Name: recovery of adult zebrafish hearts for high-throughput applications
Uploaded: 2014-12-12T15:00:00.000+00:00
Duration: 6 min 51 s
Description: Watch this Scientific Journal Video about Recovery of Adult Zebrafish Hearts for High-throughput Applications at JoVE.com

The authors would like to thank Dr. Shaun Coughlin for hosting the filming of this procedure in his laboratory, and for general support. R.A. was supported by the NIH (F32HL110489) and the Sarnoff Cardiovascular Research Foundation. S.R. was supported by a Research Fellowship of the Deutsche Forschungsgemeinschaft (DFG) and the American Heart Association (AHA). D.Y.R.S was supported by the NIH (RO1HL54737), the Packard Foundation, and the Max Planck Society.

NOT: Her zaman IACUC veya etik kurul onayı zebrafish kullanarak herhangi bir deneysel prosedür başlamadan önce yerinde olduğundan emin olun. 1. reaktifler ve kurulumu hazırlayın <ol><li> Aşağıdaki çözümleri hazırlayın. Standart zebrabalıkları kılavuzları 10 bu çözümlerin tüm tarifleri bulun. <ul><li> Yumurta 500 ml su </li><li> Yumurta Su 0.03% Tricaine 200 ml </li><li> 1x Fosfat Tamponlu Tuzlu su, 100 ml (PBS) </li><li> RBC Lizis Tamponu (isteğe bağlı) </li><li> Buz üzerinde 1.5 ml mikrofüj tüpe tercih edilen hedef tamponu (sabitleyici olarak Trizol PBS, vs.) NOT: Deri ile temas halinde Fiksatif ve Trizol zehirlidir. Bu maddelerin tutarken eldiven giyin. </li></ul></li><li> Diseksiyon kurulumu hazırlayın: <ol><li> Mikroskop üzerinde boyun ışık kaynağı yerleştirin. Diseksiyon mikroskop sahnede 9 cm Petri kabı kapağını yerleştirin ve içine 1x PBS ince bir tabaka dökmeko (çanak kendisi kolay bir diseksiyon için çok derin olduğu için kapak kullanılır). </li><li> Diseksiyon kapsamı yakın tezgah üzerinde Petri kabı kendisi (değil kapak) yerleştirin ve o 1x PBS yaklaşık 15 ml dökün. Diseksiyonu sonrası kalbi yıkamak için kullanın. Alternatif olarak, RBC Lizis Buffer kullanın. </li><li> Yer jilet, iki forseps, microscissors (isteğe bağlı) çiftleri, ve mikroskop yanında bir transfer pipet. Hızlı soğutma ile ötanazi seçilirse, bir buz kabı elde edilir. </li><li> Tricaine ile ötanazi seçilirse, 250 ml&#39;lik bir cam kabın içine yumurta su içinde% 0.03 Tricaine 200 ml dökün. Zebra balığı karkasların imhası için küçük bir biyolojik tehlike çanta hazırlayın. </li></ol></li></ol> 2. Zebra balığı hazırlayın <ol><li> Sabit balık için, mikroskop kurulum, PBS içinde durulanır sabit balık, getir. <ol><li> &gt; 10 dakika boyunca buz ile hızlı soğutma ile bütün yetişkin zebrafish öldürülür. </li><li> Periton üzerinde deri bir delik yapmak için forseps kullanın(Kalp uzak) fiksatif nüfuz etmesini sağlamak ve daha sonra, 4 ° C&#39;de, oda sıcaklığında ya da O / N, 2 saat süre ile düzeltme Tampon 10 içinde% 4 paraformaldehid içinde koymak. </li></ol></li><li> Alternatif olarak, taze balık için yer balık küçük tutma tankında ötenazi edilecek ve mikroskop kurulum getirmek. Bireysel tesisin balık protokolü ve disseke balık kalpleri için mansap kullanımları bağlı, Tricaine ile balık uyutmak veya dekapitasyon önce hızlı soğutma ile euthanize. <ol><li> Balık durana kadar, buzlu suda balık net ve yerinde yaklaşık 5 dk bir balık pick up, buz kullanmak için. </li><li> Alternatif olarak, solungaç hareketleri durana kadar çözümün beher balık ağı ve yer ile bir balık pick up, Tricaine kullanmak için. </li></ol></li><li> Hızla kuyruk yüzgecinin tarafından ötenazi balık almak ve 1x PBS ile doluydu Petri kabı kapağındaki yan yatıyordu. Razo kullanırken, bir yandan bir göğüs yüzgeci kaldırmak için forseps kullanınr bıçak sadece göğüs yüzgeci (Şekil 1A) bağlanması için posterior, diğer elinizle balık başını kesmek için. Mikroskop aracılığıyla bakarak ya da sadece doğrudan mikroskop sahnede balık görselleştirerek ya bu adımı gerçekleştirin. NOT: Taze ötenazi balık hala dekapitasyon sonra kanayacak. </li></ol><img