Albert Einstein College of Medicine başlangıç ​​fonları; Bu çalışma Ulusal Sağlık Enstitüleri (RDS 3U54AI057158-06S1 PW GM093282) tarafından kısmen desteklenmiştir.

1. Yumurta Toplama ve Dechorionation <ol><li> 35mm petri Zebra balığı yumurtaları toplamak ve aktarmak mümkün olduğu kadar su olarak kaldırmak ve sonra 1 mg / ml E3 embriyo orta Pronease D (5 mM NaCl, 0.17 mM KCl, 0.33 mM CaCl 2 · 2H 2 O, 0.33 mM MgSO eklemek koryon sindirmek için 4, pH = 7,4). </li><li> 3-5 dakika sonra, balık suyu (litre başına 60 mg &quot;anında Ocean&quot; damıtılmış H 2 O) ile dolu bir behere çanak birleştirme ve beher hafifçe yumurta ve yumurta suya &quot;düşmek&quot; için izin. </li><li> Yumurta balık üç kez su ile durulayın. En yumurta koryon piyasaya sürülecek. </li><li> Bir yangın parlatılmış cam Pasteur pipeti kullanarak, E3 embriyo orta ile dolu agaroz kaplı petri kaplarına dechorionated yumurta transferi. </li></ol> 2. GSYİH-FucAl ile Mikroenjeksiyon <ol><li> Rapor protokol 7 enjeksiyon yemekleri hazırlayın. </li><li> E3 embriyo orta ile dolu enjeksiyon yemekleri içine dechorionated yumurta transferi. </li><li> Iğne hazırlayın ve 2 mcL enjeksiyon çözüm yük. Bu çözüm, bir izleme veya 0.2 M KCl fenol kırmızısı yükleme boyası (% 0.1 w / v) olarak 20 mM ve GSYİH-FucAl chemoenzymatically sentezlenmiş 8 ya Alexa Fluor 594-dekstran (% 5 w / v) içerir. Negatif kontrol olarak, enjeksiyon çözüm GSYİH fucose ile GDP-FucAl değiştirin. </li><li> Break iğne ve enjeksiyon basıncı ve süresi 1 nL damla 9 verim ayarlayın. </li><li> Ya çözüm 1 nL yumurta enjekte edilir. </li><li> E3 embriyo orta ile dolu agaroz kaplı petri kutularının içine yumurta transferi. </li><li> Yumurta 28 ° C&#39;de inkübe ve döllenme sonrası 3-4 saat içinde döllenmemiş yumurta kaldırmak. </li></ol> 3. BTTES-Cu (I) katalize tıklayın Kimya Reaksiyon <ol><li> Embriyoların gelişim evreleri (örneğin geç gastrula, doku segmentasyonu ve erken larva), agaroz ile 96-plaka taban kat istenilen ulaştığınızda. </li><li> Her bir kuyu için 92 mcL E3 embriyo orta, (H 2 O bir 2.5 mM stok) 4 mcL Alexa Fluor-488 azid ek 2 mcL BTTES CuSO 4 06:01 karmaşık ve karıştırmak için hafifçe sallayın. </li><li> Tıklayarak kimya reaktif içeren bir yangın parlatılmış cam Pasteur pipeti kullanarak içine embriyolar transfer. Her iyi beş embriyolar daha az içermelidir. </li><li> Tıklama reaksiyon başlatmak için 3 2.5 mcL taze hazırlanmış sodyum askorbat (H 2 O, 100 mM stok) ekleyin . Her reaktifin Final konsantrasyon: Alexa Fluor-488 azid: 100 mcM; CuSO 4: 50 mcM; BTTES: 300 mcM, sodyum askorbat: 2.5 mM. </li><li> 3 dakika sonra, sonra tepki gidermek için 100 mcL E3 embriyo orta ile hemen sulandırmak, 2 mcL bathocuproine sülfonat (H 2 O 50 mM hisse senedi), biyouyumlu bir bakır şelasyon ekleyin. </li><li> Bir cam petri embriyoların transferi ve 15 ml E3 embriyo orta ile tedavi edilen embriyoların 2 kez yıkayın. </li></ol> 4. Görüntüleme <ol><li> Mattek cam alt kuyu çanak, ultra erime noktası agaroz (E3 embriyo orta% 1,2 (w / v)) bir damla koyun ve agaroz açılan bir embriyo. </li><li> Dorsal veya yanal embriyoların yerleştirin ve agaroz damla katılaşmaya 5 dakika buz üzerinde çanak. Agaroz açılan kapakları kadar çanak hafifçe E3 embriyo orta ekleyin. </li><li> Floresan ve parlak alan görüntüleri sırayla konfokal mikroskop kullanılarak elde edilir. Tüm embriyo görüntüleri 5 mikron adım aralığı kullanılarak elde edilir. Kompozit rakamlar ImageJ yazılımı kullanılarak hazırlanmıştır. </li></ol> 5. Temsilcisi Sonuçlar Şekil 1, iki adımlı bir etiketleme stratejisi iş akışı gösterir. Şekil 2, 9.5 saat sonra döllenme (hpf) BTTES aracılı CuAAC ile zebrafish embriyoların etiketleme gösterir. BTTES tris (triazolylmethyl) amin tabanlı ligand. Situ üretilen Cu (I) ile koordine dramatik CuAAC hızlandırır ve belirgin toksisite olmadan yaşayan sistemlerinde hızla Siklokatılma tepki teşvik. 3 dakikalık bir tıklama reaksiyon hemen ardından, GSYİH-FucAl tedavi edilen embriyoların sağlam bir etiket (Şekil 2, sol panel) tespit edebilmektedir. Sadece arka plan floresan GSYİH-fucose (Şekil 2, sağ panel) ile microinjected kontrol embriyolar tespit edilmiştir. <img src="/files/ftp_upload/2686/2686fig1.jpg" alt="Şekil 1" /> Şekil 1 zebrafish embriyoların saran tabaka fucosylated glukanlardır etiketleme stratejisi. <img src="/files/ftp_upload/2686/2686fig2.jpg" alt="Şekil 2" /> Şekil 2 BTTES-Cu (I)-katalize tıklayın kimyası ile zebrafish embriyogenez sırasında fucosylated glukanlardır in vivo görüntüleme. Tek hücreli aşamasında zebrafish embriyolar tek bir doz ile GDP-FucAl microinjected ve devel izin9.5 hpf op. Embriyolar daha sonra Alexa Fluor BTTES-Cu (I) 488-azid katalize tepki. Tepki embriyolar konfokal mikroskopi kullanılarak görüntülü. Aydınlık alan (alt panel); Alexa Fluor 488 floresan (üst panel) maksimum yoğunluğu z-projeksiyon görüntüleri. Ölçek çubuğu: 100 mm. Sorun Giderme <table border="1"><tbody><tr><td> Sorun </td><td> Neden </td><td> Çare </td></tr><tr><td> Embriyolar sağlıksız görünüm </td><td> Microinjected çözüm kirletici içerir </td><td> Nükleotid şekerlerin saflığı% 85 daha fazla olmalıdır. Kaynağını kontrol edin. </td></tr><tr><td> Etiketleme sonra hiçbir tepki var. </td><td> Bakır konsantrasyonu 30 mcM </td><td> Embriyoların eklerken bakır konsantrasyonu 30 mcM altında olduğunda reaksiyon hızını önemli ölçüde azalır, aşırı E3 embriyo orta ekleyerek reaksiyon çözümü sulandırmak için dikkatli olun. </td></tr><tr><td> Embriyolar reaksiyon sonra ölür </td><td> Embriyoların yanlış kullanım </td><td> Pipetlemeyin yangın cilalı ve reaksiyon kabı,% 0.5 &#39;lik agaroz bir çok ince bir tabaka ile kaplı olduğundan emin olun. </td></tr><tr><td> Görüntüler lekeli görünüm </td><td> Reaktifler düzgün embriyoların eklemeden önce karıştırılır. </td><td> Reaktiflerin Ayrıca önerilen sırayla izleyin ve tıklama kimya reaktifleri düzgün embriyoların eklemeden önce karışık olduğunu emin olun. </td></tr><tr><td> Görüntüleri embriyoların zarar </td><td> Reaksiyon sırasında Güçlü zararlardan sallayarak embriyolar </td><td> Embriyoların çözüm kez en az 10 saniye süreyle yavaşça sallayın. </td></tr><tr><td></td><td></td><td></td></tr></tbody></table>

