたGタンパク質セファロース、：TNTEで元の体積の5）と4℃で試験管ロッカー上で撹拌しながら50分間インキュベートしますC. </li><li> 20秒間11,000×gで微量遠心によってビーズを回復。 </li><li>適切な放射性ゴミ容器に上清を捨てます。 </li><li> 20秒間11,000×gで毎回ボルテックスし、微量遠心することにより、（ 表1を参照）IP洗浄緩衝液1mlでIP-ビーズを3回洗浄します。 </li><li> IP洗浄緩衝液250μlの中に再懸濁したIP-ビーズ。 </li><li> （10 mg / mlとでDMSOに溶解したDSS、​​）ジスクシンイミジルスベレートの1.5μlを添加します。ちょうどこの段階でその使用前にDSS溶液を調製します。 </li><li>攪拌しながら4℃で15分間インキュベートします。 </li><li>架橋反応をクエンチするために、500μlのOを加えます十分トリス-Cl pH7.4の在庫を補充したF IP洗浄緩衝液は、25mMのトリス-Clに到達します。トリス中の遊離アミノ基が未反応のDSSをキャプチャします。 </li><li> 20秒IP-ビーズを収集し、上清を廃棄するための11,0​​00×gで遠心分離します。 </li><li>再懸濁IP-ビーズLaemmliバッファーを減らす30μlのインチ</li><li>沸騰サンプル94℃で5分間。 </li><li>必要に応じて、製造業者のプロトコルを使用して、ガンマカウンターでサンプルを分析します。 </li></ol></li><li> 試料分析 <ol><li>変性SDS-PAGEの対象サンプル。受容体の質量のための適切な割合でポリアクリルアミドを使用し、標準的な手順の下でゲルを実行します。 </li><li>固定液中でゲルを浸し、室温で30分間（ 表1参照）。 </li><li> 15分間蒸留水でゲルを洗浄してください。 </li><li>以前に水和ろ紙にゲルを置き、サランラップフィルムでカバーしています。 </li><li> 1時間80℃で乾燥ゲル。 </li><li>白ホスホイメージャSCREにゲルを公開RT O / Nでアン。 </li><li>製造業者のプロトコルを使用して、ホスホイメージャを用いて露光画面をスキャンします。 </li></ol></li></ol>

<ol>
	<li>L&#243;pez-Casillas, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+and+expression+of+the+membrane+proteoglycan+betaglycan,+a+component+of+the+TGF-&#946;+receptor+system.">Structure and expression of the membrane proteoglycan betaglycan, a component of the TGF-&#946; receptor system.</a> Cell. 67 (4), 785-795 (1991).</li><li>Cheifetz, S., Andres, J. L., Massague, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+transforming+growth+factor-beta+receptor+type+III+is+a+membrane+proteoglycan.+Domain+structure+of+the+receptor.">The transforming growth factor-beta receptor type III is a membrane proteoglycan. Domain structure of the receptor.</a> J. Biol. Chem. 263 (32), 16984-16991 (1988).</li><li>Kamaid, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Betaglycan+knock-down+causes+embryonic+angiogenesis+defects+in+zebrafish.">Betaglycan knock-down causes embryonic angiogenesis defects in zebrafish.</a> Genesis. 53, 583-603 (2015).</li><li>Bradford, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Rapid+and+Sensitive+Method+for+the+Quantitation+of+Microgram+Quantities+of+Protein+Utilizing+the+Principle+of+Protein-Dye+Binding.">A Rapid and Sensitive Method for the Quantitation of Microgram Quantities of Protein Utilizing the Principle of Protein-Dye Binding.</a> Anal. 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L., Massagu&#233;, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Betaglycan+presents+ligand+to+the+TGF&#946;+signaling+receptor.">Betaglycan presents ligand to the TGF&#946; signaling receptor.</a> Cell. 73 (7), 1435-1444 (1993).</li><li>Towbin, H., Staehelin, T., Gordon, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophoretic+transfer+of+proteins+from+polyacrylamide+gels+to+nitrocellulose+sheets:+procedure+and+some+applications.">Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications.</a> PNAS USA. 76 (9), 4350-4354 (1979).</li><li>Maccari, F., Volpi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+and+specific+recognition+of+glycosaminoglycans+by+antibodies+after+their+separation+by+agarose+gel+electrophoresis+and+blotting+on+cetylpyridinium+chloride-treated+nitrocellulose+membranes.">Direct and specific recognition of glycosaminoglycans by antibodies after their separation by agarose gel electrophoresis and blotting on cetylpyridinium chloride-treated nitrocellulose membranes.</a> Electrophoresis. 24 (9), 1347-1352 (2003).</li><li>Volpi, N., Maccari, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glycosaminoglycan+blotting+and+detection+after+electrophoresis+separation.">Glycosaminoglycan blotting and detection after electrophoresis separation.</a> Methods Mol Biol (Clifton, N.J). 1312, 119-127 (2015).</li><li>Guesdon, J. 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The authors have nothing to disclose.

