Name: a practical guide to phylogenetics for nonexperts
Uploaded: 2014-02-05T17:00:00
Description: Watch this Scientific Journal Video about A Practical Guide to Phylogenetics for Nonexperts at JoVE.com

Vi takker medlemmene av O&#39;Halloran lab for kommentarer til manuskriptet. Vi takker The George Washington University Department of Biological Sciences og Columbian College of Arts and Sciences om midler til D. O&#39;Halloran.

En. Basic Local Alignment Search Tool (BLAST): Online-grensesnitt <ol><li> Klikk på denne linken for å besøke nettserveren ved National Center for Biotechnology Information (NCBI) BLAST en. - <a href="http://blast.ncbi.nlm.nih.gov/Blast.cgi">http://blast.ncbi.nlm.nih.gov/Blast.cgi</a> (Figur 1). </li><li> Input et FASTA formatert tekst sekvens (se Figur 2 for eksempel) i tekstboksen. </li><li> Klikk på den aktuelle BLAST programmet og relevant database eller enkeltarter...

<ol>
	<li>Altschul, S. F., Carroll, R. J., Lipman, 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=Weights+for+data+related+by+a+tree.">Weights for data related by a tree.</a> J. Mol. Biol. 207 (4), 647-653 (1989).</li><li>Akaike, 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+new+look+at+the+statistical+model+identification.">A new look at the statistical model identification.</a> IEEE Trans. Automat. Contr. 19 (6), 706-723 (1974).</li><li>Schwarz, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimating+the+dimension+of+a+model.">Estimating the dimension of a model.</a> Ann. Stat. 6 (2), 461-464 (1978).</li><li>Guindon, S., Gascuel, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple,+fast,+and+accurate+algorithm+to+estimate+large+phylogenies+by+maximum+likelihood.">A simple, fast, and accurate algorithm to estimate large phylogenies by maximum likelihood.</a> Syst. Biol. 52 (5), 696-704 (2003).</li><li>Huelsenbeck, J. P., Ronquist, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MRBAYES:+Bayesian+inference+of+phylogenetic+trees.">MRBAYES: Bayesian inference of phylogenetic trees.</a> Bioinformatics. 17 (8), 754-755 (2001).</li><li>Thompson, J. D., Higgins, D. G., Gibson, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CLUSTAL+W:+Improving+the+sensitivity+of+progressive+multiple+sequence+alignment+through+sequence+weighting,+position-specific+gap+penalties+and+weight+matrix+choice.">CLUSTAL W: Improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice.</a> Nucleic Acids Res. 22 (22), 4673-4680 (1994).</li><li>Lassmann, T., Sonnhammer, E. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kalign--an+accurate+and+fast+multiple+sequence+alignment+algorithm.">Kalign--an accurate and fast multiple sequence alignment algorithm.</a> BMC Bioinformatics. 6, 298 (2005).</li><li>Katoh, K., Kuma, K., Toh, H., Miyata, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MAFFT+version+5:+Improvement+in+accuracy+of+multiple+sequence+alignment.">MAFFT version 5: Improvement in accuracy of multiple sequence alignment.</a> Nucleic Acids Res. 33 (2), 511-518 (2005).</li><li>Katoh, K., Misawa, K., Kuma, K., Miyata, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MAFFT:+A+novel+method+for+rapid+multiple+sequence+alignment+based+on+fast+fourier+transform.">MAFFT: A novel method for rapid multiple sequence alignment based on fast fourier transform.</a> Nucleic Acids Res. 30 (14), 3059-3066 (2002).</li><li>Edgar, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MUSCLE:+Multiple+sequence+alignment+with+high+accuracy+and+high+throughput.">MUSCLE: Multiple sequence alignment with high accuracy and high throughput.</a> Nucleic Acids Res. 32 (5), 1792-1797 (2004).</li><li>Notredame, C., Higgins, D. G., Heringa, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=T-coffee:+A+novel+method+for+fast+and+accurate+multiple+sequence+alignment.">T-coffee: A novel method for fast and accurate multiple sequence alignment.</a> J. Mol. Biol. 302 (1), 205-217 (2000).</li><li>Do, C. B., Mahabhashyam, M. S., Brudno, M., Batzoglou, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ProbCons:+Probabilistic+consistency-based+multiple+sequence+alignment.">ProbCons: Probabilistic consistency-based multiple sequence alignment.</a> Genome Res. 15 (2), 330-340 (2005).</li><li>Darriba, D., Taboada, G. L., Doallo, R., Posada, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ProtTest+3:+Fast+selection+of+best-fit+models+of+protein+evolution.">ProtTest 3: Fast selection of best-fit models of protein evolution.</a> Bioinformatics. 27 (8), 1164-1165 (2011).</li><li>Page, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TreeView:+An+application+to+display+phylogenetic+trees+on+personal+computers.">TreeView: An application to display phylogenetic trees on personal computers.</a> Comput. Appl. Biosci. 12 (4), 357-358 (1996).</li><li>Darriba, D., Taboada, G. L., Doallo, R., Posada, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=jModelTest+2:+More+models,+new+heuristics+and+parallel+computing.">jModelTest 2: More models, new heuristics and parallel computing.</a> Nat. Methods. 9 (8), 772 (2012).</li><li>Chevenet, F., Brun, C., Banuls, A. L., Jacq, B., Christen, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TreeDyn:+Towards+dynamic+graphics+and+annotations+for+analyses+of+trees.">TreeDyn: Towards dynamic graphics and annotations for analyses of trees.</a> BMC Bioinformatics. 7, 439 (2006).</li></ol>