alt="Şekil 1," src="/files/ftp_upload/52248/52248fig1highres.jpg" /> Şekil 1. Zebra balığı kalp diseksiyon yetişkin zebrabalıkları anatomik yerlerinden kullanır. (A), balık başını kesmek bir forseps ile göğüs yüzgeci kaldırın ve gösterildiği gibi kırmızı noktalı çizgi boyunca keskin, temiz jilet kullanmak için. (B), balık kafası kararlı balık ağzı süre forseps bir tine yerleştirmek için Diğer tine göz genelinde yatıyor, ve ventral yüzeyi yukarı ve forseps iki dişler Petri kabı dibine kararlı olduğunu böylece daha sonra balık kafasını çevirin. (C) serbest forc kullanıneps operculum&#39;un (ok). (D) bu Kaldırma eki kesmek için, dorsal aort lümen kan (ok) gösteren bir pembe şeritli beyaz bir yapı olarak görülebilir. <a href="https://www.jove.com/files/ftp_upload/52248/52248fig1large.jpg" target="_blank">Bu rakamın büyük halini görmek için lütfen buraya tıklayınız.</a> 3. Kalp teşrih <ol><li> Mikroskop altında balık kafası gözünüzde canlandırın. Diğer tine göz (Şekil 1B) karşısında, baş dışında iken bir forseps ile, beynin aracılığıyla, balık ağızda forseps bir tine koyarak balık başını kararlı. Forseps iki dişler petri alt karşı kararlı olduğundan emin olun. Balık kafasını bu şekilde tutarak, ventral yüzeyi yukarı bakacak şekilde olmalıdır. </li><li> Diğer elinizle, vücudun (Şekil 1C ok) için operculum&#39;un ventral eki kesmek için ikinci forseps kullanabilir. Forseps ile biraz bu kaldırma dORSAL aort aort lümen (Şekil 1D ok) kan kırmızı şeritli beyaz bir yapı olarak altında görünecektir. Aort kısma ve yukarı doğru çekerek forseps ile dorsal aorta kesin; Alternatif olarak, sırt aorta kesmek için Microscissors kullanır. </li><li> Şimdi, fin dibinde vücut kıkırdak dahil olmak üzere, tabanından göğüs yüzgeci kavramak için ikinci forseps kullanımı, ve bu kaldırın. Diğer göğüs yüzgeci ile tekrarlayın. Bazen, kalp göğüs yüzgeçleri ile geliyor, bu yüzden kalp onları atılmadan önce takılı olmadığından emin olmak için bu parçaları incelemek. NOT: (zaman zaman göğüs yüzgeçleri ile kapalı geliyor olsa da) bu noktada, kalp, görünür hala bozulmamış ve kalan balık kafasına bağlı olmalıdır. Kalp şekli, onun pembe renk ve pigmentli perikard ile çevrili varlık tarafından tespit edilebilir. Balık ötenazi hızla yapılır, çünkü taze balık ötenazi kalpleri hala SLO yenerek olabilirWLY. </li><li> Her iki el forseps tutun ve ücretsiz böylece, ilk forseps ile balık kafa gidelim. Uzakta perikarttan kalp kızdırmak için her iki forseps kullanın. Kalan perikard uzak çekilirken dorsal aorta geri kalan kalbi kavrayın. NOT: Sabit veya taze olsun, kalp çevreleyen bağ dokusu daha gevrek iken çekerek nazik sağlam olduğunu. Bu nedenle, herhangi bir çevreleyen perikard dokusu bozulmamış kalp kalan uzak disseke edilebilir. </li><li> Biohazard çanta içinde kalan balık karkas atın. </li></ol> 4. Alt Uygulamaları için Kalp hazırlayın <ol><li> Forseps kullanarak, dorsal aorta / bulbusu arteriosusun kenarında kalp kavramak ve 1x PBS taze çanak kalp yerleştirin. Seçenek olarak ise, bir transfer pipeti kullanılır. Ileri ve geri PBS içinde kalp Taşı yaklaşık 10x mümkün olduğunca çok kan yıkayacak için. </li><li> Uygulamalar için her possib kaldırmak için önemli olduğule kan hücreleri, aynı arka ve ileri-hareketi ile yerine 15 ml PBS RBC Lizis Tamponu ile 9 cm&#39;lik bir Petri kabındaki yıkayın. Kalbin yapısını koruyarak (örneğin, RNA yapma), kalp boşluğunu açın ve uzak kan hücrelerinin durulama kolaylaştırmak için forseps veya Microscissors kullanmak alt uygulama için önemli değilse. </li><li> Ayrı kalp odaları istenilen edildiği uygulamalar için, birbirinden bulbusu arteriozus, atrium ve ventrikül incelemek için forseps veya Microscissors kullanın. </li><li> Buz üzerinde hedef tampon kalp, ya da ayrı ayrı odaları, aktarın. NOT: Ortak hedefler hücre ayrışma,% 4 paraformaldehid veya Trizol için tamponlar bulunmaktadır. </li></ol>

