Name: generation of marked and markerless mutants in model cyanobacterial species
Uploaded: 2016-05-29T15:00:00
Description: Watch this Scientific Journal Video about Generation of Marked and Markerless Mutants in Model Cyanobacterial Species at JoVE.com

Vi er takknemlige for Environmental Services Association Education Trust, den Syntetisk biologi i Cambridge SynBio fond og departementet for sosial rettferdighet og Empowerment, Government of India, for økonomisk støtte.

1. Utarbeidelse av Culture Media <ol><li> Forbered BG11 medium ifølge Castenholz 1988 17. <ol><li> Forbered lager løsninger av 100x BG11, sporstoffer og jern lager (tabell 1). </li><li> Fremstille separate oppløsninger av fosfat lager, Na 2 CO 3 lager, N - [tris (hydroksymetyl) metyl] -2-aminoetansulfonsyre (TES) buffer og NaHCO3 (tabell 1). </li><li> Autoklaver fosfat og Na 2 CO 3 aksjer. Filter-sterilisere...

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	<li>Zwirglmaier, K., 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=Global+phylogeography+of+marine+Synechococcus+and+Prochlorococcus+reveals+a+distinct+partitioning+of+lineages+among+oceanic+biomes.">Global phylogeography of marine Synechococcus and Prochlorococcus reveals a distinct partitioning of lineages among oceanic biomes.</a> Environ Microbiol. 10, 147-161 (2008).</li><li>Galloway, J. N., 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=Nitrogen+cycles:+past,+present,+and+future.">Nitrogen cycles: past, present, and future.</a> Biogeochemistry. 70, 153-226 (2004).</li><li>Lea-Smith, D. J., 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=Contribution+of+cyanobacterial+alkane+production+to+the+ocean+hydrocarbon+cycle.">Contribution of cyanobacterial alkane production to the ocean hydrocarbon cycle.</a> Proc Natl Acad Sci U S A. , (2015).</li><li>Howe, C. J., Barbrook, A. C., Nisbet, R. E. R., Lockhart, P. J., Larkum, A. W. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+origin+of+plastids.">The origin of plastids.</a> Philos Trans R Soc Lond B Biol Sci. 363, 2675-2685 (2008).</li><li>Lea-Smith, D. J., Bombelli, P., Vasudevan, R., Howe, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photosynthetic,+respiratory+and+extracellular+electron+transport+pathways+in+cyanobacteria.">Photosynthetic, respiratory and extracellular electron transport pathways in cyanobacteria.</a> Biochim Biophys Acta. , (2015).</li><li>McCormick, A. J., 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=Hydrogen+production+through+oxygenic+photosynthesis+using+the+cyanobacterium+Synechocystis+sp+PCC+6803+in+a+bio-photoelectrolysis+cell+(BPE)+system.">Hydrogen production through oxygenic photosynthesis using the cyanobacterium Synechocystis sp PCC 6803 in a bio-photoelectrolysis cell (BPE) system.</a> Energy Environ. Sci. 6, 2682-2690 (2013).</li><li>Bradley, R. W., Bombelli, P., Lea-Smith, D. J., Howe, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Terminal+oxidase+mutants+of+the+cyanobacterium+Synechocystis+sp.+PCC+6803+show+increased+electrogenic+activity+in+biological+photo-voltaic+systems.">Terminal oxidase mutants of the cyanobacterium Synechocystis sp. PCC 6803 show increased electrogenic activity in biological photo-voltaic systems.</a> Phys Chem Chem Phys. 15, 13611-13618 (2013).