Vårt håp for denne artikkelen er at det vil tjene som et utgangspunkt for å veilede forskere eller studenter som er nye til phylogenetics. Genomsekvense prosjekter har blitt billigere i løpet av de siste årene, og som en konsekvens av bruker etterspørsel etter denne teknologien er økende, og nå produksjon av store sekvens datasett er vanlig i små laboratorier. Disse datasettene ofte gi forskere med sett av gener som krever et fylogenetisk rammeverk for å begynne å forstå deres funksjon. Videre, fordi phyloge...

For å forstå hvordan to (eller flere) arter utviklet seg, er det først nødvendig å oppnå sekvens eller morfologiske data fra hver prøve, og disse data representerer mengdene som vi kan bruke til å måle deres forhold gjennom evolusjonære plass. Akkurat som når man måler lineær avstand, å ha flere data tilgjengelige (f.eks miles, inches, mikron) vil likestille til en mer nøyaktig måling. Ergo, er nøyaktigheten som en forsker kan utlede evolusjonære avstand sterkt påvirket av volumet av informative data tilgjengelig for å måle relasjoner. Videre, fordi forskjellige prøver utvikle seg på forskjellige priser og av ulike mekanismer, den metoden som vi bruker for å måle forholdet mellom to taxa også direkte påvirker nøyaktigheten av evolusjonære målinger. Derfor, fordi evolusjonære relasjonene ikke er observert direkte, men i stedet er ekstrapolert fra sekvens eller morfologiske data, problemet med dedusere evolusjonærrelasjoner blir en av statistikken. Phylogenetics er den grenen av biologi opptatt med å bruke statistiske modeller for å mønstre av evolusjon for å optimalt rekonstruere den evolusjonære historien mellom taxa. Denne rekonstruksjonen mellom taxa er referert til som den taxa er fylogeni. For å bygge bro over gapet i kompetanse mellom molekylærbiologer og evolusjonsbiologer vi beskriver her en trinnvis rørledning for dedusere phylogenies fra et sett av sekvenser. For det første, vi detalj trinnene involvert i databasen avhør ved hjelp av Basic Local Alignment Search Tool (BLAST 1) algoritme gjennom web-basert grensesnitt og også ved hjelp av lokale kjørbare, og dette er ofte første skritt i å få en liste over lignende sekvenser til en uidentifisert spørring, selv om enkelte forskere kan også være interessert i å samle inn data for en enkelt gruppe via web-grensesnitt som Phylota (http://www.phylota.net/). BLAST er en algoritme for comparing primære aminosyre eller nukleotid sekvens data mot en database av sekvenser for å søke etter &quot;treff&quot; som minner om spørresekvensen. BLAST-programmet ble utviklet av Stephen Altschul et al. ved National Institutes of Health (NIH) en. Den BLAST server består av et antall av forskjellige programmer, og her er en liste over noen av de mest vanlige BLAST program: i) Nucleotide-nucleotide BLAST (blastn): Dette programmet krever en DNA sekvens innspill og returnerer mest lignende DNA-sekvenser fra DNA-database som brukeren oppgir (f.eks for en bestemt organisme). ii) Protein-protein BLAST (blastp): Her kan brukeren innganger et protein sekvens og programmet returnerer de mest lignende proteinsekvenser fra protein database som brukeren angir. iii) Posisjon Spesifikke Iterativ BLAST (PSI-BLAST) (blastpgp): Den brukerundersøkelser er en protei rekkefølge som returnerer et sett av nært beslektede proteiner, og fra dette datasettet en konservert profilen genereres. Neste en ny spørring blir generert ved hjelp av bare disse konserverte &quot;motiver&quot; som blir brukt til å avhøre en database protein, og dette gir en større gruppe av proteiner hvorfra et nytt sett av konserverte &quot;motiver&quot; er trukket ut, og deretter brukt til å avhøre en database protein før et enda større antall proteiner er returnert og andre profiler er generert, og prosessen gjentas. Ved å inkludere relaterte proteiner inn i søket i hvert trinn dette programmet gjør det mulig for brukeren å identifisere sekvenser som er mer sprikende. iv) Nukleotid 6-ramme translasjons-protein (blastx): Her kan brukeren gir en nukleotidsekvens inngang som omdannes til seksramme konseptuelle translasjonsprodukter (dvs. begge tråder) mot en proteinsekvensdatabase.. v) nukleotid-6-ramme translasjons-nukleotid6-frame oversettelse (tblastx): Dette programmet tar en DNA nukleotidsekvens innspill og oversetter innspill til alle seks-frame konseptuelle oversettings produkter som det kan sammenlignes mot de seks ramme oversettelser av en nukleotidsekvensdatabasen. vi) Protein-nukleotid-6-ramme oversettelse (tblastn): Dette program anvender en proteinsekvens-inngangen til sammenlignet med alle seks leserammer av en nukleotid-sekvens-database. Deretter beskriver vi ofte brukte programmer for å generere en flersekvenssammenstilling (MSA) fra en sekvens datasettet, og dette er fulgt av en brukerguide til programmer som bestemmer de best-fit modeller av evolusjon for en sekvens datasett. Fylogenetisk rekonstruksjon er et statistisk problem, og på grunn av dette, fylogenetiske metoder må innlemme en statistisk rammeverk. Denne statistiske rammeverket blir en evolusjonær modell som inkorporerer sekvens endring i datasettet. Denne evolusjonære model består av et sett av antagelser om prosessen med nukleotid-eller amino-syreerstatninger, og den optimale modell for et bestemt datasett kan velges ved hjelp av statistisk testing. Den passer til de data av ulike modeller kan sammenlignes via likelihood ratio tester (LRTs) eller informasjons kriterier for å velge den optimale modellen innenfor et sett av mulige funn. To vanlige informasjons kriterier er Akaike informasjon kriteriet (AIC) 2 og bayesiansk informasjon kriteriet (BIC) tre. Når en optimal justering er generert, er det mange forskjellige metoder for å lage en fylogeni fra de sammenstilte data. Det finnes mange metoder for å dedusere evolusjonære relasjonene, grovt, kan de deles inn i to kategorier: distansebaserte metoder og sekvensbaserte metoder. Distansebaserte metoder beregne parvise avstander fra sekvenser, og deretter bruke disse avstander for å få treet. Sekvensbaserte metoder bruke sekvens justering direkte, og flest søk på tree plass ved hjelp av en optimalitet kriterium. Vi skissere to sekvensbaserte metoder for å rekonstruere fylogenetiske relasjoner: disse er PhyML fire som implementerer den maksimale sannsynligheten rammeverk, og MrBayes fem som bruker bayesiansk Markov Chain Monte Carlo slutning. Sannsynlighet og Bayesianske metoder gir et statistisk rammeverk for fylogenetisk rekonstruksjon. Ved å gi brukeren informasjon om brukte tre-bygningen verktøy, introduserer vi leseren til de nødvendige data som kreves for å antyde fylogenetiske relasjoner.

