Name: inducing complete polyp regeneration from the aboral physa of the starlet sea anemone nematostella vectensis
Uploaded: 2017-01-14T13:00:00
Description: Watch this Scientific Journal Video about Inducing Complete Polyp Regeneration from the Aboral Physa of the Starlet Sea Anemone Nematostella vectensis at JoVE.com

This work was supported by a New York Stem Cell Science (NYSTEM C028107) Grant to GHT.

1. Conditioning of Animals for Temperature, Nutrition and Light/Dark Cycle
<ol>
	<li>Obtain Nematostella vectensis adults from one of the numerous Nematostella labs worldwide, or a non-profit supplier (Table 1)</li>
	<li>Maintain Nematostella at constant temperature (typically between 18 and 21&#160;&#176;C) in the dark, in &#34;1/3x&#34; Artificial Sea Water (ASW) at a salinity of 12 parts per thousand (ppt). Maintain cultures in simple soda-lime glass culture dishes, typica...

<ol>
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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+understanding+tissue+regenerative+capacity+and+mechanisms+in+animals.">Advances in understanding tissue regenerative capacity and mechanisms in animals.</a> Nat Rev Genet. 11 (10), 710-722 (2010).</li><li>Galliot, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydra,+a+fruitful+model+system+for+270+years.">Hydra, a fruitful model system for 270 years.</a> Int J Dev Biol. 56 (6-8), 411-423 (2012).</li><li>Gold, D. A., Jacobs, D. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+cell+dynamics+in+Cnidaria:+are+there+unifying+principles?.">Stem cell dynamics in Cnidaria: are there unifying principles?.</a> Dev Genes Evol. 233 (1-2), 53-66 (2013).</li><li>Holstein, T. W., Hobmayer, E., Technau, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cnidarians:+an+evolutionarily+conserved+model+system+for+regeneration?.">Cnidarians: an evolutionarily conserved model system for regeneration?.</a> Dev Dyn. 226 (2), 257-267 (2003).</li><li>Amiel, A. 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=Characterization+of+Morphological+and+Cellular+Events+Underlying+Oral+Regeneration+in+the+Sea+Anemone,+Nematostella+vectensis.">Characterization of Morphological and Cellular Events Underlying Oral Regeneration in the Sea Anemone, Nematostella vectensis.</a> Int J Mol Sci. 16 (12), 28449-28471 (2015).</li><li>Warren, C. 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=Evolution+of+the+perlecan/HSPG2+gene+and+its+activation+in+regenerating+Nematostella+vectensis.">Evolution of the perlecan/HSPG2 gene and its activation in regenerating Nematostella vectensis.</a> PLoS One. 10 (4), e0124578 (2015).</li><li>Gong, Q., 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=Integrins+of+the+starlet+sea+anemone+Nematostella+vectensis.">Integrins of the starlet sea anemone Nematostella vectensis.</a> Biol Bull. 227 (3), 211-220 (2014).</li><li>Bossert, P. E., Dunn, M. P., Thomsen, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+staging+system+for+the+regeneration+of+a+polyp+from+the+aboral+physa+of+the+anthozoan+Cnidarian+Nematostella+vectensis.">A staging system for the regeneration of a polyp from the aboral physa of the anthozoan Cnidarian Nematostella vectensis.</a> Dev Dyn. 242 (11), 1320-1331 (2013).</li><li>Stefanik, D. J., Friedman, L. E., Finnerty, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collecting,+rearing,+spawning+and+inducing+regeneration+of+the+starlet+sea+anemone,+Nematostella+vectensis.">Collecting, rearing, spawning and inducing regeneration of the starlet sea anemone, Nematostella vectensis.</a> Nat Protoc. 8 (5), 916-923 (2013).</li><li>Tucker, R. 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=A+thrombospondin+in+the+anthozoan+Nematostella+vectensis+is+associated+with+the+nervous+system+and+upregulated+during+regeneration.">A thrombospondin in the anthozoan Nematostella vectensis is associated with the nervous system and upregulated during regeneration.</a> Biol Open. 2 (2), 217-226 (2013).</li><li>Passamaneck, Y. J., Martindale, M. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+proliferation+is+necessary+for+the+regeneration+of+oral+structures+in+the+anthozoan+cnidarian+Nematostella+vectensis.">Cell proliferation is necessary for the regeneration of oral structures in the anthozoan cnidarian Nematostella vectensis.</a> BMC Dev Biol. 12, (2012).</li><li>Trevino, M., Stefanik, D. J., Rodriguez, R., Harmon, S., Burton, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+canonical+Wnt+signaling+by+alsterpaullone+is+sufficient+for+oral+tissue+fate+during+regeneration+and+embryogenesis+in+Nematostella+vectensis.">Induction of canonical Wnt signaling by alsterpaullone is sufficient for oral tissue fate during regeneration and embryogenesis in Nematostella vectensis.</a> Dev Dyn. 240 (12), 2673-2679 (2011).</li><li>Renfer, E., Amon-Hassenzahl, A., Steinmetz, P. R., Technau, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+muscle-specific+transgenic+reporter+line+of+the+sea+anemone,+Nematostella+vectensis.">A muscle-specific transgenic reporter line of the sea anemone, Nematostella vectensis.</a> Proc Natl Acad Sci U S A. 107 (1), 104-108 (2010).</li><li>Burton, P. M., Finnerty, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conserved+and+novel+gene+expression+between+regeneration+and+asexual+fission+in+Nematostella+vectensis.">Conserved and novel gene expression between regeneration and asexual fission in Nematostella vectensis.</a> Dev Genes Evol. 219 (2), 79-87 (2009).</li><li>DuBuc, T. Q., Traylor-Knowles, N., Martindale, M. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Initiating+a+regenerative+response;+cellular+and+molecular+features+of+wound+healing+in+the+cnidarian+Nematostella+vectensis.">Initiating a regenerative response; cellular and molecular features of wound healing in the cnidarian Nematostella vectensis.</a> BMC Biol. 12, (2014).</li><li>Hand, C., Uhlinger, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Asexual+reproduction+by+transverse+fission+and+some+anomalies+in+the+sea+anemone+Nematostella+vectensis.">Asexual reproduction by transverse fission and some anomalies in the sea anemone Nematostella vectensis.</a> Invert Biol. 114, 9-18 (1995).</li><li>Fritzenwanker, J. H., Technau, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+gametogenesis+in+the+basal+cnidarian+Nematostella+vectensis(Anthozoa).">Induction of gametogenesis in the basal cnidarian Nematostella vectensis(Anthozoa).</a> Dev Genes Evol. 212 (2), 99-103 (2002).</li><li>Magie, C., Bossert, P., Aramli, L., Thomsen, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Science's+super+star:+The+starlet+sea+anemone+is+an+ideal+tool+for+student+inquiry.">Science's super star: The starlet sea anemone is an ideal tool for student inquiry.</a> The Science Teacher. 83 (3), 33-40 (2016).</li><li>Genikhovich, G., Technau, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+hybridization+of+starlet+sea+anemone+(Nematostella+vectensis)+embryos,+larvae,+and+polyps.">In situ hybridization of starlet sea anemone (Nematostella vectensis) embryos, larvae, and polyps.</a> Cold Spring Harb Protoc. (9), (2009).</li><li>Magie, C. R., Pang, K., Martindale, M. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genomic+inventory+and+expression+of+Sox+and+Fox+genes+in+the+cnidarian+Nematostella+vectensis.">Genomic inventory and expression of Sox and Fox genes in the cnidarian Nematostella vectensis.</a> Dev Genes Evol. 215 (12), 618-630 (2005).</li><li>Chera, S., Kaloulis, K., Galliot, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cAMP+response+element+binding+protein+(CREB)+as+an+integrative+HUB+selector+in+metazoans:+clues+from+the+hydra+model+system.">The cAMP response element binding protein (CREB) as an integrative HUB selector in metazoans: clues from the hydra model system.</a> Biosystems. 87 (2-3), 191-203 (2007).</li><li>Reitzel, A. M., Burton, P. M., Krone, C., Finnerty, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+developmental+trajectories+in+the+starlet+sea+anemone+Nematostella+vectensis:+embryogenesis,+regeneration,+and+two+forms+of+asexual+fission.">Comparison of developmental trajectories in the starlet sea anemone Nematostella vectensis: embryogenesis, regeneration, and two forms of asexual fission.</a> Invertebr Biol. 126, 99-112 (2007).</li><li>Ikmi, A., McKinney, S. A., Delventhal, K. M., Gibson, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TALEN+and+CRISPR/Cas9-mediated+genome+editing+in+the+early-branching+metazoan+Nematostella+vectensis.">TALEN and CRISPR/Cas9-mediated genome editing in the early-branching metazoan Nematostella vectensis.</a> Nat Commun. 5, 5486 (2014).</li><li>Jahnel, S. M., Walzl, M., Technau, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+epithelial+organisation+of+muscle+cells+in+the+sea+anemone+Nematostella+vectensis.">Development and epithelial organisation of muscle cells in the sea anemone Nematostella vectensis.</a> Front Zool. 11, 44 (2014).</li><li>Kelava, I., Rentzsch, F., Technau, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+eumetazoan+nervous+systems:+insights+from+cnidarians.">Evolution of eumetazoan nervous systems: insights from cnidarians.</a> Philos Trans R Soc Lond B Biol Sci. 370 (1684), (2015).</li><li>Nakanishi, N., Renfer, E., Technau, U., Rentzsch, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nervous+systems+of+the+sea+anemone+Nematostella+vectensis+are+generated+by+ectoderm+and+endoderm+and+shaped+by+distinct+mechanisms.">Nervous systems of the sea anemone Nematostella vectensis are generated by ectoderm and endoderm and shaped by distinct mechanisms.</a> Development. 139 (2), 347-357 (2012).</li><li>Richards, G. S., Rentzsch, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transgenic+analysis+of+a+SoxB+gene+reveals+neural+progenitor+cells+in+the+cnidarian+Nematostella+vectensis.">Transgenic analysis of a SoxB gene reveals neural progenitor cells in the cnidarian Nematostella vectensis.</a> Development. 141 (24), 4681-4689 (2014).</li><li>DuBuc, T. Q., 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=In+vivo+imaging+of+Nematostella+vectensis+embryogenesis+and+late+development+using+fluorescent+probes.">In vivo imaging of Nematostella vectensis embryogenesis and late development using fluorescent probes.</a> BMC Cell Biol. 15, (2014).</li><li>Kaur, J., Debnath, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autophagy+at+the+crossroads+of+catabolism+and+anabolism.">Autophagy at the crossroads of catabolism and anabolism.</a> Nat Rev Mol Cell Biol. 16 (8), 461-472 (2015).</li><li>Carroll, B., Korolchuk, V. 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Use of Nematostella as a model of wound healing and regeneration is becoming increasingly popular. Thus, it is important to be able to visualize the morphological patterns of a particular protocol before effective cellular and molecular analyses can be assigned and compared. Nematostella have a high degree of regenerative &#34;flexibility&#34;, being able to reform almost any missing structure amputated at any location, at post-planula stages of life. Thus, various investigators have examined regenerati...

