Name: efficient generation of hipsc neural lineage specific knockin reporters using the crispr/cas9 and cas9 double nickase system
Uploaded: 2015-05-28T15:00:00
Description: Watch this Scientific Journal Video about Efficient Generation of hiPSC Neural Lineage Specific Knockin Reporters Using the CRISPR/Cas9 and Cas9 Double Nickase System at JoVE.com

This work was supported by the Department of Neurosurgery, Memorial Hermann Foundation Staman Ogilvie Fund, the Bentsen Stroke Center at the University of Texas Health Science Center at Houston, and Mission Connect TIRR Foundation.

1. Design and Vector Construction for Targeting Vectors
<ol>
	<li>Once the lineage specific marker is determined, locate the genomic sequence of the gene and design the homology arms accordingly. The length of 5&#8217; homology arm is ~1 kb and of 3&#8217; homology arm is ~1.5 kb (Figure 1).</li>
	<li>Tag the reporter cassette sequentially downstream of the genomic sequence right before the stop codon, by subcloning, so that the endogenous expression is not altered or disrupted. Link the reporter, or d...

<ol>
	<li>Wang, H., 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=One-step+generation+of+mice+carrying+mutations+in+multiple+genes+by+CRISPR/Cas-mediated+genome+engineering.">One-step generation of mice carrying mutations in multiple genes by CRISPR/Cas-mediated genome engineering.</a> Cell. 153, 910-918 (2013).</li><li>Mali, P., 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=RNA-guided+human+genome+engineering+via+Cas9.">RNA-guided human genome engineering via Cas9.</a> Science. 339, 823-826 (2013).</li><li>Hwang, W. 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=Efficient+genome+editing+in+zebrafish+using+a+CRISPR-Cas+system.">Efficient genome editing in zebrafish using a CRISPR-Cas system.</a> Nature. 31, 227-229 (2013).</li><li>Friedland, A. 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=Heritable+genome+editing+in+C.+elegans+via+a+CRISPR-Cas9+system.">Heritable genome editing in C. elegans via a CRISPR-Cas9 system.</a> Nat Methods. , (2013).</li><li>DiCarlo, 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=Genome+engineering+in+Saccharomyces+cerevisiae+using+CRISPR-Cas+systems.">Genome engineering in Saccharomyces cerevisiae using CRISPR-Cas systems.</a> Nucleic Acids Res. 41, 4336-4343 (2013).</li><li>Cong, L., 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=Multiplex+genome+engineering+using+CRISPR/Cas+systems.">Multiplex genome engineering using CRISPR/Cas systems.</a> Science. 339, 819-823 (2013).</li><li>Anders, C., Niewoehner, O., Duerst, A., Jinek, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+basis+of+PAM-dependent+target+DNA+recognition+by+the+Cas9+endonuclease.">Structural basis of PAM-dependent target DNA recognition by the Cas9 endonuclease.</a> Nature. 513, 569-573 (2014).</li><li>Deltcheva, 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=CRISPR+RNA+maturation+by+trans-encoded+small+RNA+and+host+factor+RNase+III.">CRISPR RNA maturation by trans-encoded small RNA and host factor RNase III.</a> Nature. 471, 602-607 (2011).</li><li>Gasiunas, G., Barrangou, R., Horvath, P., Siksnys, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cas9-crRNA+ribonucleoprotein+complex+mediates+specific+DNA+cleavage+for+adaptive+immunity+in+bacteria.">Cas9-crRNA ribonucleoprotein complex mediates specific DNA cleavage for adaptive immunity in bacteria.</a> Proceedings of the National Academy of Sciences of the United States of America. 109, E2579-E2586 (2012).</li><li>Jinek, M., 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+programmable+dual-RNA-guided+DNA+endonuclease+in+adaptive+bacterial+immunity.">A programmable dual-RNA-guided DNA endonuclease in adaptive bacterial immunity.</a> Science. 337, 816-821 (2012).</li><li>Jinek, M., 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=RNA-programmed+genome+editing+in+human+cells.">RNA-programmed genome editing in human cells.</a> eLife. 2, e00471 (2013).</li><li>Fu, 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=High-frequency+off-target+mutagenesis+induced+by+CRISPR-Cas+nucleases+in+human+cells.">High-frequency off-target mutagenesis induced by CRISPR-Cas nucleases in human cells.