Name: use of a recombinant mosquito densovirus as a gene delivery vector for the functional analysis of genes in mosquito larvae
Uploaded: 2017-10-06T13:00:00
Description: Watch this Scientific Journal Video about Use of a Recombinant Mosquito Densovirus As a Gene Delivery Vector for the Functional Analysis of Genes in Mosquito Larvae at JoVE.com

The authors acknowledge financial support from the National Key Research and Development Program of China (2016YFC1200500 to Xiao-Guang Chen), the National Natural Science Foundation of China (81672054 and 81371846), the Research Team Programme of the Natural Science Foundation of Guangdong (2014A030312016), and the Scientific and Technological Programme of Guangzhou (201508020263). We gratefully acknowledge Professor Jonathan Carlson (Colorado State University) for kindly providing the pUCA and p7NS1-GFP plasmids and for critically reading this manuscript.

All protocols were approved by the Ethical Committee of Southern Medical University.
1. Designing an Artificial Intron
NOTE: The artificial intron used in this work is 65 bp in length, and the sequence is 5&#39;-GTAAGAGTCGATCGACGCGTTACTAACTGGTACCTCTTCTTTTTTTTTTGATATCCTGCAG-3&#39;.
<ol>
	<li>Place the HpaI restriction site on both ends of artificial intron so that HpaI digestion can release the intron from plasmids (see Figure...

