Name: visualizing bacteria in nematodes using fluorescent microscopy
Uploaded: 2012-10-19T12:00:00
Description: Watch this Scientific Journal Video about Visualizing Bacteria in Nematodes using Fluorescent Microscopy at JoVE.com

The authors wish to thank Eugenio Vivas, Kurt Heungens, Eric Martens, Charles Cowles, Darby Sugar, Eric Stabb, and Todd Ciche for their contributions to the development of this protocol and tools used. KEM and JMC were supported by National Institutes of Health (NIH) National Research Service Award T32 (AI55397 "Microbes in Health and Disease"). JMC was supported by a National Science Foundation (NSF) Graduate Research Fellowship. This work was supported by grants from the National Science Foundation (IOS-0920631 and IOS- 0950873).

1. Construction of a Fluorescent Bacterial Strain via Conjugation
<ol>
	<li>Grow the recipient strain (symbiont to be examined) and donor strain overnight. The donor strain, usually Escherichia coli, should be capable of donating DNA through conjugation and should be transformed with a plasmid (Table 2) that carries a gene encoding a fluorescent protein. Depending on the plasmid, a conjugation helper strain may also be required. If so, this strain should also be grown overnight. The donor stra...

<ol>
	<li>Holterman, M., van der Wurff, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phylum-wide+analysis+of+SSU+rDNA+reveals+deep+phylogenetic+relationships+among+nematodes+and+accelerated+evolution+toward+crown+clades.">Phylum-wide analysis of SSU rDNA reveals deep phylogenetic relationships among nematodes and accelerated evolution toward crown clades.</a> Mol. Biol. Evol. 23, 1792-1800 (2006).</li><li>Lambshead, P. J. D., Boucher, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Marine+nematode+deep-sea+biodiversity+-+hyperdiverse+or+hype.">Marine nematode deep-sea biodiversity - hyperdiverse or hype.</a> J. Biogeogr. 30, 475-485 (2003).</li><li>Poinar, G. O. J., Thomas, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Significance+of+Achromobacter+nematophilus+Poinar+and+Thomas+(Achromobacteraceae:+Eubacteriales)+in+the+development+of+the+nematode,+DD-136+(Neoaplectana+sp.+Steinernematidae).">Significance of Achromobacter nematophilus Poinar and Thomas (Achromobacteraceae: Eubacteriales) in the development of the nematode, DD-136 (Neoaplectana sp. Steinernematidae).</a> Parasitol. 56, 385-390 (1966).</li><li>Herbert, E. E., Goodrich-Blair, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Friend+and+foe:+the+two+faces+of+Xenorhabdus+nematophila.">Friend and foe: the two faces of Xenorhabdus nematophila.</a> Nat. Rev. Microbiol. 5, 634-646 (2007).</li><li>Kaya, H. K., Gaugler, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Entomopathogenic+nematodes.">Entomopathogenic nematodes.</a> Annu. Rev. Entomol. 38, 181-206 (1993).</li><li>Bird, A. F., Akhurst, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+nature+of+the+intestinal+vesicle+in+nematodes+of+the+family+Steinernematidae.">The nature of the intestinal vesicle in nematodes of the family Steinernematidae.</a> Int. J. Parasitol. 13, 599-606 (1983).</li><li>Martens, E. C., Goodrich-Blair, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Steinernema+carpocapsae+intestinal+vesicle+contains+a+subcellular+structure+with+which+Xenorhabdus+nematophila+associates+during+colonization+initiation.">The Steinernema carpocapsae intestinal vesicle contains a subcellular structure with which Xenorhabdus nematophila associates during colonization initiation.</a> Cell. Microbiol. 7, 1723-1735 (2005).</li><li>Snyder, H. A., Stock, S. P., Kim, S. K., Flores-Lara, Y., Forst, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+insights+into+the+colonization+and+release+process+of+Xenorhabdus+nematophila+and+the+morphology+and+ultrastructure+of+the+bacterial+receptacle+of+its+nematode+host,+Steinernema+carpocapsae.">New insights into the colonization and release process of Xenorhabdus nematophila and the morphology and ultrastructure of the bacterial receptacle of its nematode host, Steinernema carpocapsae.</a> Appl. Environ. Microbiol. 73, 5338-5346 (2007).</li><li>Abebe, E., Abebe-Akele, F., Morrison, J., Cooper, V., Thomas, W. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+insect+pathogenic+symbiosis+between+a+Caenorhabditis+and+Serratia.">An insect pathogenic symbiosis between a Caenorhabditis and Serratia.</a> Virulence. 2, 158-161 (2011).</li><li>Abebe, E., Jumba, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+entomopathogenic+Caenorhabditis+briggsae.">An entomopathogenic Caenorhabditis briggsae.</a> J. Exp. Biol. 213, 3223-3229 (2010).