We would like to thank the Wellcome Trust Sanger Institute for the gifts of piggyBac transposon and piggyBac transposase. This work was supported by the Butcher grant of Colorado and the NIH R01 AG041801 (W.S.C).

<ol>
	<li>Johnson, T. 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=Longevity+genes+in+the+nematode+Caenorhabditis+elegans+also+mediate+increased+resistance+to+stress+and+prevent+disease.">Longevity genes in the nematode Caenorhabditis elegans also mediate increased resistance to stress and prevent disease.</a> J Inherit Metab Dis. 25, 197-206 (2002).</li><li>Murakami, S., Salmon, A., Miller, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiplex+stress+resistance+in+cells+from+long-lived+dwarf+mice.">Multiplex stress resistance in cells from long-lived dwarf mice.</a> Faseb J. 17, 1565-1566 (2003).</li><li>Perez, V. 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E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transmission+of+mutant+phenotypes+from+ES+cells+to+adult+mice.">Transmission of mutant phenotypes from ES cells to adult mice.</a> Mamm Genome. 20, 734-740 (2009).</li><li>Ramirez-Solis, 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=Genomic+DNA+microextraction:+a+method+to+screen+numerous+samples.">Genomic DNA microextraction: a method to screen numerous samples.</a> Anal Biochem. 201, 331-335 (1992).</li><li>Uren, A. G., 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=A+high-throughput+splinkerette-PCR+method+for+the+isolation+and+sequencing+of+retroviral+insertion+sites.">A high-throughput splinkerette-PCR method for the isolation and sequencing of retroviral insertion sites.</a> Nat Protoc. 4, 789-798 (2009).</li><li>Wang, W., Bradley, A., Huang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+piggyBac+transposon-based+genome-wide+library+of+insertionally+mutated+Blm-deficient+murine+ES+cells.">A piggyBac transposon-based genome-wide library of insertionally mutated Blm-deficient murine ES cells.</a> Genome Res. 19, 667-673 (2009).</li><li>Chick, W. S., 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=Screening+for+stress-resistance+mutations+in+the+mouse.">Screening for stress-resistance mutations in the mouse.</a> Front Genet. 5, 310 (2014).</li><li>Salmon, A. B., 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=Fibroblast+cell+lines+from+young+adult+mice+of+long-lived+mutant+strains+are+resistant+to+multiple+forms+of+stress.">Fibroblast cell lines from young adult mice of long-lived mutant strains are resistant to multiple forms of stress.</a> Am J Physiol Endocrinol Metab. 289, 23-29 (2005).</li><li>Skarnes, W. 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=A+public+gene+trap+resource+for+mouse+functional+genomics.">A public gene trap resource for mouse functional genomics.</a> Nat Genet. 36, 543-544 (2015).</li><li>Baker, K. 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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+annotation+of+mouse+mutations+in+embryonic+stem+cells+by+use+of+expression+profiling.">Functional annotation of mouse mutations in embryonic stem cells by use of expression profiling.</a> Mamm Genome. 15, 1-13 (2004).</li></ol>

The authors have nothing to disclose.

Forward genetic analysis allows for an unbiased interrogation of the genome for genes responsible for a specific phenotype. This method is very powerful to uncover novel gene functions. It has been widely used in lower organisms but not in mammal, such as the mouse, mainly due to the extremely high cost associated with the infrastructure and logistics that would entail. Here, we moved the genetic screening process to the ES cell culture platform, greatly increasing the efficiency and throughput in generating mutants a...

