Nous remercions le Dr David O’Brochta et tous les membres du Réseau de recherche sur la coordination des technologies génétiques des insectes pour l’aide et la formation qu’ils nous fournissent, ainsi qu’à d’autres, sur la mise en œuvre des technologies génétiques. Nous remercions tout particulièrement Channa Aluvihare d’avoir optimisé le protocole de micromanipulation pour permettre l’injection et l’éclosion d’embryons Culex. Nous remercions également Devante Simmons et Joseph Urso, étudiants de premier cycle travaillant au laboratoire Meuti, pour leur aide à soigner et à dépister les moustiques transgéniques, et Zora Elmkami de l’ITF pour leur aide à l’élevage et à la préparation des moustiques pour l’injection. Ce travail a été soutenu par une subvention interdisciplinaire sur les semences de l’Institut des maladies infectieuses de l’OSU fournie à MEM.

<ol>
	<li>Hamer, G. L., 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=Culex+pipiens+(Diptera:+Culicidae):+a+bridge+vector+of+West+Nile+virus+to+humans.">Culex pipiens (Diptera: Culicidae): a bridge vector of West Nile virus to humans.</a> Journal of Medical Entomology. 45 (1), 125-128 (2008).</li><li>Bailey, C. L., 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=Isolation+of+St.+Louis+encephalitis+virus+from+overwintering+Culex+pipiens+mosquitoes.">Isolation of St. Louis encephalitis virus from overwintering Culex pipiens mosquitoes.</a> Science. 199 (4335), 1346-1349 (1978).</li><li>Sabry, M. <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+realistic+index+of+experimental+transmission+efficiency+for+Bancroftian+filariasis.">A new realistic index of experimental transmission efficiency for Bancroftian filariasis.</a> The Journal of Tropical Medicine and Hygiene. 94 (4), 283-290 (1991).</li><li>Cancrini, G., 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=Aedes+albopictus+and+Culex+pipiens+implicated+as+natural+vectors+of+Dirofilaria+repens+in+central+Italy.">Aedes albopictus and Culex pipiens implicated as natural vectors of Dirofilaria repens in central Italy.</a> Journal of Medical Entomology. 44 (6), 1064-1066 (2007).</li><li>Wilton, D. P., Smith, G. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ovarian+diapause+in+three+geographic+strains+of+Culex+pipiens+(Diptera:+Culicidae).">Ovarian diapause in three geographic strains of Culex pipiens (Diptera: Culicidae).</a> Journal of Medical Entomology. 22 (5), 524-528 (1985).</li><li>Mattingly, P. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Culex+pipiens+complex.">The Culex pipiens complex.</a> Transactions of the Royal Entomological Society of London. 102 (7), 331-342 (1951).</li><li>Eldridge, B. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+temperature+and+photoperiod+on+blood-feeding+and+ovarian+development+in+mosquitoes+of+the+Culex+pipiens+complex.">The effect of temperature and photoperiod on blood-feeding and ovarian development in mosquitoes of the Culex pipiens complex.</a> The American Journal of Tropical Medicine and Hygiene. 17 (1), 133-140 (1968).</li><li>Spielman, A., Wong, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Environmental+control+of+ovarian+diapause+in+Culex+pipiens.">Environmental control of ovarian diapause in Culex pipiens.</a> Annals of the Entomological Society of America. 66 (4), 905-907 (1973).</li><li>Fritz, M. L., Walker, E. D., Miller, J. R., Severson, D. W., Dworkin, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Divergent+host+preferences+of+above-and+below-ground+Culex+pipiens+mosquitoes+and+their+hybrid+offspring.">Divergent host preferences of above-and below-ground Culex pipiens mosquitoes and their hybrid offspring.</a> Medical and Veterinary Entomology. 29 (2), 115-123 (2015).</li><li>Meola, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+influence+of+temperature+and+humidity+on+embryonic+longevity+in+Aedes+aegypti.">The influence of temperature and humidity on embryonic longevity in Aedes aegypti.</a> Annals of the Entomological Society of America. 57 (4), 468-472 (1964).</li><li>Dong, S., Lin, J., Held, N. L., Clem, R. J., Passarelli, A. L., Franz, A. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heritable+CRISPR/Cas9-mediated+genome+editing+in+the+yellow+fever+mosquito,+Aedes+aegypti.">Heritable CRISPR/Cas9-mediated genome editing in the yellow fever mosquito, Aedes aegypti.</a> PloS one. 10 (3), (2015).</li><li>Kyrou, 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=A+CRISPR-Cas9+gene+drive+targeting+doublesex+causes+complete+population+suppression+in+caged+Anopheles+gambiae+mosquitoes.">A CRISPR-Cas9 gene drive targeting doublesex causes complete population suppression in caged Anopheles gambiae mosquitoes.</a> Nature Biotechnology. 36 (11), 1062-1066 (2018).</li><li>Liu, T., 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=Construction+of+an+efficient+genomic+editing+system+with+CRISPR/Cas9+in+the+vector+mosquito+Aedes+albopictus.">Construction of an efficient genomic editing system with CRISPR/Cas9 in the vector mosquito Aedes albopictus.