</li><li>Torres-Barragan, A., Suazo, A., Buhler, W. G., Cardoza, Y. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+on+the+entomopathogenicity+and+bacterial+associates+of+the+nematode+Oscheius+carolinensis.">Studies on the entomopathogenicity and bacterial associates of the nematode Oscheius carolinensis.</a> Biol. Control. 59, 123-129 (2011).</li><li>Ye, W. M., Torres-Barragan, A., Cardoza, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oscheius+carolinensis+n.+sp+(Nematoda:+Rhabditidae),+a+potential+entomopathogenic+nematode+from+vermicompost.">Oscheius carolinensis n. sp (Nematoda: Rhabditidae), a potential entomopathogenic nematode from vermicompost.</a> Nematology. 12, 121-135 (2010).</li><li>Zhang, C., Liu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterorhabditidoides+chongmingensis+gen.+nov.,+sp.+nov.+(Rhabditida:+Rhabditidae),+a+novel+member+of+the+entomopathogenic+nematodes.">Heterorhabditidoides chongmingensis gen. nov., sp. nov. (Rhabditida: Rhabditidae), a novel member of the entomopathogenic nematodes.</a> J. Invertebr. Pathol. 98, 153-168 (2008).</li><li>Martens, E. C., Heungens, K., Goodrich-Blair, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+colonization+events+in+the+mutualistic+association+between+Steinernema+carpocapsae+nematodes+and+Xenorhabdus+nematophila+bacteria.">Early colonization events in the mutualistic association between Steinernema carpocapsae nematodes and Xenorhabdus nematophila bacteria.</a> J. Bacteriol. 185, 3147-3154 (2003).</li><li>Ciche, T. A., Ensign, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=For+the+insect+pathogen,+Photorhabdus+luminescens,+which+end+of+a+nematode+is+out.">For the insect pathogen, Photorhabdus luminescens, which end of a nematode is out.</a> Appl. Environ. Microbiol. 69, 1890-1897 (2003).</li><li>Ciche, T. A., Kim, K. S., Kaufmann-Daszczuk, B., Nguyen, K. C., Hall, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+invasion+and+matricide+during+Photorhabdus+luminescens+transmission+by+Heterorhabditis+bacteriophora+nematodes.">Cell invasion and matricide during Photorhabdus luminescens transmission by Heterorhabditis bacteriophora nematodes.</a> Appl. Environ. Microbiol. 74, 2275-2287 (2008).</li><li>Easom, C. A., Joyce, S. A., Clarke, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+genes+involved+in+the+mutualistic+colonization+of+the+nematode+Heterorhabditis+bacteriophora+by+the+bacterium+Photorhabdus+luminescens.">Identification of genes involved in the mutualistic colonization of the nematode Heterorhabditis bacteriophora by the bacterium Photorhabdus luminescens.</a> BMC Microbiol. 10, 45 (2010).</li><li>Somvanshi, V. S., Kaufmann-Daszczuk, B., Kim, K. S., Mallon, S., Ciche, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photorhabdus+phase+variants+express+a+novel+fimbrial+locus,+mad,+essential+for+symbiosis.">Photorhabdus phase variants express a novel fimbrial locus, mad, essential for symbiosis.</a> Mol. Microbiol. 77, 1021-1038 (2010).</li><li>Martens, E. C., Russell, F. M., Goodrich-Blair, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+Xenorhabdus+nematophila+metabolic+mutants+yields+insight+into+stages+of+Steinernema+carpocapsae+nematode+intestinal+colonization.">Analysis of Xenorhabdus nematophila metabolic mutants yields insight into stages of Steinernema carpocapsae nematode intestinal colonization.</a> Mol. Microbiol. 51, 28-45 (2005).</li><li>Sugar, D. R., Murfin, K. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phenotypic+variation+and+host+interactions+of+Xenorhabdus+bovienii+SS-2004,+the+entomopathogenic+symbiont+of+Steinernema+jollieti+nematodes.">Phenotypic variation and host interactions of Xenorhabdus bovienii SS-2004, the entomopathogenic symbiont of Steinernema jollieti nematodes.</a> Env. Microbiol. 14, 924-939 (2012).</li><li>Cowles, C. E., Goodrich-Blair, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Xenorhabdus+nematophila+nilABC+genes+confer+the+ability+of+Xenorhabdus+spp.+to+colonize+Steinernema+carpocapsae+nematodes.">The Xenorhabdus nematophila nilABC genes confer the ability of Xenorhabdus spp. to colonize Steinernema carpocapsae nematodes.</a> J. Bacteriol. 190, 4121-4128 (2008).</li><li>Heungens, K., Cowles, C. E., Goodrich-Blair, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+Xenorhabdus+nematophila+genes+required+for+mutualistic+colonization+of+Steinernema+carpocapsae+nematodes.">Identification of Xenorhabdus nematophila genes required for mutualistic colonization of Steinernema carpocapsae nematodes.</a> Mol. Microbiol. 45, 1337-1353 (2002).