<ol>
	<li>Arnaout, R., 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=Zebrafish+model+for+human+long+QT+syndrome.">Zebrafish model for human long QT syndrome.</a> Proceedings of the National Academy of Sciences of the United States of America. 104 (27), 11316-11321 (2007).</li><li>Chi, N. C., 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=Genetic+and+physiologic+dissection+of+the+vertebrate+cardiac+conduction+system.">Genetic and physiologic dissection of the vertebrate cardiac conduction system.</a> PLoS Biology. 6 (5), 109 (2008).</li><li>Poss, K. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Getting+to+the+heart+of+regeneration+in+zebrafish.">Getting to the heart of regeneration in zebrafish.</a> Seminars in Cell &amp; Developmental Biology. 18 (1), 36-45 (2007).</li><li>Fang, Y., 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=Translational+profiling+of+cardiomyocytes+identifies+an+early+Jak1/Stat3+injury+response+required+for+zebrafish+heart+regeneration.">Translational profiling of cardiomyocytes identifies an early Jak1/Stat3 injury response required for zebrafish heart regeneration.</a> Proceedings of the National Academy of Sciences of the United States of America. 110 (33), 13416-13421 (2013).</li><li>Manoli, M., Driever, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescence-activated+cell+sorting+(FACS)+of+fluorescently+tagged+cells+from+zebrafish+larvae+for+RNA+isolation.">Fluorescence-activated cell sorting (FACS) of fluorescently tagged cells from zebrafish larvae for RNA isolation.</a> Cold Spring Harbor Protocols. 2012 (8), (2012).</li><li>Cannon, J. E., 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=Global+analysis+of+the+haematopoietic+and+endothelial+transcriptome+during+zebrafish+development.">Global analysis of the haematopoietic and endothelial transcriptome during zebrafish development.</a> Mechanisms of Development. 130 (2-3), 122-131 (2013).</li><li>Wang, Z., Gerstein, M., Snyder, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNA-Seq:+a+revolutionary+tool+for+transcriptomics.">RNA-Seq: a revolutionary tool for transcriptomics.</a> Nature Reviews Genetics. 10 (1), 57-63 (2009).</li><li>Gupta, T., Mullins, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dissection+of+organs+from+the+adult+zebrafish.">Dissection of organs from the adult zebrafish.</a> Journal of Visualized Experiments. 37, (2010).</li><li>Singleman, C., Holtzman, N. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+dissection+in+larval,+juvenile+and+adult+zebrafish,+Danio+rerio.">Heart dissection in larval, juvenile and adult zebrafish, Danio rerio.</a> Journal of Visualized Experiments. 55, (2011).</li><li>Westerfield, 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> The zebrafish book: a guide for the laboratory use of zebrafish (Brachydanio rerio. , (1993).</li></ol>

The authors have no disclosures.

Yetişkin zebrabalıkları kalp kesme yöntemleri tarif edilmiş olmasına rağmen, bu yöntemler zaman alıcıdır ve genel olarak Diseksiyon sırasında kalbin hasar görmesine neden oldu. Yetişkin kalpte çok sayıda gerekli olabilir deneyleri gerçekleştirmek için, ve / veya kalp dokusu bozulmasını önlemek alt baş uygulamalar için önemli olduğunda, geleneksel diseksiyon teknikleri kullanılarak gereken süre engelleyicidir. Benzer bir şekilde, yeniden üretilebilir, hasarsız sağlam kalpleri elde kalp ya...