<ol>
	<li>Tolle, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mosquito-borne+diseases.">Mosquito-borne diseases.</a> Current problems in pediatric and adolescent health care. 39, 97-140 (2009).</li><li>Petersen, L. R., Jamieson, D. J., Powers, A. M., Honein, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zika+Virus.">Zika Virus.</a> The New England journal of medicine. 374, 1552-1563 (2016).</li><li>Roberts, D. R., Andre, 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=Insecticide+resistance+issues+in+vector-borne+disease+control.">Insecticide resistance issues in vector-borne disease control.</a> The American journal of tropical medicine and hygiene. 50, 21-34 (1994).</li><li>Attaran, A., Roberts, D. R., Curtis, C. F., Kilama, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Balancing+risks+on+the+backs+of+the+poor.">Balancing risks on the backs of the poor.</a> Nature medicine. 6, 729-731 (2000).</li><li>Volohonsky, 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=Transgenic+Expression+of+the+Anti-parasitic+Factor+TEP1+in+the+Malaria+Mosquito+Anopheles+gambiae.">Transgenic Expression of the Anti-parasitic Factor TEP1 in the Malaria Mosquito Anopheles gambiae.</a> PLoS pathogens. 13, 1006113 (2017).</li><li>Galizi, R., 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+synthetic+sex+ratio+distortion+system+for+the+control+of+the+human+malaria+mosquito.">A synthetic sex ratio distortion system for the control of the human malaria mosquito.</a> Nature communications. 5, 3977 (2014).</li><li>Bourtzis, K., Lees, R. S., Hendrichs, J., Vreysen, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=More+than+one+rabbit+out+of+the+hat:+Radiation,+transgenic+and+symbiont-based+approaches+for+sustainable+management+of+mosquito+and+tsetse+fly+populations.">More than one rabbit out of the hat: Radiation, transgenic and symbiont-based approaches for sustainable management of mosquito and tsetse fly populations.</a> Acta tropica. 157, 115-130 (2016).</li><li>Kumar, S. S., Puttaraju, H. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improvised+microinjection+technique+for+mosquito+vectors.">Improvised microinjection technique for mosquito vectors.</a> The Indian journal of medical research. 136, 971-978 (2012).</li><li>Attardo, G. M., Higgs, S., Klingler, K. A., Vanlandingham, D. L., Raikhel, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNA+interference-mediated+knockdown+of+a+GATA+factor+reveals+a+link+to+anautogeny+in+the+mosquito+Aedes+aegypti.">RNA interference-mediated knockdown of a GATA factor reveals a link to anautogeny in the mosquito Aedes aegypti.</a> Proceedings of the National Academy of Sciences of the United States of America. 100, 13374-13379 (2003).</li><li>Singh, A. D., Wong, S., Ryan, C. P., Whyard, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oral+delivery+of+double-stranded+RNA+in+larvae+of+the+yellow+fever+mosquito,+Aedes+aegypti:+implications+for+pest+mosquito+control.">Oral delivery of double-stranded RNA in larvae of the yellow fever mosquito, Aedes aegypti: implications for pest mosquito control.</a> Journal of insect science. 13, 69 (2013).</li><li>Ward, T. W., 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+aegypti+transducing+densovirus+pathogenesis+and+expression+in+Aedes+aegypti+and+Anopheles+gambiae+larvae.">Aedes aegypti transducing densovirus pathogenesis and expression in Aedes aegypti and Anopheles gambiae larvae.</a> Insect molecular biology. 10, 397-405 (2001).</li><li>Carlson, J., Suchman, E., Buchatsky, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Densoviruses+for+control+and+genetic+manipulation+of+mosquitoes.">Densoviruses for control and genetic manipulation of mosquitoes.</a> Advances in virus research. 68, 361-392 (2006).</li><li>Barreau, C., Jousset, F. X., Bergoin, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathogenicity+of+the+Aedes+albopictus+parvovirus+(AaPV),+a+denso-like+virus,+for+Aedes+aegypti+mosquitoes.">Pathogenicity of the Aedes albopictus parvovirus (AaPV), a denso-like virus, for Aedes aegypti mosquitoes.</a> Journal of invertebrate pathology. 68, 299-309 (1996).</li><li>Liu, P., 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=Development+of+non-defective+recombinant+densovirus+vectors+for+microRNA+delivery+in+the+invasive+vector+mosquito,+Aedes+albopictus.">Development of non-defective recombinant densovirus vectors for microRNA delivery in the invasive vector mosquito, Aedes albopictus.</a> Scientific reports. 6, 20979 (2016).</li><li>Ortega, M. M., Bouamar, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Guidelines+on+Designing+MicroRNA+Sponges:+From+Construction+to+Stable+Cell+Line.">Guidelines on Designing MicroRNA Sponges: From Construction to Stable Cell Line.</a> Methods in molecular biology. 1509, 221-233 (2017).</li><li>Froger, A., Hall, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transformation+of+plasmid+DNA+into+E.+coli+using+the+heat+shock+method.">Transformation of plasmid DNA into E. coli using the heat shock method.</a> Journal of visualized experiments : JoVE. , e253 (2007).</li><li>Afanasiev, B. N., Kozlov, Y. V., Carlson, J. O., Beaty, 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=Densovirus+of+Aedes+aegypti+as+an+expression+vector+in+mosquito+cells.">Densovirus of Aedes aegypti as an expression vector in mosquito cells.</a> Experimental parasitology. 79, 322-339 (1994).</li><li>Hu, H. 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=Evolution+of+the+human-specific+microRNA+miR-941.">Evolution of the human-specific microRNA miR-941.</a> Nature communications. 3, 1145 (2012).</li><li>Sanger, F., Nicklen, S., Coulson, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA+sequencing+with+chain-terminating+inhibitors.">DNA sequencing with chain-terminating inhibitors.</a> Proceedings of the National Academy of Sciences of the United States of America. 74, 5463-5467 (1977).</li><li>Dalby, B., 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=Advanced+transfection+with+Lipofectamine+2000+reagent:+primary+neurons,+siRNA,+and+high-throughput+applications.">Advanced transfection with Lipofectamine 2000 reagent: primary neurons, siRNA, and high-throughput applications.</a> Methods (San Diego, Calif). 33, 95-103 (2004).</li><li>Gu, J. B., Dong, Y. Q., Peng, H. J., Chen, X. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+recombinant+AeDNA+containing+the+insect-specific+toxin,+BmK+IT1,+displayed+an+increasing+pathogenicity+on+Aedes+albopictus.">A recombinant AeDNA containing the insect-specific toxin, BmK IT1, displayed an increasing pathogenicity on Aedes albopictus.</a> The American journal of tropical medicine and hygiene. 83, 614-623 (2010).</li><li>Hou, Y., Zhang, H., Miranda, L., Lin, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serious+overestimation+in+quantitative+PCR+by+circular+(supercoiled)+plasmid+standard:+microalgal+pcna+as+the+model+gene.">Serious overestimation in quantitative PCR by circular (supercoiled) plasmid standard: microalgal pcna as the model gene.</a> PloS one. 5, 9545 (2010).</li><li>Ding, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+rAAV9+to+Overexpress+or+Knockdown+Genes+in+Mouse+Hearts.">Preparation of rAAV9 to Overexpress or Knockdown Genes in Mouse Hearts.</a> Journal of visualized experiments : JoVE. , (2016).</li></ol>

It is important to overcome two of the key barriers that limit rAaeDV construction. The first is the production of defective recombinant virus. It has been reported that MDV can be used as a vector to express appropriately sized foreign genes, such as scorpion insect-specific neurotoxins20 and the GFP protein; however, regardless of the construction strategy, once the ORFs of MDV are inserted or replaced with exogenous genes, virions cannot form independently unless a helper plasmid is cotransfected to supply the missing...