</a> Insect Science. 26 (6), 1045-1054 (2019).</li><li>Itokawa, K., Komagata, O., Kasai, S., Ogawa, K., Tomita, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Testing+the+causality+between+CYP9M10+and+pyrethroid+resistance+using+the+TALEN+and+CRISPR/Cas9+technologies.">Testing the causality between CYP9M10 and pyrethroid resistance using the TALEN and CRISPR/Cas9 technologies.</a> Scientific Reports. 6, 24652 (2016).</li><li>Li, M., Li, T., Liu, N., Raban, R. R., Wang, X., Akbari, O. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+for+the+generation+of+heritable+germline+mutations+in+the+disease+vector+Culex+quinquefasciatus+using+clustered+regularly+interspaced+short+palindrome+repeats-associated+protein+9.">Methods for the generation of heritable germline mutations in the disease vector Culex quinquefasciatus using clustered regularly interspaced short palindrome repeats-associated protein 9.</a> Insect Molecular Biology. 29, 214-220 (2019).</li><li>Anderson, M. E., 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=CRISPR/Cas9+gene+editing+in+the+West+Nile+Virus+vector,+Culex+quinquefasciatus+Say.">CRISPR/Cas9 gene editing in the West Nile Virus vector, Culex quinquefasciatus Say.</a> PloS one. 14 (11), (2019).</li><li>Van der Oost, J., Jore, M. M., Westra, E. R., Lundgren, M., Brouns, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CRISPR-based+adaptive+and+heritable+immunity+in+prokaryotes.">CRISPR-based adaptive and heritable immunity in prokaryotes.</a> Trends in Biochemical Sciences. 34 (8), 401-407 (2009).</li><li>Heyer, W. D., Ehmsen, K. T., Liu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+homologous+recombination+in+eukaryotes.">Regulation of homologous recombination in eukaryotes.</a> Annual Review of Genetics. 44, 113-139 (2010).</li><li>Monnerat, A. T., 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=Anopheles+albitarsis+embryogenesis:+morphological+identification+of+major+events.">Anopheles albitarsis embryogenesis: morphological identification of major events.</a> Memorias do Instituto Oswaldo Cruz. 97 (4), 589-596 (2002).</li><li>Davis, C. W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparative+study+of+larval+embryogenesis+in+the+mosquito+Culex+fatigans+Wiedemann+(Diptera:+Culicidae)+and+the+sheep-fly+Lucilia+sericata+Meigen+(Diptera:+Calliphoridae).">A comparative study of larval embryogenesis in the mosquito Culex fatigans Wiedemann (Diptera: Culicidae) and the sheep-fly Lucilia sericata Meigen (Diptera: Calliphoridae).</a> Australian Journal of Zoology. 15 (3), 547-579 (1967).</li><li>Port, F., Chen, H. M., Lee, T., Bullock, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimized+CRISPR/Cas+tools+for+efficient+germline+and+somatic+genome+engineering+in+Drosophila.">Optimized CRISPR/Cas tools for efficient germline and somatic genome engineering in Drosophila.</a> Proceedings of the National Academy of Sciences. 111 (29), 2967-2976 (2014).</li><li>Kistler, K. E., Vosshall, L. B., Matthews, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genome+engineering+with+CRISPR-Cas9+in+the+mosquito+Aedes+aegypti.">Genome engineering with CRISPR-Cas9 in the mosquito Aedes aegypti.</a> Cell Reports. 11 (1), 51-60 (2015).</li><li>Gokcezade, J., Sienski, G., Duchek, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+CRISPR/Cas9+plasmids+for+rapid+and+versatile+genome+editing+in+Drosophila.">Efficient CRISPR/Cas9 plasmids for rapid and versatile genome editing in Drosophila.</a> G3: Genes, Genomes, Genetics. 4 (11), 2279-2282 (2014).</li><li>Hwang, W. Y., 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=Efficient+in+vivo+genome+editing+using+RNA-guided+nucleases.">Efficient in vivo genome editing using RNA-guided nucleases.</a> Nature Biotechnology. 31 (3), 227-229 (2013).</li><li>Basu, 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=Silencing+of+end-joining+repair+for+efficient+site-specific+gene+insertion+after+TALEN/CRISPR+mutagenesis+in+Aedes+aegypti.">Silencing of end-joining repair for efficient site-specific gene insertion after TALEN/CRISPR mutagenesis in Aedes aegypti.</a> Proceedings of the National Academy of Sciences. 112 (13), 4038-4043 (2015).</li><li>Hammond, 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=A+CRISPR-Cas9+gene+drive+system+targeting+female+reproduction+in+the+malaria+mosquito+vector+Anopheles+gambiae.">A CRISPR-Cas9 gene drive system targeting female reproduction in the malaria mosquito vector Anopheles gambiae.</a> Nature Biotechnology. 34 (1), 78-83 (2016).</li><li>Lin, S., Staahl, B. T., Alla, R. K., Doudna, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+homology-directed+human+genome+engineering+by+controlled+timing+of+CRISPR/Cas9+delivery.">Enhanced homology-directed human genome engineering by controlled timing of CRISPR/Cas9 delivery.</a> eLife. 3, 04766 (2014).</li></ol>

RH travaille pour l’Installation de transformation des insectes, qui fournit des services de modification génétique des insectes.