<table border="0" cellpadding="0" cellspacing="0" width="713">
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		<tr height="21">
			<td height="21" style="height:21px;">BLAST webpage&#160;</td>
			<td></td>
			<td></td>
			<td><a href="http://blast.ncbi.nlm.nih.gov/Blast.cgi">http://blast.ncbi.nlm.nih.gov/Blast.cgi</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BLAST executables&#160;</td>
			<td></td>
			<td></td>
			<td><a href="ftp://ftp.ncbi.nlm.nih.gov/blast/executables/blast+/LATEST/">ftp://ftp.ncbi.nlm.nih.gov/blast/executables/blast+/LATEST/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Preformatted BLAST databases</td>
			<td></td>
			<td></td>
			<td><a href="ftp://ftp.ncbi.nlm.nih.gov/blast/db/">ftp://ftp.ncbi.nlm.nih.gov/blast/db/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Clustal</td>
			<td></td>
			<td></td>
			<td><a href="http://www.clustal.org/">http://www.clustal.org/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Kalign</td>
			<td></td>
			<td></td>
			<td><a href="http://msa.sbc.su.se/cgi-bin/msa.cgi">http://msa.sbc.su.se/cgi-bin/msa.cgi</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MAFFT</td>
			<td></td>
			<td></td>
			<td><a href="http://mafft.cbrc.jp/alignment/software/">http://mafft.cbrc.jp/alignment/software/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MUSCLE</td>
			<td></td>
			<td></td>
			<td><a href="http://www.drive5.com/muscle/">http://www.drive5.com/muscle/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">T-Coffee</td>
			<td></td>
			<td></td>
			<td><a href="http://www.tcoffee.org/Projects/tcoffee/">http://www.tcoffee.org/Projects/tcoffee/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PROBCONS</td>
			<td></td>
			<td></td>
			<td><a href="http://toolkit.tuebingen.mpg.de/probcons">http://toolkit.tuebingen.mpg.de/probcons&#160;</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Se-Al&#160;</td>
			<td></td>
			<td></td>
			<td><a href="http://tree.bio.ed.ac.uk/software/seal/">http://tree.bio.ed.ac.uk/software/seal/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BSEdit&#160;</td>
			<td></td>
			<td></td>
			<td><a href="http://www.bsedit.org/">http://www.bsedit.org/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">JalView</td>
			<td></td>
			<td></td>
			<td><a href="http://www.jalview.org/">http://www.jalview.org/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SeaView</td>
			<td></td>
			<td></td>
			<td><a href="http://pbil.univ-lyon1.fr/software/seaview.html">http://pbil.univ-lyon1.fr/software/seaview.html</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ProtTest&#160;</td>
			<td></td>
			<td></td>
			<td style="width:447px;"><a href="https://code.google.com/p/prottest3/">https://code.google.com/p/prottest3/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Java Runtime&#160;</td>
			<td></td>
			<td></td>
			<td><a href="http://www.java.com/en/download/chrome.jsp">http://www.java.com/en/download/chrome.jsp</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Readseq</td>
			<td></td>
			<td></td>
			<td><a href="http://iubio.bio.indiana.edu/cgi-bin/readseq.cgi">http://iubio.bio.indiana.edu/cgi-bin/readseq.cgi</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">jModelTest</td>
			<td></td>
			<td></td>
			<td style="width:447px;"><a href="https://code.google.com/p/jmodeltest2/">https://code.google.com/p/jmodeltest2/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PhyML</td>
			<td></td>
			<td></td>
			<td><a href="https://code.google.com/p/phyml/">https://code.google.com/p/phyml/</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MrBayes</td>
			<td></td>
			<td></td>
			<td><a href="http://mrbayes.sourceforge.net/download.php">http://mrbayes.sourceforge.net/download.php</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TreeView</td>
			<td></td>
			<td></td>
			<td><a href="http://taxonomy.zoology.gla.ac.uk/rod/treeview.html">http://taxonomy.zoology.gla.ac.uk/rod/treeview.html</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TreeDyn</td>
			<td></td>
			<td></td>
			<td style="width:447px;"><a href="http://www.treedyn.org/">http://www.treedyn.org/</a></td>
		</tr>
	</tbody>
</table>