</a> Nature Biotechnology. 31, 822-826 (2013).</li><li>Hsu, P. D., 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=DNA+targeting+specificity+of+RNA-guided+Cas9+nucleases.">DNA targeting specificity of RNA-guided Cas9 nucleases.</a> Nature Biotechnology. 31, 827-832 (2013).</li><li>Mali, P., 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=CAS9+transcriptional+activators+for+target+specificity+screening+and+paired+nickases+for+cooperative+genome+engineering.">CAS9 transcriptional activators for target specificity screening and paired nickases for cooperative genome engineering.</a> Nature Biotechnology. 31, 833-838 (2013).</li><li>Pattanayak, V., 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=High-throughput+profiling+of+off-target+DNA+cleavage+reveals+RNA-programmed+Cas9+nuclease+specificity.">High-throughput profiling of off-target DNA cleavage reveals RNA-programmed Cas9 nuclease specificity.</a> Nature Biotechnology. 31, 839-843 (2013).</li><li>Shen, 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=Efficient+genome+modification+by+CRISPR-Cas9+nickase+with+minimal+off-target+effects.">Efficient genome modification by CRISPR-Cas9 nickase with minimal off-target effects.</a> Nature Methods. 11, 399-402 (2014).</li><li>Ran, F. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Double+nicking+by+RNA-guided+CRISPR+Cas9+for+enhanced+genome+editing+specificity.">Double nicking by RNA-guided CRISPR Cas9 for enhanced genome editing specificity.</a> Cell. 154, 1380-1389 (2013).</li><li>Yang, H., Wang, H., Jaenisch, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generating+genetically+modified+mice+using+CRISPR/Cas-mediated+genome+engineering.">Generating genetically modified mice using CRISPR/Cas-mediated genome engineering.</a> Nature Protocols. 9, 1956-1968 (2014).</li><li>Yang, H., 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=One-step+generation+of+mice+carrying+reporter+and+conditional+alleles+by+CRISPR/Cas-mediated+genome+engineering.">One-step generation of mice carrying reporter and conditional alleles by CRISPR/Cas-mediated genome engineering.</a> Cell. 154, 1370-1379 (2013).</li><li>Szymczak, A. L., 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=Correction+of+multi-gene+deficiency+in+vivo+using+a+single+'self-cleaving'+2A+peptide-based+retroviral+vector.">Correction of multi-gene deficiency in vivo using a single 'self-cleaving' 2A peptide-based retroviral vector.</a> Nature Biotechnology. 22, 589-594 (2004).</li><li>Carey, B. W., 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=Reprogramming+of+murine+and+human+somatic+cells+using+a+single+polycistronic+vector.">Reprogramming of murine and human somatic cells using a single polycistronic vector.</a> Proceedings of the National Academy of Sciences of the United States of America. 106, 157-162 (2009).</li><li>Yagi, T., 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+novel+negative+selection+for+homologous+recombinants+using+diphtheria+toxin+A+fragment+gene.">A novel negative selection for homologous recombinants using diphtheria toxin A fragment gene.</a> Analytical Biochemistry. 214, 77-86 (1993).</li><li>Wu, S., Ying, G., Wu, Q., Capecchi, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+protocol+for+constructing+gene+targeting+vectors:+generating+knockout+mice+for+the+cadherin+family+and+beyond.">A protocol for constructing gene targeting vectors: generating knockout mice for the cadherin family and beyond.</a> Nature Protocols. 3, 1056-1076 (2008).</li><li>Xue, H., 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+targeted+neuroglial+reporter+line+generated+by+homologous+recombination+in+human+embryonic+stem+cells.">A targeted neuroglial reporter line generated by homologous recombination in human embryonic stem cells.</a> Stem Cells. 27, 1836-1846 (2009).</li><li>Liu, Y., Jiang, P., Deng, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=OLIG+gene+targeting+in+human+pluripotent+stem+cells+for+motor+neuron+and+oligodendrocyte+differentiation.">OLIG gene targeting in human pluripotent stem cells for motor neuron and oligodendrocyte differentiation.</a> Nature Protocols. 6, 640-655 (2011).</li></ol>