</li><li>Ducat, D. C., Way, J. C., Silver, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engineering+cyanobacteria+to+generate+high-value+products.">Engineering cyanobacteria to generate high-value products.</a> Trends Biotechnol. 29, 95-103 (2011).</li><li>Dismukes, G. C., Carrieri, D., Bennette, N., Ananyev, G. M., Posewitz, 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=Aquatic+phototrophs:+efficient+alternatives+to+land-based+crops+for+biofuels.">Aquatic phototrophs: efficient alternatives to land-based crops for biofuels.</a> Curr Opin Biotechnol. 19, 235-240 (2008).</li><li>Tan, L. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioactive+natural+products+from+marine+cyanobacteria+for+drug+discovery.">Bioactive natural products from marine cyanobacteria for drug discovery.</a> Phytochemistry. 68, 954-979 (2007).</li><li>Volk, R. B., Furkert, F. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antialgal,+antibacterial+and+antifungal+activity+of+two+metabolites+produced+and+excreted+by+cyanobacteria+during+growth.">Antialgal, antibacterial and antifungal activity of two metabolites produced and excreted by cyanobacteria during growth.</a> Microbiol Res. 161, 180-186 (2006).</li><li>Scott, S. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biodiesel+from+algae:+challenges+and+prospects.">Biodiesel from algae: challenges and prospects.</a> Curr Opin Biotechnol. 21, 277-286 (2010).</li><li>Lea-Smith, D. J., 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=Phycobilisome-deficient+strains+of+Synechocystis+sp.+PCC+6803+have+reduced+size+and+require+carbon-limiting+conditions+to+exhibit+enhanced+productivity.">Phycobilisome-deficient strains of Synechocystis sp. PCC 6803 have reduced size and require carbon-limiting conditions to exhibit enhanced productivity.</a> Plant Physiol. 165, 705-714 (2014).</li><li>Lea-Smith, D. J., 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=Thylakoid+terminal+oxidases+are+essential+for+the+cyanobacterium+Synechocystis+sp.+PCC+6803+to+survive+rapidly+changing+light+intensities.">Thylakoid terminal oxidases are essential for the cyanobacterium Synechocystis sp. PCC 6803 to survive rapidly changing light intensities.</a> Plant Physiol. 162, 484-495 (2013).</li><li>Liu, X., Sheng, J., Curtiss, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fatty+acid+production+in+genetically+modified+cyanobacteria.">Fatty acid production in genetically modified cyanobacteria.</a> Proc Natl Acad Sci U S A. 108, 6899-6904 (2011).</li><li>Xu, H., Vavilin, D., Funk, C., Vermaas, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+deletions+of+small+cab-like+proteins+in+the+cyanobacterium+Synechocystis+sp+PCC+6803+-+Consequences+for+pigment+biosynthesis+and+accumulation.">Multiple deletions of small cab-like proteins in the cyanobacterium Synechocystis sp PCC 6803 - Consequences for pigment biosynthesis and accumulation.</a> J Biol Chem. 279, 27971-27979 (2004).</li><li>Castenholz, R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Culturing+methods+for+Cyanobacteria.">Culturing methods for Cyanobacteria.</a> Method Enzymol. 167, 68-93 (1988).</li><li>Mitschke, J., 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=An+experimentally+anchored+map+of+transcriptional+start+sites+in+the+model+cyanobacterium+Synechocystis+sp+PCC6803.">An experimentally anchored map of transcriptional start sites in the model cyanobacterium Synechocystis sp PCC6803.