目的のタンパク質に対する特異的抗体を用いたウェスタンブロットの使用は、胚発生時にその発現7を研究するための貴重なツールです。しかし、高度にグリコシル化されたタンパク質のイムノブロットは、その非効率的な転送およびニトロセルロースまたはPVDF膜8,9に弱い結合に非常に成功していません。 プロテオグリカンは理由負に帯電してい...

Specific detection of proteins expressed during embryonic development is required to validate expression profiles obtained by measuring their cognate mRNAs with RT-PCR or in situ hybridization (ISH). This is commonly achieved by a western blot of embryo extracts followed by detection with specific antibodies. However, this approach is hard to apply to proteins that are in very low abundance, or that have properties that hamper their quantitative transfer during their blotting. Betaglycan, also known as the type III transforming growth factor &#946; (TGF-&#946;) receptor (TGFBR3), is an example of these difficulties. TGFBR3 is a part time membrane proteoglycan that binds TGF-&#946; through its core protein1, with notably higher affinity for the isoform TGF-&#946;2, a property that distinguishes it from any other TGF-&#946; binding protein2. TGFBR3 in the zebrafish is expressed from 8 hpf on, reaching a maximum by 72 hpf, as detected by RT-PCR of its mRNA3. 
However, despite the availability of a very specific antibody3, every attempt to detect its translated product by western blot proved unsuccessful. Reckoning that TGFBR3's proteoglycan nature, as well as putative low abundance may be accountable for this failure, a detection method, AFLIP, which takes advantage of TGFBR3 high affinity for TGF-&#946;2 was devised. In this method a protein extract from pooled embryos is allowed to specifically bind 125I-labeled TGF-&#946;2 and the receptor-ligand complexes are purified by immunoprecipitation and cross-linked before separation by SDS-PAGE. The migration patterns observed by autoradiography of the gels revealed the presence and nature of the labeled receptor species. This approach combines the ligand specificity of affinity labeling with immunoprecipitation by specific antibodies, increasing detection range, avoiding the inefficient transfer blotting of TGFBR3. Due to its inherent properties, the AFLIP assay is not a quantitative assay but can be used to confidently gauge relative experimental differences in the analyzed receptor.