</li><li>Goetsch, M., Owen, H., Goldman, B., Forst, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+the+PixA+inclusion+body+protein+of+Xenorhabdus+nematophila.">Analysis of the PixA inclusion body protein of Xenorhabdus nematophila.</a> J. Bacteriol. 188, 2706-2710 (2006).</li><li>Bhasin, A., Chaston, J. M., Goodrich-Blair, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mutational+Analyses+Reveal+Overall+Topology+and+Functional+Regions+of+NilB,+a+Bacterial+Outer+Membrane+Protein+Required+for+Host+Association+in+a+Model+of+Animal-Microbe+Mutualism.">Mutational Analyses Reveal Overall Topology and Functional Regions of NilB, a Bacterial Outer Membrane Protein Required for Host Association in a Model of Animal-Microbe Mutualism.</a> J. Bacteriol. 194, 1763-1776 (2012).</li><li>Ciche, T. A., Goffredi, S. K., Reddy, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Methods in General and Molecular Microbiology. , 394-419 (2007).</li><li>Goodrich-Blair, H., Clarke, D., Grewal, P. S., Ciche, T. A., Stock, S. P., Boemare, N., Vandenberg, J., Glazar, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Insect Pathogens, Molecular Approaches and Techniques. , 239-269 (2009).</li><li>Stock, S. P., Goodrich-Blair, H., Lacey, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Manual of Techniques in Invertebrate Pathology. , 375-425 (2012).</li><li>Martens, E. C., Gawronski-Salerno, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Xenorhabdus+nematophila+requires+an+intact+iscRSUA-hscBA-fdx+locus+to+colonize+Steinernema+carpocapsae+nematodes.">Xenorhabdus nematophila requires an intact iscRSUA-hscBA-fdx locus to colonize Steinernema carpocapsae nematodes.</a> J. Bacteriol. 185, 3678-3682 (2003).</li><li>Vivas, E. I., Goodrich-Blair, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Xenorhabdus+nematophilus+as+a+model+for+host-bacterium+interactions:+rpoS+is+necessary+for+mutualism+with+nematodes.">Xenorhabdus nematophilus as a model for host-bacterium interactions: rpoS is necessary for mutualism with nematodes.</a> J. Bacteriol. 183, 4687-4693 (2001).</li><li>White, G. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+obtaining+infective+nematode+larvae+from+cultures.">A method for obtaining infective nematode larvae from cultures.</a> Science. 66, 302-303 (1927).</li><li>Ciche, T. A., Ensign, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=For+the+insect+pathogen+Photorhabdus+luminescens,+which+end+of+a+nematode+is+out.">For the insect pathogen Photorhabdus luminescens, which end of a nematode is out.</a> Appl. Environ. Microbiol. 69, 1890-1897 (2003).</li><li>Sicard, M., Brun, N. L. e. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+native+Xenorhabdus+on+the+fitness+of+their+Steinernema+hosts:+contrasting+types+of+interaction.">Effect of native Xenorhabdus on the fitness of their Steinernema hosts: contrasting types of interaction.</a> Parasitol. Res. 91, 520-524 (2003).</li><li>Lambertsen, L., Sternberg, C., Molin, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mini-Tn7+transposons+for+site-specific+tagging+of+bacteria+with+fluorescent+proteins.">Mini-Tn7 transposons for site-specific tagging of bacteria with fluorescent proteins.</a> Environ. Microbiol. 6, 726-732 (2004).</li><li>Miller, W. G., Leveau, J. H., Lindow, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+gfp+and+inaZ+broad-host-range+promoter-probe+vectors.">Improved gfp and inaZ broad-host-range promoter-probe vectors.</a> Mol. Plant Microbe Int. 13, 1243-1250 (2000).</li><li>Teal, T. K., Lies, D. P., Wold, B. J., Newman, 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=Spatiometabolic+stratification+of+Shewanella+oneidensis+biofilms.">Spatiometabolic stratification of Shewanella oneidensis biofilms.</a> Appl. Environ. Microbiol. 72, 7324-7330 (2006).</li><li>Bao, Y., Lies, D. P., Fu, H., Roberts, G. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+improved+Tn7-based+system+for+the+single-copy+insertion+of+cloned+genes+into+chromosomes+of+Gram-negative+bacteria.">An improved Tn7-based system for the single-copy insertion of cloned genes into chromosomes of Gram-negative bacteria.</a> Gene. 109, 167-168 (1991).</li><li>Woodring, J. L., Kaya, H. 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The protocol described here provides a method for the optical detection of bacteria within a nematode host (Figure 1). This method takes advantage of the optical transparency of nematodes and the ability to fluorescently label bacteria, enabling in vivo analysis of bacteria within the nematode host (Figure 3). Specifically, this approach identifies bacterial localization within its host. By counting a nematode population and scoring for bacterial presence, the frequency of bacte...