Mosquito-borne diseases such as malaria, dengue fever, zika fever, and yellow fever, are major international public health problems that continue to account for a significant fraction of the global infectious disease burden1,2. Conventional insecticides, which have been used in response to vectors, are a major component of sustainable integrated mosquito control strategy for the prevention of mosquito-borne diseases. However, such strategies have proven to be relatively ineffective or undesirable due to the associated negative environmental impacts as well as the evolution of resistance in mosquito populations3,4. For these reasons, there is an urgent need for alternative methods of mosquito control, and the use of transgenic methods to produce sterile male mosquitoes and the release of pathogen-resistant mosquitoes have arisen as promising new control strategies. To develop effective new control methods, such as safe and effective approaches for in vivo gene delivery, the comprehensive analysis of mosquito gene function is required.
Direct microinjection of plasmid DNA, double stranded RNA (dsRNA) or small interfering RNA (siRNA) is the most commonly used in vivo gene delivery method in mosquitoes. In fact, the production of transgenic strains of mosquitoes still rely on a process of embryo microinjection5,6,7. However, microinjection has several limitations.First, this technique is technically demanding and involves complicated procedures. Second, injection causes a physical insult to the embryo, larvae, pupae, and adult, which directly affects the viability of the target organism. Third, it is difficult to immobilize mosquito larvae for microinjection because most live in an aquatic habitat and possess a characteristic wriggling movement. Fourth, the size of 1st-2nd instar larvae is 10- to 20-fold smaller than that of 4th instar and older larvae, and the cuticles of the former are more delicate. These features make it difficult to manipulate 1st-2nd instar larvae compared to those in older stages. Combined, these factors contribute to a reduced post-injection survival rate for larvae (approximately 5%) compared to adults8. Viral-based delivery systems have been developed to overcome the associated extracellular and intracellular barriers. These systems have the advantages of easy manipulation, high transduction efficiency, long-term and robust levels of expression, and the ability to produce persistent effects in vivo. Therefore, gene delivery systems utilizing retroviruses, lentiviruses, and adenoviruses have been widely used inmammalian cell lines and model species. The Sindbis viral expression system had been previously used to analyze the gene function in the adult mosquito; besides the biosafety concerns, however, the injection is still a necessary process for viral infection9. Although, the oral delivery by soaking larvae in the dsRNA solution has been reported previously as a feasible delivery method, it is unsuitable for small RNA function analysis10. So, effective viral delivery methods must still be developed for mosquitoes.
Mosquito densoviruses (MDVs) are part of the Densovirinae subfamily of Parvoviridae, and all but one fall within the genus Brevidensovirus11. MDV virions are non-enveloped and consist of a single-stranded DNA (ssDNA) genome and an icosahedral capsid (20 nm in diameter). The viral genome is approximately 4 kb in size and is replicated within the nuclei of host cells. MDVs are relatively stable in the environment and show a narrow host range with high specificity for mosquitoes. These viruses have the potential to spread and persist naturally in mosquito populations and can invade almost all organs and tissues of these insects, including the midgut, Malpighian tubules, fat body, musculature, neurons, and salivary glands12.
Intact MDV genomes can be subcloned into plasmid vectors to produce plasmid-based infectious clones; when these clones are delivered into mosquito cells, the viral genome is extracted from the plasmid vector, and infectious viral particles are produced. Because MDV has a small ssDNA genome, infectious clones are easily constructed and the viral genome can be easily manipulated11,13. These characteristics make MDV a valuable agent for examining mosquito biology. However, because nearly all of the viral genome sequence is essential for viral proliferation, the creation of recombinant virus through the replacement or insertion of foreign genes causes a loss in viral packaging and/or replication abilities, which creates a barrier for the development of MDVs as gene delivery vectors. Herein, we report using an artificial intronic small-RNA expression strategy to develop a non-defective rAaeDV in vivo RNA delivery system that has the advantages of easy plasmid construction and the maintenance of a functional virus that can produce stable and long-term expression in host cells without the need for wild-type virus. Additionally, this method allows for the easy transduction of larvae.
The protocols for the following steps are described in this study: 1) design of rAaeDVs encoding an intronic small-RNA expression cassette, 2) production of recombinant virus particles using the C6/36 packaging cell line, 3) quantitative analysis of cell-free rAaeDV genome copy numbers, and 4) infection of Ae. albopictus larvae by direct introduction of virus into the water body of the larval habitat. Overall, this work demonstrated that specific small RNAs or target genes can be overexpressed or knocked down in mosquito larvae using the developed MDV delivery system.

