Ce travail a été soutenu par les Instituts nationaux de la santé accorde F32 NS078958 (DTB) et R01 AG033620 (BG).

Une. Assembler Vol testeur <ol><li> Vol sécurisé cylindre Ring Stand 1 aide de colliers de chaîne. (Laissez environ 3 cm en dessous du cylindre pour peser plat.) (Note: Le cylindre de vol, nous utilisons est de 90 cm de long avec un diamètre de 13,5 cm.) </li><li> Insérez peser plat avec une fine couche d&#39;huile minérale sous le cylindre de vol. </li><li> Entonnoir sécurisé Ring Support 2 en utilisant un collier de serrage et griffe pince. Ajuster la hauteur de l&#39;entonnoir de sorte que le fond de l&#39;entonnoir est de niveau avec la partie supérieure du cylindre de vol. (Note: le diamètre de l&#39;entonnoir d&#39;extrémité doit être inférieur au diamètre externe de flacons placés dans les tubes de descente de façon que les flacons ne tombent pas à travers.) </li><li> Insérer le tube de chute dans la partie supérieure de l&#39;entonnoir et le fixer à l&#39;aide d&#39;une pince à griffes. (Note: Nous utilisons un tube de descente qui est de 25 cm de long goutte volent contenant des flacons de cette hauteur permet éjection cohérente de toutes les mouches avec force uniforme Le diamètre intérieur du tube de chute devrait être sligh..TLY plus grand que le diamètre extérieur de la cuvette pour permettre à la fiole de tomber librement.) </li><li> Couper feuille (s) de polyacrylamide à la bonne taille. (Remarque: Pour aider à l&#39;insertion et le retrait de la feuille, dont la largeur doit être légèrement plus petite que la circonférence intérieure du cylindre de vol). </li><li> Appliquez une fine couche de Tangle-Trap à la feuille. Laisser reposer pendant 1 heure avant de l&#39;utiliser. (Remarque: Laissez suffisamment d&#39;espace en haut et en bas de la feuille (environ 3 cm) non couché à saisir la feuille pour l&#39;insertion / retrait.) </li><li> Insérer la feuille de polyacrylamide dans le cylindre de vol. </li><li> Assembler les rails de la caméra avec supports de pin. (Remarque: veiller à ce que le bas de la piste peut soutenir la caméra sans blocage de la lentille Reportez-vous à la figure 1B..) </li><li> Ajouter bouchons et visser en place. (Remarque: place les bouchons dans des endroits qui permettront à l&#39;appareil photo pour voir la feuille de plastique toute en mode panoramique.) </li></ol> 2. Exécutez l&#39;expérience <ol> &lt;li&gt; Récupérer flacons de mouches à tester. Pour de meilleurs résultats, ne pas utiliser plus de 20 mouches / flacon. </li><li> Tapoter doucement vol à bas de flacon, débrancher, puis insérez dans le tube de chute et libérer flacon. (Note: Le flacon tombe vers le bas du tube de descente jusqu&#39;à ce qu&#39;il frappe l&#39;ouverture étroite de l&#39;entonnoir Lorsque le flacon frappe l&#39;entonnoir, les mouches sont éjectées dans le cylindre de vol.). </li><li> Soulevez le tube de descente pour enlever le flacon vide. (Remarque: les flacons multiples de mouches du même groupe de test peuvent être analysés sur une feuille de polyacrylamide unique Nous constatons que jusqu&#39;à 200 mouches (10 flacons de 20 mouches chacun) peuvent être testées et imagées facilement sur une seule feuille.. </li><li> Retirer la feuille de plastique et placez-le sur une surface plate et blanche. (Remarque: carton blanc peut être utilisé si les paillasses sont de couleur foncée.) </li><li> Assembler les rails de la caméra sur la feuille de plastique. La caméra doit être suffisamment élevée au-dessus de la feuille pour avoir à la fois le haut et le bas de la feuille dans le champ de vision. </li><li> Faites glisser la caméra le long ee piste tout en maintenant la touche &quot;capture&quot; d&#39;acquérir une image panoramique. </li><li> Le nombre de mouches atterrissent dans l&#39;huile peut être compté manuellement pour chaque essai. </li><li> Répétez les étapes 02.02 à 02.07 pour toutes les conditions d&#39;une expérience donnée. Les mouches peuvent être retirées de la feuille entre chaque essai. Sinon, plusieurs feuilles peuvent être utilisées, avec une nouvelle feuille pour chaque essai. </li></ol> 3. Collecte de données <ol><li> Ouvrez des fichiers image en utilisant le logiciel ImageJ. </li><li> les images des cultures, si nécessaire d&#39;inclure uniquement la surface d&#39;atterrissage. (Il s&#39;agit de la zone revêtue dans Tangle-Trap.) </li><li> Convertir des images en 8 bits en niveaux de gris. </li><li> Créer un «seuil» pour filtrer le fond blanc. (Image → Ajuster → Seuil). </li><li> Définissez les paramètres pour identifier chaque volée en utilisant le menu &quot;analyser des particules&quot;. (Analyser → analyser des particules) Définir les paramètres utilisés pour identifier une particule. Avec notre mis en place, nous constatons que l&#39;aide d&#39;unzone de 5-90 pixels 2 et une circularité de 0,4-1,0 permettra d&#39;identifier avec précision tous les échantillons. </li><li> Mesurer l&#39;emplacement de chaque volée en utilisant la liste générée de coordonnées pour chaque particule. Les coordonnées x en pixels peuvent être converties en centimètres pour calculer la hauteur d&#39;atterrissage. </li><li> Importer la table dans un tableur (comme Microsoft Excel). </li></ol>