<ol>
	<li>Laughlin, S. T., Bertozzi, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+the+glycome.">Imaging the glycome.</a> Proc. Natl. Acad. Sci. U. S. A. 106, 12-17 (2009).</li><li>Baskin, J. M., Bertozzi, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioorthogonal+click+chemistry:+Covalent+labeling+in+living+systems.">Bioorthogonal click chemistry: Covalent labeling in living systems.</a> Qsar Comb. Sci. 26, 1211-1219 (2007).</li><li>Soriano del Amo, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biocompatible+copper(I)+catalysts+for+in+vivo+imaging+of+glycans.">Biocompatible copper(I) catalysts for in vivo imaging of glycans.</a> J. Am. Chem. Soc. 132, 16893-16899 (2010).</li><li>Chang, P. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metabolic+labeling+of+sialic+acids+in+living+animals+with+alkynyl+sugars.">Metabolic labeling of sialic acids in living animals with alkynyl sugars.</a> Angew. Chem. Int. Ed. 48, 4030-4033 (2009).</li><li>Laughlin, S. T., Baskin, J. M., Amacher, S. L., Bertozzi, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+imaging+of+membrane-associated+glycans+in+developing+zebrafish.">In vivo imaging of membrane-associated glycans in developing zebrafish.</a> Science. 320, 664-667 (2008).</li><li>Baskin, J. M., Dehnert, K. W., Laughlin, S. T., Amacher, S. L., Bertozzi, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualizing+enveloping+layer+glycans+during+zebrafish+early+embryogenesis.">Visualizing enveloping layer glycans during zebrafish early embryogenesis.</a> Proc. Natl. Acad. Sci. U. S. A. 107, 10360-10365 (2010).</li><li>Kemp, H. A., Carmany-Rampey, A., Moens, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generating+chimeric+zebrafish+embryos+by+transplantation.">Generating chimeric zebrafish embryos by transplantation.</a> J. Vis. Exp. , (2009).</li><li>Wang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemoenzymatic+synthesis+of+GDP-L-fucose+and+the+Lewis+X+glycan+derivatives.">Chemoenzymatic synthesis of GDP-L-fucose and the Lewis X glycan derivatives.</a> Proc. Natl. Acad. Sci. U. S. A. 106, 16096-16101 (2009).</li><li>Rosen, J. N., Sweeney, M. F., Mably, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microinjection+of+zebrafish+embryos+to+analyze+gene+function.">Microinjection of zebrafish embryos to analyze gene function.</a> J. Vis. Exp. , (2009).</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 (Danio rerio). , (2007).</li><li>Kimmel, C. B., Warga, R. M., Schilling, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Origin+and+organization+of+the+zebrafish+fate+map.">Origin and organization of the zebrafish fate map.</a> Development. 108, 581-594 (1990).</li></ol>