<table border="1">
 <tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments (optional)</td>
 </tr>
 <tr>
 <td>Lipid Agar 
 (sterile)</td>
 <td></td>
 <td></td>
 <td>8 grams nutrient broth, 15 grams agar, 5 grams yeast extract, 890 ml water, 10 ml 0.2 g/ml MgCl2. 6H20, 96 ml corn syrup solution*, 4 ml corn oil* 
 Stir media while pouring plates 
 *add sterile ingredient after autoclaving </td>
 </tr>
 <tr>
 <td>Corn Syrup Solution 
 (sterile)</td>
 <td></td>
 <td></td>
 <td>7 ml corn syrup, 89 ml water 
 mix and autoclave</td>
 </tr>
 <tr>
 <td>Egg Solution</td>
 <td></td>
 <td></td>
 <td>16.6 ml 12% sodium hypochlorite, 5 ml 5M KOH, 80 ml water</td>
 </tr>
 <tr>
 <td>Lysogeny Broth 
 (sterile)</td>
 <td></td>
 <td></td>
 <td>5 grams yeast extract, 10 grams tryptone, 5 grams salt, 1 L water 
 mix and autoclave</td>
 </tr>
 <tr>
 <td>Microfuge</td>
 <td>Fisher</td>
 <td>13-100-675</td>
 <td>Any microfuge that holds microfuge tubes will work</td>
 </tr>
 <tr>
 <td>Centrifuge</td>
 <td>Beckman</td>
 <td>366802 </td>
 <td>Large table top centrifuge that holds 15 ml and 50 ml conical tubes</td>
 </tr>
 <tr>
 <td>Sterile 60 mm X 15 mm Petri Dish</td>
 <td>Fisher</td>
 <td>0875713</td>
 <td></td>
 </tr>
 <tr>
 <td>50 ml centrifuge tubes</td>
 <td>Fisher</td>
 <td>05-539-6</td>
 <td></td>
 </tr>
 <tr>
 <td>15 ml centrifuge tubes</td>
 <td>Fisher</td>
 <td>05-531-6</td>
 <td></td>
 </tr>
 <tr>
 <td>Sterile 100 mm X 20 mm Petri Dish</td>
 <td>Fisher</td>
 <td>0875711Z</td>
 <td>Deeper than standard Petri dishes</td>
 </tr>
 <tr>
 <td>24-well plate</td>
 <td>Greiner Bio-One</td>
 <td>662000-06</td>
 <td></td>
 </tr>
 <tr>
 <td>Microscope</td>
 <td></td>
 <td></td>
 <td>The microscope needs florescent capabilities compatible with your fluorophore </td>
 </tr>
 <tr>
 <td>Paraformaldehyde</td>
 <td>Electron Microscopy Sciences</td>
 <td>15710</td>
 <td></td>
 </tr>
 <tr>
 <td>PBS 
 (sterile)</td>
 <td></td>
 <td></td>
 <td>8 g NaCL 
 0.2 g KCL 
 1.44 g Na2HPO4 
 0.24 g KH2PO4 
 1 L water Adjust to a pH of 7.4 and water to 1 L and autoclave</td>
 </tr>
 <tr>
 <td>Microfuge tubes</td>
 <td>Fisher</td>
 <td>05-408-138</td>
 <td>2 ml or 1.5 ml tubes</td>
 </tr>
 <tr>
 <td>Shaker</td>
 <td></td>
 <td></td>
 <td>Any shaker that causes the liquid to gently move will work</td>
 </tr>
 <tr>
 <td>Diaminopimelic acid</td>
 <td>Sigma</td>
 <td>D-1377</td>
 <td>If needed, supplement media to a concentration or 1 mM</td>
 </tr>
 </tbody>
</table>