<ol>
	<li>Benzer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+dissection+of+behavior.">Genetic dissection of behavior.</a> Sci. Am. 229, 24-37 (1973).</li><li>Ali, Y. O., Escala, W., Ruan, K., Zhai, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assaying+locomotor,+learning,+and+memory+deficits+in+Drosophila+models+of+neurodegeneration.">Assaying locomotor, learning, and memory deficits in Drosophila models of neurodegeneration.</a> J. Vis. Exp. , e2504 (2011).</li><li>de Vries, S. E., Clandinin, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optogenetic+Stimulation+of+Escape+Behavior+in+Drosophila+melanogaster.">Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster.</a> J. Vis. Exp. , e50192 (2013).</li><li>Mundiyanapurath, S., Certel, S., Kravitz, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studying+aggression+in+Drosophila+(fruit+flies).">Studying aggression in Drosophila (fruit flies).</a> J. Vis. Exp. , e155 (2007).</li><li>Nichols, C. D., Becnel, J., Pandey, U. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+to+assay+Drosophila+behavior.">Methods to assay Drosophila behavior.</a> J. Vis. Exp. , e3795 (2012).</li><li>Shiraiwa, T., Carlson, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proboscis+extension+response+(PER)+assay+in+Drosophila.">Proboscis extension response (PER) assay in Drosophila.</a> J. Vis. Exp. , e193 (2007).</li><li>Lloyd, T. E., Taylor, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flightless+flies:+Drosophila+models+of+neuromuscular+disease.">Flightless flies: Drosophila models of neuromuscular disease.</a> Ann. N.Y. Acad. Sci. 1184, e1-e20 (2010).</li><li>Atkinson, N. S., 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=Molecular+separation+of+two+behavioral+phenotypes+by+a+mutation+affecting+the+promoters+of+a+Ca-activated+K+channel.">Molecular separation of two behavioral phenotypes by a mutation affecting the promoters of a Ca-activated K channel.</a> J. Neurosci. 20, 2988-2993 (2000).</li><li>Atkinson, N. S., Robertson, G. A., Ganetzky, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+component+of+calcium-activated+potassium+channels+encoded+by+the+Drosophila+slo+locus.">A component of calcium-activated potassium channels encoded by the Drosophila slo locus.</a> Science. 253, 551-555 (1991).</li><li>Elkins, T., Ganetzky, B., Wu, C. 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+Drosophila+mutation+that+eliminates+a+calcium-dependent+potassium+current.">A Drosophila mutation that eliminates a calcium-dependent potassium current.</a> Proc. Natl. Acad. Sci. U.S.A. 83, 8415-8419 (1986).</li><li>Gargano, J. W., Martin, I., Bhandari, P., Grotewiel, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+iterative+negative+geotaxis+(RING):+a+new+method+for+assessing+age-related+locomotor+decline+in+Drosophila.">Rapid iterative negative geotaxis (RING): a new method for assessing age-related locomotor decline in Drosophila.</a> Exp. Gerontol. 40, 386-395 (2005).</li><li>Fry, S. N., Rohrseitz, N., Straw, A. D., Dickinson, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visual+control+of+flight+speed+in+Drosophila+melanogaster.">Visual control of flight speed in Drosophila melanogaster.</a> J. Exp. Biol. 212, 1120-1130 (2009).</li><li>Mronz, M., Lehmann, F. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+free-flight+response+of+Drosophila+to+motion+of+the+visual+environment.">The free-flight response of Drosophila to motion of the visual environment.</a> J. Exp. Biol. 211, 2026-2045 (2008).</li></ol>

Les auteurs n&#39;ont aucun conflit d&#39;intérêt à divulguer.