Ömür stres direnci ile samimi bir ilişki vardır. Genel olarak, uzun ömürlü türler genellikle hidrojen peroksit paraquatın (PQ), UV, ısı ve ağır metaller 1,2 gibi birden stres, doğru direncin artmasına işlemini göstermektedir. Bunun aksine, strese karşı artan hassasiyet, kısalmış ömür ve / veya daha fazla hastalık eğilimli fenotipi tahmin etmek eğilimindedir. Anti-oksidanın, tutucu yolu uzun hayvana gerilme direnci veren önemli bir rol oynadığı tahmin edilmektedir. Bununla birlikte, birkaç istisna dışında, çeşitli anti-oksidan enzimler (örneğin, akciğer), manipülasyonlara sahip transgenik hayvanların çeşitli çalışmalar, oksitleyici kirleticilerin alınmasına yönelik enzim düzeyi artan yaşam süresi ya da sağlık aralığı 3 arttırmadığını gösterir. Bu veriler sürekli olarak uzun ömürlü hayvanlarda gözlenen stres direnç özelliği henüz ortaya için diğer hücresel yolların aracılık ettiğini göstermektedir. Biz tarafsız bir ileriye aldıGenetik mutasyona uğramış bir yaklaşım üzerine, kültürlü embriyonik kök (ES) hücrelerde stres direnci fenotipi olabilir genleri tanımlamak için. ES hücreleri Bu çalışmada iki ana avantaj sağlar: (1) sofistike genetik manipülasyonlar ES hücrelerinin genomunun modifiye edilmesi için kullanılabilir; ve (2) ekranında elde herhangi bir strese karşı ES hücreleri ile doğrudan ömrü, sağlık yayılma ölçmek için bütün hayvan çalışmalarında içine hızlı şekilde çevrilmesine izin veren fare üretimi için de kullanılabilir. Bu yazıda Blm alleller bir tetrasiklin duyarlı eleman tarafından kontrol altına bulundukları C9 ES hücre hattı kullanımını tarif. Doksisiklin (Ortodoks) tedavisi geçici kardeş kromatid değişimi artan olaya lider BLM ifadesini kapalı. Bu kısa vadeli Blm knock-out heterozigot nüfus içerisindeki homozigot mutasyon üretimi için izin stres direnci için çekinik mutasyonlar tarama sürecinde yakalanan olabilir ki. BizAyrıca rastgele genom genlerin mutasyona bir poli-A tuzak kaseti (PB-UPA) eklemek için mutajen olarak piggyBac (PB) transpozonun kullanımını tarif. Poli-A tuzağı ile bir gen bozulması olan hücreler, G418 dirençli hale ve gen-trap mutantlar (gen trap kütüphanesi) oluşan bir koleksiyon yapılmış ve daha sonra, karşı stres olan mutant klonları için tarandı olabilir, böylece elde edilebilir. Seçim kurtarıldı Stres dirençli klonlar eklemeleri sayısı (qPCR) arasında bağlamda moleküler tekniklerle oldukça hızlı karakterize edilebilir, ekleme site (splinkerette PCR), bozulmuş gen (ŞOK) kimliği ve onun ifade seviyesi ( RT-qPCR). PB yerleştirme Yabani tür bir DNA dizisini ve bu nedenle geri stres direnci kaybını test klonu MPB transpozazın geçici ifade yolu ile remobilized edilebilir. Bunlar önce yapılmalıdır mutasyon nedenselliğini onaylamak için güçlü yollar vardırpahalı bir fare üretimi. Önceki çalışmalar stres maruz kalan hücreler pluripotency 4,5 kaybettiklerini gösterdi. Böylece, bu protokolde, stres ile tedavi olmaz mutant hücreler kümesi bir yineleme, korunması başarılı fare üretimi için kritik öneme sahiptir. Bizim laboratuvar hem istek üzerine diğer araştırmacılar için kullanılabilir, C9 ES hücre hattı ve PB-UPA vektörü tasarladı. Burada rapor edilen protokol, stres dayanıklı klonların (Şekil 1B) izole etmek için replika plaka ve stres seçimi, ardından PB-UPA (Şekil 1A) gen tuzak ES hücreleri, de novo arşivinin oluşturulması yoluyla başlar. Biz paraquat, hücreler içinde güçlü bir serbest kök üretici madde ile noktası göstermiştir. Hemen hemen, örneğin herhangi bir sitotoksik bileşik veya toksin, ER stres (örneğin, thapsigargin ve tunikamisin), nöronal oksitleyici (örneğin, MPP +, 6-hidroksi dopamin ve rotenon), ısı ve ağırmetaller (örneğin, Cd, Se), ilgili dirençli mutantların seçmek için bir yöntem adapte edilebilir.