<table border="0" cellpadding="0" cellspacing="0" width="670">
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Disuccinimidyl suberate (DSS)</td>
			<td style="width:168px;">ThermoFisher Scientific</td>
			<td style="width:119px;">21555</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Protein G Sephraose 4 Fast Flow</td>
			<td style="width:168px;">GE Healthcare Life Sciences</td>
			<td style="width:119px;">17-0618-01</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Gel Dryer Model 583&#160;</td>
			<td style="width:168px;">BIO-RAD</td>
			<td style="width:119px;">1651745</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Typhoon 9400</td>
			<td style="width:168px;">GE Healthcare Life Sciences</td>
			<td style="width:119px;">63-0055-78</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Cobra II Auto gamma counter</td>
			<td style="width:168px;">Packard</td>
			<td style="width:119px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Exposure Cassette</td>
			<td style="width:168px;">Molecular Dynamics</td>
			<td style="width:119px;">63-0035-44</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">NaCl</td>
			<td style="width:168px;">J.T. Baker</td>
			<td style="width:119px;">3624</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">KCl</td>
			<td style="width:168px;">J.T. Baker</td>
			<td style="width:119px;">3040</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Na2HPO4</td>
			<td style="width:168px;">J.T. Baker</td>
			<td style="width:119px;">3828</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">K2HPO4</td>
			<td style="width:168px;">J.T. Baker</td>
			<td style="width:119px;">3246</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">CH4O</td>
			<td style="width:168px;">J.T. Baker</td>
			<td style="width:119px;">9070</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">C2H4O2</td>
			<td style="width:168px;">J.T. Baker</td>
			<td style="width:119px;">9508</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">CH2O</td>
			<td style="width:168px;">J.T. Baker</td>
			<td style="width:119px;">2106</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">SDS</td>
			<td style="width:168px;">Sigma-Aldrich</td>
			<td style="width:119px;">L4509</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">EDTA</td>
			<td style="width:168px;">Sigma-Aldrich</td>
			<td style="width:119px;">ED</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Triton X-100</td>
			<td style="width:168px;">Sigma-Aldrich</td>
			<td style="width:119px;">T9284</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">CaCl2</td>
			<td style="width:168px;">Sigma-Aldrich</td>
			<td style="width:119px;">C3306</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">NaHCO3</td>
			<td style="width:168px;">Fisher Scientific</td>
			<td style="width:119px;">S233</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PMSF</td>
			<td style="width:168px;">Sigma-Aldrich</td>
			<td style="width:119px;">P7626</td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Crystal Sea Marine Mix</td>
			<td style="width:168px;">Marine Enterprises International</td>
			<td style="width:119px;">http://www.meisalt.com/Crystal-Sea-Marinemix</td>
			<td></td>
		</tr>
	</tbody>
</table>

affinity labeling detection of endogenous receptors from zebrafish embryos

By combining the powers of Affinity Labeling and Immunoprecipitation (AFLIP), a technique for the detection of low abundance receptors in zebrafish embryos has been implemented. This technique takes advantage of the selectivity and sensitivity conferred by affinity labeling of a given receptor by its ligand with the specificity of the immunoprecipitation. We have used AFLIP to detect the type III TGF-&#946; receptor (TGFBR3), also know as betaglycan, during early zebrafish development. AFLIP was instrumental in validating the efficacy of a TGFBR3 morphant zebrafish phenotype. In the first step, embryo protein extracts are prepared and used to generate 125I-TGF-&#946;2-TGFBR3 complexes that are purified by immunoprecipitation. Later, these complexes are covalently cross-linked and revealed using SDS-PAGE separation and autoradiography detection. This technique requires the availability of a labeled ligand for, and a specific antibody against, the receptor to be detected, and shall be easily adapted to identify any growth factor or cytokine receptor that meets these requirements.

図1は AFLIPで得られた代表的な結果を示しています。 125 I-リガンドから来レーン1の信号は、共有ゼブラフィッシュβグリカンコアタンパク質（BGコア、150 kDaのマーカー以下）またはグリコサミノグリカンのアタッチメント（GAG、スミアによってそのプロテオグリカンの形に加工されたBGコアのいずれかにリンクされています）170キロダルトンから?...

Watch this Scientific Journal Video about Affinity Labeling Detection of Endogenous Receptors from Zebrafish Embryos at JoVE.com

Affinity Labeling Detection of Endogenous Receptors from Zebrafish Embryos

A novel technique for the detection of low abundance endogenous receptors present in zebrafish embryos is described. We have named it AFLIP because it consists of affinity labeling of the receptor by its ligand linked to immunoprecipitation.

ゼブラフィッシュ胚からの内因性受容体の親和性ラベリング検出

By combining the powers of Affinity Labeling and Immunoprecipitation (AFLIP), a technique for the detection of low abundance receptors in zebrafish ...

affinity-labeling-detection-endogenous-receptors-from-zebrafish

Research

JoVE Journal

Developmental Biology

5.6K ビュー.  Universidad Nacional Autónoma de México. A novel technique for the detection of low abundance endogenous receptors present in zebrafish embryos is described. We have named it AFLIP because it consists of affinity labeling of the receptor by its ligand linked to immunoprecipitation.