</a> Proc Natl Acad Sci U S A. 108, 2124-2129 (2011).</li><li>Ried, J. L., Collmer, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+nptI-sacB-sacR+cartridge+for+constructing+directed,+unmarked+mutations+in+gram-negative+bacteria+by+marker+exchange-eviction+mutagenesis.">An nptI-sacB-sacR cartridge for constructing directed, unmarked mutations in gram-negative bacteria by marker exchange-eviction mutagenesis.</a> Gene. 57, 239-246 (1987).</li><li>Vieira, J., Messing, 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+pUC+plasmids,+an+M13mp7-derived+system+for+insertion+mutagenesis+and+sequencing+with+synthetic+universal+primers.">The pUC plasmids, an M13mp7-derived system for insertion mutagenesis and sequencing with synthetic universal primers.</a> Gene. 19, 259-268 (1982).</li><li>Vermaas, W. F. J., Williams, J. G. K., Rutherford, A. W., Mathis, P., Arntzen, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetically+Engineered+Mutant+of+the+Cyanobacterium+Synechocystis+6803+Lacks+the+Photosystem-Ii+Chlorophyll-Binding+Protein+Cp-47.">Genetically Engineered Mutant of the Cyanobacterium Synechocystis 6803 Lacks the Photosystem-Ii Chlorophyll-Binding Protein Cp-47.</a> Proc Natl Acad Sci U S A. 83, 9474-9477 (1986).</li><li>Westphal, S., Heins, L., Soll, J., Vothknecht, U. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vipp1+deletion+mutant+of+Synechocystis:+A+connection+between+bacterial+phage+shock+and+thylakoid+biogenesis?.">Vipp1 deletion mutant of Synechocystis: A connection between bacterial phage shock and thylakoid biogenesis?.</a> Proc Natl Acad Sci U S A. 98, 4243-4248 (2001).</li><li>Zhang, S. Y., Shen, G. Z., Li, Z. K., Golbeck, J. H., Bryant, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vipp1+Is+Essential+for+the+Biogenesis+of+Photosystem+I+but+Not+Thylakoid+Membranes+in+Synechococcus+sp+PCC+7002.">Vipp1 Is Essential for the Biogenesis of Photosystem I but Not Thylakoid Membranes in Synechococcus sp PCC 7002.</a> J Biol Chem. 289, 15904-15914 (2014).</li><li>Taroncher-Oldenberg, G., Nishina, K., Stephanopoulos, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+and+analysis+of+the+polyhydroxyalkanoate-specific+beta-ketothiolase+and+acetoacetyl+coenzyme+A+reductase+genes+in+the+cyanobacterium+Synechocystis+sp+strain+PCC6803.">Identification and analysis of the polyhydroxyalkanoate-specific beta-ketothiolase and acetoacetyl coenzyme A reductase genes in the cyanobacterium Synechocystis sp strain PCC6803.</a> Appl Environ Microbiol. 66, 4440-4448 (2000).</li><li>Hein, S., Tran, H., Steinbuchel, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synechocystis+sp.+PCC6803+possesses+a+two-component+polyhydroxyalkanoic+acid+synthase+similar+to+that+of+anoxygenic+purple+sulfur+bacteria.">Synechocystis sp. PCC6803 possesses a two-component polyhydroxyalkanoic acid synthase similar to that of anoxygenic purple sulfur bacteria.</a> Arch Microbiol. 170, 162-170 (1998).</li><li>Ng, A. H., Berla, B. M., Pakrasi, H. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fine+tuning+of+photoautotrophic+protein+production+by+combining+promoters+and+neutral+sites+in+Synechocystis+6803,+a+cyanobacterium.">Fine tuning of photoautotrophic protein production by combining promoters and neutral sites in Synechocystis 6803, a cyanobacterium.</a> Appl Environ Microbiol. , (2015).</li></ol>