En utilisant les méthodes décrites ici, nous avons été en mesure d&#39;évaluer rapidement les performances de vol d&#39;un grand nombre de mutants de drosophile, offrant une plus grande efficacité qu&#39;auparavant. Pour nos expériences, nous nous séparons systématiquement hommes et les femmes et les élever à faible densité (moins de 20 mouches / flacon) pour limiter l&#39;agression qui pourrait endommager les ailes. Une autre considération importante est de bien contrôler les différences de perf...

Drosophila a longtemps été utilisée pour étudier la base génétique du comportement 1, et les chercheurs ont mis au point un certain nombre de façons d&#39;analyser différents types de comportements 2-6. Les mouches ont été particulièrement utiles pour fournir des modèles utiles de troubles neuromusculaires 7. Un test couramment utilisé pour étudier le comportement locomoteur des performances de vol. Le testeur de vol initial est utile pour identifier les ponts mutants défectueux et pour l&#39;évaluation quantitative de la capacité de vol 1, mais il a plusieurs inconvénients qui limitent son application pour les écrans à haut débit: l&#39;utilisation de bouteilles enduites d&#39;huile est salissant et fastidieux, certaines fonctionnalités telles que la longueur du cylindre et l&#39;introduction des mouches dans le tube avec une force variable de réduire la précision quantitative, et il est difficile de récupérer vol direct à partir de l&#39;appareil d&#39;essai. Pour surmonter ces limitations, nous avons modifié le testeur de vol pour inclure un certain nombre d&#39;améliorations. Nous avons ajouté un &quot;drop tuêtre &quot;d&#39;introduire mouches pour éliminer la variabilité entre les expériences et les utilisateurs. Nous utilisons des feuilles d&#39;acrylique amovibles recouvertes d&#39;un adhésif qui permet de faciliter le nettoyage et la récupération de vol individuels. Nous avons augmenté la longueur du tube de vol d&#39;améliorer la précision quantitative et de fiabilité. Enfin , nous utilisons un appareil photo numérique et des logiciels d&#39;imagerie pour calculer les hauteurs d&#39;atterrissage de vol. Nous croyons que ces améliorations seront utiles à tous les laboratoires intéressés à mener des écrans génétiques à grande échelle pour les défauts de performances de vol.