a practical guide to phylogenetics for nonexperts

Mange forskere, tvers utrolig variert foci, søker phylogenetics til deres problemstilling (er). Men mange forskere er ny på dette emnet, og så det presenterer iboende problemer. Her vi samle en praktisk innføring i phylogenetics for nonexperts. Vi skissere i en steg-for-steg måte, en rørledning for å generere pålitelige phylogenies fra gensekvensen datasett. Vi begynner med en bruker-guide for likhetssøkeverktøy via elektroniske grensesnitt samt lokale kjørbare. Neste, vi utforske programmer for å generere flere sekvenssammenstillinger fulgt av protokoller for å bruke programvare for å bestemme best tilpasning modeller av evolusjon. Vi deretter skissere protokoller for å rekonstruere fylogenetiske relasjoner via maximum likelihood og Bayesianske kriterier og til slutt beskrive verktøy for å visualisere fylogenetiske trær. Selv om dette er på ingen måte en uttømmende beskrivelse av fylogenetiske tilnærminger, gjør det gi leseren praktisk starter information på viktige programmer som vanligvis benyttes av phylogeneticists. Visjonen for denne artikkelen vil være at det kan tjene som et praktisk treningsverktøy for forskere fatt på fylogenetiske studier og også tjene som en pedagogisk ressurs som kan bli innlemmet i et klasserom eller undervisning-lab.

Finne likheter til en spørring tillater forskerne å tilskrive en potensiell identitet til nye sekvenser og også antyde sammenhenger mellom sekvenser. Filen input type for BLAST en er FASTA formatert tekst sekvens eller GenBank sjonsnummer. FASTA formatert sekvensen begynner med en beskrivelse linje angitt med et &quot;&gt;&quot;-tegnet (figur 2). Beskrivelsen må følge umiddelbart etter &quot;&gt;&quot;-tegnet, sekvensen (dvs.. Nukleotider eller aminosyrer) følger beskrivelsen p...

Watch this Scientific Journal Video about A Practical Guide to Phylogenetics for Nonexperts at JoVE.com

A Practical Guide to Phylogenetics for Nonexperts

Her beskriver vi en steg-for-steg-rørledningen for å generere pålitelige phylogenies fra nucleotide eller aminosyre sekvens datasett. Denne veiledningen tar sikte på å betjene forskere eller studenter nye til fylogenetisk analyse.