<table border="0">
	<tbody>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vector</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>PB-UPA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>mPBase</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>mPBasePuro</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue Culture&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>500-ml Stericup filters</td>
			<td>EMD Millipore</td>
			<td>SCGPU05RE</td>
		</tr>
		<tr>
			<td>250-ml Stericup filters</td>
			<td>EMD Millipore</td>
			<td>SCGPU02RE</td>
		</tr>
		<tr>
			<td>50-ml Steriflip-GV filters</td>
			<td>EMD Millipore</td>
			<td>SE1M179M6</td>
		</tr>
		<tr>
			<td>KO DMEM</td>
			<td>Life Technologies</td>
			<td>10829-018</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Sigma-Aldrich</td>
			<td>D6429</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Tissue Culture Biologicals</td>
			<td>104</td>
		</tr>
		<tr>
			<td>Heat Inactivated FBS</td>
			<td>Sigma-Aldrich</td>
			<td>F4135-500</td>
		</tr>
		<tr>
			<td>LIF</td>
			<td>EMD Millipore</td>
			<td>ESG1107</td>
		</tr>
		<tr>
			<td>Non-essential Amino Acids</td>
			<td>Life Technologies</td>
			<td>11140-050</td>
		</tr>
		<tr>
			<td>GlutaMAX</td>
			<td>Life Technologies</td>
			<td>35050-061</td>
		</tr>
		<tr>
			<td>Pen/Strep</td>
			<td>Life Technologies</td>
			<td>15140148</td>
		</tr>
		<tr>
			<td>&#946;-Mercaptoethanol</td>
			<td>Life Technologies</td>
			<td>21985-023</td>
		</tr>
		<tr>
			<td>Methyl Viologen dichloride (Paraquat)</td>
			<td>Sigma-Aldrich</td>
			<td>856177</td>
		</tr>
		<tr>
			<td>Dimethyl Sulphoxide Hybri-MAX</td>
			<td>Sigma-Aldrich</td>
			<td>D2650</td>
		</tr>
		<tr>
			<td>EmbryoMAX 0.1% gelatin</td>
			<td>EMD Millipore</td>
			<td>ES006B</td>
		</tr>
		<tr>
			<td>DPBS/Modified</td>
			<td>HyClone</td>
			<td>SH30028.02</td>
		</tr>
		<tr>
			<td>0.25% Trypsin-EDTA</td>
			<td>Life Technologies</td>
			<td>25200-056</td>
		</tr>
		<tr>
			<td>T25 Flask</td>
			<td>Corning</td>
			<td>353108</td>
		</tr>
		<tr>
			<td>T75 flask</td>
			<td>Corning</td>
			<td>353135</td>
		</tr>
		<tr>
			<td>100-mm&#160; plate</td>
			<td>Corning</td>
			<td>353003</td>
		</tr>
		<tr>
			<td>150-mm&#160; plate</td>
			<td>Corning</td>
			<td>430599</td>
		</tr>
		<tr>
			<td>96-well&#160; plate</td>
			<td>Corning</td>
			<td>3585</td>
		</tr>
		<tr>
			<td>96-well U-bottom plate</td>
			<td>Corning</td>
			<td>3799</td>
		</tr>
		<tr>
			<td>24-well plate</td>
			<td>Corning</td>
			<td>3526</td>
		</tr>
		<tr>
			<td>50-ml reservoir&#160;</td>
			<td>Corning</td>
			<td>4870</td>
		</tr>
		<tr>
			<td>15-ml tubes</td>
			<td>VWR International, LLC</td>
			<td>82050-276</td>
		</tr>
		<tr>
			<td>Primary Mouse Embryonic Fibroblasts</td>
			<td>EMD Millipore</td>
			<td>PMEF-NL</td>
		</tr>
		<tr>
			<td>DR4 Mouse Embryonic Fibroblasts</td>
			<td>Applied StemCell</td>
			<td>ASF-1001</td>
		</tr>
		<tr>
			<td>Mitomycin C</td>
			<td>Fisher BioReagents&#160;</td>
			<td>BP25312</td>
		</tr>
		<tr>
			<td>Geneticin (G418)</td>
			<td>Life Technologies</td>
			<td>11811-023</td>
		</tr>
		<tr>
			<td>Doxycycline</td>
			<td>Fisher BioReagents&#160;</td>
			<td>BP26531</td>
		</tr>
		<tr>
			<td>Cryotubes</td>
			<td>Thermo Scientific</td>
			<td>377267</td>
		</tr>
		<tr>
			<td>Centrifuge&#160;</td>
			<td>Eppendorf</td>
			<td>Centrifuge 5702</td>
		</tr>
		<tr>
			<td>TC10 cell counter</td>
			<td>Bio-Rad</td>
			<td></td>
		</tr>
		<tr>
			<td>Counting Slides (for TC10)</td>
			<td>Bio-Rad</td>
			<td>1450011</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Electroporation&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Gene Pulser Xcell</td>
			<td>Bio-Rad</td>
			<td>1652611</td>
		</tr>
		<tr>
			<td>Gene Pulser Cuvettes (4 mm gap)</td>
			<td>Bio-Rad</td>
			<td>1652088</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Molecular Biology&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Thermal Cycler</td>
			<td>Eppendorf</td>
			<td>Mastercylcer ep Gradient&#160; S</td>
		</tr>
		<tr>
			<td>Puregene Core kit B</td>
			<td>Qiagen</td>
			<td>158745</td>
		</tr>
		<tr>
			<td>Topo-TA Cloning kit</td>
			<td>Life Technologies&#160;</td>
			<td>450030</td>
		</tr>
		<tr>
			<td>High Capacity cDNA synthesis kit</td>
			<td>Applied Biosystems</td>
			<td>4368814</td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Fisher BioReagents&#160;</td>
			<td>BP358-212</td>
		</tr>
		<tr>
			<td>100% ethanol</td>
			<td>Decon Laboratories, Inc.</td>
			<td>2716</td>
		</tr>
		<tr>
			<td>Double Processed Tissue Culture Water</td>
			<td>Sigma-Aldrich</td>
			<td>W3500</td>
		</tr>
		<tr>
			<td>Sau3A1</td>
			<td>New England BioLabs</td>
			<td>R0169L</td>
		</tr>
		<tr>
			<td>T4 DNA Ligase</td>
			<td>New England BioLabs</td>
			<td>M0202T</td>
		</tr>
		<tr>
			<td>EcoRV</td>
			<td>New England BioLabs</td>
			<td>R3195S</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>96-well Lysis Buffer (Ramires-Solis et al. 1992)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Trizma Base</td>
			<td>Sigma-Aldrich</td>
			<td>T1503</td>
		</tr>
		<tr>
			<td>Hydrochloric Acid</td>
			<td>Fisher BioReagents&#160;</td>
			<td>A144-212</td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>Sigma-Aldrich</td>
			<td>E5134</td>
		</tr>
		<tr>
			<td>N-Lauroylsarcosine sodium salt</td>
			<td>Sigma-Aldrich</td>
			<td>L5777</td>
		</tr>
		<tr>
			<td>Proteinase-K</td>
			<td>Fisher BioReagents&#160;</td>
			<td>BP1700</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Electrophoresis</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Mini-Sub Cell GT</td>
			<td>Bio-Rad</td>
			<td>170-4469EDU</td>
		</tr>
		<tr>
			<td>LE Agarose&#160;</td>
			<td>GeneMate</td>
			<td>E3120500</td>
		</tr>
		<tr>
			<td>Ethidium Bromide&#160;</td>
			<td>Fisher BioReagents&#160;</td>
			<td>BP1302</td>
		</tr>
		<tr>
			<td>100 BP DNA Ladder</td>
			<td>New England BioLabs</td>
			<td>N3231S</td>
		</tr>
		<tr>
			<td>1Kb DNA Ladder</td>
			<td>New England BioLabs</td>
			<td>N3232S</td>
		</tr>
		<tr>
			<td>2-log DNA Ladder</td>
			<td>New England BioLabs</td>
			<td>N3200L</td>
		</tr>
	</tbody>
</table>

