Name: tissue determination using the animal cap transplant (act) assay in xenopus laevis
Uploaded: 2010-05-16T17:00:00
Description: Watch this Scientific Journal Video about Tissue Determination Using the Animal Cap Transplant ACT Assay in Xenopus laevis at JoVE.com

This work was supported by grants from Research to Prevent Blindness (Career Development Awards to MEZ and ASV and an unrestricted grant to the Department of Ophthalmology), the E. Matilda Zeigler Foundation (MEZ and ASV) and the National Eye Institute/NIH (MEZ, grants R01EY015748 and R01EY017964).

Part I. Set-up for the ACT Assay
<ol>
	<li>Generate capped RNA for injection as suggested by the manufacturer, using their phenol:chloroform purification method (e.g. mMessage mMachine Kit; Applied Biosystems/Ambion, Austin, TX). RNA encoding a fluorescent protein is used as a tracer. We transcribe either yellow fluorescent protein (YFP) or mCherry 5 cDNA, which is in a pCS2+ expression vector.</li>
	<li>Pull borosilicate glass capillary tubes to form tapered glass tips using a micropipette puller. We use...

<ol>
	<li>Smith, W. C., Harland, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+cloning+of+noggin,+a+new+dorsalizing+factor+localized+to+the+Spemann+organizer+in+Xenopus+embryos.">Expression cloning of noggin, a new dorsalizing factor localized to the Spemann organizer in Xenopus embryos.</a> Cell. 70, 829-840 (1992).</li><li>Lamb, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+induction+by+the+secreted+polypeptide+noggin.">Neural induction by the secreted polypeptide noggin.</a> Science. 262, 713-718 (1993).</li><li>Green, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+Methods+in+Developmental+Biology:+Xenopus+&#38;+Zebrafish.">Molecular Methods in Developmental Biology: Xenopus &#38; Zebrafish.</a> Methods in Developmental Biology. , (1999).</li><li>Viczian, A. S., Solessio, E. C., Lyou, Y., Zuber, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+functional+eyes+from+pluripotent+cells.">Generation of functional eyes from pluripotent cells.</a> PLoS Biol. 7, e1000174-e1000174 (2009).</li><li>Shaner, N. C., Steinbach, P. A., Tsien, R. 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+guide+to+choosing+fluorescent+proteins.">A guide to choosing fluorescent proteins.</a> Nat Methods. 2, 905-909 (2005).</li><li>Brown, A. L., Johnson, B. E., Goodman, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Making+patch-pipettes+and+sharp+electrodes+with+a+programmable+puller.">Making patch-pipettes and sharp electrodes with a programmable puller.</a> J Vis Exp. , (2008).</li><li>Lan, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noggin+Elicits+Retinal+Fate+in+Xenopus+Animal+Cap+Embryonic+Stem+Cells.">Noggin Elicits Retinal Fate in Xenopus Animal Cap Embryonic Stem Cells.</a> Stem Cells. , (2009).</li></ol>

In this video, we have demonstrated our version of classic techniques used by Xenopus biologists, which we rearranged to create the animal cap transplant assay. At room temperature, Xenopus embryos develop very quickly through stages 9 and 15. By placing them at 14&deg;C, the development of the embryo is slowed down and many more transplants can be performed in one experiment. If it is necessary to grow the embryos to older stages (&gt;42/43), then we recommend using transgenic venus YFP animals, since ...

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		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
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<tr>
<td>mMessage mMachine SP6 Kit</td>
<td>&nbsp;</td>
<td>Applied Biosystems/Ambion</td>
<td>AM1340</td>
<td>&nbsp;</td>
<tr>
<td>Borosilicate Capillary Tubes (1.0mm OD x 0.5mm ID)</td>
<td>&nbsp;</td>
<td>FHC, Inc</td>
<td>27-30-1</td>
<td>&nbsp;</td>
<tr>
<td>Sutter Micropipette Puller</td>
<td>&nbsp;</td>
<td>Sutter Instruments, Inc.</td>
<td>P-97</td>
<td>&nbsp;</td>
<tr>
<td>Gentamicin sulfate [50 mg/ml]</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>BW17-528Z</td>
<td>&nbsp;</td>
<tr>
<td>Sylgard/elastomer Kit 1.1lb</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>NC9644388</td>
<td>&nbsp;</td>
<tr>
<td>60 x 15 mm polystyrene petri dish</td>
<td>&nbsp;</td>
<td>USA Scientific</td>
<td>8609-0160</td>
<td>&nbsp;</td>
<tr>
<td>human chorionic gonadotropin</td>
<td>&nbsp;</td>
<td>Intervet</td>
<td>22219</td>
<td>&nbsp;</td>
<tr>
<td>Pico-Injector Microinjection Systems</td>
<td>&nbsp;</td>
<td>Harvard Apparatus</td>
<td>650003</td>
<td>&nbsp;</td>
<tr>
<td>Torrey Pines Scientific ECHOtherm Incubator</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>11-680-21</td>
<td>&nbsp;</td>
<tr>
<td>Transfer pipette</td>
<td>&nbsp;</td>
<td>Krackeler</td>
<td>6290-20635A</td>
<td>&nbsp;</td>
<tr>
<td>Dumostar #5 Forceps</td>
<td>&nbsp;</td>
<td>Fisher</td>
<td>11295-10</td>
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tissue determination using the animal cap transplant (act) assay in xenopus laevis

Many proteins play a dual role in embryonic development. Those that regulate cell fate determination in a specific tissue can also affect the development of a larger region of the embryo. This makes defining its role in a particular tissue difficult to analyze. For example, noggin overexpression in Xenopus laevis embryos causes the expansion of the entire anterior region, including the eye1,2. From this result, it is not known if Noggin plays a direct role in eye determination or that by causing an expansion of neural tissue, Noggin indirectly affects eye formation. Having this complex phenotype makes studying its eye-specific role in cell fate determination difficult to analyze. We have developed an assay that overcomes this problem. Taking advantage of the pluripotent nature of the Xenopus laevis animal cap 3, we have developed an assay to test the ability of gene product(s), like noggin or the eye field transcription factors (EFTFs), to transform caps into particular tissue or cell types by transplanting this tissue onto the side of the embryo 4. While we have found either Noggin protein treatment or a collection of transcription factors can determine retinal cell fate in animal caps, this procedure could be used to identify gene product(s) involved in specifying other tissues as well.

Watch this Scientific Journal Video about Tissue Determination Using the Animal Cap Transplant ACT Assay in Xenopus laevis at JoVE.com

Tissue Determination Using the Animal Cap Transplant ACT Assay in Xenopus laevis

Animal caps overexpressing gene product(s) are transplanted to the flank of developing Xenopus laevis embryos in order to establish whether tissue is determined.

Tissue Determination Using the Animal Cap Transplant (ACT) Assay in Xenopus laevis

Many proteins play a dual role in embryonic development. Those that regulate cell fate determination in a specific tissue can also affect the development ...

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