visualizing bacteria in nematodes using fluorescent microscopy

Symbioses, the living together of two or more organisms, are widespread throughout all kingdoms of life. As two of the most ubiquitous organisms on earth, nematodes and bacteria form a wide array of symbiotic associations that range from beneficial to pathogenic 1-3. One such association is the mutually beneficial relationship between Xenorhabdus bacteria and Steinernema nematodes, which has emerged as a model system of symbiosis 4. Steinernema nematodes are entomopathogenic, using their bacterial symbiont to kill insects 5. For transmission between insect hosts, the bacteria colonize the intestine of the nematode's infective juvenile stage 6-8. Recently, several other nematode species have been shown to utilize bacteria to kill insects 9-13, and investigations have begun examining the interactions between the nematodes and bacteria in these systems 9.
We describe a method for visualization of a bacterial symbiont within or on a nematode host, taking advantage of the optical transparency of nematodes when viewed by microscopy. The bacteria are engineered to express a fluorescent protein, allowing their visualization by fluorescence microscopy. Many plasmids are available that carry genes encoding proteins that fluoresce at different wavelengths (i.e. green or red), and conjugation of plasmids from a donor Escherichia coli strain into a recipient bacterial symbiont is successful for a broad range of bacteria. The methods described were developed to investigate the association between Steinernema carpocapsae and Xenorhabdus nematophila 14. Similar methods have been used to investigate other nematode-bacterium associations 9,15-18and the approach therefore is generally applicable.
The method allows characterization of bacterial presence and localization within nematodes at different stages of development, providing insights into the nature of the association and the process of colonization 14,16,19. Microscopic analysis reveals both colonization frequency within a population and localization of bacteria to host tissues 14,16,19-21. This is an advantage over other methods of monitoring bacteria within nematode populations, such as sonication 22or grinding 23, which can provide average levels of colonization, but may not, for example, discriminate populations with a high frequency of low symbiont loads from populations with a low frequency of high symbiont loads. Discriminating the frequency and load of colonizing bacteria can be especially important when screening or characterizing bacterial mutants for colonization phenotypes 21,24. Indeed, fluorescence microscopy has been used in high throughput screening of bacterial mutants for defects in colonization 17,18, and is less laborious than other methods, including sonication 22,25-27and individual nematode dissection 28,29.

Watch this Scientific Journal Video about Visualizing Bacteria in Nematodes using Fluorescent Microscopy at JoVE.com

Visualizing Bacteria in Nematodes using Fluorescent Microscopy

To study the mutualism between Xenorhabdus bacteria and Steinernema nematodes, methods were developed to monitor bacterial presence and location within nematodes. The experimental approach, which can be applied to other systems, entails engineering bacteria to express the green fluorescent protein and visualizing, using fluorescence microscopy bacteria within the transparent nematode.

 
Symbioses, the living together of two or more organisms, are widespread throughout all kingdoms of life. As two of the most ubiquitous organisms on ...

visualizing-bacteria-in-nematodes-using-fluorescent-microscopy

Research

JoVE Journal

Biology

Visualizing the Live Drosophila Glial-neuromuscular Junction with Fluorescent Dyes

Our project identified GFP labeled glial structures at the developing larval fly neuromuscular synapse. To look at development of live glial-nerve-muscle synapses, we developed a larval tissue preparation that had features of live intact larvae, but also had good optical properties.  This new preparation also allowed for access of perfusates to the synapse.  We used fly larvae, immersed them in artificial hemolymph, and relaxed their normal rhythmic body contractions by chilling them. Next we dissected off the posterior segments of each animal and with a blunt insect pin pushed the mouth parts backward through the body cavity.  This everted the larval body wall, like turning a sock inside-out.  We completed the dissection with ultra-fine dissection scissors and thus exposed the visceral side of the body wall muscles. The glial structures at the NMJ expressed membrane targeted GFP under the control of glial specific promoters. The post-synaptic membrane, the SSR (Subsynaptic Reticula) in muscle expressed synaptically targeted dsRed. We needed to acutely label the motor neuron terminals, the third part of the synapse. To do this we applied primary antibodies to HRP, conjugated to a far-red emitting flurophore.  To test for dye diffusion properties into the perisynaptic space between the motor neuron terminals and the SSR, we applied a solution of large Dextran molecules conjugated to far-red emitting flurophore and collected images.