forward genetic approach to uncover stress resistance genes in mice &#8212; a high-throughput screen in es cells

Phenotype-driven genetic screens in mice is a powerful technique to uncover gene functions, but are often hampered by extremely high costs, which severely limits its potential. We describe here the use of mouse embryonic stem (ES) cells as surrogate cells to screen for a phenotype of interest and subsequently introduce these cells into a host embryo to develop into a living mouse carrying the phenotype. This method provides (1) a cost effective, high-throughput platform for genetic screen in mammalian cells; (2) a rapid way to identify the mutated genes and verify causality; and (3) a short-cut to develop mouse mutants directly from these selected ES cells for whole animal studies. We demonstrated the use of paraquat (PQ) to select resistant mutants and identify mutations that confer oxidative stress resistance. Other stressors or cytotoxic compounds may also be used to screen for resistant mutants to uncover novel genetic determinants of a variety of cellular stress resistance.

Tipik bir mutajenez deneyde, transfeksiyon PB-UPA ve MPB transpozaz ile 3 x 10 7 ES hücrelerinin toplam oluşur. Iki bağımsız deneyin üretilen gen tuzak ES hücre sayısı, Tablo 1 &#39;de özetlenmiştir. Gen tuzak etkinliği, yaklaşık 0.04%&#39; dir. Kombine gen tuzak kütüphaneleri 22400 bağımsız mutantlar, fare genomu hakkında tam bir kapsama (23.000 kodlayan genlerin) içerirler. Aşırı kapsama tekrarlanan mutasyon yoluyla daha mutantlar üreten ve / veya süreci ölçeklem...

Watch this Scientific Journal Video about Forward Genetic Approach to Uncover Stress Resistance Genes in Mice â€” A High-throughput Screen in ES Cells at JoVE.com

Forward Genetic Approach to Uncover Stress Resistance Genes in Mice &amp;#8212; A High-throughput Screen in ES Cells

Stres direnci uzun ömürlü özelliklerinden biridir ve genetik yönetilmeye bilinmektedir. Burada, uzun ömürlü çalışmaları için fare modelleri geliştirmek için hangi ES hücreleri stres direnci kazandıran mutasyonlar taranması için tarafsız bir yüksek verimli bir yöntem geliştirdi.

İleri Genetik Yaklaşım Farelerde Stres Direnci Genler ortaya çıkarmak için - ES Hücrelerde bir Yüksek verim Ekranı

Phenotype-driven genetic screens in mice is a powerful technique to uncover gene functions, but are often hampered by extremely high costs, which severely ...

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Research

JoVE Journal

Developmental Biology

Forward Genetic Approach to Uncover Stress Resistance Genes in Mice &#8212; A High-throughput Screen in ES Cells

8.1K Görüntüleme.  University of Colorado Denver.  Stres direnci uzun ömürlü özelliklerinden biridir ve genetik yönetilmeye bilinmektedir. Burada, uzun ömürlü çalışmaları için fare modelleri geliştirmek için hangi ES hücreleri stres direnci kazandıran mutasyonlar taranması için tarafsız bir yüksek verimli bir yöntem geliştirdi. 