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			<td height="33" style="height:33px;width:216px;">Putty knife</td>
			<td style="width:171px;">Home Depot</td>
			<td style="width:132px;">630147</td>
			<td style="width:185px;"><a href="http://www.homedepot.com">www.homedepot.com</a></td>
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		<tr height="33">
			<td height="33" style="height:33px;width:216px;">Pine back band moulding ( x2 )</td>
			<td style="width:171px;">Home Depot</td>
			<td style="width:132px;">156469</td>
			<td><a href="http://www.homedepot.com">www.homedepot.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">Furring Strip Board</td>
			<td style="width:171px;">Home Depot</td>
			<td style="width:132px;">164704</td>
			<td><a href="http://www.homedepot.com">www.homedepot.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">Tangle Trap Insect Trap Coating</td>
			<td style="width:171px;">BioControl Network</td>
			<td style="width:132px;">268941</td>
			<td><a href="http://www.biconet.com">www.biconet.com</a></td>
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		<tr height="33">
			<td height="33" style="height:33px;width:216px;">Laptop Computer </td>
			<td style="width:171px;">Apple</td>
			<td style="width:132px;">_</td>
			<td><a href="http://www.apple.com/mac/">www.apple.com/mac/</a></td>
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		<tr height="33">
			<td height="33" style="height:33px;width:216px;">mineral oil</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:132px;">BP26291</td>
			<td><a href="http://www.fishersci.com">www.fishersci.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">white poster board</td>
			<td style="width:171px;">Staples</td>
			<td style="width:132px;">247403</td>
			<td><a href="http://www.staples.com">www.staples.com</a></td>
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		<tr height="33">
			<td height="33" style="height:33px;width:216px;">polystyrene weighing dish</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:132px;">S67091A</td>
			<td><a href="http://www.fishersci.com">www.fishersci.com</a></td>
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		<tr height="33">
			<td height="33" style="height:33px;width:216px;">ImageJ Software</td>
			<td style="width:171px;">National Institutes of Health</td>
			<td style="width:132px;">_</td>
			<td>http://rsb.info.nih.gov/ij/</td>
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		<tr height="33">
			<td height="33" style="height:33px;width:216px;">digital camera</td>
			<td style="width:171px;">Sony</td>
			<td style="width:132px;">DSC-TX7</td>
			<td style="width:185px;"><a href="http://www.store.sony.com">www.store.sony.com</a></td>
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		<tr height="33">
			<td height="33" style="height:33px;width:216px;">fine forceps</td>
			<td style="width:171px;">Fine Science Tools</td>
			<td style="width:132px;">_</td>
			<td><a href="http://www.finescience.com">www.finescience.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">polycarbonate cylinder (drop tube)</td>
			<td style="width:171px;">mcMaster-Carr</td>
			<td style="width:132px;">8585K62</td>
			<td><a href="http://www.mcmaster.com">www.mcmaster.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">flight cylinder (acrylic)</td>
			<td style="width:171px;">mcMaster-Carr</td>
			<td style="width:132px;">8486K943</td>
			<td><a href="http://www.mcmaster.com">www.mcmaster.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">polycarbonate sheets</td>
			<td style="width:171px;">mcMaster-Carr</td>
			<td style="width:132px;">85585K25</td>
			<td><a href="http://www.mcmaster.com">www.mcmaster.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">ring stand (x2)</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:132px;">S47808</td>
			<td><a href="http://www.fishersci.com">www.fishersci.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">ring support</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:132px;">S47791</td>
			<td><a href="http://www.fishersci.com">www.fishersci.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">Three-prong extension clamps (x2)</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:132px;">05-769-7Q</td>
			<td><a href="http://www.fishersci.com">www.fishersci.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">funnel</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:132px;">10-500-3</td>
			<td><a href="http://www.fishersci.com">www.fishersci.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">chain clamps (x2)</td>
			<td style="width:171px;">VWR</td>
			<td style="width:132px;">21573-275</td>
			<td><a href="http://www.vwr.com">www.vwr.com</a></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:216px;">glass vials</td>
			<td style="width:171px;">VWR</td>
			<td style="width:132px;">66020-198</td>
			<td><a href="http://www.vwr.com/">www.vwr.com</a></td>
		</tr>
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an improved method for accurate and rapid measurement of flight performance in drosophila

Drosophila s&#39;est avéré être un système de modèle utile pour l&#39;analyse du comportement, y compris le vol. Le testeur de vol chute impliqué initiale vole dans une huile revêtu graduée; hauteur d&#39;atterrissage a permis de mesurer les performances de vol en évaluant comment les mouches loin tomberont avant de produire une poussée suffisante pour prendre contact avec la paroi du cylindre. Nous décrivons ici une version mise à jour de l&#39;appareil de contrôle de vol avec quatre améliorations majeures. Tout d&#39;abord, nous avons ajouté un &quot;tube de descente&quot; de veiller à ce que toutes les mouches entrent dans le cylindre de vol à une vitesse similaire entre les essais, ce qui élimine la variabilité entre les utilisateurs. Deuxièmement, nous avons remplacé le revêtement de l&#39;huile de feuilles de plastique amovibles revêtus de Tangle-Trap, un adhésif conçu pour capturer des insectes vivants. Troisièmement, nous utilisons un cylindre plus de permettre la discrimination plus précise de la capacité de vol. Quatrième nous utilisons un appareil photo numérique et des logiciels d&#39;imagerie pour automatiser la notation des performances de vol. Ces améliorations permettent de rapIdentifiant, l&#39;évaluation quantitative du comportement de vol, utile pour les grands ensembles de données et les écrans génétiques à grande échelle.

<html> La figure 1A montre un schéma de l&#39;ensemble de testeur de vol mis à jour. Figure 1B illustre la conception de la voie permettre à l&#39;appareil de prendre une image panoramique sans bloquer le champ de vision. Les résultats représentatifs sont présentés dans la figure 2, où les performances de vol de mouches mutantes slowpoke, qui ont un vol défaut 8-10 connu, sont comparées au type sauvage Canton-S vole. Contrôle vole ...