En praktisk guide til Phylogenetics for Nonexperts

Many researchers, across incredibly diverse foci, are applying phylogenetics to their research question(s). However, many researchers are new to this ...

a-practical-guide-to-phylogenetics-for-nonexperts

Research

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Biology

The Ladder Rung Walking Task: A Scoring System and its Practical Application.

Progress in the development of animal models for/stroke, spinal cord injury, and other neurodegenerative disease requires tests of high sensitivity to elaborate distinct aspects of motor function and to determine even subtle loss of movement capacity. To enhance efficacy and resolution of testing, tests should permit qualitative and quantitative measures of motor function and be sensitive to changes in performance during recovery periods. The present study describes a new task to assess skilled walking in the rat to measure both forelimb and hindlimb function at the same time. Animals are required to walk along a horizontal ladder on which the spacing of the rungs is variable and is periodically changed. Changes in rung spacing prevent animals from learning the absolute and relative location of the rungs and so minimize the ability of the animals to compensate for impairments through learning. In addition, changing the spacing between the rungs allows the test to be used repeatedly in long-term studies. Methods are described for both quantitative and qualitative description of both fore- and hindlimb performance, including limb placing, stepping, co-ordination. Furthermore, use of compensatory strategies is indicated by missteps or compensatory steps in response to another limb&#x2019;s misplacement. 

The ladder rung walking task is a new test to assess skilled walking and measure both forelimb and hindlimb placing, stepping, and inter-limb co-ordination.

Progress in the development of animal models for/stroke, spinal cord injury, and other neurodegenerative disease requires tests of high sensitivity to ...

A Practical Approach to Genetic Inducible Fate Mapping: A Visual Guide to Mark and Track Cells In Vivo

Fate maps are generated by marking and tracking cells in vivo to determine how progenitors contribute to specific structures and cell types in developing and adult tissue. An advance in this concept is Genetic Inducible Fate Mapping (GIFM), linking gene expression, cell fate, and cell behaviors in vivo, to create fate maps based on genetic lineage.
GIFM exploits X-CreER lines where X is a gene or set of gene regulatory elements that confers spatial expression of a modified bacteriophage protein, Cre recombinase (CreERT). CreERT contains a modified estrogen receptor ligand binding domain which renders CreERT sequestered in the cytoplasm in the absence of the drug tamoxifen. The binding of tamoxifen releases CreERT, which translocates to the nucleus and mediates recombination between DNA sequences flanked by loxP sites. In GIFM, recombination typically occurs between a loxP flanked Stop cassette preceding a reporter gene such as GFP.
Mice are bred to contain either a region- or cell type-specific CreER and a conditional reporter allele. Untreated mice will not have marking because the Stop cassette in the reporter prevents further transcription of the reporter gene. We administer tamoxifen by oral gavage to timed-pregnant females, which provides temporal control of CreERT release and subsequent translocation to the nucleus removing the Stop cassette from the reporter. Following recombination, the reporter allele is constitutively and heritably expressed. This series of events marks cells such that their genetic history is indelibly recorded. The recombined reporter thus serves as a high fidelity genetic lineage tracer that, once on, is uncoupled from the gene expression initially used to drive CreERT.
We apply GIFM in mouse to study normal development and ascertain the contribution of genetic lineages to adult cell types and tissues. We also use GIFM to follow cells on mutant genetic backgrounds to better understand complex phenotypes that mimic salient features of human genetic disorders.
This video article guides researchers through experimental methods to successfully apply GIFM. We demonstrate the method using our well characterized Wnt1-CreERT;mGFP mice by administering tamoxifen at embryonic day (E)8.5 via oral gavage followed by dissection at E12.5 and analysis by epifluorescence stereomicroscopy. We also demonstrate how to micro-dissect fate mapped domains for explant preparation or FACS analysis and dissect adult fate-mapped brains for whole mount fluorescent imaging. Collectively, these procedures allow researchers to address critical questions in developmental biology and disease models.

A Practical Approach to Genetic Inducible Fate Mapping: A Visual Guide to Mark and Track Cells In Vivo

Genetic Inducible Fate Mapping (GIFM) marks and tracks cells with fine spatial and temporal control in vivo and elucidates how cells from a specific genetic lineage contribute to developing and adult tissues. Demonstrated here are the techniques required to fate map E12.5 mouse embryos for epifluorescent and explant analysis.

Fate maps are generated by marking and tracking cells in vivo to determine how progenitors contribute to specific structures and cell types in developing ...