Gene targeting is an essential tool in characterizing gene functions. However, the relatively low efficiency demands labor-intensive and time-consuming work. Recently development on genome editing tools such as the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas (CRISPR-associated) system has greatly improved the targeting efficiency. This manuscript describes a protocol for generating lineage specific human induced pluripotent stem cell (hiPSC) reporter using CRISPR/Cas system assisted homologous recombination. Steps ...

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas (CRISPR-associated) system, together with other genome editing tools, has revolutionized the human genome manipulation in recent years1-7. Major components in the CRISPR/Cas9 system are single guide RNA (sgRNA) and Cas9. Cas9 is an RNA-guided type II DNA endonuclease. It has two nuclease domains, HNH and RuvC, which are responsible for making DNA double-stranded breaks (DSBs) at a specific genomic region next to a protospacer adjacent motif (PAM)7-10.An sgRNA has a combined function of that of crRNA and tracrRNA, two adaptive immunity RNA molecules identified in bacteria (such as Streptococcus pyogenes) and archaea to fight against DNA invasion of exogenous sources9-11. When appropriately designed and co-introduced to mammalian cells, the sgRNA recognizes the PAM sequence, base-pairs with the complementary strand of target DNA, and guides and transactivates Cas9 to cleave at both DNA strands immediately upstream of PAM7. Subsequently, homologous directed recombination (HDR, in the presence of a targeting vector) or non-homologous end joining (NHEJ) will occur to repair the DSBs. Transgenes such as cDNAs, reporter cassettes, or antibiotic resistant fragments can be integrated, and transgenic or knockin lines made.
Although the CRISPR/Cas9 system is highly efficient and relatively specific, undesired off-target activities have been reported12-15. To minimize off-target events, Cas9 nickases (Cas9n) have also been engineered9,10,14,16,17. Cas9n (Cas9 D10A or Cas9 H840A) is Cas9 enzyme with mutations at one of the two nuclease domains, which only elicits a nick at one strand of DNA. To achieve cleavage at both strands, two sgRNAs are designed to guide a pair of nickases, which cuts separately at nearby loci of the two different DNA strands. The &#8220;double nicking&#8221; strategy requires a more stringent design than the conventional Cas9 platform, and offers both high efficiency and high specificity for gene editing experiments.
This manuscript describes a protocol for generating lineage specific human induced pluripotent stem cell (hiPSC) reporter using CRISPR/Cas system assisted homologous recombination. Steps for obtaining the necessary components for making neural lineage reporter lines using the CRISPR/Cas system mediated genome editing are described, with a focus on construction of targeting vectors and sgRNAs. This protocol has been successfully repeated in multiple hiPSC lines including those derived from healthy individuals and from patients with CNS diseases. Genes targeted in our laboratory include OLIG2, HB9 (MNX1), NEUROG2, SOX1, ALDH1L1 and SOD1. Targeting efficiency from CRISPR/Cas system mediated homologous recombination in hiPSCs ranges from 20-40%, which is consistent with previous reports1,18,19. Compared to a typical efficiency of 1-2% in conventional gene targeting experiments, the targeting efficiency is significantly improved.