The observation of regeneration in a single hydra was the seminal event in the advent of biology as an experimental science1,2. Regeneration remains a phenomenon of extraordinarily broad appeal to biologist and lay person alike. The potential for developmental biologists, clinicians, biomedical scientists and tissue engineers to understand and overcome the limits on human regeneration makes regeneration biology more than intrinsically interesting.
Now, with the use of emerging technologies such as genome sequencing and gain and loss of function tools, the field is poised to tease apart regenerative mechanisms and to ultimately understand how various species can regenerate while others cannot. The degree of commonality in molecular, cellular and morphological responses remains to be elucidated, but so far it appears that the basic responses among animals that can regenerate is more similar than would have been imagined only a decade ago3.
Cnidarians in particular are facile at regenerating almost all of their body parts amid a broad spectrum of morphological diversity. From the solitary fresh water polyp, Hydra along with the tiny marine polyps that build immense coral reefs, to the complex colonial siphonophores, such as the Portuguese Man-O-War, regeneration is often a mode of reproduction, in addition to a mechanism for repairing or reforming damaged or lost body parts resulting from injury and predation. Whether the diverse species of Cnidaria use similar or different mechanisms for regeneration is a fundamentally interesting question4-6.
We, and others have been developing the anthozoan, Nematostella vectensis as a model for regeneration7-17. We recently developed a staging system for describing regeneration of an entire body from a morphologically uniform piece of tissue bisected from the aboral end of the polyp10. While Nematostella polyps can regenerate when bisected at any level, we chose to cut adults at an aboral position in the most morphologically simple region, the physa, in part because this is close to the normal plane of natural asexual fission18, and also because it permits observation and molecular analyses of how an entire body is reassembled from the simplest morphological components.
The Nematostella Regeneration Staging System (NRSS) provides a relatively simple set of morphological benchmarks that could be used to score the progress of any aspect of regeneration by an amputated physa, under normal culture conditions or experimentally perturbed situations such as small molecule treatments, genetic manipulation, or environmental alteration. As anticipated, the NRSS is becoming adopted as a morphological scaffold on which the cellular and molecular events of regeneration can be referenced10.
Finally our method of cutting produces a gaping hole several orders of magnitude greater than the pin point puncture used in a recent study17, yet both wounds heal in around 6 hours. Documenting the visually arresting and distinct phases of wound closure should suggest experimental approaches to explain the apparent independence of the size of a wound and the time it takes to close. Thus, a deeper visual understanding of the aboral amputation process, provided by this protocol, will aid further investigations into this model regeneration system and broaden the application of this staging system using Nematostella vectensis.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Nematostella vectensis, adults</td>
			<td>Marine Biological Lab (MBL)</td>
			<td></td>
			<td>non-profit supplier</td>
		</tr>
		<tr>
			<td>Glass Culture Dish, 250 ml</td>
			<td>Carolina Biological Supply</td>
			<td>741004</td>
			<td>250 ml</td>
		</tr>
		<tr>
			<td>Glass Culture Dish, 1,500 ml</td>
			<td>Carolina Biological Supply</td>
			<td>741006</td>
			<td>1,500 ml</td>
		</tr>
		<tr>
			<td>Polyethylene transfer pipette, 5ml&#160;</td>
			<td>USA Scientific&#160;</td>
			<td>1022-2500</td>
			<td>narrow bore, graduated</td>
		</tr>
		<tr>
			<td>Polyethylene transfer pipet, tapered</td>
			<td>Samco</td>
			<td>202-205</td>
			<td>cut off 1 inch of tip to make wide bore</td>
		</tr>
		<tr>
			<td>Disposable Scalpel</td>
			<td>Feather Safety Razor Co. Ltd</td>
			<td>no. 10</td>
			<td>blade should be curved</td>
		</tr>
		<tr>
			<td>#5 Dumont Fine point tweezers</td>
			<td>Roboz</td>
			<td>RS5045</td>
			<td>alternative suppliers available</td>
		</tr>
		<tr>
			<td>Pyrex petri dish, 100 mm diameter</td>
			<td>Corning&#160;</td>
			<td>3160</td>
			<td>can substitute other glass petri plates</td>
		</tr>
		<tr>
			<td>Sterile 6 well plate</td>
			<td>Corning Falcon&#160;</td>
			<td>353046</td>
			<td>or similar from other manufacturer</td>
		</tr>
		<tr>
			<td>Sterile 12 well plate</td>
			<td>Nunc&#160;</td>
			<td>150628</td>
			<td>or similar from other manufacturer</td>
		</tr>
		<tr>
			<td>Sterile 24 well plate</td>
			<td>Cellstar, Greiner bio-one</td>
			<td>662-160</td>
			<td>or similar from other manufacturer</td>
		</tr>
		<tr>
			<td>Brine shrimp hathery kit</td>
			<td>San Francisco Bay; drsfostersmith.com</td>
			<td>CD-154005</td>
			<td>option for growing brine shrimp</td>
		</tr>
		<tr>
			<td>pyrex baking dish</td>
			<td>common in grocery stores</td>
			<td></td>
			<td>option for growing brine shrimp</td>
		</tr>
		<tr>
			<td>artificial seawater mix 50 gal or more&#160;</td>
			<td>Instant Ocean; drsfoster-smith.com</td>
			<td>CD-116528</td>
			<td>others brands may suffice</td>
		</tr>
		<tr>
			<td>Plastic tub for stock ASW preparation</td>
			<td>various</td>
			<td></td>
			<td>common 25 gallon plastic trash can OK</td>
		</tr>
		<tr>
			<td>Polypropylene Carboy</td>
			<td>Carolina Biological Supply</td>
			<td>716391</td>
			<td>For working stock of ASW @ 12 ppt</td>
		</tr>
		<tr>
			<td>Beaker, Graduated, 4,000ml</td>
			<td>PhytoTechnology Laboratories</td>
			<td>B199</td>
			<td>For dilution of 36 ppt ASW to 12 ppt</td>
		</tr>
		<tr>
			<td>Stereomicroscope and light source</td>
			<td>various&#160;</td>
			<td></td>
			<td>with continuous 1 - 40x magnification&#160;</td>
		</tr>
	</tbody>
</table>