Ce protocole présente des méthodes pour introduire des mutations spécifiques dans le génome des moustiques Culex et peut également être utilisé pour modifier le génome d’autres moustiques. Le protocole est important en ce qu’il fournit des détails spécifiques non seulement sur la façon de préparer les matériaux d’injection, mais aussi un aperçu vidéo détaillé de la façon d’inciter les moustiques à pondre des œufs, ainsi que sur la façon de préparer et d’injecter ces œufs. Nous r?...

Les moustiques Culex sont répartis dans toutes les régions tempérées et tropicales du monde et transmettent plusieurs virus mortels dont le virus du Nil occidental1,l’encéphalite de Saint-Louis2 ainsi que les nématodes filaires qui causent le ver du cœur canin3 et l’éléphantiasis4. Les membres du complexe Culex pipiens, qui comprend Cx. quinquefasciatus, Cx. pipiens pipiens et Cx. pipiens molestus, présentent des variations frappantes dans de nombreux aspects de leur biologie. Par exemple, alors que Cx. quinquefasciatus et Cx. pipiens molestus sont incapables d’entrer dans une dormance hivernante5,6, Cx. pipiens pipiens affichent des réponses saisonnières robustes et entrent en diapause en réponse à des jours courts7,8. De plus, Cx. pipiens molestus a tendance à être plus anthropophile tandis que Cx. pipiens et Cx. quinquefasciatus sont plus zoophiles6. Cependant, aux États-Unis et dans de nombreux autres endroits du monde, ces espèces se croisent, ce qui a de fortes implications pour la transmission de maladies en tant qu’hybrides du Cx. pipiens pipiens et du Cx. pipiens molestus sont des mangeoires opportunistes et mordront à la fois les oiseaux et les humains9, servant ainsi de vecteurs de pont pour le virus du Nil occidental. L’étude de ces aspects et d’autres aspects fascinants de la biologie des moustiques Culex a été entravée, en partie parce que les moustiques Culex sont légèrement plus difficiles à élever en laboratoire que les moustiques Aedes, qui produisent des œufs quiescents et résistants à la dessiccation10 et parce que les outils moléculaires fonctionnels ne sont pas aussi bien développés pour les espèces Culex. 
L’édition du génome CRISPR/ Cas9 est une technologie puissante qui a été utilisée pour évaluer la biologie de plusieurs espèces importantes de moustiques11,12,13, y compris le moustique domestique du Sud, Culex quinquefasciatus14,15,16. Cette technologie, développée par Jennifer Doudna et Emmanuelle Charpentier, exploite une défense bactérienne naturelle contre les virus par des endonucléases bactériennes associées à CRISPR (protéines Cas; voir revue par Van der Oost et al.17). Lorsqu’elles sont injectées dans des embryons animaux, les protéines Cas9 en combinaison avec un ARN guide approprié peuvent produire des cassures double brin dans le génome. Ceci est le plus souvent fait en utilisant la protéine Cas9 qui est complexée avec des ARN guides, qui dirige l’activité de l’endonucléase vers une région spécifique du génome. Une fois que la protéine Cas9 a créé une rupture double brin spécifique au site, la machinerie cellulaire tente de réparer la rupture en utilisant l’un des deux mécanismes. La première consiste à ligaturer les deux extrémités ensemble par jointure d’extrémité non homologue (NHEJ), qui est sujette aux erreurs et produit souvent des insertions et des délétions hors cadre dans le génome qui peuvent entraîner des protéines non fonctionnelles, générant ainsi une mutation knock-out. Alternativement, la machinerie cellulaire peut utiliser la réparation dirigée par homologie (HDR) en trouvant des séquences similaires pour réparer correctement la rupture. La séquence similaire peut être fournie par le deuxième chromosome dans l’organisme (voir revue18). Cependant, si la séquence réparée correspond exactement à la séquence originale, la protéine Cas9 sera capable de couper à nouveau l’ADN. Alternativement, les chercheurs peuvent également inclure un plasmide donneur qui contient des séquences homologues de chaque côté du site coupé de la séquence cible avec une séquence de réparation alternative – souvent une protéine marqueur fluorescente, une version modifiée du gène original ou une autre modification – qui peut être copiée et insérée dans le génome, ou « knocked-in ».
Le timing est essentiel lors de l’injection d’embryons, et c’est particulièrement le cas lors de l’utilisation de l’édition du génome CRISPR / Cas9 pour créer des mutations chez les insectes. En effet, la protéine Cas9 et les aRNg n’ont la plus grande capacité à générer des mutations que lorsque l’embryon est dans son état syncytial, avant que les membranes cellulaires ne se soient formées et lorsque plusieurs noyaux sont accessibles à l’intérieur de l’embryon. Pour les moustiques, les noyaux atteignent la périphérie ~ 2-4 heures après la ponte, en fonction de la température19, et donc une micro-injection réussie doit se produire avant cette heure. De plus, la protéine Cas9 coupera tout ADN nucléaire auquel elle peut accéder, de sorte que l’individu résultant de l’injection contiendra une mosaïque de cellules, certaines ayant la mutation souhaitée et d’autres non. Pour que ces mutations soient héritées avec succès, la protéine Cas9 doit couper l’ADN qui réside dans la lignée germinale qui donnera naissance aux futurs ovules et spermatozoïdes. Pour s’assurer que des mutations sont générées dans la lignée germinale, il est préférable d’injecter tous les matériaux proches de l’emplacement des cellules polaires dans l’embryon, qui sont les progéniteurs de la lignée germinale de l’insecte. Les cellules polaires sont situées près de l’extrémité postérieure des embryons de Culex 20. En plus d’injecter des embryons, il est impératif d’élaborer un plan minutieux pour le croisement et le dépistage de la progéniture afin de détecter la mutation souhaitée.
Ce protocole décrit comment générer des ARNg et les complexer avec la protéine Cas9 pour préparer des mélanges d’injection, ainsi que comment inciter les moustiques femelles de Culex pipiens à pondre des œufs et comment préparer et injecter ces œufs pour l’édition du génome médiée par CRISPR / Cas9. De plus, nous décrivons comment élever, croiser et dépister les embryons injectés et leur descendance pour confirmer que la mutation souhaitée a été obtenue. En utilisant ce protocole, nous avons généré des mutations nulles pour un gène d’intérêt, cycle,dans la souche Buckeye de Culex pipiens. Cette souche a été établie à l’origine en 2013 à partir de moustiques collectés sur le terrain à Columbus, Ohio et est maintenue par le laboratoire Meuti. Ce protocole peut être utilisé pour des études supplémentaires qui nécessitent l’édition du génome CRISPR / Cas9 chez les moustiques Culex, ainsi que d’autres espèces de moustiques, et, plus généralement, est pertinent pour l’utilisation de l’édition du génome CRISPR / Cas9 à toute espèce d’insecte.