Video: Forward Genetic Approach to Uncover Stress Resistance Genes in Mice &#8212; A High-throughput Screen in ES Cells

An Optogenetic Approach for Assessing Formation of Neuronal Connections in a Co-culture System

Here we describe a protocol to generate a co-culture consisting of 2 different neuronal populations. Induced pluripotent stem cells (iPSCs) are reprogrammed from human fibroblasts using episomal vectors. Colonies of iPSCs can be observed 30 days after initiation of fibroblast reprogramming. Pluripotent colonies are manually picked and grown in neural induction medium to permit differentiation into neural progenitor cells (NPCs). iPSCs rapidly convert into neuroepithelial cells within 1 week and retain the capability to self-renew when maintained at a high culture density. Primary mouse NPCs are differentiated into astrocytes by exposure to a serum-containing medium for 7 days and form a monolayer upon which embryonic day 18 (E18) rat cortical neurons (transfected with channelrhodopsin-2 (ChR2)) are added. Human NPCs tagged with the fluorescent protein, tandem dimer Tomato (tdTomato), are then seeded onto the astrocyte/cortical neuron culture the following day and allowed to differentiate for 28 to 35 days. We demonstrate that this system forms synaptic connections between iPSC-derived neurons and cortical neurons, evident from an increase in the frequency of synaptic currents upon photostimulation of the cortical neurons. This co-culture system provides a novel platform for evaluating the ability of iPSC-derived neurons to create synaptic connections with other neuronal populations.

A protocol to generate a co-culture system consisting of neurons derived from induced pluripotent stem cells (iPSCs), primary cortical neurons and astrocytes is described. This co-culture system allows detection of the formation of synaptic contacts and circuits between new, iPSC-derived neurons and pre-existing cortical neurons expressing channelrhodopsin-2.

Bir Co-kültür Sistemde nöronal bağlantıları Oluşumunda değerlendirilmesi için bir optogenetic Yaklaşım

Here we describe a protocol to generate a co-culture consisting of 2 different neuronal populations. Induced pluripotent stem cells (iPSCs) are ...

Gelişim Biyolojisi

Technique to Target Microinjection to the Developing Xenopus Kidney

The embryonic kidney of Xenopus&#160;laevis (frog), the pronephros, consists of a single nephron, and can be used as a model for kidney disease. Xenopus embryos are large, develop externally, and can be easily manipulated by microinjection or surgical procedures. In addition, fate maps have been established for early Xenopus embryos. Targeted microinjection into the individual blastomere that will eventually give rise to an organ or tissue of interest can be used to selectively overexpress or knock down gene expression within this restricted region, decreasing secondary effects in the rest of the developing embryo. In this protocol, we describe how to utilize established Xenopus fate maps to target the developing Xenopus kidney (the pronephros), through microinjection into specific blastomere of 4- and 8-cell embryos. Injection of lineage tracers allows verification of the specific targeting of the injection. After embryos have developed to stage 38 - 40, whole-mount immunostaining is used to visualize pronephric development, and the contribution by targeted cells to the pronephros can be assessed. The same technique can be adapted to target other tissue types in addition to the pronephros.

Technique to Target Microinjection to the Developing Xenopus Kidney

Here, we present a protocol to use fate maps and lineage tracers to target injections into individual blastomeres that give rise to the kidney of Xenopus laevis embryos.

Gelişmekte olan mikroenjeksiyon Hedef Tekniği<em&gt; Xenopus</em&gt; Böbrek

The embryonic kidney of Xenopus&#160;laevis (frog), the pronephros, consists of a single nephron, and can be used as a model for kidney disease. Xenopus ...

A Simple Method to Identify Kinases That Regulate Embryonic Stem Cell Pluripotency by High-throughput Inhibitor Screening

Embryonic stem cells (ESCs) can self-renew or differentiate into all cell types, a phenomenon known as pluripotency. Distinct pluripotent states have been described, termed &#34;na&#239;ve&#34; and &#34;primed&#34; pluripotency. The mechanisms that control na&#239;ve-primed transition are poorly understood. In particular, we remain poorly informed about protein kinases that specify na&#239;ve and primed pluripotent states, despite increasing availability of high-quality tool compounds to probe kinase function. Here, we describe a scalable platform to perform targeted small molecule screens for kinase regulators of the na&#239;ve-primed pluripotent transition in mouse ESCs. This approach utilizes simple cell culture conditions and standard reagents, materials and equipment to uncover and validate kinase inhibitors with hitherto unappreciated effects on pluripotency. We discuss potential applications for this technology, including screening of other small molecule collections such as increasingly sophisticated kinase inhibitors and emerging libraries of epigenetic tool compounds.