<p class="jove_content"&gt; Görüntüleme biyomoleküllerin<em&gt; In vivo</em&gt; Kendi doğal ortamlarında kendi biyolojik faaliyetleri kritik bilgiler sağlar. Bu video, zebrafish embriyoların saran tabaka fucosylated glukanlardır etiketleme BTTES aracılı biyouyumlu CuAAC ile GSYİH FucAl ile tek hücreli aşamada embriyo ve ikinci bir adım fluorofor konjugasyon microinjecting tarafından gerçekleştirilen nasıl göstermek<sup&gt; 3</sup&gt;. Sağlam etiketleme 2-3 dakika içinde elde edilebilir ve etiketli glukanlardır 2.5 hpf olarak erken saptanabilir. Önemlisi, tek bir doz GSYİH-FucAl 96 hpf kadar saptanabilir alkin bağımlı floresan sinyalini verebilmesidir. Aynı yaklaşım, iki sıralı CuAAC üzerinden zebrafish gelişmekte alkin etiketli fucosides ticaretini izlemek için çok renkli zaman atlamalı görüntüleme deneyleri uzatılabilir. Ancak, etiketleme sadece tıklama kimya reaktiflerin düşük doku penetrasyon derinliği nedeniyle blastodisc saran bir tabaka elde edilir. Sabitleme ve permeabilizing metabolik GSYİH-FucAl ile tedavi edilen embriyoların, iç vücut parçaları etiketleme biz de elde edebilirsiniz. Zebrafish kaderi haritası aşağıdaki blastula aşamaları (4 hpf) ve (5.3 hpf) gastrulasyon başlangıcı arasında nakli kolayca etiketsiz hosts alkin etiketli donör embriyolar yapılabilir beri<sup&gt; 10, 11</sup&gt; Bu bir manipülasyon istismar, embriyonun gelişimi sırasında özel soy bu glukanlardır tahsisi izlemek için izin verebilir.</p&gt;<p class="jove_content"Birçok azid ve alkin Fonksiyonlu reaktifler piyasada bulunan&gt; gibi, sadece metabolik manipülasyonlar etiketli glukanlardır üretmek için gerekli<em&gt; In vivo</em&gt; Tıklayın modifikasyon bu işlem için. Bu nedenle, burada açıklanan kimyasal araçları sialik asit içeren diğer glukanlardır, örneğin glukanlardır eğitim için doğrudan uygulanabilir<sup&gt; 4</sup&gt; Ve<em&gt; N</em&gt;-Acetylgalactosamine<sup&gt; 5, 6</sup&gt; Zebrafish embriyolar ve diğer canlı sistemlerde (bu Monosakkaritler azid etiketli metabolik öncüleri Invitrogen piyasada mevcut olan).</p