ビデオ: Affinity Labeling Detection of Endogenous Receptors from Zebrafish Embryos

Mechanical Vessel Injury in Zebrafish Embryos

Zebrafish (Danio rerio) embryos have proven to be a powerful model for studying a variety of developmental and disease processes. External development and optical transparency make these embryos especially amenable to microscopy, and numerous transgenic lines that label specific cell types with fluorescent proteins are available, making the zebrafish embryo an ideal system for visualizing the interaction of vascular, hematopoietic, and other cell types during injury and repair in vivo. Forward and reverse genetics in zebrafish are well developed, and pharmacological manipulation is possible. We describe a mechanical vascular injury model using micromanipulation techniques that exploits several of these features to study responses to vascular injury including hemostasis and blood vessel repair. Using a combination of video and timelapse microscopy, we demonstrate that this method of vascular injury results in measurable and reproducible responses during hemostasis and wound repair. This method provides a system for studying vascular injury and repair in detail in a whole animal model.

This article describes a method for creating a mechanical vessel injury in zebrafish embryos. This injury model provides a platform for studying hemostasis, injury-related inflammation, and wound healing in an organism ideally suited for real-time microscopy.

ゼブラフィッシュ胚における機械的血管損傷

Zebrafish (Danio rerio) embryos have proven to be a powerful model for studying a variety of developmental and disease processes.  External development ...

発生生物学

Application of the DNA-Specific Stain Methyl Green in the Fluorescent Labeling of Embryos

Methyl green has long been known as a histological stain with a specific affinity for DNA, although its fluorescent properties have remained unexplored until recently. In this article, we illustrate the method for preparing a methyl green aqueous stock solution, that when diluted can be used as a very convenient fluorescent nuclear label for fixed cells and tissues. Easy procedures to label whole zebrafish and chick embryos are detailed, and examples of images obtained shown. Methyl green is maximally excited by red light, at 633 nm, and emits with a relatively sharp spectrum that peaks at 677 nm. It is very inexpensive, non-toxic, highly stable in solution and very resistant to photobleaching when bound to DNA. Its red emission allows for unaltered high resolution scanning confocal imaging of nuclei in thick specimens. Finally, this methyl green staining protocol is compatible with other cell staining procedures, such as antibody labeling, or actin filaments labeling with fluorophore-conjugated phalloidin.

A method for fluorescent staining of fixed biological material with the specific DNA label methyl green is described. Methyl green is used in a diluted aqueous solution and is very resistant to photobleaching. Its far-red emission allows for deep specimen imaging, making it particularly adequate for whole embryos.

胚の蛍光標識でDNA特異的染色メチルグリーンの応用

Methyl green has long been known as a histological stain with a specific affinity for DNA, although its fluorescent properties have remained unexplored ...

Isolation and Characterization of Single Cells from Zebrafish Embryos

The zebrafish (Danio rerio) is a powerful model organism to study vertebrate development. Though many aspects of zebrafish embryonic development have been described at the morphological level, little is known about the molecular basis of cellular changes that occur as the organism develops. With recent advancements in microfluidics and multiplexing technologies, it is now possible to characterize gene expression in single cells. This allows for investigation of heterogeneity between individual cells of specific cell populations to identify and classify cell subtypes, characterize intermediate states that occur during cell differentiation, and explore differential cellular responses to stimuli. This study describes a protocol to isolate viable, single cells from zebrafish embryos for high throughput multiplexing assays. This method may be rapidly applied to any zebrafish embryonic cell type with fluorescent markers. An extension of this method may also be used in combination with high throughput sequencing technologies to fully characterize the transcriptome of single cells. As proof of principle, the relative abundance of cardiac differentiation markers was assessed in isolated, single cells derived from nkx2.5 positive cardiac progenitors. By evaluation of gene expression at the single cell level and at a single time point, the data support a model in which cardiac progenitors coexist with differentiating progeny. The method and work flow described here is broadly applicable to the zebrafish research community, requiring only a labeled transgenic fish line and access to microfluidics technologies.