Zebrafish are an excellent model for studying heart development and human disease1,2. Specific advantages include the translucent nature of zebrafish embryos, the availability of many genetic mutants and transgenic reporter lines, and the availability of genome editing technologies. In addition to their advantages for studying early heart development, zebrafish are an ideal system for studying vertebrate heart regeneration3.
More recently, adult zebrafish are playing an important part in bioinformatics approaches to studying cardiovascular development and disease, due to their relatively large clutch size and relatively quick and inexpensive breeding compared to other vertebrate models. Promising techniques include ribosome profiling, RNA-Seq, and cell dissociation and FACS sorting4-7. However, for these techniques the quality of the data can depend on obtaining a large number of samples in a rapid, efficient, and reproducible manner, before gene regulatory, metabolic, transcriptional, and other changes occur.
Dissection of adult zebrafish organs has been described in the past8,9. However, previous approaches to dissection of the heart were slow, ran the risk of damaging the heart during dissection, required special tools, and/or required fixation of the zebrafish prior to dissection; for these reasons, past approaches to zebrafish adult heart dissection were not optimized for high-throughput applications and/or applications requiring fresh tissue.
Here, we describe a method for adult zebrafish heart dissection that is simple, fast, efficient, and reproducible, while preserving cardiac morphology. This method does not include cutting into the pericardial space and therefore does not risk damaging the heart during dissection. Instead, this method relies on anatomical landmarks of the zebrafish, and therefore, it is highly reproducible. This dissection method is also versatile in that it can be used on fresh or fixed fish, and on zebrafish as young as one month old. Finally, this method results in minimal suffering to the zebrafish because after anesthesia and/or rapid cooling, the fish is additionally decapitated and pithed in the course of the dissection procedure.

<table><tbody><tr><td>Small tank for transporting fish</td><td>Aquaneering</td><td>ZHCT100</td><td></td></tr><tr><td>Fish net</td><td>Petsmart</td><td>36-16731</td><td></td></tr><tr><td>250 ml glass beaker</td><td>Kimble</td><td>14005-250</td><td></td></tr><tr><td>9 cm polystyrene Petri dish</td><td>Nunc</td><td>172958</td><td></td></tr><tr><td>Razor blade</td><td>Personna American Safety Razor Company</td><td>94-120-71</td><td></td></tr><tr><td>2 Dumont #5SF forceps</td><td>Fine Science Tools</td><td>11252-00</td><td></td></tr><tr><td>Dissecting microscope</td><td>Olympus</td><td>SZX16</td><td></td></tr><tr><td>Tricaine</td><td>Sigma</td><td>A-5040</td><td></td></tr><tr><td>Plastic transfer pipette</td><td>Thermo Scientific</td><td>202-20S</td><td></td></tr><tr><td>Gooseneck light source</td><td>Dolan-Jenner Industries, Inc</td><td>Fiber-Lite 180 Illuminator, 181 Dual Gooseneck System</td><td></td></tr><tr><td>Fluorescent light source</td><td>Lumen Dynamics</td><td>X-Cite 120Q</td><td>optional</td></tr><tr><td>Micro-scissors</td><td>Biomedical Research Instruments, Inc</td><td>11-1000</td><td>optional</td></tr><tr><td>RBC lysis buffer</td><td>eBioscience</td><td>00-4333-57</td><td>optional</td></tr></tbody></table>

recovery of adult zebrafish hearts for high-throughput applications

Geliştirme, rejenerasyon okuyan ve hastalık hücre ayrışma ve RNA, DNA ve protein saflaştırılması için erişkin kalplerinde kullanımına doğru genişleyen için zebra balığı model sistem kullanımı. Bu uygulamaların hepsi düzenleyici geni, metabolik ve ölümden sonra başlar diğer değişiklikleri önlemek için zebrabalıkları kalplerin önemli sayıda hızlı iyileşme talep. Yetişkin zebrabalıkları kalpler de mutantların çeşitli kalp yapısını incelemek için ve kalp rejenerasyonu çalışmak için gereklidir. Ancak, geleneksel Zebra balığı kalp diseksiyon yavaş ve zor ve yetişkin zebrabalıkları kalplerin büyük ölçekli diseksiyonu sıkıcı hale özel araçlar gerektirir. Geleneksel yöntemler de diseksiyonu sırasında kalp zarar riskini barındırır. Burada, biz, hızlı, tekrarlanabilir ve kalp mimarisini koruyan yetişkin zebrabalıkları kalplerin diseksiyon için bir yöntem açıklanmaktadır. Ayrıca, bu yöntem özel araçlar gerektirmez, Zebra balığı için ağrısızcan taze veya sabit örnekler üzerinde yapılabilir, ve bir aylık gibi genç zebrafish yapılabilir. açıklanan yaklaşım kardiyovasküler araştırma için yetişkin zebrafish kullanımını genişletiyor.

Bu yöntem kullanılarak, bir yetişkin, zebra balığı, kalp, geleneksel yöntemler kullanılarak 8 üzerinde 5 dakika ile karşılaştırıldığında, en az 1 dakika içinde parçalara edilebilir. Geleneksel yöntemler 8 perikard içine körü körüne kesme ve bu nedenle yaygın atrium veya bulbus arteriozus (Şekil 2B) hasar veya kaybına neden gerektirir ise, bu yöntem kullanılarak disseke Kalpler, (Şekil 2A) güvenilir sağlam. Parçalara Kalpler yapısa...