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	<tbody>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Artificial Membrane Feeder</td>
			<td style="width:121px;">Hemotek</td>
			<td style="width:119px;">SP5W1-3</td>
			<td style="width:167px;">Company location: Blackburn, UK</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">ATP</td>
			<td style="width:121px;">Invitrogen</td>
			<td style="width:119px;">18330019</td>
			<td style="width:167px;">Company location: Carlsbad, CA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Borosilicate glass mirocapillary tubes, 1 mm outer diameter</td>
			<td style="width:121px;">World Precision Instruments</td>
			<td style="width:119px;">1B100-6</td>
			<td style="width:167px;">Company Location: Sarasota, FL, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">BV10 Needle Beveler</td>
			<td style="width:121px;">Sutter Instruments</td>
			<td style="width:119px;">BV-10-B</td>
			<td style="width:167px;">Company Location: Nobato, CA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Whatman Circular filter paper (12.5 cm)</td>
			<td style="width:121px;">Sigma Aldrich</td>
			<td style="width:119px;">WHA1001125</td>
			<td style="width:167px;">Company Location: St. Louis, MO, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Conical tube (50 mL)</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">339652</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Fisherbrand course filter paper with fast flow rate</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">09-800</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Cover glass (24 x 40 mm)</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">50-311-20</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Dental dam</td>
			<td style="width:121px;">Henry Schein Inc</td>
			<td style="width:119px;">1010171</td>
			<td style="width:167px;">Company Location: Melville, NY USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Scotch double-sided tape</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">NC0879005</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">FemtoJet 4i microinjector</td>
			<td style="width:121px;">Eppendorf</td>
			<td style="width:119px;">5252000021</td>
			<td style="width:167px;">Company Location: Hamburg, Germany</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Glass vial (2 dram)</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">033401C</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Halocarbon oil</td>
			<td style="width:121px;">Sigma Aldrich</td>
			<td style="width:119px;">H8898-50ML</td>
			<td style="width:167px;">Company Location: St. Louis, MO, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">P-2000 Laser Needle Puller</td>
			<td style="width:121px;">Sutter Instruments</td>
			<td style="width:119px;">P-2000/G</td>
			<td style="width:167px;">Company Location: Nobato, CA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Parafilm</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">50-998-944</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">PC-100 Weighted Needle Puller</td>
			<td style="width:121px;">Narishige</td>
			<td style="width:119px;">PC-100</td>
			<td style="width:167px;">This is compatabile with the earlier PC-10 model, which has been discontinued. Company Location: Amityville, NY, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Phire Direct PCR Kit</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">F140WH</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Kodak Photo-Flo (1%)</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">50-268-05</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Quartz glass mirocapillary tubes, 1 mm outer diameter</td>
			<td style="width:121px;">Capillary Tube Supplies Limited</td>
			<td style="width:119px;">QGCT 1.0</td>
			<td style="width:167px;">Company Location: Cornwall, UK</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Guide-it&#8482; sgRNA Screening Kit</td>
			<td style="width:121px;">Takara, Bio USA</td>
			<td style="width:119px;">632639</td>
			<td style="width:167px;">This kit allows you to determine if gRNAs cut DNA sequences in vitro. Company Location: Mountain View, CA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Sigmacote</td>
			<td style="width:121px;">Sigma Aldrich</td>
			<td style="width:119px;">SL2-100ML</td>
			<td style="width:167px;">Company Location: St. Louis, MO, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Small petri dishes (35X10 mm)</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">50-190-0273</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Sodium citrate chicken blood</td>
			<td style="width:121px;">Lampire biologicals</td>
			<td style="width:119px;">7201406</td>
			<td style="width:167px;">Company Location: Everett, PA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Fisherbrand Square petri dish (10 cm x 10 cm)</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">FB0875711A</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Tegaderm</td>
			<td style="width:121px;">Henry Schein Inc.</td>
			<td style="width:119px;">7771180</td>
			<td style="width:167px;">Company Location: Melville, NY USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Tropical fish food</td>
			<td style="width:121px;">Tetramin</td>
			<td style="width:119px;">N/A</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Whatman filter paper</td>
			<td style="width:121px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">09-927-826</td>
			<td style="width:167px;">Company Location: Waltham, MA, USA</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Whatman filter paper, 4.25 cm</td>
			<td style="width:121px;">Sigma Aldrich</td>
			<td style="width:119px;">1001-042</td>
			<td style="width:167px;">Company Location: St. Louis, MO, USA</td>
		</tr>
	</tbody>
</table>