inducing complete polyp regeneration from the aboral physa of the starlet sea anemone nematostella vectensis

Cnidarians, and specifically Hydra, were the first animals shown to regenerate damaged or severed structures, and indeed such studies arguably launched modern biological inquiry through the work of Trembley more than 250 years ago. Presently the study of regeneration has seen a resurgence using both &#34;classic&#34; regenerative organisms, such as the Hydra, planaria and Urodeles, as well as a widening spectrum of species spanning the range of metazoa, from sponges through mammals. Besides its intrinsic interest as a biological phenomenon, understanding how regeneration works in a variety of species will inform us about whether regenerative processes share common features and/or species or context-specific cellular and molecular mechanisms. The starlet sea anemone, Nematostella vectensis, is an emerging model organism for regeneration. Like Hydra, Nematostella is a member of the ancient phylum, cnidaria, but within the class anthozoa, a sister clade to the hydrozoa that is evolutionarily more basal. Thus aspects of regeneration in Nematostella will be interesting to compare and contrast with those of Hydra and other cnidarians. In this article, we present a method to bisect, observe and classify regeneration of the aboral end of the Nematostella adult, which is called the physa. The physa naturally undergoes fission as a means of asexual reproduction, and either natural fission or manual amputation of the physa triggers re-growth and reformation of complex morphologies. Here we have codified these simple morphological changes in a Nematostella Regeneration Staging System (the NRSS). We use the NRSS to test the effects of chloroquine, an inhibitor of lysosomal function that blocks autophagy. The results show that the regeneration of polyp structures, particularly the mesenteries, is abnormal when autophagy is inhibited.

The progression of morphological events during regeneration in severed physa is shown in Figure 1A, which includes representative views of physa at each NRSS stage. The typical physa cut site is indicated on the adult (arrowheads). The photographs in Figure 1A show progressive regeneration of oral and body structures from freshly cut physa through fully formed polyp. Figure 1B, C show&#160;the arrangement of internal septa, the mesenterie...

Watch this Scientific Journal Video about Inducing Complete Polyp Regeneration from the Aboral Physa of the Starlet Sea Anemone Nematostella vectensis at JoVE.com

Inducing Complete Polyp Regeneration from the Aboral Physa of the Starlet Sea Anemone Nematostella vectensis

Here we demonstrate how to induce and monitor regeneration in the Starlet Sea Anemone Nematostella vectensis, a model cnidarian anthozoan. We demonstrate how to amputate and categorize regeneration using a morphological staging system, and we use this system to reveal a requirement for autophagy in regenerating polyp structures.

Inducing Complete Polyp Regeneration from the Aboral Physa of the Starlet Sea Anemone Nematostella vectensis

Cnidarians, and specifically Hydra, were the first animals shown to regenerate damaged or severed structures, and indeed such studies arguably launched ...