Watch this Scientific Journal Video about An Improved Method for Accurate and Rapid Measurement of Flight Performance in Drosophila at JoVE.com

An Improved Method for Accurate and Rapid Measurement of Flight Performance in Drosophila

Nous décrivons ici une méthode de mesure rapide et précise des performances de vol chez la drosophile, permettant le criblage à haut débit.

Une méthode améliorée pour la mesure précise et rapide des performances de vol en<em&gt; Drosophila</em

Drosophila has proven to be a useful model system for analysis of behavior, including flight. The initial flight tester involved dropping flies into an ...

an-improved-method-for-accurate-rapid-measurement-flight-performance

Research

JoVE Journal

Biology

An Improved Method for Accurate and Rapid Measurement of Flight Performance in Drosophila

11.6K vues.  University of Wisconsin-Madison.  Nous décrivons ici une méthode de mesure rapide et précise des performances de vol chez la drosophile, permettant le criblage à haut débit. 

Vidéo: An Improved Method for Accurate and Rapid Measurement of Flight Performance in Drosophila

Pyrosequencing: A Simple Method for Accurate Genotyping

Pharmacogenetic research benefits first-hand from the abundance of information provided by the completion of the Human Genome Project. With such a tremendous amount of data available comes an explosion of genotyping methods. Pyrosequencing(R) is one of the most thorough yet simple methods to date used to analyze polymorphisms. It also has the ability to identify tri-allelic, indels, short-repeat polymorphisms, along with determining allele percentages for methylation or pooled sample assessment. In addition, there is a standardized control sequence that provides internal quality control. This method has led to rapid and efficient single-nucleotide polymorphism evaluation including many clinically relevant polymorphisms. The technique and methodology of Pyrosequencing is explained.


Pyrosequencing(R) is one of the most thorough yet simple methods to date used to analyze polymorphisms. This method has led to rapid and efficient single-nucleotide polymorphism evaluation including many clinically relevant polymorphisms. The technique and methodology of Pyrosequencing is explained.

Pyroséquençage: une méthode simple pour le génotypage précis

Pharmacogenetic research benefits first-hand from the abundance of information provided by the completion of the Human Genome Project. With such a ...

Recherche

Biologie

High-resolution Measurement of Odor-Driven Behavior in Drosophila Larvae

Olfactory responses in Drosophila larvae have been traditionally studied in Petri dishes comprising a single peripheral odor source. In this behavioral paradigm, the experimenter usually assumes that the rapid diffusion of odorant molecules from the source leads to the creation of a stable gradient in the dish. To establish a quantitative correlation between sensory inputs and behavioral responses, it is necessary to achieve a more thorough characterization of the odorant stimulus conditions. In this video article, we describe a new method allowing the construction of odorant gradients with stable and controllable geometries. We briefly illustrate how these gradients can be used to screen for olfactory defects (full and partial anosmia) and to study more subtle features of chemotaxis behavior.

In this video article, we describe a new method allowing the construction of odorant gradients with stable and controllable geometries. We briefly illustrate how these gradients can be used to screen for olfactory defects (full and partial anosmia) and to study more subtle features of chemotaxis behavior.

Haute résolution de mesure du comportement Odor-Driven dans les larves de drosophile

Olfactory responses in Drosophila larvae have been traditionally studied in Petri dishes comprising a single peripheral odor source. In this behavioral ...

A Magnetic Tether System to Investigate Visual and Olfactory Mediated Flight Control in Drosophila

It has been clear for many years that insects use visual cues to stabilize their heading in a wind stream. Many animals track odors carried in the wind. As such, visual stabilization of upwind tracking directly aids in odor tracking. But do olfactory signals directly influence visual tracking behavior independently from wind cues? Also, the recent deluge of research on the neurophysiology and neurobehavioral genetics of olfaction in Drosophila has motivated ever more technically sophisticated and quantitative behavioral assays. Here, we modified a magnetic tether system originally devised for vision experiments by equipping the arena with narrow laminar flow odor plumes. A fly is glued to a small steel pin and suspended in a magnetic field that enables it to yaw freely. Small diameter food odor plumes are directed downward over the fly s head, eliciting stable tracking by a hungry fly. Here we focus on the critical mechanics of tethering, aligning the magnets, devising the odor plume, and confirming stable odor tracking.