Watch this Scientific Journal Video about Recovery of Adult Zebrafish Hearts for High-throughput Applications at JoVE.com

Recovery of Adult Zebrafish Hearts for High-throughput Applications

Use of zebrafish for cardiovascular research is expanding towards research on adult hearts. For these applications, quick and simple isolation of cardiac tissues is key to avoid post-mortem changes and to obtain an adequate number of samples. Here, we describe a fast and reproducible method for dissecting adult zebrafish hearts.

Yüksek verim Uygulamaları Yetişkin Zebra Hearts Kurtarma

Use of the zebrafish model system for studying development, regeneration, and disease is expanding toward use of adult hearts for cell dissociation and ...

recovery-of-adult-zebrafish-hearts-for-high-throughput-applications

Research

JoVE Journal

Biology

12.2K Görüntüleme.  University of California San Francisco. Use of zebrafish for cardiovascular research is expanding towards research on adult hearts. For these applications, quick and simple isolation of cardiac tissues is key to avoid post-mortem changes and to obtain an adequate number of samples. Here, we describe a fast and reproducible method for dissecting adult zebrafish hearts.

Video: Recovery of Adult Zebrafish Hearts for High-throughput Applications

Large-scale Zebrafish Embryonic Heart Dissection for Transcriptional Analysis

The zebrafish embryonic heart is composed of only a few hundred cells, representing only a small fraction of the entire embryo. Therefore, to prevent the cardiac transcriptome from being masked by the global embryonic transcriptome, it is necessary to collect sufficient numbers of hearts for further analyses. Furthermore, as zebrafish cardiac development proceeds rapidly, heart collection and RNA extraction methods need to be quick in order to ensure homogeneity of the samples. Here, we present a rapid manual dissection protocol for collecting functional/beating hearts from zebrafish embryos. This is an essential prerequisite for subsequent cardiac-specific RNA extraction to determine cardiac-specific gene expression levels by transcriptome analyses, such as quantitative real-time polymerase chain reaction (RT-qPCR). The method is based on differential adhesive properties of the zebrafish embryonic heart compared with other tissues; this allows for the rapid physical separation of cardiac from extracardiac tissue by a combination of fluidic shear force disruption, stepwise filtration and manual collection of transgenic fluorescently labeled hearts.

To analyse cardiac gene expression profiles during zebrafish heart development, total RNA has to be extracted from isolated hearts. Here, we present a protocol for collecting functional/beating hearts by rapid manual dissection from zebrafish embryos to obtain cardiac-specific mRNA.

Transkripsiyonal Analiz Büyük ölçekli Zebra balığı Embriyonik Kalp Diseksiyon

The zebrafish embryonic heart is composed of only a few hundred cells, representing only a small fraction of the entire embryo. Therefore, to prevent the ...

Gelişim Biyolojisi

Induction of Myocardial Infarction in Adult Zebrafish Using Cryoinjury

The mammalian heart is incapable of significant regeneration following an acute injury such as myocardial infarction1. By contrast, urodele amphibians and teleost fish retain a remarkable capacity for cardiac regeneration with little or no scarring throughout life2,3. It is not known why only some non-mammalian vertebrates can recreate a complete organ from remnant tissues4,5. To understand the molecular and cellular differences between regenerative responses in different species, we need to use similar approaches for inducing acute injuries.
In mammals, the most frequently used model to study cardiac repair has been acute ischemia after a ligation of the coronary artery or tissue destruction after cryoinjury6,7. The cardiac regeneration in newts and zebrafish has been predominantly studied after a partial resection of the ventricular apex2,3. Recently, several groups have established the cryoinjury technique in adult zebrafish8-10. This method has a great potential because it allows a comparative discussion of the results obtained from the mammalian and non-mammalian species.
Here, we present a method to induce a reproducible disc-shaped infarct of the zebrafish ventricle by cryoinjury. This injury model is based on rapid freezing-thawing tissue, which results in massive cell death of about 20% of cardiomyocytes of the ventricular wall. First, a small incision was made through the chest with iridectomy scissors to access the heart. The ventricular wall was directly frozen by applying for 23-25 seconds a stainless steel cryoprobe precooled in liquid nitrogen. To stop the freezing of the heart, fish water at room temperature was dropped on the tip of the cryoprobe. The procedure is well tolerated by animals, with a survival rate of 95%.
To characterize the regenerative process, the hearts were collected and fixed at different days after cryoinjury. Subsequently, the specimen were embedded for cryosectioning. The slides with sections were processed for histological analysis, in situ hybridization and immunofluorescence. This undertaking enhances our understanding of the factors that are required for the regenerative plasticity in the zebrafish, and provide new insights into the machinery of cardiac regeneration. A conceptual and molecular understanding of heart regeneration in zebrafish will impact both developmental biology and regenerative medicine.