Visualizing the Live Drosophila Glial-neuromuscular Junction with Fluorescent Dyes

We described structural features of the Glia-neuromuscular synapses in a novel Inside-out tissue preparation of live fly larvae using fluorescent dyes with confocal microscopy. We labeled live neuron terminals with fluorescent primary antibodies to HRP, and also visualized the perisynaptic space with fluorescent Dextrans.

Our project identified GFP labeled glial structures at the developing larval fly neuromuscular synapse. To look at development of live glial-nerve-muscle ...

Visualizing Single Molecular Complexes In Vivo Using Advanced Fluorescence Microscopy

Full insight into the mechanisms of living cells can be achieved only by investigating the key processes that elicit and direct events at a cellular level. To date the shear complexity of biological systems has caused precise single-molecule experimentation to be far too demanding, instead focusing on studies of single systems using relatively crude bulk ensemble-average measurements. However, many important processes occur in the living cell at the level of just one or a few molecules; ensemble measurements generally mask the stochastic and heterogeneous nature of these events. Here, using advanced optical microscopy and analytical image analysis tools we demonstrate how to monitor proteins within a single living bacterial cell to a precision of single molecules and how we can observe dynamics within molecular complexes in functioning biological machines. The techniques are directly relevant physiologically. They are minimally-perturbative and non-invasive to the biological sample under study and are fully attuned for investigations in living material, features not readily available to other single-molecule approaches of biophysics. In addition, the biological specimens studied all produce fluorescently-tagged protein at levels which are almost identical to the unmodified cell strains ("genomic encoding"), as opposed to the more common but less ideal approach for generating significantly more protein than would occur naturally ('plasmid expression'). Thus, the actual biological samples which will be investigated are significantly closer to the natural organisms, and therefore the observations more relevant to real physiological processes.

Visualizing Single Molecular Complexes In Vivo Using Advanced Fluorescence Microscopy

Here we demonstrate the protocols for performing single-molecule fluorescence microscopy on living bacterial cells to enable functional molecular complexes to be detected, tracked and quantified.

Full insight into the mechanisms of living cells can be achieved only by investigating the key processes that elicit and direct events at a cellular ...

Visualizing Single-molecule DNA Replication with Fluorescence Microscopy

We describe a simple fluorescence microscopy-based real-time method for observing DNA replication at the single-molecule level. A circular, forked DNA template is attached to a functionalized glass coverslip and replicated extensively after introduction of replication proteins and nucleotides (Figure 1). The growing product double-strand DNA (dsDNA) is extended with laminar flow and visualized by using an intercalating dye. Measuring the position of the growing DNA end in real time allows precise determination of replication rate (Figure 2). Furthermore, the length of completed DNA products reports on the processivity of replication. This experiment can be performed very easily and rapidly and requires only a fluorescence microscope with a reasonably sensitive camera.


This protocol demonstrates a simple single-molecule fluorescence microscopy technique for visualizing DNA replication by individual replisomes in real time.

We describe a simple fluorescence microscopy-based real-time method for observing DNA replication at the single-molecule level. A circular, forked DNA ...

Intravital Microscopy for Imaging Subcellular Structures in Live Mice Expressing Fluorescent Proteins

Here we describe a procedure to image subcellular structures in live rodents that is based on the use of confocal intravital microscopy. As a model organ, we use the salivary glands of live mice since they provide several advantages. First, they can be easily exposed to enable access to the optics, and stabilized to facilitate the reduction of the motion artifacts due to heartbeat and respiration. This significantly facilitates imaging and tracking small subcellular structures. Second, most of the cell populations of the salivary glands are accessible from the surface of the organ. This permits the use of confocal microscopy that has a higher spatial resolution than other techniques that have been used for in vivo imaging, such as two-photon microscopy. Finally, salivary glands can be easily manipulated pharmacologically and genetically, thus providing a robust system to investigate biological processes at a molecular level.
In this study we focus on a protocol designed to follow the kinetics of the exocytosis of secretory granules in acinar cells and the dynamics of the apical plasma membrane where the secretory granules fuse upon stimulation of the beta-adrenergic receptors. Specifically, we used a transgenic mouse that co-expresses cytosolic GFP and a membrane-targeted peptide fused with the fluorescent protein tandem-Tomato. However, the procedures that we used to stabilize and image the salivary glands can be extended to other mouse models and coupled to other approaches to label in vivo cellular components, enabling the visualization of various subcellular structures, such as endosomes, lysosomes, mitochondria, and the actin cytoskeleton.

Intravital microscopy is a powerful tool that enables imaging various biological processes in live animals. In this article, we present a detailed method for imaging the dynamics of subcellular structures, such as the secretory granules, in the salivary glands of live mice.