Here we describe how to tether a fly in an olfactory magnetic-tether (OMT) apparatus. We describe how to align the rare-earth magnets and odor ports, and how to set mass flow rates for both the stimulus delivery and vacuum suction to achieve optimal odor tracking.

Un système d&#39;attache magnétique d&#39;enquêter sur les visuels et olfactifs Flight Control Mediated chez la drosophile

It has been clear for many years that insects use visual cues to stabilize their heading in a wind stream. Many animals track odors carried in the wind. ...

Visually Mediated Odor Tracking During Flight in Drosophila

Flying insects use visual cues to stabilize their heading in a wind stream. Many animals additionally track odors carried in the wind. As such, visual stabilization of upwind tracking directly aids in odor tracking. But do olfactory signals directly influence visual tracking behavior independently from wind cues? Additionally, recent advances in olfactory molecular genetics and neurophysiology have motivated novel quantitative behavioral analyses to assess the behavioral influence of (e.g.) genetically inactivating specific olfactory activation circuits. We modified a magnetic tether system originally devised for vision experiments by equipping the arena with narrow laminar flow odor plumes. Here we focus on experiments that can be performed after a fly is tethered and is able to navigate in the magnetic arena. We show how to acquire video images optimized for measuring body angle, how to judge stable odor tracking, and we illustrate two experiments to examine the influence of visual cues on odor tracking.

Here we describe how to optimize the acquired video image for an olfactory magnetic-tether (OMT) apparatus. We also describe two sample experimental protocols for studying visuo-olfactory fusion.

Visuellement Suivi Odeur Mediated Pendant le vol chez la drosophile

Flying insects use visual cues to stabilize their heading in a wind stream. Many animals additionally track odors carried in the wind. As such, visual ...

An Improved Method of RNA Isolation from Loblolly Pine (P. taeda L.) and Other Conifer Species

Tissues isolated from conifer species, particularly those belonging to the Pinaceae family, such as loblolly pine (Pinus taeda L.), contain high concentrations of phenolic compounds and polysaccharides that interfere with RNA purification. Isolation of high-quality RNA from these species requires rigorous tissue collection procedures in the field and the employment of an RNA isolation protocol comprised of multiple organic extraction steps in order to isolate RNA of sufficient quality for microarray and other genomic analyses. The isolation of high-quality RNA from field-collected loblolly pine samples can be challenging, but several modifications to standard tissue and RNA isolation procedures greatly improve results. The extent of general RNA degradation increases if samples are not properly collected and transported from the field, especially during large-scale harvests. Total RNA yields can be increased significantly by pulverizing samples in a liquid nitrogen freezer mill prior to RNA isolation, especially when samples come from woody tissues. This is primarily due to the presence of oxidizing agents, such as phenolic compounds, and polysaccharides that are both present at high levels in extracts from the woody tissues of most conifer species. If not removed, these contaminants can carry over leading to problems, such as RNA degradation, that result in low yields and a poor quality RNA sample. Carryover of phenolic compounds, as well as polysaccharides, can also reduce or even completely eliminate the activity of reverse transcriptase or other polymerases commonly used for cDNA synthesis. In particular, RNA destined to be used as template for double-stranded cDNA synthesis in the generation of cDNA libraries, single-stranded cDNA synthesis for PCR or qPCR's, or for the synthesis of microarray target materials must be of the highest quality if researchers expect to obtain optimal results. RNA isolation techniques commonly employed for many other plant species are often insufficient in their ability to remove these contaminants from conifer samples and thus do not yield total RNA samples suitable for downstream manipulations. In this video we demonstrate methods for field collection of conifer tissues, beginning with the felling of a forty year-old tree, to the harvesting of phloem, secondary xylem, and reaction wood xylem. We also demonstrate an RNA isolation protocol that has consistently yielded high-quality RNA for subsequent enzymatic manipulations.

An Improved Method of RNA Isolation from Loblolly Pine P. taeda L. and Other Conifer Species

Many plant tissues, including phloem and xylem from loblolly pine (Pinus taeda L.), contain high levels of phenolics and polysaccharides that interfere with RNA purification. This presentation discusses techniques for the harvest of field-grown tissues and isolation of RNA of sufficient quality for microarrays and other genomic analyses.