A Practical and Novel Method to Extract Genomic DNA from Blood Collection Kits for Plasma Protein Preservation

Laboratory tests can be done on the cellular or fluid portions of the blood. The use of different blood collection tubes determines the portion of the blood that can be analyzed (whole blood, plasma or serum). Laboratories involved in studying the genetic basis of human disorders rely on anticoagulated whole blood collected in EDTA-containing vacutainer as the source of DNA for genetic / genomic analysis. Because most clinical laboratories perform biochemical, serologic and viral testing as a first step in phenotypic outcome investigation, anticoagulated blood is also collected in heparin-containing tube (plasma tube). Therefore when DNA and plasma are needed for simultaneous and parallel analyses of both genomic and proteomic data, it is customary to collect blood in both EDTA and heparin tubes. If blood could be collected in a single tube and serve as a source for both plasma and DNA, that method would be considered an advancement to existing methods. The use of the compacted blood after plasma extraction represents an alternative source for genomic DNA, thus minimizing the amount of blood samples processed and reducing the number of samples required from each patient. This would ultimately save time and resources.
The BD P100 blood collection system for plasma protein preservation were created as an improved method over previous plasma or serum collection tubes1, to stabilize the protein content of blood, enabling better protein biomarker discovery and proteomics experimentation from human blood. The BD P100 tubes contain 15.8 ml of spray-dried K2EDTA and a lyophilized proprietary broad spectrum cocktail of protease inhibitors to prevent coagulation and stabilize the plasma proteins. They also include a mechanical separator, which provides a physical barrier between plasma and cell pellets after centrifugation. Few methods have been devised to extract DNA from clotted blood samples collected in old plasma tubes2-4. Challenges from these methods were mainly associated with the type of separator inside the tubes (gel separator) and included difficulty in recovering the clotted blood, the inconvenience of fragmenting or dispersing the clot, and obstruction of the clot extraction by the separation gel.
We present the first method that extracts and purifies genomic DNA from blood drawn in the new BD P100 tubes. We compare the quality of the DNA sample from P100 tubes to that from EDTA tubes. Our approach is simple and efficient. It involves four major steps as follows: 1) the use of a plasma BD P100 (BD Diagnostics, Sparks, MD, USA) tube with mechanical separator for blood collection, 2) the removal of the mechanical separator using a combination of sucrose and a sterile paperclip metallic hook, 3) the separation of the buffy coat layer containing the white cells and 4) the isolation of the genomic DNA from the buffy coat using a regular commercial DNA extraction kit or a similar standard protocol.

We are describing a new method of isolating genomic DNA from whole blood collected for plasma/serology. After plasma collection, the compacted blood is usually discarded. Our novel method represents a significant improvement over existing methods and makes DNA and plasma available from a single collection, without requesting additional blood.

En praktisk og Novel metode for å utvinne genomisk DNA fra Blodprøverør Kits for Plasma Protein Preservation

Laboratory tests can be done on the cellular or  fluid portions of the blood. The use of different blood collection tubes  determines the portion of the ...

V3 Stain-free Workflow for a Practical, Convenient, and Reliable Total Protein Loading Control in Western Blotting

The western blot is a very useful and widely adopted lab technique, but its execution is challenging. The workflow is often characterized as a &#34;black box&#34; because an experimentalist does not know if it has been performed successfully until the last of several steps. Moreover, the quality of western blot data is sometimes challenged due to a lack of effective quality control tools in place throughout the western blotting process. Here we describe the V3 western workflow, which applies stain-free technology to address the major concerns associated with the traditional western blot protocol. This workflow allows researchers: 1) to run a gel in about 20-30 min; 2) to visualize sample separation quality within 5 min after the gel run; 3) to transfer proteins in 3-10 min; 4) to verify transfer efficiency quantitatively; and most importantly 5) to validate changes in the level of the protein of interest using total protein loading control. This novel approach eliminates the need of stripping and reprobing the blot for housekeeping proteins such as &#946;-actin, &#946;-tubulin, GAPDH, etc. The V3 stain-free workflow makes the western blot process faster, transparent, more quantitative&#160;and reliable.

V3 workflow is a western blot procedure using stain-free gels. The stain-free technology allows researchers to visualize protein separation quality, to verify the transfer efficiency, and most importantly, to validate the change in the protein of interest using total protein quantification as a reliable loading control.

V3 Flekkfri arbeidsflyt for en praktisk, praktisk og pålitelig total proteinlastekontroll i vestlig blotting

The western blot is a very useful and widely adopted lab technique, but its execution is challenging. The workflow is often characterized as a &#34;black ...

A Guide to Modern Quantitative Fluorescent Western Blotting with Troubleshooting Strategies

The late 1970s saw the first publicly reported use of the western blot, a technique for assessing the presence and relative abundance of specific proteins within complex biological samples. Since then, western blotting methodology has become a common component of the molecular biologists experimental repertoire. A cursory search of PubMed using the term &#8220;western blot&#8221; suggests that in excess of two hundred and twenty thousand published manuscripts have made use of this technique by the year 2014. Importantly, the last ten years have seen technical imaging advances coupled with the development of sensitive fluorescent labels which have improved sensitivity and yielded even greater ranges of linear detection. The result is a now truly Quantifiable Fluorescence based Western Blot (QFWB) that allows biologists to carry out comparative expression analysis with greater sensitivity and accuracy than ever before. Many &#8220;optimized&#8221; western blotting methodologies exist and are utilized in different laboratories. These often prove difficult to implement due to the requirement of subtle but undocumented procedural amendments. This protocol provides a comprehensive description of an established and robust QFWB method, complete with troubleshooting strategies.