Here we describe a procedure to image subcellular structures in live rodents that is based on the use of confocal intravital microscopy. As a model organ, ...

Super-resolution Imaging of the Cytokinetic Z Ring in Live Bacteria Using Fast 3D-Structured Illumination Microscopy (f3D-SIM)

Imaging of biological samples using fluorescence microscopy has advanced substantially with new technologies to overcome the resolution barrier of the diffraction of light allowing super-resolution of live samples. There are currently three main types of super-resolution techniques &#8211; stimulated emission depletion (STED), single-molecule localization microscopy (including techniques such as PALM, STORM, and GDSIM), and structured illumination microscopy (SIM). While STED and single-molecule localization techniques show the largest increases in resolution, they have been slower to offer increased speeds of image acquisition. Three-dimensional SIM (3D-SIM) is a wide-field fluorescence microscopy technique that offers a number of advantages over both single-molecule localization and STED. Resolution is improved, with typical lateral and axial resolutions of 110 and 280 nm, respectively and depth of sampling of up to 30 &#181;m from the coverslip, allowing for imaging of whole cells. Recent advancements (fast 3D-SIM) in the technology increasing the capture rate of raw images allows for fast capture of biological processes occurring in seconds, while significantly reducing photo-toxicity and photobleaching. Here we describe the use of one such method to image bacterial cells harboring the fluorescently-labelled cytokinetic FtsZ protein to show how cells are analyzed and the type of unique information that this technique can provide.

Super-resolution Imaging of the Cytokinetic Z Ring in Live Bacteria Using Fast 3D-Structured Illumination Microscopy f3D-SIM

Spatiotemporal information about dynamic proteins inside live cells is crucial for understanding biology. A type of super-resolution microscopy called fast 3D-structured illumination microscopy (f3D-SIM) reveals unique information about the cytokinetic Z ring in bacteria: both its bead-like appearance and the rapid dynamics of FtsZ within the ring.

Imaging of biological samples using fluorescence microscopy has advanced substantially with new technologies to overcome the resolution barrier of the ...

In vivo Clonal Tracking of Hematopoietic Stem and Progenitor Cells Marked by Five Fluorescent Proteins using Confocal and Multiphoton Microscopy

We developed and validated a fluorescent marking methodology for clonal tracking of hematopoietic stem and progenitor cells (HSPCs) with high spatial and temporal resolution to study in vivo hematopoiesis using the murine bone marrow transplant experimental model. Genetic combinatorial marking using lentiviral vectors encoding fluorescent proteins (FPs) enabled cell fate mapping through advanced microscopy imaging. Vectors encoding five different FPs: Cerulean, EGFP, Venus, tdTomato, and mCherry were used to concurrently transduce HSPCs, creating a diverse palette of color marked cells. Imaging using confocal/two-photon hybrid microscopy enables simultaneous high resolution assessment of uniquely marked cells and their progeny in conjunction with structural components of the tissues. Volumetric analyses over large areas reveal that spectrally coded HSPC-derived cells can be detected non-invasively in various intact tissues, including the bone marrow (BM), for extensive periods of time following transplantation. Live studies combining video-rate multiphoton and confocal time-lapse imaging in 4D demonstrate the possibility of dynamic cellular and clonal tracking in a quantitative manner.

In vivo Clonal Tracking of Hematopoietic Stem and Progenitor Cells Marked by Five Fluorescent Proteins using Confocal and Multiphoton Microscopy

Combinatorial 5 fluorescent proteins marking of hematopoietic stem and progenitor cells allows in vivo clonal tracking via confocal and two-photon microscopy, providing insights into bone marrow hematopoietic architecture during regeneration. This method allows non-invasive fate mapping of spectrally-coded HSPCs-derived cells in intact tissues for extensive periods of time following transplantation.

We developed and validated a fluorescent marking methodology for clonal tracking of hematopoietic stem and progenitor cells (HSPCs) with high spatial and ...

Colorimetric Detection of Bacteria Using Litmus Test

There are increasing demands for simple but still effective methods that can be used to detect specific pathogens for point-of-care or field applications. Such methods need to be user-friendly and produce reliable results that can be easily interpreted by both specialists and non-professionals. The litmus test for pH is simple, quick, and effective as it reports the pH of a test sample via a simple color change. We have developed an approach to take advantage of the litmus test for bacterial detection. The method exploits a bacterium-specific RNA-cleaving DNAzyme to achieve two functions: recognizing a bacterium of interest and providing a mechanism to control the activity of urease. Through the use of magnetic beads immobilized with a DNAzyme-urease conjugate, the presence of bacteria in a test sample is relayed to the release of urease from beads to solution. The released urease is transferred to a test solution to hydrolyze urea into ammonia, resulting in an increase of pH that can be visualized using the classic litmus test.