Une méthode améliorée d&#39;isolement d&#39;ARN à partir de pin taeda ( P. taeda L.) et d&#39;autres conifères

Tissues isolated from conifer species, particularly those belonging to the Pinaceae family, such as loblolly pine (Pinus taeda L.), contain high ...

Endurance Training Protocol and Longitudinal Performance Assays for Drosophila melanogaster

One of the most pressing problems facing modern medical researchers is the surging levels of obesity, with the consequent increase in associated disorders such as diabetes and cardiovascular disease 1-3. An important topic of research into these associated health problems involves the role of endurance exercise as a beneficial intervention.
Exercise training is an inexpensive, non-invasive intervention with several beneficial results, including reduction in excess body fat 4, increased insulin sensitivity in skeletal muscle 5, increased anti-inflammatory and antioxidative responses 6, and improved contractile capacity in cardiomyocytes 7. Low intensity exercise is known to increase mitochondrial activity and biogenesis in humans 8 and mice, with the transcriptional coactivator PGC1-&alpha; as an important intermediate 9,10. 
Despite the importance of exercise as a tool for combating several important age-related diseases, extensive longitudinal genetic studies have been impeded by the lack of an endurance training protocol for a short-lived genetic model species. The variety of genetic tools available for use with Drosophila, together with its short lifespan and inexpensive maintenance, make it an appealing model for further study of these genetic mechanisms. With this in mind we have developed a novel apparatus, known as the Power Tower, for large scale exercise-training in Drosophila melanogaster 11. The Power Tower utilizes the flies' instinctive negative geotaxis behavior to repetitively induce rapid climbing. Each time the machine lifts, then drops, the platform of flies, the flies are induced to climb. Flies continue to respond as long as the machine is in operation or until they become too fatigued to respond. Thus, the researcher can use this machine to provide simultaneous training to large numbers of age-matched and genetically identical flies. Additionally, we describe associated assays useful to track longitudinal progress of fly cohorts during training.

Endurance Training Protocol and Longitudinal Performance Assays for Drosophila melanogaster

We describe the first endurance training protocol for an important genetic model species, Drosophila melanogaster, and outline several assays to chart improvements in mobility following training.

Protocole entraînement d&#39;endurance et de performance Tests longitudinales pour Drosophila melanogaster

One of the most pressing problems facing modern medical researchers is the surging levels of obesity, with the consequent increase in associated disorders ...

Measurement of Lifespan in Drosophila melanogaster

Aging is a phenomenon that results in steady physiological deterioration in nearly all organisms in which it has been examined, leading to reduced physical performance and increased risk of disease. Individual aging is manifest at the population level as an increase in age-dependent mortality, which is often measured in the laboratory by observing lifespan in large cohorts of age-matched individuals. Experiments that seek to quantify the extent to which genetic or environmental manipulations impact lifespan in simple model organisms have been remarkably successful for understanding the aspects of aging that are conserved across taxa and for inspiring new strategies for extending lifespan and preventing age-associated disease in mammals.
The vinegar fly, Drosophila melanogaster, is an attractive model organism for studying the mechanisms of aging due to its relatively short lifespan, convenient husbandry, and facile genetics. However, demographic measures of aging, including age-specific survival and mortality, are extraordinarily susceptible to even minor variations in experimental design and environment, and the maintenance of strict laboratory practices for the duration of aging experiments is required. These considerations, together with the need to practice careful control of genetic background, are essential for generating robust measurements. Indeed, there are many notable controversies surrounding inference from longevity experiments in yeast, worms, flies and mice that have been traced to environmental or genetic artifacts1-4. In this protocol, we describe a set of procedures that have been optimized over many years of measuring longevity in Drosophila using laboratory vials. We also describe the use of the dLife software, which was developed by our laboratory and is available for download (<a href="http://sitemaker.umich.edu/pletcherlab/software">http://sitemaker.umich.edu/pletcherlab/software</a>). dLife accelerates throughput and promotes good practices by incorporating optimal experimental design, simplifying fly handling and data collection, and standardizing data analysis. We will also discuss the many potential pitfalls in the design, collection, and interpretation of lifespan data, and we provide steps to avoid these dangers.

Measurement of Lifespan in Drosophila melanogaster

Drosophila melanogaster is a powerful model organism for exploring the molecular basis of longevity regulation. This protocol will discuss the steps involved in generating a reproducible, population-based measurement of longevity as well as potential pitfalls and how to avoid them.