Here, we present a quantitative and scalable protocol to perform targeted small molecule screens for kinase regulators of the na&#239;ve-primed pluripotent transition.

Embriyonik Kök Hücre Pluripotansını Yüksek Verimli İnhibitör Taramayla Düzenleyen Kinazları Tanımlamak İçin Basit Bir Yöntem

Embryonic stem cells (ESCs) can self-renew or differentiate into all cell types, a phenomenon known as pluripotency. Distinct pluripotent states have been ...

A Novel Mammary Fat Pad Transplantation Technique to Visualize the Vessel Generation of Vascular Endothelial Stem Cells

Endothelial cells (ECs) are the fundamental building blocks of the vascular architecture and mediate vascular growth and remodeling to ensure proper vessel development and homeostasis. However, studies on endothelial lineage hierarchy remain elusive due to the lack of tools to gain access as well as to directly evaluate their behavior in vivo. To address this shortcoming, a new tissue model to study angiogenesis using the mammary fat pad has been developed. The mammary gland develops mostly in the postnatal stages, including puberty and pregnancy, during which robust epithelium proliferation is accompanied by extensive vascular remodeling. Mammary fat pads provide space, matrix, and rich angiogenic stimuli from the growing mammary epithelium. Furthermore, mammary fat pads are located outside the peritoneal cavity, making them an easily accessible grafting site for assessing the angiogenic potential of exogenous cells. This work also describes an efficient tracing approach using fluorescent reporter mice to specifically label the targeted population of vascular endothelial stem cells (VESCs) in vivo. This lineage tracing method, coupled with subsequent tissue whole-mount microscopy, enable the direct visualization of targeted cells and their descendants, through which the proliferation capability can be quantified and the differentiation commitment can be fate-mapped. Using these methods, a population of bipotent protein C receptor (Procr) expressing VESCs has recently been identified in multiple vascular systems. Procr+ VESCs, giving rise to both new ECs and pericytes, actively contribute to angiogenesis during development, homeostasis, and injury repair. Overall, this manuscript describes a new mammary fat pad transplantation and in vivo lineage tracing techniques that can be used to evaluate the stem cell properties of VESCs.

This work demonstrates a novel approach to assess the proliferation, differentiation, and vessel-forming potential of vascular endothelial stem cells (VESCs) through mammary fat pad transplantation followed by whole-mount tissue preparation for microscopic observation. A lineage tracing strategy to investigate the behavior of VESCs in vivo is also presented.

Vasküler Endotelyal Kök Hücrelerin Damar Oluşumunu Görselleştirmek İçin Yeni Bir Göğüs Göğsü Transplantasyon Tekniği

Endothelial cells (ECs) are the fundamental building blocks of the vascular architecture and mediate vascular growth and remodeling to ensure proper ...

A Standardized Approach for Multispecies Purification of Mammalian Male Germ Cells by Mechanical Tissue Dissociation and Flow Cytometry

Fluorescence-activated cell sorting (FACS) has been one of the methods of choice to isolate enriched populations of mammalian testicular germ cells. Currently, it allows the discrimination of up to 9 murine germ cell populations with high yield and purity. This high-resolution in discrimination and purification is possible due to unique changes in chromatin structure and quantity throughout spermatogenesis. These patterns can be captured by flow cytometry of male germ cells stained with fluorescent DNA-binding dyes such as Hoechst-33342 (Hoechst). Herein is a detailed description of a recently developed protocol to isolate mammalian testicular germ cells. Briefly, single cell suspensions are generated from testicular tissue by mechanical dissociation, double stained with Hoechst and propidium iodide (PI) and processed by flow cytometry. A serial gating strategy, including the selection of live cells (PI negative) with different DNA content (Hoechst intensity), is used during FACS sorting to discriminate up to 5 germ cell types. These include, with corresponding average purities (determined by microscopy evaluation): spermatogonia (66%), primary (71%) and secondary (85%) spermatocytes, and spermatids (90%), further separated into round (93%) and elongating (87%) subpopulations. Execution of the entire workflow is straightforward, allows the isolation of 4 cell types simultaneously with the appropriate FACS machine, and can be performed in less than 2 h. As reduced processing time is crucial to preserve the physiology of ex vivo cells, this method is ideal for downstream high-throughput studies of male germ cell biology. Moreover, a standardized protocol for multispecies purification of mammalian germ cells eliminates methodological sources of variables and allows a single set of reagents to be used for different animal models.

This work describes the standardization of a method to obtain purified germ cell populations from testicular tissue of different mammalian species. It is a straightforward protocol that combines mechanical testis dissociation, staining with Hoechst-33342 and propidium iodide, and FACS sorting, with wide applications in comparative studies of male reproductive biology.