preparing and injecting embryos of culex mosquitoes to generate null mutations using crispr/cas9

Les moustiques Culex sont les principaux vecteurs de plusieurs maladies qui ont un impact négatif sur la santé humaine et animale, y compris le virus du Nil occidental et les maladies causées par des nématodes filaires tels que le ver du cœur canin et l’éléphantasis. Récemment, l’édition du génome CRISPR / Cas9 a été utilisée pour induire des mutations dirigées par le site en injectant une protéine Cas9 qui a été complexée avec un ARN guide (aRNg) dans des embryons fraîchement pondus de plusieurs espèces d’insectes, y compris des moustiques appartenant aux genres Anopheles et Aedes. Manipuler et injecter des moustiques Culex est légèrement plus difficile car ces moustiques pondent leurs œufs debout dans des radeaux plutôt que individuellement comme d’autres espèces de moustiques. Nous décrivons ici comment concevoir des ARNg, les complexer avec la protéine Cas9, induire des moustiques femelles de Culex pipiens à pondre des œufs, et comment préparer et injecter des embryons nouvellement pondus pour la microinjection avec Cas9 / ARNg. Nous décrivons également comment élever et dépister les moustiques injectés pour la mutation souhaitée. Les résultats représentatifs démontrent que cette technique peut être utilisée pour induire des mutations dirigées vers le site dans le génome des moustiques Culex et, avec de légères modifications, peut également être utilisée pour générer des mutants nuls chez d’autres espèces de moustiques.

En utilisant le protocole décrit, nous avons pu injecter avec succès des embryons de Cx. pipiens, et observé un taux de survie élevé parmi les embryons injectés (~55%, Figure 1). Les essais antérieurs avaient un pourcentage de survie plus faible, probablement parce que l’antérieur du follicule de l’œuf était attaché à la bande de pansement médical, empêchant les larves de moustiques de s’échapper du chorion et de nager avec succès dans l’eau. S’assurer que ...

Watch this Scientific Journal Video about Preparing and Injecting Embryos of Culex Mosquitoes to Generate Null Mutations using CRISPR/Cas9 at JoVE.com

Preparing and Injecting Embryos of Culex Mosquitoes to Generate Null Mutations using CRISPR/Cas9

CRISPR/Cas9 est de plus en plus utilisé pour caractériser la fonction des gènes dans les organismes non modèles. Ce protocole décrit comment générer des lignées knock-out de Culex pipiens,de la préparation de mélanges d’injection à l’obtention et à l’injection d’embryons de moustiques, ainsi que la façon d’élever, de croiser et de dépister les moustiques injectés et leur progéniture pour les mutations souhaitées.

Préparation et injection d’embryons de moustiques Culex pour générer des mutations nulles à l’aide de CRISPR/Cas9

Culex mosquitoes are the major vectors of several diseases that negatively impact human and animal health including West Nile virus and diseases caused by ...

preparing-injecting-embryos-culex-mosquitoes-to-generate-null

Research

JoVE Journal

Biology

Preparing and Injecting Embryos of Culex Mosquitoes to Generate Null Mutations using CRISPR/Cas9

6.7K vues.  The Ohio State University. CRISPR/Cas9 est de plus en plus utilisé pour caractériser la fonction des gènes dans les organismes non modèles. Ce protocole décrit comment générer des lignées knock-out de Culex pipiens,de la préparation de mélanges d’injection à l’obtention et à l’injection d’embryons de moustiques, ainsi que la façon d’élever, de croiser et de dépister les moustiques injectés et leur progéniture pour les mutations souhaitées.