Zebrafish represents a valuable model to study the mechanisms of heart regeneration in vertebrates. Here, we present a protocol for induction of a heart infarct in adult zebrafish using cryoinjury. This method results in massive cell death within 20% of the ventricular wall, similar to that observed in mammalian infarcts.

Yetişkin Zebra balığı Myokard İnfarktüsü İndüksiyon Cryoinjury kullanma

The mammalian heart is incapable of significant regeneration following an acute injury such as myocardial infarction1. By contrast, urodele amphibians and ...

Tıp

Nanoparticle-mediated siRNA Gene-silencing in Adult Zebrafish Heart

Mammals have a very limited capacity to regenerate the heart after myocardial infarction. On the other hand, the adult zebrafish regenerates its heart after apex resection or cryoinjury, making it an important model organism for heart regeneration study. However, the lack of loss-of-function methods for adult organs has restricted insights into the mechanisms underlying heart regeneration. RNA interference via different delivery systems is a powerful tool for silencing genes in mammalian cells and model organisms. We have previously reported that siRNA-encapsulated nanoparticles successfully enter cells and result in a remarkable gene-specific knockdown in the regenerating adult zebrafish heart. Here, we present a simple, rapid, and efficient protocol for the dendrimer-mediated siRNA delivery and gene-silencing in the regenerating adult zebrafish heart. This method provides an alternative approach for determining gene functions in adult organs in zebrafish and can be extended to other model organisms as well.

It remains a major challenge to develop conditional gene-knockout or effective gene-knockdown in adult zebrafish organs. Here we report a protocol for performing nanoparticle-mediated siRNA gene-silencing in adult zebrafish heart, thus providing a new loss-of-function method for studying adult organs in zebrafish and other model organisms.

Nanopartikül aracılı siRNA Gene susturmak yetişkin zebra balığı kalbinde

Mammals have a very limited capacity to regenerate the heart after myocardial infarction. On the other hand, the adult zebrafish regenerates its heart ...

High-Frequency Ultrasound Echocardiography to Assess Zebrafish Cardiac Function

The zebrafish (Danio rerio) has become a very popular model organism in cardiovascular research, including human cardiac diseases, largely due to its embryonic transparency, genetic tractability, and amenity to rapid, high-throughput studies. However, the loss of transparency limits heart function analysis at the adult stage, which complicates modeling of age-related heart conditions. To overcome such limitations, high-frequency ultrasound echocardiography in zebrafish is emerging as a viable option. Here, we present a detailed protocol to assess cardiac function in adult zebrafish by non-invasive echocardiography using high-frequency ultrasound. The method allows visualization and analysis of zebrafish heart dimension and quantification of important functional parameters, including heart rate, stroke volume, cardiac output, and ejection fraction. In this method, the fish are anesthetized and kept underwater and can be recovered after the procedure. Although high-frequency ultrasound is an expensive technology, the same imaging platform can be used for different species (e.g., murine and zebrafish) by adapting different transducers. Zebrafish echocardiography is a robust method for cardiac phenotyping, useful in the validation and characterization of disease models, particularly late-onset diseases; drug screens; and studies of heart injury, recovery, and regenerative capacity.

We describe a protocol to assess heart morphology and function in adult zebrafish using high-frequency echocardiography. The method allows visualization of the heart and subsequent quantification of functional parameters, such as heart rate (HR), cardiac output (CO), fractional area change (FAC), ejection fraction (EF), and blood inflow and outflow velocities.

Zebrafish Kardiyak Fonksiyondeğerlendirmek için Yüksek Frekanslı Ultrason Ekokardiyografi

The zebrafish (Danio rerio) has become a very popular model organism in cardiovascular research, including human cardiac diseases, largely due to its ...