This protocol describes a method for isolating single cells from zebrafish embryos, enriching for cells of interest, capturing zebrafish cells in microfluidic based single cell multiplex systems, and assessing gene expression from single cells.

ゼブラフィッシュ胚からの単一細胞の単離とキャラクタリゼーション

The zebrafish (Danio rerio) is a powerful model organism to study vertebrate development. Though many aspects of zebrafish embryonic development have been ...

Generation of Parabiotic Zebrafish Embryos by Surgical Fusion of Developing Blastulae

Surgical parabiosis of two animals of different genetic backgrounds creates a unique scenario to study cell-intrinsic versus cell-extrinsic roles for candidate genes of interest, migratory behaviors of cells, and secreted signals in distinct genetic settings. Because parabiotic animals share a common circulation, any blood or blood-borne factor from one animal will be exchanged with its partner and vice versa. Thus, cells and molecular factors derived from one genetic background can be studied in the context of a second genetic background. Parabiosis of adult mice has been &#160;used extensively to research aging, cancer, diabetes, obesity, and brain development. More recently, parabiosis of zebrafish embryos has been used to study the developmental biology of hematopoiesis. In contrast to mice, the transparent nature of zebrafish embryos permits the direct visualization of cells in the parabiotic context, making it a uniquely powerful method for investigating fundamental cellular and molecular mechanisms. The utility of this technique, however, is limited by a steep learning curve for generating the parabiotic zebrafish embryos. This protocol provides a step-by-step method on how to surgically fuse the blastulae of two zebrafish embryos of different genetic backgrounds to investigate the role of candidate genes of interest. In addition, the parabiotic zebrafish embryos are tolerant to heat shock, making temporal control of gene expression possible. This method does not require a sophisticated set-up and has broad applications for studying cell migration, fate specification, and differentiation in vivo during embryonic development.

This protocol provides step-by-step instruction on how to generate parabiotic zebrafish embryos of different genetic backgrounds. When combined with the unparalleled imaging capabilities of the zebrafish embryo, this method provides a uniquely powerful means to investigate cell-autonomous versus non-cell-autonomous functions for candidate genes of interest.

胞胚の開発の外科的融合による並体結合ゼブラフィッシュ胚の生成

Surgical parabiosis of two animals of different genetic backgrounds creates a unique scenario to study cell-intrinsic versus cell-extrinsic roles for ...

Ploidy Manipulation of Zebrafish Embryos with Heat Shock 2 Treatment

Manipulation of ploidy allows for useful transformations, such as diploids to tetraploids, or haploids to diploids. In the zebrafish Danio rerio, specifically the generation of homozygous gynogenetic diploids is useful in genetic analysis because it allows the direct production of homozygotes from a single heterozygous mother. This article describes a modified protocol for ploidy duplication based on a heat pulse during the first cell cycle, Heat Shock 2 (HS2). Through inhibition of centriole duplication, this method results in a precise cell division stall during the second cell cycle. The precise one-cycle division stall, coupled to unaffected DNA duplication, results in whole genome duplication. Protocols associated with this method include egg and sperm collection, UV treatment of sperm, in vitro fertilization and heat pulse to cause a one-cell cycle division delay and ploidy duplication. A modified version of this protocol could be applied to induce ploidy changes in other animal species.

A modified protocol for ploidy manipulation uses a heat shock to induce a one-cycle stall in cytokinesis in the early embryo. This protocol is demonstrated in the zebrafish but may be applicable to other species.

熱ショック2処理とゼブラフィッシュ胚の倍数性マニピュレーション

Manipulation of ploidy allows for useful transformations, such as diploids to tetraploids, or haploids to diploids. In the zebrafish Danio rerio, ...

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 ...