The advancement of western blotting using fluorescence has allowed detection of subtle changes in protein expression enabling quantitative analyses. Here we describe a robust methodology for detection of a range of proteins across a variety of species and tissue types. A strategy to overcome common technical problems is also provided.

A Guide to Modern Kvantitativ Fluorescent Western Blotting med Feilsøking Strategier

The late 1970s saw the first publicly reported use of the western blot, a technique for assessing the presence and relative abundance of specific proteins ...

Endotracheal Intubation of Rabbits Using a Polypropylene Guide Catheter

Endotracheal intubation in rabbits can be challenging due to their unusual anatomy. Achieving a patent airway during anesthesia is critical for the avoidance of airway obstruction, prevention of gastric tympany, and to allow ventilatory support. Due to the difficulty of intubation, alternative methods such as the use of laryngeal mask airways or laryngeal tubes have been explored. However, these methods do not result in direct access to the trachea and thus may present a risk for development of complications. In addition, lack of direct intubation of the trachea can result in personnel exposure to waste anesthetic gases. Numerous methods for endotracheal intubation have been described, including blind placement, use of a fiberoptic laryngoscope or endoscope, and cricoid placement. Despite these numerous publications, many still struggle to achieve success. Here we provide a detailed description of an intubation technique that can be taught with minimal training with a short time to proficiency. Briefly, after administration of injectable anesthesia and proper positioning of the rabbit, a polypropylene catheter is placed into the trachea by direct visualization using a laryngoscope. The catheter is then used as a guide to direct the endotracheal tube into the trachea. This method allows for intubation without the need for expensive equipment and can be performed by a single individual without the need for an assistant. In conclusion, this technique can be easily taught and performed at very little cost in any clinical or research setting.

Endotracheal intubation in rabbits is challenging due to their unusual anatomy. Here we present a technique for direct intubation of the trachea using a polypropylene catheter as a guide. This method utilizes relatively inexpensive supplies, requires minimal training, and can be easily performed in any clinical setting.

Endotracheal intubasjon kaniner ved hjelp av en polypropylen Guide kateter

Endotracheal intubation in rabbits can be challenging due to their unusual anatomy. Achieving a patent airway during anesthesia is critical for the ...

Practical Use of RNA Interference: Oral Delivery of Double-stranded RNA in Liposome Carriers for Cockroaches

RNA interference (RNAi) has been widely applied for uncovering the biological functions of numerous genes, and has been envisaged as a pest control tool operating by disruption of essential gene expression. Although different methods, such as injection, feeding, and soaking, have been reported for successful delivery of double-stranded RNA (dsRNA), the efficiency of RNAi through oral delivery of dsRNA is highly variable among different insect groups. The German cockroach, Blattella germanica, is highly sensitive to the injection of dsRNA, as shown by many studies published previously. The present study describes a method to demonstrate that the dsRNA encapsulated with liposome carriers is sufficient to retard the degradation of dsRNA by midgut juice. Notably, the continuous feeding of dsRNA encapsulated by liposomes significantly reduces the tubulin expression in the midgut, and led to the death of cockroaches. In conclusion, the formulation and utilization of dsRNA lipoplexes, which protect dsRNA against nucleases, could be a practical use of RNAi for insect pest control in the future.

This manuscript demonstrates the depletion of gene expression in the midgut of the German cockroach through oral ingestion of double-stranded RNA encapsulated in liposomes.

Praktisk bruk av RNA støy: muntlig levering av Double-strandet i Liposome stativer for Cockroaches

RNA interference (RNAi) has been widely applied for uncovering the biological functions of numerous genes, and has been envisaged as a pest control tool ...

A Sectioning, Coring, and Image Processing Guide for High-Throughput Cortical Bone Sample Procurement and Analysis for Synchrotron Micro-CT