<table width="901">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="24">
			<td height="24" style="width:401px;height:24px;">Centrifuge machine</td>
			<td style="width:215px;">Thermo Scientific</td>
			<td style="width:119px;">75004260</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">Centrifuge System</td>
			<td style="width:215px;">Beckman Coulter</td>
			<td style="width:119px;">363118</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">GeneJET Gel Extraction Kit</td>
			<td style="width:215px;">Thermo Scientific</td>
			<td style="width:119px;">K0691</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">E.Z.N.A. Plasmid Midi Kit</td>
			<td style="width:215px;">Omega Biotech</td>
			<td style="width:119px;">D6904</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">Purified Agar</td>
			<td style="width:215px;">OXOID</td>
			<td style="width:119px;">LP0028A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">FastAP Thermosensitive Alkaline Phosphatase (1 U/&#181;L)</td>
			<td style="width:215px;">Thermo Scientific</td>
			<td style="width:119px;">EF0651</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">FastDigest HpaI</td>
			<td style="width:215px;">Thermo Scientific</td>
			<td style="width:119px;">FD1034</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">FastDigest XbaI</td>
			<td style="width:215px;">Thermo Scientific</td>
			<td style="width:119px;">FD0684</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">T4 DNA Ligase (5 U/&#181;L)</td>
			<td style="width:215px;">Thermo Scientific</td>
			<td style="width:119px;">EL0011</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">TransStbl3 Chemically Competent Cell</td>
			<td style="width:215px;">Beijing Transgen Biotech</td>
			<td style="width:119px;">CD521-01</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">Ampicillin&#160;</td>
			<td style="width:215px;">Beijing Tiangen Biotech</td>
			<td style="width:119px;">RT501</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">Roswell Park Memorial Institute (RPMI) 1640 medium</td>
			<td style="width:215px;">Gibco&#65292; Life Technologies</td>
			<td style="width:119px;">&#160;21875109</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">Fetal Bovine Serum&#65288; Australia Origin&#65289;</td>
			<td style="width:215px;">Gibco&#65292; Life Technologies</td>
			<td style="width:119px;">10099141</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">penicillin/streptomycin</td>
			<td style="width:215px;">Gibco&#65292; Life Technologies</td>
			<td style="width:119px;">15070063</td>
			<td></td>
		</tr>
		<tr height="23">
			<td height="23" style="width:401px;height:23px;">Lipofectamine 2000 Transfection Reagent</td>
			<td style="width:215px;">&#160;Invitrogen&#65292;Life Technologies</td>
			<td style="width:119px;">11668019</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">Proteinase K</td>
			<td style="width:215px;">Promega</td>
			<td>MC5008</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">DNase I (RNase-free)</td>
			<td style="width:215px;">&#160;Invitrogen&#65292;Life Technologies</td>
			<td style="width:119px;">AM2222</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:401px;height:21px;">SuperReal PreMix Plus (SYBR Green)</td>
			<td style="width:215px;">Beijing Tiangen Biotech</td>
			<td style="width:119px;">FP205</td>
			<td></td>
		</tr>
	</tbody>
</table>

use of a recombinant mosquito densovirus as a gene delivery vector for the functional analysis of genes in mosquito larvae

In vivo microinjection is the most commonly used gene transfer technique for analyzing the gene functions in individual mosquitoes. However, this method requires a more technically demanding operation and involves complicated procedures, especially when used in larvae due to their small size, relatively thin and fragile cuticle, and high mortality, which limit its application. In contrast, viral vectors for gene delivery have been developed to surmount extracellular and intracellular barriers. These systems have the advantages of easy manipulation, high gene transduction efficiency, long-term maintenance of gene expression, and the ability to produce persistent effects in vivo. Mosquito densoviruses (MDVs) are mosquito-specific, small single-stranded DNA viruses that can effectively deliver foreign nucleic acids into mosquito cells; however, the replacement or insertion of foreign genes to create recombinant viruses typically causes a loss of packaging and/or replication abilities, which is a barrier to the development of these viruses as delivery vectors.
Herein, we report using an artificial intronic small-RNA expression strategy to develop a non-defective recombinant Aedes aegypti densovirus (AaeDV) in vivo delivery system. Detailed procedures for the construction, packaging and quantitative analysis of the rAaeDV vectors, and for larval infection are described.
This study demonstrates, for the first time, the feasibility of developing a non-defective recombinant MDV micro RNA (miRNA) expression system, and thus providing a powerful tool for the functional analysis of genes in mosquito and establishing a basis for the application of viral paratransgenesis for controlling mosquito-borne diseases. We demonstrated that Aedes albopictus 1st instar larvae could be easily and effectively infected by introducing the virus into the water body of the larvae breeding site and that the developed rAaeDVs could be used to overexpress or knock down the expression of a specific target gene in larvae, providing a tool for the functional analysis of mosquito genes.