Vidéo: Preparing and Injecting Embryos of Culex Mosquitoes to Generate Null Mutations using CRISPR/Cas9

Injection of An. stephensi Embryos to Generate Malaria-resistant Mosquitoes

The introduction of exogenous genes into the genomes of mosquitoes requires microinjection techniques tailored to the specific species of interest. This video protocol demonstrates a method used by the James laboratory to microinject DNA constructs into Anopheles stephensi embryos for the generation of transformed mosquitoes. Techniques for preparing microinjection needles, collecting and preparing embryos and performing the microinjection are illustrated.

Anopheles stephensi mosquitoes are vectors for malaria inhabiting India and throughout Asia. This video demonstrates the technique for performing microinjections of this species with transgenes that will confer resistance to the malaria to the mosquito. Much of the methodology demonstrated in this video is applicable to microinjection techniques of other mosquito species.

Injection d&#39;un. Embryons stephensi pour générer le paludisme résistant à moustiques

The introduction of exogenous genes into the genomes of mosquitoes requires microinjection techniques tailored to the specific species of interest. This ...

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Biologie

Microinjection of A. aegypti Embryos to Obtain Transgenic Mosquitoes

In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue fever.  The techniques for correctly preparing microinjection needles, dessicating embryos, and performing microinjection are demonstrated.

In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue fever. The techniques for correctly preparing microinjection needles, dessicating embryos, and performing microinjection are demonstrated.

Microinjection d&#39;embryons aegypti a. Pour obtenir les moustiques transgéniques

In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue ...

Harvesting and Preparing Drosophila Embryos for Electrophysiological Recording and Other Procedures

Drosophila is a premier genetic model for the study of both embryonic development and functional neuroscience. Traditionally, these fields are quite isolated from each other, with largely independent histories and scientific communities. However, the interface between these usually disparate fields is the developmental programs underlying acquisition of functional electrical signaling properties and differentiation of functional chemical synapses during the final phases of neural circuit formation. This interface is a critically important area for investigation. In Drosophila, these phases of functional development occur during a period of &lt;8 hours (at 25&deg;C) during the last third of embryogenesis. This late developmental period was long considered intractable to investigation owing to the deposition of a tough, impermeable epidermal cuticle. A breakthrough advance was the application of water-polymerizing surgical glue that can be locally applied to the cuticle to enable controlled dissection of late-stage embryos. With a dorsal longitudinal incision, the embryo can be laid flat, exposing the ventral nerve cord and body wall musculature to experimental investigation. This system has been heavily used to isolate and characterize genetic mutants that impair embryonic synapse formation, and thus reveal the molecular mechanisms governing the specification and differentiation of synapse connections and functional synaptic signaling properties.

Harvesting and Preparing Drosophila Embryos for Electrophysiological Recording and Other Procedures

This technique exposes the Drosophila embryonic neuromusculature for immunohistochemistry or electrophysiological recording. It is useful for studying early events in neuromuscular development or performing electrophysiology in mutants that cannot hatch.

La récolte et la préparation Drosophile Les embryons destinés à l&#39;enregistrement électrophysiologique et autres procédures

Drosophila is a premier genetic model for the study of both embryonic development and functional neuroscience. Traditionally, these fields are quite ...

Generation of Genomic Deletions in Mammalian Cell Lines via CRISPR/Cas9

The prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9 system may be re-purposed for site-specific eukaryotic genome engineering. CRISPR/Cas9 is an inexpensive, facile, and efficient genome editing tool that allows genetic perturbation of genes and genetic elements. Here we present a simple methodology for CRISPR design, cloning, and delivery for the production of genomic deletions. In addition, we describe techniques for deletion, identification, and characterization. This strategy relies on cellular delivery of a pair of chimeric single guide RNAs (sgRNAs) to create two double strand breaks (DSBs) at a locus in order to delete the intervening DNA segment by non-homologous end joining (NHEJ) repair. Deletions have potential advantages as compared to single-site small indels given the efficiency of biallelic modification, ease of rapid identification by PCR, predictability of loss-of-function, and utility for the study of non-coding elements. This approach can be used for efficient loss-of-function studies of genes and genetic elements in mammalian cell lines.

CRISPR/Cas9 is a robust system to produce disruption of genes and genetic elements. Here we describe a protocol for the efficient creation of genomic deletions in mammalian cell lines using CRISPR/Cas9.

Génération de suppressions génomiques dans des lignées cellulaires de mammifères via CRISPR / Cas9

The prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9 system may be re-purposed for site-specific ...