Bone is a dynamic and mechanically active tissue that changes in structure over the human lifespan. The products of the bone remodeling process have been studied substantially using traditional two-dimensional techniques. Recent advancements in X-ray imaging technology via desktop micro-computed tomography (&#181;CT) and synchrotron radiation micro-computed tomography (SR&#181;CT) have allowed for the acquisition of high-resolution three-dimensional (3D) scans of a larger field of view (FOV) than other 3D imaging techniques (e.g., SEM) providing a more complete picture of microscopic structures within human cortical bone. The specimen should be accurately centered within the FOV, however, to limit the appearance of streak artifacts known to impact data analysis. Previous studies have reported procurement of irregularly shaped rectilinear bone blocks that result in imaging artifacts due to uneven edges or image truncation. We have applied a geological sampling protocol (coring) to procure consistently sized cortical bone core specimens for SR&#181;CT experiments from the anterior aspect of human femora. This coring method is efficient and minimally destructive to tissue. It creates uniform cylindrical samples that decrease imaging artifacts by nature of being isometric during rotation and providing a uniform path length for X-ray beams throughout scanning. Image processing of X-ray tomographic data of cored and irregularly shaped samples confirms the potential of the technique to improve visualization and analysis of cortical bone microarchitecture. A goal of this protocol is to deliver a reliable and repeatable method for the extraction of cortical bone cores that is adaptable for various types of high-resolution bone imaging experiments. An overarching goal of the work is to create a standardized cortical bone procurement for SR&#181;CT that is affordable, consistent, and straightforward. This procedure may further be adapted by researchers in related fields who commonly evaluate hard composite materials such as in biological anthropology, geosciences, or material sciences.

We employed a geological (coring) sampling protocol to procure cortical bone specimens of uniform size for SR&#181;CT experiments from the anterior aspect of human femora. This method is minimally destructive, efficient, results in cylindrical specimens that minimize imaging artifacts from irregular sample shapes and improves microarchitectural visualization and analysis.

En snittings-, kordings- og bildebehandlingsveiledning for kortikale beinprøveinnkjøp og -analyse for Synchrotron Micro-CT

Bone is a dynamic and mechanically active tissue that changes in structure over the human lifespan. The products of the bone remodeling process have been ...

A Step-by-Step Guide to Mosquito Electroantennography

Female mosquitoes are the deadliest animals on earth, claiming the lives of more than 1 million people every year due to pathogens they transmit when acquiring a blood-meal. To locate a host to feed on, mosquitoes rely on a wide range of sensory cues, including visual, mechanical, thermal, and olfactory. The study details a technique, electroantennography (EAG), that allows researchers to assess whether the mosquitoes can detect individual chemicals and blends of chemicals in a concentration-dependent manner. When coupled with gas-chromatography (GC-EAG), this technique allows to expose the antennae to a full headspace/complex mixture and determines which chemicals present in the sample of interest, the mosquito can detect. This is applicable to host body odors as well as plant floral bouquets or other ecologically relevant odors (e.g., oviposition sites odorants). Here, we described a protocol that permits long durations of preparation responsiveness time and is applicable to both female and male mosquitoes from multiple genera, including Aedes, Culex, Anopheles, and Toxorhynchites mosquitoes. As olfaction plays a major part in mosquito-host interactions and mosquito biology in general, EAGs and GC-EAG can reveal compounds of interest for the development of new disease vector control strategies (e.g., baits). Complemented with behavioral assays, the valence (e.g., attractant, repellent) of each chemical can be determined.

The present article details a step-by-step protocol for successful and low noise electroantennograms in several genera of mosquitoes, including both females and males.

En trinnvis guide til Mosquito Electroantennography

Female mosquitoes are the deadliest animals on earth, claiming the lives of more than 1 million people every year due to pathogens they transmit when ...

Utvikle en ovariektomisert musemodell med forhøyet FSH-nivå

Exploring Independent Effects of Follicle-Stimulating Hormone In Vivo in a Mouse Model

During the transition from a reproductive to a nonreproductive phase (menopause), many women experience significant physiological and pathological changes, including decreased bone mass, increased blood lipids, and increased visceral adiposity. Levels of follicle-stimulating hormone (FSH) rise during the menopausal transition. Many studies have shown that FSH in various extragonadal tissues and organs is associated with the pathogenesis of multiple diseases. Thus, building an animal model that can help study the independent effects of FSH in vivo is particularly important. In this study, C57BL/6 female mice were ovariectomized and supplemented with estradiol valerate (OVX + E2) to eliminate the effect of the hypothalamic-pituitary-gonadal axis. The OVX + E2 mice received solvent (N.S.) or different doses of recombinant FSH via intraperitoneal injection to create a mouse model (OVF) characterized by relatively stable estrogen and rising FSH levels. Thus, we successfully generated an experimental mouse model to mimic the early stage of menopause transition, characterized by elevated serum FSH levels. The OVF model has the advantages of being stable, low cost, and easy to operate, which is suitable for studies to explore the extragonadal actions of FSH. Here, we describe detailed protocols for the mouse OVF model.

Forfatter Spotlight: Undersøkelse av forholdet mellom FSH og patofysiologiske endringer hos perimenopausale kvinner - Innsikt fra en musemodell 

Follicle-stimulating hormone (FSH) in various extragonadal tissues and organs is associated with the pathogenesis of multiple diseases. The ovariectomized and FSH-treated mouse model (OVF) can be used to explore the extragonadal actions of FSH.