Strategies for rAaeDV construction&#160; 
A defective rAaeDV vector was generated to express the DsRed gene in mosquito larvae. The resulting plasmid contained a NS1-DsRed fusion protein cassette with the VP protein deleted (Figure 1A). rAaeDV plasmids containing expression constructs for miRNA, miRNA sponge, shRNA and amiRNA were designed (shown in Figure 1B). For example, ...

Watch this Scientific Journal Video about Use of a Recombinant Mosquito Densovirus As a Gene Delivery Vector for the Functional Analysis of Genes in Mosquito Larvae at JoVE.com

Use of a Recombinant Mosquito Densovirus As a Gene Delivery Vector for the Functional Analysis of Genes in Mosquito Larvae

We report using an artificial intronic small RNA expression strategy to develop a non-defective recombinant Aedes aegypti densovirus (AaeDV) in vivo delivery system. A detailed procedure for the construction, packaging, and quantitative analysis of the rAaeDV vectors as well as for larval infection is described.

In vivo microinjection is the most commonly used gene transfer technique for analyzing the gene functions in individual mosquitoes. However, this method ...

Research

JoVE Journal

Developmental Biology

Differentiation of a Human Neural Stem Cell Line on Three Dimensional Cultures, Analysis of MicroRNA and Putative Target Genes

Neural stem cells (NSCs) are capable of self-renewal and differentiation into neurons, astrocytes and oligodendrocytes under specific local ...

Mosaic Zebrafish Transgenesis for Functional Genomic Analysis of Candidate Cooperative Genes in Tumor Pathogenesis

Comprehensive genomic analysis has uncovered surprisingly large numbers of genetic alterations in various types of cancers.  To robustly and efficiently ...

Capturing Tissue Repair in Zebrafish Larvae with Time-lapse Brightfield Stereomicroscopy

The zebrafish larval tail fin is ideal for studying tissue regeneration due to the simple architecture of the larval fin-fold, which comprises of two ...

Analysis of Zebrafish Larvae Skeletal Muscle Integrity with Evans Blue Dye

The zebrafish model is an emerging system for the study of neuromuscular disorders.  In the study of neuromuscular diseases, the integrity of the muscle ...

Methods to Examine the Lymph Gland and Hemocytes in Drosophila Larvae

Methods to Examine the Lymph Gland and Hemocytes in Drosophila Larvae

Many parallels exist between the Drosophila and mammalian hematopoietic systems, even though Drosophila lack the lymphoid lineage that characterize ...

Rapid Isolation of BMPR-IB+ Adipose-Derived Stromal Cells for Use in a Calvarial Defect Healing Model

Invasive cancers, major injuries, and infection can cause bone defects that are too large to be reconstructed with preexisting bone from the patient's own ...

Hypoxic Preconditioning of Marrow-derived Progenitor Cells As a Source for the Generation of Mature Schwann Cells

This manuscript describes a means to enrich for neural progenitors from the marrow stromal cell (MSC) population and thereafter to direct them to the ...

A Method for Characterizing Embryogenesis in Arabidopsis

A Method for Characterizing Embryogenesis in Arabidopsis

Given the highly predictable nature of their development, Arabidopsis embryos have been used as a model for studies of morphogenesis in plants. However, ...

A Novel Use of Three-dimensional High-frequency Ultrasonography for Early Pregnancy Characterization in the Mouse

High-frequency ultrasonography (HFUS) is a common method to non-invasively monitor the real-time development of the human fetus in utero. The mouse is ...

Generation of Scaffold-free, Three-dimensional Insulin Expressing Pancreatoids from Mouse Pancreatic Progenitors In Vitro

Generation of Scaffold-free, Three-dimensional Insulin Expressing Pancreatoids from Mouse Pancreatic Progenitors In Vitro

The pancreas is a complex organ composed of many different cell types that work together to regulate blood glucose homeostasis and digestion. These cell ...