Silencing the Spark: CRISPR/Cas9 Genome Editing in Weakly Electric Fish

Electroreception and electrogenesis have changed in the evolutionary history of vertebrates. There is a striking degree of convergence in these independently derived phenotypes, which share a common genetic architecture. This is perhaps best exemplified by the numerous convergent features of gymnotiforms and mormyrids, two species-rich teleost clades that produce and detect weak electric fields and are called weakly electric fish. In the 50 years since the discovery that weakly electric fish use electricity to sense their surroundings and communicate, a growing community of scientists has gained tremendous insights into evolution of development, systems and circuits neuroscience, cellular physiology, ecology, evolutionary biology, and behavior. More recently, there has been a proliferation of genomic resources for electric fish. Use of these resources has already facilitated important insights with regards to the connection between genotype and phenotype in these species. A major obstacle to integrating genomics data with phenotypic data of weakly electric fish is a present lack of functional genomics tools. We report here a full protocol for performing CRISPR/Cas9 mutagenesis that utilizes endogenous DNA repair mechanisms in weakly electric fish. We demonstrate that this protocol is equally effective in both the mormyrid species Brienomyrus brachyistius and the gymnotiform Brachyhypopomus gauderio by using CRISPR/Cas9 to target indels and point mutations in the first exon of the sodium channel gene scn4aa. Using this protocol, embryos from both species were obtained and genotyped to confirm that the predicted mutations in the first exon of the sodium channel scn4aa were present. The knock-out success phenotype was confirmed with recordings showing reduced electric organ discharge amplitudes when compared to uninjected size-matched controls.

Here, a protocol is presented to produce and rear CRISPR/Cas9 genome knockout electric fish. Outlined in detail are the required molecular biology, breeding, and husbandry requirements for both a gymnotiform and a mormyrid, and injection techniques to produce Cas9-induced indel F0 larvae.

Electroreception and electrogenesis have changed in the evolutionary history of vertebrates. There is a striking degree of convergence in these ...

Genome Engineering of Primary Human B Cells Using CRISPR/Cas9

B cells are lymphocytes derived from hematopoietic stem cells and are a key component of the humoral arm of the adaptive immune system. They make attractive candidates for cell-based therapies because of their ease of isolation from peripheral blood, their ability to expand in vitro, and their longevity in vivo. Additionally, their normal biological function&#8212;to produce large amounts of antibodies&#8212;can be utilized to express very large amounts of a therapeutic protein, such as a recombinant antibody to fight infection, or an enzyme for the treatment of enzymopathies. Here, we provide detailed methods for isolating primary human B cells from peripheral blood mononuclear cells (PBMCs) and activating/expanding isolated B cells in vitro. We then demonstrate the steps involved in using the CRISPR/Cas9 system for site-specific KO of endogenous genes in B cells. This method allows for efficient KO of various genes, which can be used to study the biological functions of genes of interest. We then demonstrate the steps for using the CRISPR/Cas9 system together with a recombinant, adeno-associated, viral (rAAV) vector for efficient site-specific integration of a transgene expression cassette in B cells. Together, this protocol provides a step-by-step engineering platform that can be used in primary human B cells to study biological functions of genes as well as for the development of B-cell therapeutics.

Here we provide a detailed, step-by-step protocol for CRISPR/Cas9-based genome engineering of primary human B cells for gene knockout (KO) and knock-in (KI) to study biological functions of genes in B cells and the development of B-cell therapeutics.

Ingénierie génomique des cellules B humaines primaires à l’aide de CRISPR/Cas9

B cells are lymphocytes derived from hematopoietic stem cells and are a key component of the humoral arm of the adaptive immune system. They make ...

TGF-&#946;-mediated Endothelial to Mesenchymal Transition (EndMT) and the Functional Assessment of EndMT Effectors using CRISPR/Cas9 Gene Editing

In response to specific external cues and the activation of certain transcription factors, endothelial cells can differentiate into a mesenchymal-like phenotype, a process that is termed endothelial to mesenchymal transition (EndMT). Emerging results have suggested that EndMT is causally linked to multiple human diseases, such as fibrosis and cancer. In addition, endothelial-derived mesenchymal cells may be applied in tissue regeneration procedures, as they can be further differentiated into various cell types (e.g., osteoblasts and chondrocytes). Thus, the selective manipulation of EndMT may have clinical potential. Like epithelial-mesenchymal transition (EMT), EndMT can be strongly induced by the secreted cytokine transforming growth factor-beta (TGF-&#946;), which stimulates the expression of so-called EndMT transcription factors (EndMT-TFs), including Snail and Slug. These EndMT-TFs then up- and downregulate the levels of mesenchymal and endothelial proteins, respectively. Here, we describe methods to investigate TGF-&#946;-induced EndMT in vitro, including a protocol to study the role of particular TFs in TGF-&#946;-induced EndMT. Using these techniques, we provide evidence that TGF-&#946;2 stimulates EndMT in murine pancreatic microvascular endothelial cells (MS-1 cells), and that the genetic depletion of Snail using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated gene editing, abrogates this phenomenon. This approach may serve as a model to interrogate potential modulators of endothelial biology, and can be used to perform genetic or pharmacological screens in order to identify novel regulators of EndMT, with potential application in human disease.