Memeli Erkek Germ Hücrelerinin Çok Denekli Saflaştırılmasında Standart Bir Yaklaşım, Mekanik Doku Ayrılma ve Akış Sitometrisi ile

Fluorescence-activated cell sorting (FACS) has been one of the methods of choice to isolate enriched populations of mammalian testicular germ cells. ...

Application of RNAi and Heat-shock-induced Transcription Factor Expression to Reprogram Germ Cells to Neurons in C. elegans

Studying the cell biological processes during converting the identities of specific cell types provides important insights into mechanism that maintain and protect cellular identities. The conversion of germ cells into specific neurons in the nematode Caenorhabditis elegans (C. elegans) is a powerful tool for performing genetic screens in order to dissect regulatory pathways that safeguard established cell identities. Reprogramming of germ cells to a specific type of neurons termed ASE requires transgenic animals that allow broad over-expression of the Zn-finger transcription factor (TF) CHE-1. Endogenous CHE-1 is expressed exclusively in two head neurons and is required to specify the glutamatergic ASE neurons fate, which can easily be visualized by the gcy-5prom::gfp reporter. A trans gene containing the heat-shock promoter-driven che-1 gene expression construct allows broad mis-expression of CHE-1 in the entire animal upon heat-shock treatment. The combination of RNAi against the chromatin-regulating factor LIN-53 and heat-shock-induced che-1 over-expression leads to reprogramming of germ cell into ASE neuron-like cells. We describe here the specific RNAi procedure and appropriate conditions for heat-shock treatment of transgenic animals in order to successfully induce germ cell to neuron conversion.

Application of RNAi and Heat-shock-induced Transcription Factor Expression to Reprogram Germ Cells to Neurons in C. elegans

This protocol describes how to study cellular processes during cell fate conversion in Caenorhabditis elegans in vivo. Using transgenic animals, allowing heat-shock promoter-driven overexpression of the neuron fate-inducing transcription factor CHE-1 and RNAi-mediated depletion of the chromatin-regulating factor LIN-53 germ cell to neuron reprogramming can be observed in vivo.

Uygulama için yeniden programlamak Germ hücreleri için C. elegans nöronlarda RNAi ve transkripsiyon faktörü ifade ısı şok bağlı

Studying the cell biological processes during converting the identities of specific cell types provides important insights into mechanism that maintain ...

Visualizing the Node and Notochordal Plate In Gastrulating Mouse Embryos Using Scanning Electron Microscopy and Whole Mount Immunofluorescence

The post-implantation mouse embryo undergoes major shape changes after the initiation of gastrulation and morphogenesis. A hallmark of morphogenesis is the formation of the transient organizers, the node and notochordal plate, from cells that have passed through the primitive streak. The proper formation of these signaling centers is essential for the development of the body plan and techniques to visualize them are of high interest to mouse developmental biologists. The node and notochordal plate lie on the ventral surface of gastrulating mouse embryos around embryonic day (E) 7.5 of development. The node is a cup-shaped structure whose cells possess a single slender cilium each. The proper subcellular localization and rotation of the cilia in the node pit determines left-right asymmetry. The notochordal plate cells also possess single cilia albeit shorter than those of the node cells. The notochordal plate forms the notochord which acts as an important signaling organizer for somitogenesis and neural patterning. Because the cells of the node and notochordal plate are transiently present on the surface and possess cilia, they can be visualized using scanning electron microscopy (SEM). Among other techniques used to visualize these structures at the cellular level is whole mount immunofluorescence (WMIF) using the antibodies against the proteins that are highly expressed in the node and notochordal plate. In this report, we describe our optimized protocols to perform SEM and WMIF of the node and notochordal plate in developing mouse embryos to help in the assessment of tissue shape and cellular organization in wild-type and gastrulation mutant embryos.

The node and notochordal plate are transient signaling organizers in developing mouse embryos that can be visualized using several techniques. Here, we describe in detail how to perform two of the techniques to study their structure and morphogenesis: 1) scanning electron microscopy (SEM); and 2) whole mount immunofluorescence (WMIF).

Düğüm ve Notochordal plaka Gastrulating fare embriyo Tarama elektron mikroskobu ve bütün Dağı ayirt kullanarak görselleştirme

The post-implantation mouse embryo undergoes major shape changes after the initiation of gastrulation and morphogenesis. A hallmark of morphogenesis is ...