Heart Dissection in Larval, Juvenile and Adult Zebrafish, Danio rerio

Zebrafish have become a beneficial and practical model organism for the study of embryonic heart development (see recent reviews1-6), however, work examining post-embryonic through adult cardiac development has been limited7-10. Examining the changing morphology of the maturing and aging heart are restricted by the lack of techniques available for staging and isolating juvenile and adult hearts. In order to analyze heart development over the fish's lifespan, we dissect zebrafish hearts at numerous stages and photograph them for further analysis11. The morphological features of the heart can easily be quantified and individual hearts can be further analyzed by a host of standard methods. Zebrafish grow at variable rates and maturation correlates better with fish size than age, thus, post-fixation, we photograph and measure fish length as a gauge of fish maturation. This protocol explains two distinct, size dependent dissection techniques for zebrafish, ranging from larvae 3.5mm standard length (SL) with hearts of 100&mu;m ventricle length (VL), to adults, with SL of 30mm and VL 1mm or larger. Larval and adult fish have quite distinct body and organ morphology. Larvae are not only significantly smaller, they have less pigment and each organ is visually very difficult to identify. For this reason, we use distinct dissection techniques.
We used pre-dissection fixation procedures, as we discovered that hearts dissected directly after euthanization have a more variable morphology, with very loose and balloon like atria compared with hearts removed following fixation. The fish fixed prior to dissection, retain in vivo morphology and chamber position (data not shown). In addition, for demonstration purposes, we take advantage of the heart (myocardial) specific GFP transgenic Tg(myl7:GFP)twu34 (12), which allows us to visualize the entire heart and is particularly useful at early stages in development when the cardiac morphology is less distinct from surrounding tissues. Dissection of the heart makes further analysis of the cell and molecular biology underlying heart development and maturation using in situ hybridization, immunohistochemistry, RNA extraction or other analytical methods easier in post-embryonic zebrafish. This protocol will provide a valuable technique for the study of cardiac development maturation and aging.

Heart Dissection in Larval, Juvenile and Adult Zebrafish, Danio rerio

A clear, standardized method for dissection and isolation of the zebrafish heart at multiple developmental stages are described. Annotation and quantification techniques are also discussed.

Larvaların Kalp Diseksiyon, Çocuk ve Yetişkin Zebra balığı, Danio rerio</em

Zebrafish have become a beneficial and practical model organism for the study of embryonic heart development (see recent reviews1-6), however, work ...

Biyoloji

Immunostaining of Dissected Zebrafish Embryonic Heart 

Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology and genetics 1,2. About 100-200 embryos are readily available every week from a single pair of adult fish. The transparent embryos that develop ex utero make them ideal for assessing cardiac defects 3. The expression of any gene can be manipulated via morpholino technology or RNA injection 4. Moreover, forward genetic screens have already generated a list of mutants that affect different perspectives of cardiogenesis 5. 
Whole mount immunostaining is an important technique in this animal model to reveal the expression pattern of the targeted protein to a particular tissue 6. However, high resolution images that can reveal cellular or subcellular structures have been difficult, mainly due to the physical location of the heart and the poor penetration of the antibodies. 
 Here, we present a method to address these bottlenecks by dissecting heart first and then conducting the staining process on the surface of a microscope slide. To prevent the loss of small heart samples and to facilitate solution handling, we restricted the heart samples within a circle on the surface of the microscope slides drawn by an immEdge pen. After the staining, the fluorescence signals can be directly observed by a compound microscope. 
Our new method significantly improves the penetration for antibodies, since a heart from an embryonic fish only consists of few cell layers. High quality images from intact hearts can be obtained within a much reduced procession time for zebrafish embryos aged from day 2 to day 6. Our method can be potentially extended to stain other organs dissected from either zebrafish or other small animals.

Immunostaining of Dissected Zebrafish Embryonic Heart

A rapid way to conduct immunostaining of zebrafish embryonic heart is described. Compared to the whole mount immunostaining approach, this method dramatically increases the penetration of the antibodies, which allows obtaining high resolution images that reveal cellular/subcellular structures in the heart within a much reduced processing time.

Zebra balığı Embriyonik Kalp Dissected, immün

Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology ...

Assessment of Swim Endurance and Swim Behavior in Adult Zebrafish

Due to their renowned regenerative capacity, adult zebrafish are a premier vertebrate model to interrogate mechanisms of innate spinal cord regeneration. Following complete transection of their spinal cord, zebrafish extend glial and axonal bridges across severed tissue, regenerate neurons proximal to the lesion, and regain their swim capacities within 8 weeks of injury. Recovery of swim function is thus a central readout for functional spinal cord repair. Here, we describe a set of behavioral assays to quantify zebrafish motor capacity inside an enclosed swim tunnel. The goal of these methods is to provide quantifiable measurements of swim endurance and swim behavior in adult zebrafish. For swim endurance, zebrafish are subjected to a constantly increasing water current velocity until exhaustion, and time at exhaustion is reported. For swim behavior assessment, zebrafish are subjected to low current velocities and swim videos are captured with a dorsal view of the fish. Percent activity, burst frequency, and time spent against the water current provide quantifiable readouts of swim behavior. We quantified swim endurance and swim behavior in wild-type zebrafish before injury and after spinal cord transection. We found that zebrafish lose swim function after spinal cord transection and gradually regain that capacity between 2 and 6 weeks post-injury. The methods described in this study could be applied to neurobehavioral, musculoskeletal, skeletal muscle regeneration, and neural regeneration studies in adult zebrafish.

Capable of functional recovery after spinal cord injury, adult zebrafish is a premier model system to elucidate innate mechanisms of neural regeneration. Here, we describe swim endurance and swim behavior assays as functional readouts of spinal cord regeneration.