<table border="0" cellpadding="0" cellspacing="0" width="664">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Name of Material/Equipment</td>
			<td style="width:265px;">Vendor</td>
			<td style="width:141px;">Catalog no.</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">pStart-K</td>
			<td>Addgene</td>
			<td>20346</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">pWS-TK6&#160;</td>
			<td>Addgene</td>
			<td>20350</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">pKD3&#160;</td>
			<td>Addgene</td>
			<td>45604</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">pKD46</td>
			<td>The Coli Genetic Stock Center, CGSC</td>
			<td>7634</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">PGK-neo-bpA sequence&#160;</td>
			<td>Addgene</td>
			<td>13442</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Human BAC clones of target genes&#160;</td>
			<td>https://bacpac.chori.org</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">JDS246 (Cas9-003), Mammalian codon-optimized streptococcus pyogenes Cas9-3X Flag</td>
			<td>Addgene</td>
			<td>43861</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">MLM3636, Human-gRNA-ExpressionVector with U6 promoter&#160;</td>
			<td>Addgene</td>
			<td>43860</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">pX335-U6-Chimeric_BB-CBh-hSpCas9n(D10A)</td>
			<td>Addgene</td>
			<td>42335</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">sgRNA design, ZiFit</td>
			<td>http://zifit.partners.org/ZiFiT/</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Off target prediction tool CasOT</td>
			<td colspan="2">http://eendb.zfgenetics.org/casot/download.php</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Perl</td>
			<td>http://www.perl.org/get.html</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">NCBI</td>
			<td>http://www.ncbi.nlm.nih.gov/</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">BLAT</td>
			<td colspan="2">https://genome.ucsc.edu/cgi-bin/hgBlat?command=start</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">sgRNA Primer synthesis</td>
			<td>Sigma</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">One shot Top10 Electrocomp E. Coli Competent cells</td>
			<td>Life Technologies</td>
			<td>C4040-50</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">AccuPrime Pfx SupperMix</td>
			<td>Life Technologies</td>
			<td>12344-040</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Restriction enzymes</td>
			<td>NEB and Life Technologies</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Zymoclean Gel DNA Recovery Kit</td>
			<td>Zymo Researech</td>
			<td>D4007</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">DNA quick extraction buffer&#160;</td>
			<td>Epicentre</td>
			<td>QE0905T</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Herculase II Fusion DNA Polymerases</td>
			<td>Agilent Technologies</td>
			<td>600675</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Digestion buffer 2</td>
			<td>New England Biolab</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">6X DNA Loading Dye</td>
			<td>Thermo Scientific</td>
			<td>R0611</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">TeSR-E8 Kit for hESC/hiPSC Maintenance</td>
			<td>Stem Cell Technologies</td>
			<td>05940</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">UltraPure Agarose&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td>16500-100</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">50xTAE</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">B49</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Essential 8 medium&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">A1517001</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:259px;">Dulbecco&#8217;s Phosphate Buffered Saline without Calcium and Magnesium&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">A12856-01</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">D-MEM/F12 with Glutamax&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">10565018</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">D-MEM with Glutamax&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">10566040</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:259px;">Fetal Bovine Serum-ES cell qualified&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">10439</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Knockout serum replacement&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">10828010</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">2-mercaptoethanol 1000X&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">21985023</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Non Essential Amino Acid&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">11140050</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Stempro Accutase&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">A1110501</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Dispase&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">17105-041</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">0.25% Trypsin- EDTA solution&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">25200-056</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Geltrex&#160;</td>
			<td style="width:265px;">Life Technologies&#160;&#160;&#160;</td>
			<td style="width:141px;">12760-013</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">ROCK inhibitor Y-27632</td>
			<td style="width:265px;">Millipore</td>
			<td style="width:141px;">&#160;&#160; SCM075</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">SMC4 reagent&#160;</td>
			<td style="width:265px;">BD</td>
			<td style="width:141px;">354357</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Neomycin resistant MEF&#160;</td>
			<td style="width:265px;">Millipore</td>
			<td style="width:141px;">PMEF-NL</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Hygromycin resistant MEF&#160;</td>
			<td style="width:265px;">Millipore</td>
			<td style="width:141px;">PMEF-HL</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">G418 (Geneticin)</td>
			<td style="width:265px;">LifeTechnologies</td>
			<td style="width:141px;">11811</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Hygromycin B&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">10687010</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:259px;">FIAU (Fialuridine, 1-2-Deoxy-2-fluoro-&#223;-D-arabinofuranosyl-5-iodouracil</td>
			<td style="width:265px;">&#160;Moravek Biochemicals and Radiochemicals</td>
			<td style="width:141px;">&#160;&#160; M251</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Electroporator: Gene Pulser Xcell&#160;</td>
			<td style="width:265px;">Bio-Rad</td>
			<td style="width:141px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">0.4 cm electroporation cuvette&#160;</td>
			<td style="width:265px;">Bio-Rad</td>
			<td style="width:141px;">165-2088</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:259px;">DIG-High prime DNA labeling and detection starter kit II&#160;</td>
			<td style="width:265px;">Roche</td>
			<td style="width:141px;">11585614910</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Hybridization denature solution&#160;</td>
			<td style="width:265px;">VWR</td>
			<td style="width:141px;">82021-478</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">PCR DIG probe synthesis kit&#160;</td>
			<td style="width:265px;">Roche</td>
			<td style="width:141px;">11636090910</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">DIG wash set&#160;</td>
			<td style="width:265px;">Roche</td>
			<td style="width:141px;">11585762001</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Anti-Digoxigenin (DIG-AP)</td>
			<td style="width:265px;">Roche</td>
			<td style="width:141px;">11093274910</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">CSPD chemiluminescence system&#160;</td>
			<td style="width:265px;">Roche</td>
			<td style="width:141px;">11755633001</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">DIG wash and block buffer set&#160;</td>
			<td style="width:265px;">Roche</td>
			<td style="width:141px;">11585762001</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">50X TAE buffer&#160;</td>
			<td style="width:265px;">Life Technologies</td>
			<td style="width:141px;">24710030</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:259px;">Blotting buffer (25 mM Tris pH 7.4,&#160; 0.15 M NaCl,&#160; 0.1% Tween20)</td>
			<td style="width:265px;"></td>
			<td style="width:141px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Hoefer Ultraviolet Crosslinker&#160;</td>
			<td style="width:265px;">Fisher Scientific</td>
			<td style="width:141px;">03-500-308</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Spermidine&#160;</td>
			<td style="width:265px;">Fisher</td>
			<td style="width:141px;">AC13274-0010</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Tris HCl 2M ( pH 7.5 )</td>
			<td style="width:265px;">VWR</td>
			<td style="width:141px;">&#160;&#160; 200064-506</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:259px;">Denville Scientific blue bio film 8x10&#160;</td>
			<td style="width:265px;">Fisher</td>
			<td style="width:141px;">nc9550782</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:259px;">DNA molecular weight marker II ( DIG-labeled )</td>
			<td style="width:265px;">Roche</td>
			<td style="width:141px;">11218590910</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:259px;">Amersham Blotting membrane Hybond-N+&#160;</td>
			<td style="width:265px;">Roche</td>
			<td style="width:141px;">95038-400</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Pyrex glass drying tray&#160;</td>
			<td style="width:265px;">Fisher</td>
			<td style="width:141px;">15-242A</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Kimberly-Clark C-fold paper towels&#160;</td>
			<td style="width:265px;">Fisher</td>
			<td style="width:141px;">06-666-32B</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Whatman 3MM paper ( 26X41)</td>
			<td style="width:265px;">Fisher</td>
			<td style="width:141px;">&#160;&#160; 05-713-336</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Hybridization bag&#160;</td>
			<td style="width:265px;">Roche</td>
			<td style="width:141px;">11666649001</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Hybridization tubes&#160;</td>
			<td style="width:265px;">Fisher</td>
			<td style="width:141px;">13-247-300</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:259px;">Hybridization oven rotisserie Shake &#39;n&#39; Stack&#160;</td>
			<td style="width:265px;">Fisher</td>
			<td style="width:141px;">HBMSOV14110</td>
		</tr>
	</tbody>
</table>

efficient generation of hipsc neural lineage specific knockin reporters using the crispr/cas9 and cas9 double nickase system