Mesure de la durée de vie en<em&gt; Drosophila melanogaster</em

Aging is a phenomenon that results in steady physiological deterioration in nearly all organisms in which it has been examined, leading to reduced ...

An Innovative Method for Exosome Quantification and Size Measurement

Although the biological importance of exosomes has recently gained an increasing amount of scientific and clinical attention, much is still unknown about their complex pathways, their bioavailability and their diverse functions in health and disease. Current work focuses on the presence and the behavior of exosomes (in vitro as well as in vivo) in the context of different human disorders, especially in the fields of oncology, gynecology and cardiology.
Unfortunately, neither a consensus regarding a gold standard for exosome isolation exists, nor is there an agreement on such a method for their quantitative analysis. As there are many methods for the purification of exosomes and also many possibilities for their quantitative and qualitative analysis, it is difficult to determine a combination of methods for the ideal approach. 
Here, we demonstrate nanoparticle tracking analysis (NTA), a semi-automated method for the characterization of exosomes after isolation from human plasma by ultracentrifugation. The presented results show that this approach for isolation, as well as the determination of the average number and size of exosomes, delivers reproducible and valid data, as confirmed by other methods, such as scanning electron microscopy (SEM).

A method for isolation of exosomes from whole blood and further analysis by nanoparticle tracking using a semi-automatic instrument is presented in this article. The presented technology provides an extremely sensitive method for visualizing and analyzing particles in liquid suspension.

Une méthode innovante pour Exosome Quantification et Taille Mesure

Although the biological importance of exosomes has recently gained an increasing amount of scientific and clinical attention, much is still unknown about ...

Measurement of Metabolic Rate in Drosophila using Respirometry

Metabolic disorders are a frequent problem affecting human health. Therefore, understanding the mechanisms that regulate metabolism is a crucial scientific task. Many disease causing genes in humans have a fly homologue, making Drosophila a good model to study signaling pathways involved in the development of different disorders. Additionally, the tractability of Drosophila simplifies genetic screens to aid in identifying novel therapeutic targets that may regulate metabolism. In order to perform such a screen a simple and fast method to identify changes in the metabolic state of flies is necessary. In general, carbon dioxide production is a good indicator of substrate oxidation and energy expenditure providing information about metabolic state. In this protocol we introduce a simple method to measure CO2 output from flies. This technique can potentially aid in the identification of genetic perturbations affecting metabolic rate.

Measurement of Metabolic Rate in Drosophila using Respirometry

Metabolic disorders are among one of the most common diseases in humans. The genetically tractable model organism D. melanogaster can be used to identify novel genes that regulate metabolism. This paper describes a relatively simple method which allows studying the metabolic rate in flies by measuring their CO2 production.

Mesure des taux métabolique dans<em&gt; Drosophila</em&gt; En utilisant Respirométrie

Metabolic disorders are a frequent problem affecting human health. Therefore, understanding the mechanisms that regulate metabolism is a crucial ...

Filtration Isolation of Nucleic Acids:  A Simple and Rapid DNA Extraction Method

FINA, filtration isolation of nucleic acids, is a novel extraction method which utilizes vertical filtration via a separation membrane and absorbent pad to extract cellular DNA from whole blood in less than 2 min. The blood specimen is treated with detergent, mixed briefly and applied by pipet to the separation membrane. The lysate wicks into the blotting pad due to capillary action, capturing the genomic DNA on the surface of the separation membrane. The extracted DNA is retained on the membrane during a simple wash step wherein PCR inhibitors are wicked into the absorbent blotting pad. The membrane containing the entrapped DNA is then added to the PCR reaction without further purification. This simple method does not require laboratory equipment and can be easily implemented with inexpensive laboratory supplies. Here we describe a protocol for highly sensitive detection and quantitation of HIV-1 proviral DNA from 100 &#181;l whole blood as a model for early infant diagnosis of HIV that could readily be adapted to other genetic targets.

We describe here a simple and rapid paper-based DNA extraction method of HIV proviral DNA from whole blood detected by quantitative PCR. This protocol can be extended for use in detecting other genetic markers or using alternative amplification methods.

Filtration Isolement des acides nucléiques: Une méthode d&#39;extraction de l&#39;ADN simple et rapide

FINA, filtration isolation of nucleic acids, is a novel extraction method which utilizes vertical filtration via a separation membrane and absorbent pad ...