De mest kritiske trinn i generering av umerkede mutanter er: 1) forsiktig plasmid utforming for å sikre at bare det aktuelle området blir endret; 2) å sikre at prøvene fortsatt axenic, spesielt når dyrket på sukrose; 3) plettetransformerte celler for merket mutant generasjon innledning på BG11 agarplater mangler antibiotika, etterfulgt av tilsetning av agar pluss antibiotika 24 timer senere; 4) dyrking merket mutanter for 4 hele dager før plating på BG11 pluss sukrose agarskåler: 5) at merket mutanter er fullt...

Cyanobakterier er en evolusjonært gammel og mangfoldig phylum av bakterier som finnes i nesten alle naturlige miljøet på jorda. I marine økosystemer er de spesielt rikt og spiller en sentral rolle i mange næringssykluser, sto for omtrent halvparten av karbonfiksering 1, flertallet av nitrogenfiksering 2 og hundrevis av millioner av tonn med hydrokarbonproduksjon tre i havet årlig. Kloroplaster, organeller ansvarlig for fotosyntesen i eukaryote alger og planter, er sannsynlig å ha utviklet seg fra en cyanobacterium som ble oppslukt av en vertsorganisme 4. Cyanobakterier har vist seg å være nyttige modellorganismer for studiet av fotosyntese, elektrontransport 5 og biokjemiske veier, mange av dem er konservert i planter. I tillegg cyanobakterier i økende grad brukes til produksjon av mat, biodrivstoff 6, elektrisitet 7 og industrielle forbindelser 8, på grunn av deres highly effektiv konvertering av vann og CO 2 til biomasse ved hjelp av solenergi 9. kan dyrkes mange arter være på ikke-dyrkbar jord med minimal næringsstoffer og sjøvann, noe som tyder på at cyanobakterier potensielt kan dyrkes i stor skala uten at det påvirker landbruksproduksjon. Visse arter er også kilder for naturlige produkter, blant annet soppdrepende, antibakterielle og anti-cancerforbindelsene 10,11. Evnen til å generere mutanter er nøkkelen til å forstå cyanobacterial fotosyntese, biokjemi og fysiologi, og essensielt for utvikling av stammer til industrielle formål. Flertallet av publiserte studier generere genmodifiserte stammer ved innsetting av en antibiotikaresistens kassett inn i området av interesse. Dette begrenser antall mutasjoner som kan innføres i en stamme, som bare noen få antibiotikaresistens kassetter er tilgjengelig for bruk i cyanobakterier. Stammer som inneholder gener som gir antibiotikaresistens remotstands kan ikke brukes til industriell produksjon i åpne dammer, noe som sannsynligvis vil være den eneste kostnadseffektiv måte å produsere biodrivstoff og andre lav verdi produkter 12. Den generasjonen av umerkede mutanter overvinner disse begrensningene. Umerkede mutanter ikke inneholder noe fremmed DNA, hvis hensikt er inkludert, og kan manipuleres flere ganger. Derfor er det mulig å generere så mange endringer i en belastning som ønsket. I tillegg kan polare effekter på gener nedstrøms av modifikasjonen området reduseres til et minimum, slik at mer nøyaktig endring av organismen 13. For å generere mutantstammer, selvmords plasmider som inneholder to DNA-fragmenter identisk til regioner i den cyanobacterial kromosomet som flankerer genet som skal fjernes (betegnet 5 &#39;og 3&#39; flankerende regioner) blir først konstruert. To gener blir så innsatt mellom disse flankerende områder. En av disse koder for en antibiotisk resistens-protein; den andre koder SACB, som prodUCES levansukrase, en forbindelse overdragelse følsomhet for sukrose. I det første trinn av fremgangsmåten, som er merket mutanter, dvs. stammer inneholdende noe fremmed DNA, blir generert. Plasmidkonstruksjonen blandes med de cyanobakterielle celler og DNA tas opp naturligvis av organismen. Transformanter blir utvalgt ved vekst på agarplater inneholdende det passende antibiotikum og den mutante genotype bekreftet ved PCR. Selvmords plasmider kan ikke gjenskape innenfor belastningen av interesse. Derfor noen antibiotikaresistente kolonier vil resultere fra en rekombinasjon, hvorved genet av interesse inn i kromosomet. For å generere umerkede mutanter, er den markerte mutant deretter blandet med en andre selvmord plasmid som inneholder bare de 5 &#39;og 3&#39; flankerende regioner. Men hvis innskudd av fremmed DNA er nødvendig, et plasmid bestående av den 5 &#39;og 3&#39; flankerende regioner med en kassett som inneholder gener av interesse er satt inn mellom disse DNA-fragmenter, kan anvendes. SeleDette skjer er via vekst på agarplater inneholdende sukrose. Som sukrose er dødelig for cellene når det SACB genproduktet blir uttrykt, er de eneste cellene som overlever er de hvor en andre rekombinerings-hendelse har inntruffet, hvorved sukrose følsomhet genet, i tillegg til det antibiotiske resistensgenet, er blitt rekombinert ut av kromosom og på plasmidet. Som en konsekvens av den recombinational utvekslingen kan de flankerende områder og en hvilken som helst DNA mellom dem satt inn i kromosomet. Vi har med hell brukt disse metodene for å generere flere kromosommutasjoner i samme stamme av Synechocystis sp. PCC6803 (heretter referert til som Synechocystis) 13,14, for å innføre enkeltpunktmutasjoner i et gen av interesse 13 og for ekspresjon av genet kassetter. Mens generasjonen av umerkede knockouts har blitt vist før vårt arbeid i Synechocystis 15,16, en detaljert metode, hjulpet aven visuell presentasjon av de kritiske trinn, er ikke offentlig tilgjengelig. Vi har også søkt samme metode for generering av merkede knockouts i en annen modell cyanobacterium, Synechococcus sp. PCC7002 (heretter referert til som Synechococcus). Denne protokollen gir en klar og enkel metode for å generere mutanter og en hurtig protokoll for validering og lagring av disse stammene.