Visualization of Cellular Electrical Activity in Zebrafish Early Embryos and Tumors

Bioelectricity, endogenous electrical signaling mediated by ion channels and pumps located on the cell membrane, plays important roles in signaling processes of excitable neuronal and muscular cells and many other biological processes, such as embryonic developmental patterning. However, there is a need for in vivo electrical activity monitoring in vertebrate embryogenesis. The advances of genetically encoded fluorescent voltage indicators (GEVIs) have made it possible to provide a solution for this challenge. Here, we describe how to create a transgenic voltage indicator zebrafish using the established voltage indicator, ASAP1 (Accelerated Sensor of Action Potentials 1), as an example. The Tol2 kit and a ubiquitous zebrafish promoter, ubi, were chosen in this study. We also explain&#160;the processes of Gateway site-specific cloning, Tol2 transposon-based zebrafish transgenesis, and the imaging process for early-stage fish embryos and fish tumors using regular epifluorescent microscopes. Using this fish line, we found that there are cellular electric voltage changes during zebrafish embryogenesis, and fish larval movement. Furthermore, it was observed that in a few zebrafish malignant peripheral nerve sheath tumors, the tumor cells were generally polarized compared to the surrounding normal tissues.

Here, we show the process of creating a cellular electric voltage reporter zebrafish line to visualize embryonic development, movement, and fish tumor cells in vivo.

ゼブラフィッシュ初期胚および腫瘍の細胞の電気的活動の可視化

Bioelectricity, endogenous electrical signaling mediated by ion channels and pumps located on the cell membrane, plays important roles in signaling ...

A Layered Mounting Method for Extended Time-Lapse Confocal Microscopy of Whole Zebrafish Embryos

Dynamics of development can be followed by confocal time-lapse microscopy of live transgenic zebrafish embryos expressing fluorescence in specific tissues or cells. A difficulty with imaging whole embryo development is that zebrafish embryos grow substantially in length. When mounted as regularly done in 0.3-1% low melt agarose, the agarose imposes growth restriction, leading to distortions in the soft embryo body. Yet, to perform confocal time-lapse microscopy, the embryo must be immobilized. This article describes a layered mounting method for zebrafish embryos that restrict the motility of the embryos while allowing for the unrestricted growth. The mounting is performed in layers of agarose at different concentrations. To demonstrate the usability of this method, whole embryo vascular, neuronal and muscle development was imaged in transgenic fish for 55 consecutive hours. This mounting method can be used for easy, low-cost imaging of whole zebrafish embryos using inverted microscopes without requirements of molds or special equipment.

This article describes a method to mount fragile zebrafish embryos for extended time-lapse confocal microscopy. This low-cost method is easy to perform using regular glass-bottom microscopy dishes for imaging on any inverted microscope. The mounting is performed in layers of agarose at different concentrations.

ゼブラフィッシュ胚全体の延長タイムラプス共焦点顕微鏡法の層状取り付け法

Dynamics of development can be followed by confocal time-lapse microscopy of live transgenic zebrafish embryos expressing fluorescence in specific tissues ...

Whole Mount Immunohistochemistry in Zebrafish Embryos and Larvae

Immunohistochemistry is a widely used technique to explore protein expression and localization during both normal developmental and disease states. Although many immunohistochemistry protocols have been optimized for mammalian tissue and tissue sections, these protocols often require modification and optimization for non-mammalian model organisms. Zebrafish are increasingly used as a model system in basic, biomedical, and translational research to investigate the molecular, genetic, and cell biological mechanisms of developmental processes. Zebrafish offer many advantages as a model system but also require modified techniques for optimal protein detection. Here, we provide our protocol for whole-mount fluorescence immunohistochemistry in zebrafish embryos and larvae. This protocol additionally describes several different mounting strategies that can be employed and an overview of the advantages and disadvantages each strategy provides. We also describe modifications to this protocol to allow detection of chromogenic substrates in whole mount tissue and fluorescence detection in sectioned larval tissue. This protocol is broadly applicable to the study of many developmental stages and embryonic structures.

Here, we present a protocol for fluorescent antibody-mediated detection of proteins in whole preparations of zebrafish embryos and larvae.

ゼブラフィッシュ胚と幼虫の全山免疫賦形化学

Immunohistochemistry is a widely used technique to explore protein expression and localization during both normal developmental and disease states. ...