The overall goal of this procedure is to illustrate the predictable series of morphological changes that occurred during the regeneration of a complete polyp from a tiny section of tissue removed from the aboral tip of nematostella vectensis This method can help answer key questions in regeneration biology, such as how cells at the site of a wound reorganize and deploy to remake the missing structures. I first had the idea for this method because I wanted to see how relatively complex polyp could put itself back together starting with the least amount of morphological information. Visual demonstration of this method is critical because stage progression after the initial wounding is sometimes obscured by a mucous membrane.Generally individuals new to this method will struggle to obtain a complete separation of the tissue at the wound site, because of the soft, sticky, gelatinous nature of the polyp. Begin this procedure with conditioning of nematostella vectensis as described in the text protocol. It's especially important when using this technique that the animals selected are the same size, and have the same culture history, such as identical feeding and other condition parameters.Remove the dish of selected animals from the incubator into room light at least one hour prior to amputation. Use a wide bore plastic pipette to transfer the five animals from the pool to be amputated into the bottom of a sterile glass cutting dish of 100 millimeter diameter containing artificial seawater at a salinity of 12 parts per thousand. Place the dish onto the stage of a stereo microscope with variable magnification between 10 to 40x.Select size-matched polyps of approximately the same length and place them in a bowl separated from the colony for three days prior to amputation. Using a sterile scalpel, amputate the aboral physa from each polyp to obtain a section of the physa that is approximately as long as it is wide and containing no mesentery. To achieve this, place the scalpel blade in contact with the animal at the desired site of amputation.Do this either unassisted or by gently grasping the animal's body with a number five forceps. Cut through the tissue by leveraging the curved blade of the scalpel in a rocking motion across the body. Remove each amputated donor polyp from the dish and return it to a separate bowl labeled pooled amputees.After dating the bowl, return it to stock culture. Rinse the excised physa that remain in the cutting dish in artificial seawater at a salinity of 12 parts per 1, 000. Then, transfer each physa to a separate sterile well in a multi-well cell culture plate that has 10 milliliters of artificial seawater at a salinity of 12 parts per 1, 000 in each well.Repeat these steps to collect at least five physa in each well to be reserved for each experimental treatment. Place the plate containing the physa into a temperature-regulated incubator at a fixed temperature determined by the desired rate of regeneration. Score the physa using a stereo compound microscope with variable magnification.Score the freshly cut nematostella physa as stage zero, and continue scoring at the same time each day post-amputation, or DPA, using the NRSS. Score the physa as stage zero if a freshly cut physa appears as a cup-shaped mass resembling a flacid ballon with an open wound site that is likely visible. Score a physa as stage one if the amputation wound appears closed.Score a physa as stage two if the surface of the aural pole appears inflated, revealing eight raised arches arranged in a radially symmetric pattern and separated by grooves. At stage two, observe small hemispherical blebs at the apex of the arches that are about as tall as wide, likely transient, and initial comprised by a single ectodermal cell layer. As the physa ages, it may become encased in mucous, which should be carefully removed with forceps.Score a physa as stage three if the buds of the tentacles containing endodermal and ectodermal tissue layers are stably formed at the aural end of at least some radial arches. Score a physa as stage four if the physa contains eight distinct visible mesenteries that extend in a coelenteron from insertions in the body wall with aural aboral lengths that are more than twice their radial width measured from where they appear to connect to the pharynx at its aboral end, or enterostome. Finally, score a physa as stage five if the physa has more than four mesenteries with pleating, and the pleating is more full and sinuous than at stage four.At stage five, the animal has an almost normal adult appearance, but there are no visible gonadal cells. This group of control nematostella physa treated with 0.1 percent DMSO have regenerated completely to stage five. Physa treated with chloroquine, however, failed to completely form completed mesenteries.A closeup shows both the presence and lack of pleating in the mesenteries in a physa that was incubated in chloroquine. This graph illustrates the aggregate results of chloroquine treatment. Any treatment between 10 and 50 micromolar caused similar defects, mostly the lack of complete reformation of mesenteries in that the mesenteries lack pleating.Once mastered, this technique can be done in less than an hour for each six-well plate containing 30 cut physa. Scoring is rapid, perhaps requiring a half hour for each replicate plate. After watching this video, you should have a good understanding of how to amputate the physa to visualize the morphological changes that occur during the regeneration of a complete polyp from a tiny section of aboral tissue.The main advantage of this technique is that it provides morphological stages in which to pin the molecular events underlying the regeneration of a complete polyp from a cup of visually uniform tissue. While attempting this procedure, it's important to remember to precondition the animals with respect to nutritional history, to bisect to exclude adult mesentery, and to standardize the size of the regenerating physa to reduce variation within treatments. Following this procedure, the effects of genetic mutations or signaling pathway perturbations with small molecules, for example, could be assessed.Or morphogenetic changes could be correlated with microscopic analysis of self-proliferation, lineage tracing, or site two gene expression. This technique will pave the way for researchers in the field of regeneration biology to explore the cell biology, signaling pathways, and morphogenetic processes that underlie the remarkable regenerative capacity of this model organism.