<table border="1"><tbody><tr><td> Reaktifin Adı </td><td> Şirket </td><td> Katalog numarası </td></tr><tr><td> Bakır (II) sülfat pentahidrat </td><td> Sigma-Aldrich </td><td> 203165 </td></tr><tr><td> Alexa Fluor 488 azid </td><td> Invitrogen </td><td> A10266 </td></tr><tr><td> dekstran, Alexa Fluor 594 </td><td> Invitrogen </td><td> D-22.913 </td></tr><tr><td> (+)-Sodyum L-askorbat </td><td> Sigma-Aldrich </td><td> A7631 </td></tr><tr><td> Bathocuproinedisulfonic asit </td><td> Acros Organics </td><td> 164060010 </td></tr><tr><td> Cam alt kuyu çanak </td><td> Mattek </td><td> P35G-1.5-14-C </td></tr></tbody></table>

imaging glycans in zebrafish embryos by metabolic labeling and bioorthogonal click chemistry

In vivo Görüntüleme glukanlardır azid veya alkin etiketli Monosakkaritler 1, 2 ya da organizma hücreleri tedavi ederek son zamanlarda bir bioorthogonal kimyasal muhabiri stratejisi kullanılarak etkin olmuştur. Glukanıdır biyosentetik makine tarafından işlenen değiştirilmiş Monosakkaritler, hücre yüzeyinde glycoconjugates içine dahil edilmiştir. Bioorthogonal azid veya alkin etiketleri sonra görünüm için floresan problar ile kovalent konjugasyon, izin veya zenginleştirme ve glycoproteomic analiz afinite probları. Saran tabaka fucosylated glukanlardır etiketleme 1) GSYİH-5-alkynylfucose (GSYİH FucAl), 2 ile tek hücreli aşamada embriyo mikroenjeksiyon): Bu protokol da dahil olmak üzere genellikle zebrafish embriyolar fucosylated glukanlardır noninvaziv görüntüleme için kullanılan prosedürler açıklanmaktadır biyouyumlu konfokal mikroskopi 3 Cu (I) katalize azid-alkin Siklokatılma (CuAAC), ve 3) görüntüleme ile azid-konjuge fluorophores zebrafish embriyolar. Burada açıklanan yöntem glukanlardır diğer sınıflar, örneğin glukanlardır içeren sialik asit 4 ve N-acetylgalactosamine 5, 6, gelişmekte olan Zebra balığı ve diğer canlı organizmaların kolayca görselleştirmek için uzatılabilir.

Watch this Scientific Journal Video about Imaging Glycans in Zebrafish Embryos by Metabolic Labeling and Bioorthogonal Click Chemistry at JoVE.com

Imaging Glycans in Zebrafish Embryos by Metabolic Labeling and Bioorthogonal Click Chemistry

Zebra balığı embriyolar alkin etiketli glukanlardır hızlı, noninvaziv ve sağlam etiketleme için izin veren bir tıkla-kimya temelli yöntem açıklanmıştır. Bu çalışmada geç gastrulasyon aşamasında zebrafish embriyoların saran tabaka Fucosylated glukanlardır görüntülenmiştir.

Metabolik Etiketleme ve Bioorthogonal tıklayın Kimya Zebra balığı Embriyolar Görüntüleme glukanlardır

Imaging glycans in vivo has recently been enabled using a bioorthogonal chemical reporter strategy by treating cells or organisms with azide- or ...

imaging-glycans-zebrafish-embryos-metabolic-labeling-bioorthogonal

Nanyang Technological University

Research

JoVE Journal

Biology

13.6K Görüntüleme.  Albert Einstein College of Medicine, Yeshiva University. Zebra balığı embriyolar alkin etiketli glukanlardır hızlı, noninvaziv ve sağlam etiketleme için izin veren bir tıkla-kimya temelli yöntem açıklanmıştır. Bu çalışmada geç gastrulasyon aşamasında zebrafish embriyoların saran tabaka Fucosylated glukanlardır görüntülenmiştir.