Gene targeting is a critical approach for characterizing gene functions in modern biomedical research. However, the efficiency of gene targeting in human cells has been low, which prevents the generation of human cell lines at a desired rate. The past two years have witnessed a rapid progression on improving efficiency of genetic manipulation by genome editing tools such as the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas (CRISPR-associated) system. This manuscript describes a protocol for generating lineage specific human induced pluripotent stem cell (hiPSC) reporters using CRISPR/Cas system assisted homologous recombination. Procedures for obtaining necessary components for making neural lineage reporter lines using the CRISPR/Cas system, focusing on construction of targeting vectors and single guide RNAs, are described. This protocol can be extended to platform establishment and mutation correction in hiPSCs.

Targeting vectors with all necessary components including homology arms, reporter cassette, positive and negative selection cassettes are constructed (Figure 1). Based on the endogenous genomic locus, multiple (2 to 3) sgRNAs (if using the Cas9 system) or sgRNA pairs (if using the Cas9n double nickase strategy) are designed and constructed into human-gRNA-expression vector MLM3636 or pX335-U6-Chimeric_BB-CBh-hSpCas9n (D10A) backbones (Figure 2). Before transfecting hiPSCs, the sgRNAs are...

Watch this Scientific Journal Video about Efficient Generation of hiPSC Neural Lineage Specific Knockin Reporters Using the CRISPR/Cas9 and Cas9 Double Nickase System at JoVE.com

Efficient Generation of hiPSC Neural Lineage Specific Knockin Reporters Using the CRISPR/Cas9 and Cas9 Double Nickase System

Genome editing tools such as the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas (CRISPR-associated) system have greatly improved gene targeting efficiency in human induced pluripotent stem cells (hiPSCs). This manuscript describes a protocol for generating lineage specific hiPSC reporter using CRISPR/Cas system assisted homologous recombination.

Gene targeting is a critical approach for characterizing gene functions in modern biomedical research. However, the efficiency of gene targeting in human ...

efficient-generation-hipsc-neural-lineage-specific-knockin-reporters

Research

JoVE Journal

Developmental Biology

Alginate Encapsulation of Pluripotent Stem Cells Using a Co-axial Nozzle

Pluripotent stem cells (PS cells) are the focus of intense research due to their role in regenerative medicine and drug screening. However, the development of a mass culture system would be required for using PS cells in these applications. Suspension culture is one promising culture method for the mass production of PS cells, although some issues such as controlling aggregation and limiting shear stress from the culture medium are still unsolved. In order to solve these problems, we developed a method of calcium alginate (Alg-Ca) encapsulation using a co-axial nozzle. This method can control the size of the capsules easily by co-flowing N2 gas. The controllable capsule diameter must be larger than 500 &#181;m because too high a flow rate of N2 gas causes the breakdown of droplets and thus heterogeneous-sized capsules. Moreover, a low concentration of Alg-Na and CaCl2 causes non-spherical capsules. Although an Alg-Ca capsule without a coating of Alg-PLL easily dissolves enabling the collection of cells, they can also potentially leak out from capsules lacking an Alg-PLL coating. Indeed, an alginate-PLL coating can prevent cellular leakage but is also hard to break. This technology can be used to research the stem cell niche as well as the mass production of PS cells because encapsulation can modify the micro-environment surrounding cells including the extracellular matrix and the concentration of secreted factors.

We established a method of encapsulating pluripotent stem cells (PS cells) into alginate hydrogel capsules using a co-axial nozzle. This prevents cells from aggregating excessively and limits the shear stress experienced by cells in suspension culture. The technique is applicable to the mass production of PS cells as well as research on stem cell niche.

Pluripotent stem cells (PS cells) are the focus of intense research due to their role in regenerative medicine and drug screening.  However, the ...

Stable and Efficient Genetic Modification of Cells in the Adult Mouse V-SVZ for the Analysis of Neural Stem Cell Autonomous and Non-autonomous Effects

Relatively quiescent somatic stem cells support life-long cell renewal in most adult tissues. Neural stem cells in the adult mammalian brain are restricted to two specific neurogenic niches: the subgranular zone of the dentate gyrus in the hippocampus and the ventricular-subventricular zone (V-SVZ; also called subependymal zone or SEZ) in the walls of the lateral ventricles. The development of in vivo gene transfer strategies for adult stem cell populations (i.e. those of the mammalian brain) resulting in long-term expression of desired transgenes in the stem cells and their derived progeny is a crucial tool in current biomedical and biotechnological research. Here, a direct in vivo method is presented for the stable genetic modification of adult mouse V-SVZ cells that takes advantage of the cell cycle-independent infection by LVs and the highly specialized cytoarchitecture of the V-SVZ niche. Specifically, the current protocol involves the injection of empty LVs (control) or LVs encoding specific transgene expression cassettes into either the V-SVZ itself, for the in vivo targeting of all types of cells in the niche, or into the lateral ventricle lumen, for the targeting of ependymal cells only. Expression cassettes are then integrated into the genome of the transduced cells and fluorescent proteins, also encoded by the LVs, allow the detection of the transduced cells for the analysis of cell autonomous and non-autonomous, niche-dependent effects in the labeled cells and their progeny.