<table border="0" cellpadding="0" cellspacing="0" width="645">
	<tbody>
		<tr height="25">
			<td height="25" style="height:25px;width:237px;">NaNO3</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">S5506</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">MgSO4.7H2O</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">230391</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">CaCl2</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">C1016</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">citric acid</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">C0759</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">Na2EDTA</td>
			<td style="width:123px;">Fisher</td>
			<td style="width:119px;">EDT002</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">H3BO3</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">339067</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">MnCl2.4H2O</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">M3634</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">ZnSO4.7H2O</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">Z4750</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">Na2MoO4.2H2O</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">331058</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">CuSO4.5H2O</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">209198</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">Co(NO3)2.6H2O</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">239267</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ferric ammonium citrate</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">F5879</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">K2HPO4</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">P3786</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">Na2CO3</td>
			<td style="width:123px;">Fisher</td>
			<td style="width:119px;">SODC001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TES</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">T1375</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">NaHCO3</td>
			<td style="width:123px;">Fisher</td>
			<td style="width:119px;">SODH001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">HEPES</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">H3375</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">cyanocobalamin</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">47869</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">Na2S2O3</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">72049</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">Bacto agar</td>
			<td style="width:123px;">BD</td>
			<td style="width:119px;">214010</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">Sucrose</td>
			<td style="width:123px;">Fisher</td>
			<td style="width:119px;">SUC001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">Petri dish 90 mm triple vented</td>
			<td style="width:123px;">Greiner</td>
			<td style="width:119px;">633185</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">0.2 &#181;m filters</td>
			<td style="width:123px;">Sartorius</td>
			<td style="width:119px;">16534</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">100 mL conical flasks</td>
			<td style="width:123px;">Pyrex</td>
			<td style="width:119px;">CON004</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">Parafilm M 100 mm x38 m</td>
			<td style="width:123px;">Bemis</td>
			<td style="width:119px;">FIL003</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Phusion high fidelity DNA polymerase&#160;</td>
			<td style="width:123px;">Phusion</td>
			<td style="width:119px;">F-530</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Agarose</td>
			<td style="width:123px;">Melford</td>
			<td style="width:119px;">MB1200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DNA purification kit&#160;</td>
			<td style="width:123px;">MoBio</td>
			<td style="width:119px;">12100-300</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">Restriction endonucleases</td>
			<td style="width:123px;">NEB</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">T4 ligase</td>
			<td style="width:123px;">Thermo Scientific</td>
			<td style="width:119px;">EL0011</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">Luria Bertani broth</td>
			<td style="width:123px;">Invitrogen</td>
			<td style="width:119px;">12795-027</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">MES</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">M8250</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">Kanamycin sulfate</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">60615</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">Ampicillin</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">A9518</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">GeneJET plasmid miniprep kit</td>
			<td style="width:123px;">Thermo Scientific</td>
			<td style="width:119px;">K0503</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">14 mL round-bottom tube</td>
			<td style="width:123px;">BD falcon</td>
			<td style="width:119px;">352059</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">GoTaq G2 Flexi DNA polymerase</td>
			<td style="width:123px;">Promega</td>
			<td style="width:119px;">M7805</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">425-600 &#181;m glass beads</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">G8772</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">Glycerol</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">G5516</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">DMSO</td>
			<td style="width:123px;">Sigma</td>
			<td style="width:119px;">D8418</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">Fluorescent bulbs</td>
			<td style="width:123px;">Gro-Lux</td>
			<td style="width:119px;">69</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:237px;">HT multitron photobioreactor</td>
			<td style="width:123px;">Infors</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

generation of marked and markerless mutants in model cyanobacterial species

Cyanobacteria are ecologically important organisms and potential platforms for production of biofuels and useful industrial products. Genetic manipulation of cyanobacteria, especially model organisms such as Synechocystis sp. PCC6803 and Synechococcus sp. PCC7002, is a key tool for both basic and applied research. Generation of unmarked mutants, whereby chromosomal alterations are introduced into a strain via insertion of an antibiotic resistance cassette (a manipulatable fragment of DNA containing one or more genes), followed by subsequent removal of this cassette using a negative selectable marker, is a particularly powerful technique. Unmarked mutants can be repeatedly genetically manipulated, allowing as many alterations to be introduced into a strain as desired. In addition, the absence of genes encoding antibiotic resistance proteins in the mutated strain is desirable, as it avoids the possibility of 'escape' of antibiotic resistant organisms into the environment. However, detailed methods for repeated rounds of genetic manipulation of cyanobacteria are not well described in the scientific literature. Here we provide a comprehensive description of this technique, which we have successfully used to generate mutants with multiple deletions, single point mutations within a gene of interest and insertion of novel gene cassettes.