Video: Imaging Glycans in Zebrafish Embryos by Metabolic Labeling and Bioorthogonal Click Chemistry

Two-photon axotomy and time-lapse confocal imaging in live zebrafish embryos

Zebrafish have long been utilized to study the cellular and molecular mechanisms of development by time-lapse imaging of the living transparent embryo. Here we describe a method to mount zebrafish embryos for long-term imaging and demonstrate how to automate the capture of time-lapse images using a confocal microscope. We also describe a method to create controlled, precise damage to individual branches of peripheral sensory axons in zebrafish using the focused power of a femtosecond laser mounted on a two-photon microscope. The parameters for successful two-photon axotomy must be optimized for each microscope. We will demonstrate two-photon axotomy on both a custom built two-photon microscope and a Zeiss 510 confocal/two-photon to provide two examples.

Zebrafish trigeminal sensory neurons can be visualized in a transgenic line expressing GFP driven by a sensory neuron specific promoter 1. We have adapted this zebrafish trigeminal model to directly observe sensory axon regeneration in living zebrafish embryos. Embryos are anesthetized with tricaine and positioned within a drop of agarose as it solidifies. Immobilized embryos are sealed within an imaging chamber filled with phenylthiourea (PTU) Ringers. We have found that embryos can be continuously imaged in these chambers for 12-48 hours. A single confocal image is then captured to determine the desired site of axotomy. The region of interest is located on the two-photon microscope by imaging the sensory axons under low, non-damaging power. After zooming in on the desired site of axotomy, the power is increased and a single scan of that defined region is sufficient to sever the axon. Multiple location time-lapse imaging is then set up on a confocal microscope to directly observe axonal recovery from injury.

Here we describe a method for mounting zebrafish embryos for long-term imaging, two-photon imaging and tissue-damage techniques, and time-lapse confocal imaging.

İki foton axotomy ve zaman atlamalı konfokal görüntüleme canlı zebrafish embriyolar

Zebrafish have long been utilized to study the cellular and molecular mechanisms of development by time-lapse imaging of the living transparent embryo.  ...

Biyoloji

Generating Chimeric Zebrafish Embryos by Transplantation

One of the most powerful tools used to gain insight into complex developmental processes is the analysis of chimeric embryos. A chimera is defined as an organism that contains cells from more than one animal; mosaics are one type of chimera in which cells from more than one genotype are mixed, usually wild-type and mutant. In the zebrafish, chimeras can be readily made by transplantation of cells from a donor embryo into a host embryo at the appropriate embryonic stage. Labeled donor cells are generated by injection of a lineage marker, such as a fluorescent dye, into the one-cell stage embryo. Labeled donor cells are removed from donor embryos and introduced into unlabeled host embryos using an oil-controlled glass pipette mounted on either a compound or dissecting microscope. Donor cells can in some cases be targeted to a specific region or tissue of the developing blastula or gastrula stage host embryo by choosing a transplantation site in the host embryo based on well-established fate maps.

A step-by-step guide to generating targeted chimeric zebrafish embryos by transplantation at the blastula or gastrula stage.

Transplantasyon Kimerik Zebra balığı Embriyolar Yaratma

One of the most powerful tools used to gain insight into complex developmental processes is the analysis of chimeric embryos. A chimera is defined as an ...

Imaging Cell Shape Change in Living Drosophila Embryos

The developing Drosophila melanogaster embryo undergoes a number of cell shape changes that are highly amenable to live confocal imaging. Cell shape changes in the fly are analogous to those in higher organisms, and they drive tissue morphogenesis. So, in many cases, their study has direct implications for understanding human disease (Table 1)1-5. On the sub-cellular scale, these cell shape changes are the product of activities ranging from gene expression to signal transduction, cell polarity, cytoskeletal remodeling and membrane trafficking. Thus, the Drosophila embryo provides not only the context to evaluate cell shape changes as they relate to tissue morphogenesis, but also offers a completely physiological environment to study the sub-cellular activities that shape cells.
The protocol described here is designed to image a specific cell shape change called cellularization. Cellularization is a process of dramatic plasma membrane growth, and it ultimately converts the syncytial embryo into the cellular blastoderm. That is, at interphase of mitotic cycle 14, the plasma membrane simultaneously invaginates around each of ~6000 cortically anchored nuclei to generate a sheet of primary epithelial cells. Counter to previous suggestions, cellularization is not driven by Myosin-2 contractility6, but is instead fueled largely by exocytosis of membrane from internal stores7. Thus, cellularization is an excellent system for studying membrane trafficking during cell shape changes that require plasma membrane invagination or expansion, such as cytokinesis or transverse-tubule (T-tubule) morphogenesis in muscle.
Note that this protocol is easily applied to the imaging of other cell shape changes in the fly embryo, and only requires slight adaptations such as changing the stage of embryo collection, or using "embryo glue" to mount the embryo in a specific orientation (Table 1)8-19. In all cases, the workflow is basically the same (Figure 1). Standard methods for cloning and Drosophila transgenesis are used to prepare stable fly stocks that express a protein of interest, fused to Green Fluorescent Protein (GFP) or its variants, and these flies provide a renewable source of embryos. Alternatively, fluorescent proteins/probes are directly introduced into fly embryos via straightforward micro-injection techniques9-10. Then, depending on the developmental event and cell shape change to be imaged, embryos are collected and staged by morphology on a dissecting microscope, and finally positioned and mounted for time-lapse imaging on a confocal microscope.