Here we describe a procedure based on the use of lentiviral particles for the long-term genetic modification of neural stem cells and/or their adjacent ependymal cells in the adult ventricular-subventricular neurogenic niche which allows the separate analysis of cell autonomous and non-autonomous, niche-dependent effects on neural stem cells.

Relatively quiescent somatic stem cells support life-long cell renewal in most adult tissues. Neural stem cells in the adult mammalian brain are ...

A Method for Lineage Tracing of Corneal Cells Using Multi-color Fluorescent Reporter Mice

Lineage tracing experiments define the origin, fate and behavior of cells in a specific tissue or organism. This technique has been successfully applied for many decades, revealing seminal findings in developmental biology. More recently, it was adopted by stem cell biologists to identify and track different stem cell populations with minimal experimental intervention. The recent developments in mouse genetics, the availability of a large number of mouse strains, and the advancements in fluorescent microscopy allow the straightforward design of powerful lineage tracing systems for various tissues with basic expertise, using commercially available tools. We have recently taken advantage of this powerful methodology to explore the origin and fate of stem cells at the ocular surface using R26R-Confetti mouse. This model offers a multi-color genetic system, for the expression of 4 fluorescent genes in a random manner. Here we describe the principles of this methodology and provide an adaptable protocol for designing lineage tracing experiments; specifically for the corneal epithelium as well as for other tissues.

In this article we describe the principles for designing and performing a multi-color lineage tracing experiment using R26R-Confetti mice. We provide a specific protocol for tracking corneal epithelial cells which can be modified for other tissues of interest.

Lineage tracing experiments define the origin, fate and behavior of cells in a specific tissue or organism. This technique has been successfully applied ...

Generating CRISPR/Cas9 Mediated Monoallelic Deletions to Study Enhancer Function in Mouse Embryonic Stem Cells

Enhancers control cell identity by regulating tissue-specific gene expression in a position and orientation independent manner. These enhancers are often located distally from the regulated gene in intergenic regions or even within the body of another gene. The position independent nature of enhancer activity makes it difficult to match enhancers with the genes they regulate. Deletion of an enhancer region provides direct evidence for enhancer activity and is the gold standard to reveal an enhancer's role in endogenous gene transcription. Conventional homologous recombination based deletion methods have been surpassed by recent advances in genome editing technology which enable rapid and precisely located changes to the genomes of numerous model organisms. CRISPR/Cas9 mediated genome editing can be used to manipulate the genome in many cell types and organisms rapidly and cost effectively, due to the ease with which Cas9 can be targeted to the genome by a guide RNA from a bespoke expression plasmid. Homozygous deletion of essential gene regulatory elements might lead to lethality or alter cellular phenotype whereas monoallelic deletion of transcriptional enhancers allows for the study of cis-regulation of gene expression without this confounding issue. Presented here is a protocol for CRISPR/Cas9 mediated deletion in F1 mouse embryonic stem (ES) cells (Mus musculus129 x Mus castaneus). Monoallelic deletion, screening and expression analysis is facilitated by single nucleotide polymorphisms (SNP) between the two alleles which occur on average every 125 bp in these cells.

Experimental validation of enhancer activity is best approached by loss-of-function analysis. Presented here is an efficient protocol that uses CRISPR/Cas9 mediated deletion to study allele-specific regulation of gene transcription in F1 ES cells which contain a hybrid genome (Mus musculus129 x Mus castaneus).

Enhancers control cell identity by regulating tissue-specific gene expression in a position and orientation independent manner. These enhancers are often ...

Co-localization of Cell Lineage Markers and the Tomato Signal

The cell lineage tracing system has been used predominantly in developmental biology studies. The use of Cre recombinase allows for the activation of the reporter in a specific cell line and all progeny. Here, we used the cell lineage tracing technique to demonstrate that chondrocytes directly transform into osteoblasts and osteocytes during long bone and mandibular condyle development using two kinds of Cre, Col10a1-Cre and Aggrecan-CreERT2 (Agg-CreERT2), crossed with Rosa26tdTomato. Both Col10 and aggrecan are well-recognized markers for chondrocytes.
On this basis, we developed a new method-cell lineage tracing in conjunction with fluorescent immunohistochemistry-to define cell fate by analyzing the expression of specific cell markers. Runx2 (a marker for early-stage osteogenic cells) and Dentin matrix protein1 (DMP1; a marker for late-stage osteogenic cells) were used to identify chondrocyte-derived bone cells and their differentiation status. This combination not only broadens the application of cell lineage tracing, but also simplifies the generation of compound mice. More importantly, the number, location, and differentiation statuses of parent cell progeny are displayed simultaneously, providing more information than cell lineage tracing alone. In conclusion, the co-application of cell lineage tracing techniques and immunofluorescence is a powerful tool for investigating cell biology in vivo.