Yetişkin Zebra Balıklarında Yüzme Dayanıklılığı ve Yüzme Davranışının Değerlendirilmesi

Due to their renowned regenerative capacity, adult zebrafish are a premier vertebrate model to interrogate mechanisms of innate spinal cord regeneration. ...

Nörobilim

Anesthesia-free Heartbeat Measurements in Freely Moving Zebrafish

Zebrafish (Danio rerio) is a widely used model organism in physiological, pharmacological, and toxicological research due to its genetic similarity to humans and transparent embryonic stage, which facilitates non-invasive cardiovascular studies. However, current methods for heart rate assessment in zebrafish often rely on anesthesia to immobilize the subject, introducing physiological alterations that compromise data accuracy and reproducibility. This study presents a novel, anesthesia-free technique for measuring heartbeat in freely moving zebrafish larvae, addressing a critical limitation in cardiovascular research. The proposed approach integrates shortwave-infrared imaging with machine-learning-based heart tracking, allowing for precise and continuous cardiac activity monitoring in non-immobilized specimens. A convolutional neural network was trained to detect the heart region, and a photoplethysmographic signal was extracted from image sequences to determine heart rate. Experimental validation demonstrated the method's reliability and consistency across multiple test conditions. A key benefit of the methodology is its ability to preserve the natural physiological state of zebrafish, minimizing stress-induced artifacts. This non-invasive, label-free technique offers significant advantages for studying cardiovascular physiology, drug cardiotoxicity, and environmental toxicology, expanding the potential applications of zebrafish as a model for biomedical research.

The study aims to develop technology for anesthesia-free heartbeat measurements in moving zebrafish. Our approach combines shortwave-infrared imaging and machine-learning-based tracking of the heart. It is a non-invasive, label-free, and user-friendly technique that suits a wide range of studies on the zebrafish model.

Zebrafish (Danio rerio) is a widely used model organism in physiological, pharmacological, and toxicological research due to its genetic similarity to ...

Biyomühendislik

Intrathoracic Injection for the Study of Adult Zebrafish Heart

The adult zebrafish heart provides a powerful model in cardiac regeneration research. Although the strength of this system is based on transgenic approaches, a rapid delivery of exogenous factors provides a complementary technique in functional studies. Here, we present a method that relies on administration of a few microliters of solution into the pericardial cavity without causing myocardial damage. Intrathoracic (IT) injections can efficiently deliver proteins and chemical compounds directly onto the heart surface. The injected substances diffuse through the epicardium into the underlying cardiac tissues. Compared to intraperitoneal (IP) injections, the main advantage of intrathoracic injections is the focal administration of the tested factors on the target organ. The delivery of molecules directly into the pericardium is a suitable strategy for studies of cardiac preconditioning and regeneration in adult zebrafish.

This method relies on the injection of 0.5&#8722;3 &#956;L of solution into the thorax of adult zebrafish. The procedure efficiently delivers proteins and chemical compounds into the proximity of the zebrafish heart without damaging the organ. The approach is suitable for testing effects of exogenous factors on various tissues of the heart.

Yetişkin zebrafish kalp çalışması için intratorasik enjeksiyon

The adult zebrafish heart provides a powerful model in cardiac regeneration research. Although the strength of this system is based on transgenic ...

In Vivo Surface Electrocardiography for Adult Zebrafish

The electrocardiogram waveforms of adult zebrafish and those of humans are remarkably similar. These electrocardiogram similarities enhance the value of zebrafish not only as a research model for human cardiac electrophysiology and myopathies but also as a surrogate model in high throughput pharmaceutical screening for potential cardiotoxicities to humans, such as QT prolongation. As such, in vivo electrocardiography for adult zebrafish is an electrical phenotyping tool that is necessary, if not indispensable, for cross-sectional or longitudinal in vivo electrophysiological characterizations. However, too often, the lack of a reliable, practical, and cost-effective recording method remains a major challenge preventing this in vivo diagnostic tool from becoming more readily accessible. Here, we describe a practical, straightforward approach to in vivo electrocardiography for adult zebrafish using a low-maintenance, cost-effective, and comprehensive system that yields consistent, reliable recordings. We illustrate our protocol using healthy adult male zebrafish of 12-18 months of age. We also introduce a rapid real-time interpretation strategy for quality validation to ensure data accuracy and robustness early in the electrocardiogram recording process.

Here, we present a reliable, minimally invasive, and cost-effective method to record and interpret electrocardiograms in live anesthetized adult zebrafish.

Yetişkin zebrafish için In vivo yüzey elektrokardiyografi

The electrocardiogram waveforms of adult zebrafish and those of humans are remarkably similar. These electrocardiogram similarities enhance the value of ...