Imaging Cell Shape Change in Living Drosophila Embryos

Early development of the fruit fly, Drosophila melanogaster, is characterized by a number of cell shape changes that are well suited for imaging approaches. This article will describe basic tools and methods required for live confocal imaging of Drosophila embryos, and will focus on a cell shape change called cellularization.

Living Görüntüleme Hücre Şekli Değiştir Drosophila Embriyolar

The developing Drosophila melanogaster embryo undergoes a number of cell shape changes that are highly amenable to live confocal imaging.  Cell shape ...

Measuring Cell Cycle Progression Kinetics with Metabolic Labeling and Flow Cytometry

Precise control of the initiation and subsequent progression through the various phases of the cell cycle are of paramount importance in proliferating cells. Cell cycle division is an integral part of growth and reproduction and deregulation of key cell cycle components have been implicated in the precipitating events of carcinogenesis 1,2. Molecular agents in anti-cancer therapies frequently target biological pathways responsible for the regulation and coordination of cell cycle division 3. Although cell cycle kinetics tend to vary according to cell type, the distribution of cells amongst the four stages of the cell cycle is rather consistent within a particular cell line due to the consistent pattern of mitogen and growth factor expression. Genotoxic events and other cellular stressors can result in a temporary block of cell cycle progression, resulting in arrest or a temporary pause in a particular cell cycle phase to allow for instigation of the appropriate response mechanism. 
The ability to experimentally observe the behavior of a cell population with reference to their cell cycle progression stage is an important advance in cell biology. Common procedures such as mitotic shake off, differential centrifugation or flow cytometry-based sorting are used to isolate cells at specific stages of the cell cycle 4-6. These fractionated, cell cycle phase-enriched populations are then subjected to experimental treatments. Yield, purity and viability of the separated fractions can often be compromised using these physical separation methods. As well, the time lapse between separation of the cell populations and the start of experimental treatment, whereby the fractionated cells can progress from the selected cell cycle stage, can pose significant challenges in the successful implementation and interpretation of these experiments.
Other approaches to study cell cycle stages include the use of chemicals to synchronize cells. Treatment of cells with chemical inhibitors of key metabolic processes for each cell cycle stage are useful in blocking the progression of the cell cycle to the next stage. For example, the ribonucleotide reductase inhibitor hydroxyurea halts cells at the G1/S juncture by limiting the supply of deoxynucleotides, the building blocks of DNA. Other notable chemicals include treatment with aphidicolin, a polymerase alpha inhibitor for G1 arrest, treatment with colchicine and nocodazole, both of which interfere with mitotic spindle formation to halt cells in M phase and finally, treatment with the DNA chain terminator 5-fluorodeoxyridine to initiate S phase arrest 7-9. Treatment with these chemicals is an effective means of synchronizing an entire population of cells at a particular phase. With removal of the chemical, cells rejoin the cell cycle in unison. Treatment of the test agent following release from the cell cycle blocking chemical ensures that the drug response elicited is from a uniform, cell cycle stage-specific population. However, since many of the chemical synchronizers are known genotoxic compounds, teasing apart the participation of various response pathways (to the synchronizers vs. the test agents) is challenging. 
Here we describe a metabolic labeling method for following a subpopulation of actively cycling cells through their progression from the DNA replication phase, through to the division and separation of their daughter cells. Coupled with flow cytometry quantification, this protocol enables for measurement of kinetic progression of the cell cycle in the absence of either mechanically- or chemically- induced cellular stresses commonly associated with other cell cycle synchronization methodologies 10. In the following sections we will discuss the methodology, as well as some of its applications in biomedical research.