We developed two sets of tracing combinations in Rosa26tdtomato (ubiquitously expressed in all cells)/Cre (specifically expressed in chondrocytes) mice: one with 2.3Col1a1-GFP (specific to osteoblasts) and one with immunofluorescence (specific to bone cells). The data demonstrate the direct transformation of chondrocytes into bone cells.

The cell lineage tracing system has been used predominantly in developmental biology studies. The use of Cre recombinase allows for the activation of the ...

Cell Lineage Analyses and Gene Function Studies Using Twin-spot MARCM

Mosaic analysis with a repressible cell marker (MARCM) is a positive mosaic labeling system that has been widely applied in Drosophila neurobiological studies to depict intricate morphologies and to manipulate the function of genes in subsets of neurons within otherwise unmarked and unperturbed organisms. Genetic mosaics generated in the MARCM system are mediated through site-specific recombination between homologous chromosomes within dividing precursor cells to produce both marked (MARCM clones) and unmarked daughter cells during mitosis. An extension of the MARCM method, called twin-spot MARCM (tsMARCM), labels both of the twin cells derived from a common progenitor with two distinct colors. This technique was developed to enable the retrieval of useful information from both hemi-lineages. By comprehensively analyzing different pairs of tsMARCM clones, the tsMARCM system permits high-resolution neural lineage mapping to reveal the exact birth-order of the labeled neurons produced from common progenitor cells. Furthermore, the tsMARCM system also extends gene function studies by permitting the phenotypic analysis of identical neurons of different animals. Here, we describe how to apply the tsMARCM system to facilitate studies of neural development in Drosophila.

Here, we present a protocol for a mosaic labeling technique that permits the visualization of neurons derived from a common progenitor cell in two distinct colors. This facilitates neural lineage analysis with the capability of birth-dating individual neurons and studying gene function in the same neurons of different individuals.

Mosaic analysis with a repressible cell marker (MARCM) is a positive mosaic labeling system that has been widely applied in Drosophila neurobiological ...

CRISPR/Cas9 Technology in Restoring Dystrophin Expression in iPSC-Derived Muscle Progenitors

Duchenne muscular dystrophy (DMD) is a severe progressive muscle disease caused by mutations in the dystrophin gene, which ultimately leads to the exhaustion of muscle progenitor cells. Clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) gene editing has the potential to restore the expression of the dystrophin gene. Autologous induced pluripotent stem cells (iPSCs)-derived muscle progenitor cells (MPC) can replenish the stem/progenitor cell pool, repair damage, and prevent further complications in DMD without causing an immune response. In this study, we introduce a combination of CRISPR/Cas9 and non-integrated iPSC technologies to obtain muscle progenitors with recovered dystrophin protein expression. Briefly, we use a non-integrating Sendai vector to establish an iPSC line from dermal fibroblasts of Dmdmdx mice. We then use the CRISPR/Cas9 deletion strategy to restore dystrophin expression through a non-homologous end joining of the reframed dystrophin gene. After PCR validation of exon23 depletion in three colonies from 94 picked iPSC colonies, we differentiate iPSC into MPC by doxycycline (Dox)-induced expression of MyoD, a key transcription factor playing a significant role in regulating muscle differentiation. Our results show the feasibility of using CRISPR/Cas9 deletion strategy to restore dystrophin expression in iPSC-derived MPC, which has significant potential for developing future therapies for the treatment of DMD.

Here, we present a Cas9-based exon23 deletion protocol to restore dystrophin expression in iPSC from Dmdmdx mouse-derived skin fibroblasts and directly differentiate iPSCs into myogenic progenitor cells (MPC) using the Tet-on MyoD activation system.

Duchenne muscular dystrophy (DMD) is a severe progressive muscle disease caused by mutations in the dystrophin gene, which ultimately leads to the ...