inducing-complete-polyp-regeneration-from-aboral-physa-starlet-sea

Research

JoVE Journal

Developmental Biology

Efficient Derivation of Retinal Pigment Epithelium Cells from Stem Cells

No cure has been discovered for age-related macular degeneration (AMD), the leading cause of vision loss in people over the age of 55. AMD is complex multifactorial disease with an unknown etiology, although it is largely thought to occur due to death or dysfunction of the retinal pigment epithelium (RPE), a monolayer of cells that underlies the retina and provides critical support for photoreceptors. RPE cell replacement strategies may hold great promise for providing therapeutic relief for a large subset of AMD patients, and RPE cells that strongly resemble primary human cells (hRPE) have been generated in multiple independent labs, including our own. In addition, the uses for iPS-RPE are not limited to cell-based therapies, but also have been used to model RPE diseases. These types of studies may not only elucidate the molecular bases of the diseases, but also serve as invaluable tools for developing and testing novel drugs. We present here an optimized protocol for directed differentiation of RPE from stem cells. Adding nicotinamide and either Activin A or IDE-1, a small molecule that mimics its effects, at specific time points, greatly enhances the yield of RPE cells. Using this technique we can derive large numbers of low passage RPE in as early as three months.

Stem cell-derived retinal pigment epithelium (RPE) cells may be used for multiple applications including cell-based therapies for retinal degeneration, disease modeling, and drug studies. Here we present a simple protocol for reproducibly deriving RPE from stem cells.

No cure has been discovered for age-related macular degeneration  (AMD), the leading cause of vision loss in people over the age of 55. AMD is complex ...

Assaying Blood Cell Populations of the Drosophila melanogaster Larva

In vertebrates, hematopoiesis is regulated by inductive microenvironments (niches). Likewise, in the invertebrate model organism&#160;Drosophila melanogaster, inductive microenvironments known as larval Hematopoietic Pockets (HPs) have been identified as anatomical sites for the development and regulation of blood cells (hemocytes), in particular of the self-renewing macrophage lineage.&#160;HPs are segmentally repeated pockets between the epidermis and muscle layers of the larva, which also comprise sensory neurons of the peripheral nervous system. In the larva, resident (sessile) hemocytes are exposed to anti-apoptotic, adhesive and proliferative cues from these sensory neurons and potentially other components of the HPs, such as the lining muscle and epithelial layers. During normal development, gradual release of resident hemocytes from the HPs fuels the population of circulating hemocytes, which culminates in the release of most of the resident hemocytes at the beginning of metamorphosis. Immune assaults, physical injury or mechanical disturbance trigger the premature release of resident hemocytes into circulation. The switch of larval hemocytes between resident locations and circulation raises the need for a common standard/procedure to selectively isolate and quantify these two populations of blood cells from single Drosophila larvae. Accordingly, this protocol describes an automated method to release and quantify the resident and circulating hemocytes from single larvae. The method facilitates ex vivo approaches, and may be adapted to serve a variety of developmental stages of Drosophila and other invertebrate organisms.

Assaying Blood Cell Populations of the Drosophila melanogaster Larva

Drosophila blood cells, or hemocytes, cycle between resident sites and circulation. In the larva, resident (sessile) hemocytes localize to inductive microenvironments, the Hematopoietic Pockets, while circulating hemocytes move freely in the hemolymph. The goal of this protocol is the standardized isolation and quantification of these two, behaviorally distinct but interchanging, hemocyte populations.

In vertebrates, hematopoiesis is regulated by inductive microenvironments (niches). Likewise, in the invertebrate model organism&#160;Drosophila ...

Use of the TetON System to Study Molecular Mechanisms of Zebrafish Regeneration

The zebrafish has become a very important model organism for studying vertebrate development, physiology, disease, and tissue regeneration. A thorough understanding of the molecular and cellular mechanisms involved requires experimental tools that allow for inducible, tissue-specific manipulation of gene expression or signaling pathways. Therefore, we and others have recently adapted the TetON system for use in zebrafish. The TetON system facilitates temporally and spatially-controlled gene expression and we have recently used this tool to probe for tissue-specific functions of Wnt/beta&#8211;catenin signaling during zebrafish tail fin regeneration. Here we describe the workflow for using the TetON system to achieve inducible, tissue-specific gene expression in the adult regenerating zebrafish tail fin. This includes the generation of stable transgenic TetActivator and TetResponder lines, transgene induction and techniques for verification of tissue-specific gene expression in the fin regenerate. Thus, this protocol serves as blueprint for setting up a functional TetON system in zebrafish and its subsequent use, in particular for studying fin regeneration.

Here we outline the workflow for using the TetON system to achieve tissue-specific gene expression in the adult regenerating zebrafish tail fin.

The zebrafish has become a very important model organism for studying vertebrate development, physiology, disease, and tissue regeneration. A thorough ...