TGF-&#946;-mediated Endothelial to Mesenchymal Transition EndMT and the Functional Assessment of EndMT Effectors using CRISPR/Cas9 Gene Editing

We describe methods to investigate TGF-&#946;2-induced EndMT in endothelial cells by observing cell morphology changes and examining the expression EndMT-related marker changes using immunofluorescence staining. CRISPR/Cas9 gene editing was described and used to deplete the gene encoding Snail to investigate its role in TGF-&#946;2-induced EndMT.

Transition endothéliale à mésenchymateuse médiée par TGF-β (EndMT) et évaluation fonctionnelle des effecteurs EndMT à l’aide de l’édition du gène CRISPR/Cas9

In response to specific external cues and the activation of certain transcription factors, endothelial cells can differentiate into a mesenchymal-like ...

Preparing Irradiated and Marked Male Aedes aegypti Mosquitoes for Release in an Operational Sterile Insect Technique Program

The control of such human diseases as dengue, Zika, and chikungunya relies on the control of their vector, the Aedes aegypti mosquito, because there is no prevention. Control of mosquito vectors can rely on chemicals applied to the immature and adult stages, which can contribute to the mortality of non-targets and more importantly, lead to insecticide resistance in the vector. The sterile insect technique (SIT) is a method of controlling populations of pests through the release of sterilized adult males that mate with wild females to produce non-viable offspring. This paper describes the process of producing sterile males for use in an operational SIT program for the control of Aedes aegypti mosquitoes. Outlined here are the steps used in the program including rearing and maintaining a colony, separating male and female pupae, irradiating and marking adult males, and shipping Aedes aegypti males to the release site. Also discussed are procedural caveats, program limitations, and future objectives.

Preparing Irradiated and Marked Male Aedes aegypti Mosquitoes for Release in an Operational Sterile Insect Technique Program

The sterile insect technique (SIT) is used to control specific, medically important mosquito populations that may be resistant to chemical controls. Here, we describe a method of mass rearing and preparation of sterile male mosquitoes for release in an operational SIT program targeting the Aedes aegypti mosquito.

Préparation de moustiques mâles Aedes aegypti irradiés et marqués en vue de leur libération dans le cadre d’un programme opérationnel de techniques d’insectes stériles

The control of such human diseases as dengue, Zika, and chikungunya relies on the control of their vector, the Aedes aegypti mosquito, because there is no ...

Construction of Homozygous Mutants of Migratory Locust Using CRISPR/Cas9 Technology

The migratory locust, Locusta migratoria, is not only one of the worldwide plague locusts that caused huge economic losses to human beings but also an important research model for insect metamorphosis. The CRISPR/Cas9 system can accurately locate at a specific DNA locus and cleave within the target site, efficiently introducing double-strand breaks to induce target gene knockout or integrate new gene fragments into the specific locus. CRISPR/Cas9-mediated genome editing is a powerful tool for addressing questions encountered in locust research as well as a promising technology for locust control. This study provides a systematic protocol for CRISPR/Cas9-mediated gene knockout with the complex of Cas9 protein and single guide RNAs (sgRNAs) in migratory locusts. The selection of target sites and design of sgRNA are described in detail, followed by in vitro synthesis and verification of the sgRNAs. Subsequent procedures include egg raft collection and tanned-egg separation to achieve successful microinjection with low mortality rate, egg culture,&#160;preliminary estimation of the mutation rate, locust breeding as well as detection, preservation, and passage of the mutants to ensure population stability of the edited locusts. This method can be used as a reference for CRISPR/Cas9 based gene editing applications in migratory locusts as well as in other insects.

This study provides a systematically optimized procedure of CRISPR/Cas9 ribonuclease-based construction of homozygous locust mutants as well as a detailed method for cryopreservation and resuscitation of the locust eggs.

Construction de mutants homozygotes du criquet migrateur à l’aide de la technologie CRISPR/Cas9

The migratory locust, Locusta migratoria, is not only one of the worldwide plague locusts that caused huge economic losses to human beings but also an ...

CRISPR/Cas9 Gene Editing of Hematopoietic Stem and Progenitor Cells for Gene Therapy Applications

CRISPR/Cas9 is a highly versatile and efficient gene-editing tool adopted widely to correct various genetic mutations. The feasibility of gene manipulation of hematopoietic stem and progenitor cells (HSPCs) in vitro makes HSPCs an ideal target cell for gene therapy. However, HSPCs moderately lose their engraftment and multilineage repopulation potential in ex vivo culture. In the present study, ideal culture conditions are described that improves HSPC engraftment and generate an increased number of gene-modified cells in vivo. The current report displays optimized in vitro culture conditions, including the type of culture media, unique small molecule cocktail supplementation, cytokine concentration, cell culture plates, and culture density. In addition to that, an optimized HSPC gene-editing procedure, along with the validation of the gene-editing events, are provided. For in vivo validation, the gene-edited HSPCs infusion and post-engraftment analysis in mouse recipients are displayed. The results demonstrated that the culture system increased the frequency of functional HSCs in vitro, resulting in robust engraftment of gene-edited cells in vivo.

The present protocol describes an optimized hematopoietic stem and progenitor cell (HSPC) culture procedure for the robust engraftment of gene-edited cells in vivo.