Three-dimensional Angiogenesis Assay System using Co-culture Spheroids Formed by Endothelial Colony Forming Cells and Mesenchymal Stem Cells

Studies in the field of angiogenesis have been aggressively growing in the last few decades with the recognition that angiogenesis is a hallmark of more than 50 different pathological conditions, such as rheumatoid arthritis, oculopathy, cardiovascular diseases, and tumor metastasis. During angiogenesis drug development, it is crucial to use in vitro assay systems with appropriate cell types and proper conditions to reflect the physiologic angiogenesis process. To overcome limitations of current in vitro angiogenesis assay systems using mainly endothelial cells, we developed a 3-dimensional (3D) co-culture spheroid sprouting assay system. Co-culture spheroids were produced by two human vascular cell precursors, endothelial colony forming cells (ECFCs) and mesenchymal stem cells (MSCs) with a ratio of 5 to 1. ECFCs+MSCs spheroids were embedded into type I collagen matrix to mimic the in vivo extracellular environment. A real-time cell recorder was utilized to continuously observe the progression of angiogenic sprouting from spheroids for 24 h. Live cell fluorescent labeling technique was also applied to tract the localization of each cell type during sprout formation. Angiogenic potential was quantified by counting the number of sprouts and measuring the cumulative length of sprouts generated from the individual spheroids. Five randomly-selected spheroids were analyzed per experimental group. Comparison experiments demonstrated that ECFCs+MSCs spheroids showed greater sprout number and cumulative sprout length compared with ECFCs-only spheroids. Bevacizumab, an FDA-approved angiogenesis inhibitor, was tested with the newly-developed co-culture spheroid assay system to verify its potential to screen anti-angiogenic drugs. The IC50 value for ECFCs+MSCs spheroids compared to the ECFCs-only spheroids was closer to the effective plasma concentration of bevacizumab obtained from the xenograft tumor mouse model. The present study suggests that the 3D ECFCs+MSCs spheroid angiogenesis assay system is relevant to physiologic angiogenesis, and can predict an effective plasma concentration in advance of animal experiments.

Three-dimensional co-culture spheroid angiogenesis assay system is designed to mimic the physiologic angiogenesis. Co-culture spheroids are formed by two human vascular cell precursors, ECFCs and MSCs, and embedded in collagen gel. The new system is effective for evaluating angiogenic modulators, and provides more relevant information to the in vivo study.

Studies in the field of angiogenesis have been aggressively growing in the last few decades with the recognition that angiogenesis is a hallmark of more ...

Efficient Neural Differentiation using Single-Cell Culture of Human Embryonic Stem Cells

In vitro differentiation of human embryonic stem cells (hESCs) has transformed the ability to study human development on both biological and molecular levels and provided cells for use in regenerative applications. Standard approaches for hESC culture using colony type culture to maintain undifferentiated hESCs and embryoid body (EB) and rosette formation for differentiation into different germ layers are inefficient and time-consuming. Presented here is a single-cell culture method using hESCs instead of a colony-type culture. This method allows maintenance of the characteristic features of undifferentiated hESCs, including expression of hESC markers at levels comparable to colony type hESCs. In addition, the protocol presents an efficient method for neural progenitor cell (NPC) generation from single-cell type hESCs that produces NPCs within 1 week. These cells highly express several NPC marker genes and can differentiate into various neural cell types, including dopaminergic neurons and astrocytes. This single-cell culture system for hESCs will be useful in investigating the molecular mechanisms of these processes, studies of certain diseases, and drug discovery screens.

Presented here is a protocol for the generation of a single-cell culture of human embryonic stem cells and their subsequent differentiation into neural progenitor cells. The protocol is simple, robust, scalable, and suitable for drug screening and regenerative medicine applications.

In vitro differentiation of human embryonic stem cells (hESCs) has transformed the ability to study human development on both biological and molecular ...

An Optimized O9-1/Hydrogel System for Studying Mechanical Signals in Neural Crest Cells

Neural crest cells (NCCs) are vertebrate embryonic multipotent cells that can migrate and differentiate into a wide array of cell types that give rise to various organs and tissues. Tissue stiffness produces mechanical force, a physical cue that plays a critical role in NCC differentiation; however, the mechanism remains unclear. The method described here provides detailed information for the optimized generation of polyacrylamide hydrogels of varying stiffness, the accurate measurement of such stiffness, and the evaluation of the impact of mechanical signals in O9-1 cells, a NCC line that mimics in vivo NCCs.
Hydrogel stiffness was measured using atomic force microscopy (AFM) and indicated different stiffness levels accordingly. O9-1 NCCs cultured on hydrogels of varying stiffness showed different cell morphology and gene expression of stress fibers, which indicated varying biological effects caused by mechanical signal changes. Moreover, this established that varying the hydrogel stiffness resulted in an efficient in vitro system to manipulate mechanical signaling by altering gel stiffness and analyzing the molecular and genetic regulation in NCCs. O9-1 NCCs can differentiate into a wide range of cell types under the influence of the corresponding differentiation media, and it is convenient to manipulate chemical signals in vitro. Therefore, this in vitro system is a powerful tool to study the role of mechanical signaling in NCCs and its interaction with chemical signals, which will help researchers better understand the molecular and genetic mechanisms of neural crest development and diseases.

Detailed step-by-step protocols are described here for studying mechanical signals in vitro using multipotent O9-1 neural crest cells and polyacrylamide hydrogels of varying stiffness.

Neural crest cells (NCCs) are vertebrate embryonic multipotent cells that can migrate and differentiate into a wide array of cell types that give rise to ...