We describe a protocol for colorimetric detection of E. coli using a modified litmus test that takes advantage of an RNA-cleaving DNAzyme, urease, and magnetic beads.

There are increasing demands for simple but still effective methods that can be used to detect specific pathogens for point-of-care or field applications. ...

Visualizing Stromule Frequency with Fluorescence Microscopy

Stromules, or "stroma-filled tubules", are narrow, tubular extensions from the surface of the chloroplast that are universally observed in plant cells but whose functions remain mysterious. Alongside growing attention on the role of chloroplasts in coordinating plant responses to stress, interest in stromules and their relationship to chloroplast signaling dynamics has increased in recent years, aided by advances in fluorescence microscopy and protein fluorophores that allow for rapid, accurate visualization of stromule dynamics. Here, we provide detailed protocols to assay stromule frequency in the epidermal chloroplasts of Nicotiana benthamiana, an excellent model system for investigating chloroplast stromule biology. We also provide methods for visualizing chloroplast stromules in vitro by extracting chloroplasts from leaves. Finally, we outline sampling strategies and statistical approaches to analyze differences in stromule frequencies in response to stimuli, such as environmental stress, chemical treatments, or gene silencing. Researchers can use these protocols as a starting point to develop new methods for innovative experiments to explore how and why chloroplasts make stromules.

Protocols to investigate the dynamics of chloroplast stromules, the stroma-filled tubules that extend from the surface of chloroplasts, are described.

Stromules, or "stroma-filled tubules", are narrow, tubular extensions from the surface of the chloroplast that are universally observed in plant cells but ...

Split Green Fluorescent Protein System to Visualize Effectors Delivered from Bacteria During Infection

Bacteria, one of the most important causative agents of various plant diseases, secrete a set of effector proteins into the host plant cell to subvert the plant immune system. During infection cytoplasmic effectors are delivered to the host cytosol via a type III secretion system (T3SS). After delivery into the plant cell, the effector(s) targets the specific compartment(s) to modulate host cell processes for survival and replication of the pathogen. Although there has been some research on the subcellular localization of effector proteins in the host cells to understand their function in pathogenicity by using fluorescent proteins, investigation of the dynamics of effectors directly injected from bacteria has been challenging due to the incompatibility between the T3SS and fluorescent proteins.
Here, we describe our recent method of an optimized split superfolder green fluorescent protein system (sfGFPOPT) to visualize the localization of effectors delivered via the bacterial T3SS in the host cell. The sfGFP11 (11th &#946;-strand of sfGFP)-tagged effector secreted through the T3SS can be assembled with a specific organelle targeted sfGFP1-10OPT (1-10th &#946;-strand of sfGFP) leading to fluorescence emission at the site. This protocol provides a procedure to visualize the reconstituted sfGFP fluorescence signal with an effector protein from Pseudomonas syringae in a particular organelle in the Arabidopsis and Nicotiana benthamiana plants.

Fluorescent protein-based approaches to monitor effectors secreted by bacteria into host cells are challenging. This is due to the incompatibility between fluorescent proteins and the type-III secretion system. Here, an optimized split superfolder GFP system is used for visualization of effectors secreted by bacteria into the host plant cell.

Bacteria, one of the most important causative agents of various plant diseases, secrete a set of effector proteins into the host plant cell to subvert the ...

Visualizing Lymph Node Structure and Cellular Localization using Ex-Vivo Confocal Microscopy

Lymph nodes (LNs) are organs spread within the body, where the innate immune responses can connect with the adaptive immunity. In fact, LNs are strategically interposed in the path of the lymphatic vessels, allowing intimate contact of tissue antigens with all resident immune cells in the LN. Thus, understanding the cellular composition, distribution, location and interaction using ex vivo whole LN imaging will add to the knowledge on how the body coordinates local and systemic immune responses. This protocol shows an ex vivo imaging strategy following an in vivo administration of fluorescent-labeled antibodies that allows a very reproducible and easy-to-perform methodology by using conventional confocal microscopes and stock reagents. Through subcutaneous injection of antibodies, it is possible to label different cell populations in draining LNs without affecting tissue structures that can be potentially damaged by a conventional immunofluorescence microscopy technique.

This protocol describes a technique to image different cell populations in draining lymph nodes without alterations in the organ structure.