The Complete and Updated "Rotifer Polyculture Method" for Rearing First Feeding Zebrafish

The zebrafish (Danio rerio) is a model organism of increasing importance in many fields of science. One of the most demanding technical aspects of culture of this species in the laboratory is rearing first-feeding larvae to the juvenile stage with high rates of growth and survival. The central management challenge of this developmental period revolves around delivering highly nutritious feed items to the fish on a nearly continuous basis without compromising water quality. Because larval zebrafish are well-adapted to feed on small zooplankton in the water column, live prey items such as brachionid rotifers, Artemia, and Paramecium are widely recognized as the feeds of choice, at least until the fish reach the juvenile stage and are able to efficiently feed on processed diets. This protocol describes a method whereby newly hatched zebrafish larvae are cultured together with live saltwater rotifers (Brachionus plicatilis) in the same system. This polyculture approach provides fish with an "on-demand", nutrient-rich live food source without producing chemical waste at levels that would otherwise limit performance. Importantly, because the system harnesses both the natural high productivity of the rotifers and the behavioral preferences of the fish, the labor involved with maintenance is low. The following protocol details an updated, step-by-step procedure that incorporates rotifer production (scalable to any desired level) for use in a polyculture of zebrafish larvae and rotifers that promotes maximal performance during the first 5 days of exogenous feeding.

The Complete and Updated &quot;Rotifer Polyculture Method&quot; for Rearing First Feeding Zebrafish

Larval zebrafish are adapted to feed on zooplankton. It is possible to capitalize on this natural feature in the laboratory by growing first feeding fish together in the same system with live saltwater rotifers. This "polyculture" strategy promotes high growth and survival with minimal labor and disturbance to the larvae.

The zebrafish (Danio rerio) is a model organism of increasing importance in many fields of science.  One of the most demanding technical aspects of ...

The Power of Simplicity: Sea Urchin Embryos as in Vivo Developmental Models for Studying Complex Cell-to-cell Signaling Network Interactions

Remarkably few cell-to-cell signal transduction pathways are necessary during embryonic development to generate the large variety of cell types and tissues in the adult body form. Yet, each year more components of individual signaling pathways are discovered, and studies indicate that depending on the context there is significant cross-talk among most of these pathways. This complexity makes studying cell-to-cell signaling in any in vivo developmental model system a difficult task. In addition, efficient functional analyses are required to characterize molecules associated with signaling pathways identified from the large data sets generated by next generation differential screens. Here, we illustrate a straightforward method to efficiently identify components of signal transduction pathways governing cell fate and axis specification in sea urchin embryos. The genomic and morphological simplicity of embryos similar to those of the sea urchin make them powerful in vivo developmental models for understanding complex signaling interactions. The methodology described here can be used as a template for identifying novel signal transduction molecules in individual pathways as well as the interactions among the molecules in the various pathways in many other organisms.

The Power of Simplicity: Sea Urchin Embryos as in Vivo Developmental Models for Studying Complex Cell-to-cell Signaling Network Interactions

This video article details a straightforward in vivo methodology that can be used to systematically and efficiently characterize components of complex signaling pathways and regulatory networks in many invertebrate embryos.

Remarkably few cell-to-cell signal transduction pathways are necessary during embryonic development to generate the large variety of cell types and ...

Chemical Amputation and Regeneration of the Pharynx in the Planarian Schmidtea mediterranea

Planarians are flatworms that are extremely efficient at regeneration. They owe this ability to a large number of stem cells that can rapidly respond to any type of injury. Common injury models in these animals remove large amounts of tissue, which damages multiple organs. To overcome this broad tissue damage, we describe here a method to selectively remove a single organ, the pharynx, in the planarian Schmidtea mediterranea. We achieve this by soaking animals in a solution containing the cytochrome oxidase inhibitor sodium azide. Brief exposure to sodium azide causes extrusion of the pharynx from the animal, which we call &#34;chemical amputation.&#34;&#160;Chemical amputation removes the entire pharynx, and generates a small wound where the pharynx attaches to the intestine. After extensive rinsing, all amputated animals regenerate a fully functional pharynx in approximately one week. Stem cells in the rest of the body drive regeneration of the new pharynx. Here, we provide a detailed protocol for chemical amputation, and describe both histological and behavioral methods to assess successful amputation and regeneration.

Chemical Amputation and Regeneration of the Pharynx in the Planarian Schmidtea mediterranea

The planarian Schmidtea mediterranea is an excellent model for studying stem cells and tissue regeneration. This publication describes a method to selectively remove one organ, the pharynx, by exposing animals to the chemical sodium azide. This protocol also outlines methods for monitoring pharynx regeneration.

Planarians are flatworms that are extremely efficient at regeneration. They owe this ability to a large number of stem cells that can rapidly respond to ...

Methods for the Study of Regeneration in Stentor

Cells need to be able to regenerate their parts to recover from external perturbations. The unicellular ciliate Stentor coeruleus is an excellent model organism to study wound healing and subsequent cell regeneration. The Stentor genome became available recently, along with modern molecular biology methods, such as RNAi. These tools make it possible to study single-cell regeneration at the molecular level. The first section of the protocol covers establishing Stentor cell cultures from single cells or cell fragments, along with general guidelines for maintaining Stentor cultures. Culturing Stentor in large quantities allows for the use of valuable tools like biochemistry, sequencing, and mass spectrometry. Subsequent sections of the protocol cover different approaches to inducing regeneration in Stentor. Manually cutting cells with a glass needle allows studying the regeneration of large cell parts, while treating cells with either sucrose or urea allows studying the regeneration of specific structures located at the anterior end of the cell. A method for imaging individual regenerating cells is provided, along with a rubric for staging and analyzing the dynamics of regeneration. The entire process of regeneration is divided in three stages. By visualizing the dynamics of the progression of a population of cells through the stages, the heterogeneity in regeneration timing is demonstrated.