Tracking subtle changes in the progression and kinetics of cell cycle stages can be accomplished by use of a combination of metabolic labeling of nucleic acids with BrdU and total genomic DNA staining via Propidium Iodide. This method avoids the need of chemical synchronization of cycling cells, thereby preventing the introduction of non-specific DNA damage, which in turn affects cell cycle progression.

Metabolik Etiketleme ve Flow Sitometri ile Hücre Döngüsü İlerleme Kinetik Ölçüm

Precise control of the initiation and subsequent progression through the various phases of the cell cycle are of paramount importance in proliferating ...

Metabolic Profile Analysis of Zebrafish Embryos

A growing goal in the field of metabolism is to determine the impact of genetics on different aspects of mitochondrial function. Understanding these relationships will help to understand the underlying etiology for a range of diseases linked with mitochondrial dysfunction, such as diabetes and obesity. Recent advances in instrumentation, has enabled the monitoring of distinct parameters of mitochondrial function in cell lines or tissue explants. Here we present a method for a rapid and sensitive analysis of mitochondrial function parameters in vivo during zebrafish embryonic development using the Seahorse bioscience XF 24 extracellular flux analyser. This protocol utilizes the Islet Capture microplates where a single embryo is placed in each well, allowing measurement of bioenergetics, including: (i) basal respiration; (ii) basal mitochondrial respiration (iii) mitochondrial respiration due to ATP turnover; (iv) mitochondrial uncoupled respiration or proton leak and (iv) maximum respiration. Using this approach embryonic zebrafish respiration parameters can be compared between wild type and genetically altered embryos (mutant, gene over-expression or gene knockdown) or those manipulated pharmacologically. It is anticipated that dissemination of this protocol will provide researchers with new tools to analyse the genetic basis of metabolic disorders in vivo in this relevant vertebrate animal model.

Zebrafish represent a powerful vertebrate model that has been under-utilised for metabolic studies. Here we describe a rapid way to measure the in vivo metabolic profile of developing zebrafish that allows the comparison of different mitochondrial function parameters between genetically or pharmacologically manipulated embryos, thereby increasing the applicability of this organism.

Zebra balığı Embriyolar Metabolik Profil Analizi

A growing goal in the field of metabolism is to determine the impact of genetics on different aspects of mitochondrial function. Understanding these ...

Metabolic Labeling of Leucine Rich Repeat Kinases 1 and 2 with Radioactive Phosphate

Leucine rich repeat kinases 1 and 2 (LRRK1 and LRRK2) are paralogs which share a similar domain organization, including a serine-threonine kinase domain, a Ras of complex proteins domain (ROC), a C-terminal of ROC domain (COR), and leucine-rich and ankyrin-like repeats at the N-terminus. The precise cellular roles of LRRK1 and LRRK2 have yet to be elucidated, however LRRK1 has been implicated in tyrosine kinase receptor signaling1,2, while LRRK2 is implicated in the pathogenesis of Parkinson's disease3,4. In this report, we present a protocol to label the LRRK1 and LRRK2 proteins in cells with 32P orthophosphate, thereby providing a means to measure the overall phosphorylation levels of these 2 proteins in cells. In brief, affinity tagged LRRK proteins are expressed in HEK293T cells which are exposed to medium containing 32P-orthophosphate. The 32P-orthophosphate is assimilated by the cells after only a few hours of incubation and all molecules in the cell containing phosphates are thereby radioactively labeled. Via the affinity tag (3xflag) the LRRK proteins are isolated from other cellular components by immunoprecipitation. Immunoprecipitates are then separated via SDS-PAGE, blotted to PVDF membranes and analysis of the incorporated phosphates is performed by autoradiography (32P signal) and western detection (protein signal) of the proteins on the blots. The protocol can readily be adapted to monitor phosphorylation of any other protein that can be expressed in cells and isolated by immunoprecipitation.

Leucine rich repeat kinases 1 and 2 (LRRK1 and LRRK2) are multidomain proteins which encode both GTPase and kinase domains and which are phosphorylated in cells. Here, we present a protocol to label LRRK1 and LRRK2 in cells with 32P orthophosphate, thereby providing a means to measure their overall cellular phophorylation levels.

Lösin zengin metabolik etiketleme Fosfat ile radyoaktif Kinazlar 1 ve 2, tekrar

Leucine rich repeat kinases 1 and 2 (LRRK1 and LRRK2) are paralogs which share a similar domain organization, including a serine-threonine kinase domain, ...