In Vitro Generation of Somite Derivatives from Human Induced Pluripotent Stem Cells

In response to signals such as WNTs, bone morphogenetic proteins (BMPs), and sonic hedgehog (SHH) secreted from surrounding tissues, somites (SMs) give rise to multiple cell types, including the myotome (MYO), sclerotome (SCL), dermatome (D), and syndetome (SYN), which in turn develop into skeletal muscle, axial skeleton, dorsal dermis, and axial tendon/ligament, respectively. Therefore, the generation of SMs and their derivatives from human induced pluripotent stem cells (iPSCs) is critical to obtain pluripotent stem cells (PSCs) for application in regenerative medicine and for disease research in the field of orthopedic surgery. Although the induction protocols for MYO and SCL from PSCs have been previously reported by several researchers, no study has yet demonstrated the induction of SYN and D from iPSCs. Therefore, efficient induction of fully competent SMs remains a major challenge. Here, we recapitulate human SM patterning with human iPSCs in vitro by mimicking the signaling environment during chick/mouse SM development, and report on methods of systematic induction of SM derivatives (MYO, SCL, D, and SYN) from human iPSCs under chemically defined conditions through the presomitic mesoderm (PSM) and SM states. Knowledge regarding chick/mouse&#160;SM development was successfully applied to the induction of SMs with human iPSCs. This method could be a novel tool for studying human somitogenesis and patterning without the use of embryos and for cell-based therapy and disease modeling.

We present here a protocol for the differentiation of human induced pluripotent stem cells into each somite derivative (myotome, sclerotome, dermatome, and syndetome) in chemically defined conditions, which has applications in future disease modeling and cell-based therapies in orthopedic surgery.

Somite türevleri indüklenen insan nesil Vitro Pluripotent kök hücreler

In response to signals such as WNTs, bone morphogenetic proteins (BMPs), and sonic hedgehog (SHH) secreted from surrounding tissues, somites (SMs) give ...

Assessment of Oxidative Damage in the Primary Mouse Ocular Surface Cells/Stem Cells in Response to Ultraviolet-C (UV-C) Damage

The ocular surface is subjected to regular wear and tear due to various environmental factors. Exposure to UV-C radiation constitutes an occupational health hazard. Here, we demonstrate the exposure of primary stem cells from the mouse ocular surface to UV-C radiation. Reactive oxygen species (ROS) formation is the readout of the extent of oxidative stress/damage. In an experimental in vitro setting, it is also essential to assess the percentage of dead cells generated due to oxidative stress. In this article, we will demonstrate the 2&#39;,7&#39;-Dichlorofluoresceindiacetate (DCFDA) staining of UV-C exposed mouse primary ocular surface stem cells and their quantification based on the fluorescent images of DCFDA staining. DCFDA staining directly corresponds to ROS generation. We also demonstrate the quantification of dead and live cells by simultaneous staining with propidium iodide (PI) and Hoechst 3332 respectively and the percentage of DCFDA (ROS positive) and PI positive cells.

Assessment of Oxidative Damage in the Primary Mouse Ocular Surface Cells/Stem Cells in Response to Ultraviolet-C UV-C Damage

This protocol demonstrates the simultaneous detection of reactive oxygen species (ROS), live cells, and dead cells in live primary cultures from mouse ocular surface cells. 2&#39;,7&#39;-Dichlorofluoresceindiacetate, propidium iodide, and Hoechst staining are used to assess the ROS, dead cells, and live cells, respectively, followed by imaging and analysis.

Ultraviyole-C (UV-C) Hasarına Yanıt Olarak Birincil Fare Oküler Yüzey Hücrelerinde/Kök Hücrelerinde Oksidatif Hasarın Değerlendirilmesi

The ocular surface is subjected to regular wear and tear due to various environmental factors. Exposure to UV-C radiation constitutes an occupational ...

Performing Human Skeletal Muscle Xenografts in Immunodeficient Mice

Treatment effects observed in animal studies often fail to be recapitulated in clinical trials. While this problem is multifaceted, one reason for this failure is the use of inadequate laboratory models. It is challenging to model complex human diseases in traditional laboratory organisms, but this issue can be circumvented through the study of human xenografts. The surgical method we describe here allows for the creation of human skeletal muscle xenografts, which can be used to model muscle disease and to carry out preclinical therapeutic testing. Under an Institutional Review Board (IRB)-approved protocol, skeletal muscle specimens are acquired from patients and then transplanted into NOD-Rag1null IL2r&gamma;null (NRG) host mice. These mice are ideal hosts for transplantation studies due to their inability to make mature lymphocytes and are thus unable to develop cell-mediated and humoral adaptive immune responses. Host mice are anaesthetized with isoflurane, and the mouse tibialis anterior and extensor digitorum longus muscles are removed. A piece of human muscle is then placed in the empty tibial compartment and sutured to the proximal and distal tendons of the peroneus longus muscle. The xenografted muscle is spontaneously vascularized and innervated by the mouse host, resulting in robustly regenerated human muscle that can serve as a model for preclinical studies.

Complex human diseases can be challenging to model in traditional laboratory model systems. Here, we describe a surgical approach to model human muscle disease through the transplantation of human skeletal muscle biopsies into immunodeficient mice.

İmmün eksik farelerde İnsan İskelet Kası Ksenogreftlerinin

Treatment effects observed in animal studies often fail to be recapitulated in clinical trials. While this problem is multifaceted, one reason for this ...