Methods for the Study of Regeneration in Stentor

The giant ciliate, Stentor coeruleus, is an excellent system to study regeneration and wound healing. We present procedures for establishing Stentor cell cultures from single cells or cell fragments, inducing regeneration by cutting cells, chemically inducing the regeneration of membranellar band and oral apparatus, imaging, and analysis of cell regeneration.

Cells need to be able to regenerate their parts to recover from external perturbations. The unicellular ciliate Stentor coeruleus is an excellent model ...

A Simplified and Efficient Method to Isolate Primary Human Keratinocytes from Adult Skin Tissue

Primary human keratinocytes isolated from fresh skin tissues and their expansion in vitro have been widely used for laboratory research and for clinical applications. The conventional isolation method of human keratinocytes involves a two-step sequential enzymatic digestion procedure, which has been proven to be inefficient in generating primary cells from adult tissues due to the low cell recovery rate and reduced cell viability. We recently reported an advanced method to isolate human primary epidermal progenitor cells from skin tissues that utilizes the Rho kinase inhibitor Y-27632 in the medium. Compared with the traditional protocol, this new method is simpler, easier, and less time-consuming, and increases epithelial stem cell yield and enhances their stem cell characteristics. Moreover, the new methodology does not require the separation of the epidermis from the dermis, and, therefore, is suitable for isolating cells from different types of adult tissues. This new isolation method overcomes the major shortcomings of conventional methods and is more suitable for producing large numbers of epidermal cells with high potency both for laboratory and for clinical applications. Here, we describe the new method in detail.

Here we present a protocol to efficiently isolate primary human keratinocytes from adult skin tissues. This method simplifies the conventional procedure by using the ROCK Inhibitor Y-27632 in the inoculation medium to spontaneously separate epidermal cells from dermal cells.

Primary human keratinocytes isolated from fresh skin tissues and their expansion in vitro have been widely used for laboratory research and for clinical ...

Generation of 3D Skin Organoid from Cord Blood-derived Induced Pluripotent Stem Cells

The skin is the body&#8217;s largest organ and has many functions. The skin acts as a physical barrier and protector of the body and regulates bodily functions. Biomimetics is the imitation of the models, systems, and elements of nature for the purpose of solving complex human problems1. Skin biomimetics is a useful tool for in vitro disease research and in vivo regenerative medicine. Human induced pluripotent stem cells (iPSCs) have the characteristic of unlimited proliferation and the ability of differentiation to three germ layers. Human iPSCs are generated from various primary cells, such as blood cells, keratinocytes, fibroblasts, and more. Among them, cord blood mononuclear cells (CBMCs) have emerged as an alternative cell source from the perspective of allogeneic regenerative medicine. CBMCs are useful in regenerative medicine because human leukocyte antigen (HLA) typing is essential to the cell banking system. We provide a method for the differentiation of CBMC-iPSCs into keratinocytes and fibroblasts and for generation of a 3D skin organoid. CBMC-iPSC-derived keratinocytes and fibroblasts have characteristics similar to a primary cell line. The 3D skin organoids are generated by overlaying an epidermal layer onto a dermal layer. By transplanting this 3D skin organoid, a humanized mice model is generated. This study shows that a 3D human iPSC-derived skin organoid may be a novel, alternative tool for dermatologic research in vitro and in vivo.

We propose a protocol that shows how to differentiate induced pluripotent stem cell-derived keratinocytes and fibroblasts and generate a 3D skin organoid, using these keratinocytes and fibroblasts. This protocol contains an additional step of generating a humanized mice model. The technique presented here will improve dermatologic research.

The skin is the body&#8217;s largest organ and has many functions. The skin acts as a physical barrier and protector of the body and regulates bodily ...

Genotyping of Sea Anemone during Early Development

Described here is a PCR-based protocol to genotype the gastrula stage embryo of the anthozoan cnidarian Nematostella vectensis without sacrificing the life of the animal. Following in vitro fertilization and de-jellying, zygotes are allowed to develop for 24 h at room temperature to reach the early- to mid-gastrula stage. The gastrula embryos are then placed on an agarose gel bed in a Petri dish containing seawater. Under the dissecting microscope, a tungsten needle is used to surgically separate an aboral tissue fragment from each embryo. Post-surgery embryos are then allowed to heal and continue development. Genomic DNA is extracted from the isolated tissue fragment and used as a template for locus-specific PCR. The genotype can be determined based on the size of PCR products or presence/absence of allele-specific PCR products. Post-surgery embryos are then sorted according to the genotype. The duration of the entire genotyping process depends on the number of embryos to be screened, but it minimally requires 4&#8211;5 h. This method can be used to identify knockout mutants from a genetically heterogeneous population of embryos and enables analyses of phenotypes during development.

The goal of this protocol is to genotype the sea anemone Nematostella vectensis during gastrulation without sacrificing the embryo.

Described here is a PCR-based protocol to genotype the gastrula stage embryo of the anthozoan cnidarian Nematostella vectensis without sacrificing the ...