Plasmid utforming er avgjørende for vellykket dannelse av både merkede og umerkede mutanter. Figur 1 gir et eksempel på plasmid A og B som brukes for å generere en delesjonsmutant i den Synechocystis genene cpcC1 og cpcC2 13. I hvert tilfelle ble de 5 &#39;og 3&#39; flankerende regioner er tilnærmet 900-1,000 bp. Redusert flankerer regioner kan brukes selv om den minste vi har lykkes trialed har vært om lag 500 bp. Plasmid B ka...

Watch this Scientific Journal Video about Generation of Marked and Markerless Mutants in Model Cyanobacterial Species at JoVE.com

Generation of Marked and Markerless Mutants in Model Cyanobacterial Species

Introducing multiple genomic alterations into cyanobacteria is an essential tool in the development of strains for industrial and basic research purposes. We describe a system for generating unmarked mutants in the model cyanobacterial species Synechocystis sp. PCC6803 and marked mutants in Synechococcus sp. PCC7002.

Generering av merkede og Markerless Mutanter i Modell cyanobacterial Arter

Cyanobacteria are ecologically important organisms and potential platforms for production of biofuels and useful industrial products. Genetic manipulation ...

Research

JoVE Journal

Biology

Paradigms for Pharmacological Characterization of C. elegans Synaptic Transmission Mutants

The nematode, Caenorhabditis elegans, has become an expedient model for studying neurotransmission. C. elegans is unique among animal models, as the ...

Neurocircuit Assays for Seizures in Epilepsy Mutants of Drosophila

Neurocircuit Assays for Seizures in Epilepsy Mutants of Drosophila

Drosophila melanogaster is a useful tool for studying seizure like activity. A variety of mutants in which seizures can be induced through either physical ...

Lens Transplantation in Zebrafish and its Application in the Analysis of Eye Mutants

The lens plays an important role in the development of the optic cup[1,2]. Using the zebrafish as a model organism, questions regarding lens development ...

A Noninvasive Hair Sampling Technique to Obtain High Quality DNA from Elusive Small Mammals

Noninvasive genetic sampling approaches are becoming increasingly important to study wildlife populations. A number of studies have reported using ...

Generation, Purification, and Characterization of Cell-invasive DISC1 Protein Species

Generasjon, rensing og karakterisering av Cell-invasive Disc1 Protein Arter

Protein aggregation is seen as a general hallmark of chronic, degenerative brain conditions like, for example, in the neurodegenerative diseases ...

Detecting, Visualizing and Quantitating the Generation of Reactive Oxygen Species in an Amoeba Model System

Oppdager, visualisere og kvantifisere generasjon av reaktive oksygen arter i en Amoeba Model System

Reactive oxygen species (ROS) comprise a range of reactive and short-lived, oxygen-containing molecules, which are dynamically interconverted or ...

Rapid and Efficient Zebrafish Genotyping Using PCR with High-resolution Melt Analysis

Rask og effektiv Sebrafisk Genotyping Bruke PCR med høy oppløsning Melt Analysis

Zebrafish is a powerful vertebrate model system for studying development, modeling disease, and performing drug screening. Recently a variety of genetic ...

Efficient Generation Human Induced Pluripotent Stem Cells from Human Somatic Cells with Sendai-virus

Effektiv Generation Menneskelig indusert pluripotent stamceller fra menneskelige somatiske celler med Sendai-virus

A few years ago, the establishment of human induced pluripotent stem cells (iPSCs) ushered in a new era in biomedicine. Potential uses of human iPSCs ...

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

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

In vivo Klonal Sporing av Hematopoetiske Stem og stamceller Preget av fem Fluorescent Proteiner bruker Confocal og multiphoton Mikros

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

Microbiota Analysis Using Two-step PCR and Next-generation 16S rRNA Gene Sequencing

Bakterieflora analyse ved hjelp av to-trinns PCR og neste generasjons 16S rRNA Gene sekvensering

The human gut is colonized by trillions of bacteria that support physiologic functions such as food metabolism, energy harvesting, and regulation of the ...