Analysis of Oxidative Stress in Zebrafish Embryos

High levels of reactive oxygen species (ROS) may cause a change of cellular redox state towards oxidative stress condition. This situation causes oxidation of molecules (lipid, DNA, protein) and leads to cell death. Oxidative stress also impacts the progression of several pathological conditions such as diabetes, retinopathies, neurodegeneration, and cancer. Thus, it is important to define tools to investigate oxidative stress conditions not only at the level of single cells but also in the context of whole organisms. Here, we consider the zebrafish embryo as a useful in vivo system to perform such studies and present a protocol to measure in vivo oxidative stress. Taking advantage of fluorescent ROS probes and zebrafish transgenic fluorescent lines, we develop two different methods to measure oxidative stress in vivo: i) a &#8220;whole embryo ROS-detection method&#8221; for qualitative measurement of oxidative stress and ii) a &#8220;single-cell&#160;ROS detection method&#8221; for quantitative measurements of oxidative stress. Herein, we demonstrate the efficacy of these procedures by increasing oxidative stress in tissues by oxidant agents and physiological or genetic methods. This protocol is amenable for forward genetic screens and it will help address cause-effect relationships of ROS in animal models of oxidative stress-related pathologies such as neurological disorders and cancer.

Here we report a protocol to measure oxidative stress in living zebrafish embryos. This procedure allows reactive oxygen species (ROS) detection in both whole embryo tissues and single-cell populations. This protocol will accomplish both qualitative and quantitative analyses.

Zebra balığı Embriyolar Oksidatif Stres Analizi

High levels of reactive oxygen species (ROS) may cause a change of cellular redox state towards oxidative stress condition. This situation causes ...

Semi-automated Imaging of Tissue-specific Fluorescence in Zebrafish Embryos

Zebrafish embryos are a powerful tool for large-scale screening of small molecules. Transgenic zebrafish that express fluorescent reporter proteins are frequently used to identify chemicals that modulate gene expression. Chemical screens that assay fluorescence in live zebrafish often rely on expensive, specialized equipment for high content screening. We describe a procedure using a standard epifluorescence microscope with a motorized stage to automatically image zebrafish embryos and detect tissue-specific fluorescence. Using transgenic zebrafish that report estrogen receptor activity via expression of GFP, we developed a semi-automated procedure to screen for estrogen receptor ligands that activate the reporter in a tissue-specific manner. In this video we describe procedures for arraying zebrafish embryos at 24-48 hours post fertilization (hpf) in a 96-well plate and adding small molecules that bind estrogen receptors. At 72-96 hpf, images of each well from the entire plate are automatically collected and manually inspected for tissue-specific fluorescence. This protocol demonstrates the ability to detect estrogens that activate receptors in heart valves but not in liver.

Described here is a protocol for semi-automated imaging of tissue-specific fluorescence in zebrafish embryos.

Zebra balığı Embriyolar Doku spesifik Floresans yarı otomatik Görüntüleme

Zebrafish embryos are a powerful tool for large-scale screening of small molecules. Transgenic zebrafish that express fluorescent reporter proteins are ...

Measurement of Metabolic Rate in Drosophila using Respirometry

Metabolic disorders are a frequent problem affecting human health. Therefore, understanding the mechanisms that regulate metabolism is a crucial scientific task. Many disease causing genes in humans have a fly homologue, making Drosophila a good model to study signaling pathways involved in the development of different disorders. Additionally, the tractability of Drosophila simplifies genetic screens to aid in identifying novel therapeutic targets that may regulate metabolism. In order to perform such a screen a simple and fast method to identify changes in the metabolic state of flies is necessary. In general, carbon dioxide production is a good indicator of substrate oxidation and energy expenditure providing information about metabolic state. In this protocol we introduce a simple method to measure CO2 output from flies. This technique can potentially aid in the identification of genetic perturbations affecting metabolic rate.

Measurement of Metabolic Rate in Drosophila using Respirometry

Metabolic disorders are among one of the most common diseases in humans. The genetically tractable model organism D. melanogaster can be used to identify novel genes that regulate metabolism. This paper describes a relatively simple method which allows studying the metabolic rate in flies by measuring their CO2 production.

Metabolik Oranı Ölçümü<em&gt; Drosophila</em&gt; Respirometrik kullanarak

Metabolic disorders are a frequent problem affecting human health. Therefore, understanding the mechanisms that regulate metabolism is a crucial ...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2].
We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells.
Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space.

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and movement.

Yetişkin Fare Kalvaryal Kemik İliği içinde Hematopoietik kök hücrelerin Vivo 4-Boyutlu Takip

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...