Funding: this work was supported by the National Science Foundation of China (32270538), the National Key R&#38;D Program of China (2022YFF0710603), the Natural Science Foundation of Beijing (6222046), and the CAS strategic funding via the CAS-CSIRO funding scheme (152111KYSB20210011) awarded to G.H.W. Author contributions: all authors developed the scope and focus of the review and contributed to the writing of the manuscript.

1. Preparation of germ-free&#160;Nasonia rearing medium
<ol>
	<li>Place the commercially available L. sericata pupae (see Table of Materials) on a surface that can accommodate all the pupae, such as a tray or a sheet of paper. Discard any underdeveloped larvae, dark old pupae, empty pupal shells, sawdust, or other impurities. Keep only young pupae that are brownish-red in color and transfer them to a beaker (approximately 3,000-4,000 pupae). 
	NOTE: After conducting many experiments, it was found that the medium made from the dark old pupae easily turned dark and stopped the development of germ-free wasps. This phenomenon did not occur when using the young brownish-red pupae to produce medium. The reason for this is still unclear and requires further investigation to verify it.</li>
	<li>Add enough deionized water to the beaker to cover the entire surface of the pupae. Wrap the mouth of the beaker with tinfoil or gauze, shake the beaker to clean the impurities on the surface of the pupae, and then pour out the water. Repeat three to five times.</li>
	<li>Place the cleaned L. sericata pupae in the filter tank of a garlic press, squeeze hard, and collect the tissue fluid of the L. sericata pupae in a 50 mL sterile centrifuge tube. Then, pour out the pupa dregs and put new pupae in the filter tank of the garlic press until all are squeezed. 
	NOTE: Compared to the needle extrusion device used by Wang et al.14, the garlic press is more convenient and can separate the interstitial fluid more thoroughly. This advancement lays the foundation for large-scale production and long-term storage of NRM.</li>
	<li>Centrifuge the mixture at 4 &#176;C (25,000 x g) for 10 min. After centrifugation, the mixture will be separated into three layers from bottom to top: sediment layer, protein layer, and fat layer (Figure 1).</li>
	<li>To prevent clogging during filtration, aspirate the protein layer using a 18&#160;G sterile needle and transfer it to a new 50 mL conical sterile polypropylene centrifuge tube.</li>
	<li>Add commercial liquid Drosophila medium (see Table of Materials) to the protein extract at a 1:1 ratio. 
	NOTE: More convenient commercialized L. sericata was used as the host and NRM raw material, compared with NRMv3. Therefore, the nutritional ratio was adjusted from 1:2 to 1:1 based on NRMv3, which was more suitable for the growth and development of sterile Nasonia (Figure 2).</li>
	<li>Filter the mixed medium (Drosophila medium and protein extract of L. sericata pupa) using a vacuum filtration system with different pore sizes (8, 1.2, 0.8, and 0.45 &#181;m; see Table of Materials) to remove particles of different sizes. To prevent clogging, change the filter paper when the flow slows down. 
	NOTE: The use of a new 50 mL sterile centrifuge tube is required for each filtration.</li>
	<li>Centrifuge the liquid again at 4 &#176;C (15,000 x g) for 10 min and sterilize the supernatant medium through a 0.22 &#181;m syringe filter. Repeat the above steps once.</li>
	<li>Store the culture medium at -20 &#176;C after aliquoting (Figure 3A) for long-term storage. 
	&#8203;NOTE: To prevent contamination and repeated freezing and thawing, it is recommended to open each tube of NRM only once when using the culture medium after packaging (Figure 3A).</li>
</ol>
2. Germ-free egg collection
<ol>
	<li>To ensure a stable male-to-female ratio in offspring, place the pupae in a Drosophila vial during the pupal stage at a ratio of 50 females to 15 males because of their haploid genetic characteristics (males develop from haploid cells, while females develop from diploid cells that result from fertilized eggs)4,15.
	<ol>
		<li>After emerging to adults, allow the males and females to mate for 1.5 days, and then put about 40 L. sericata pupae into the vial. Within 12-24 h after parasitization, use a sterile dissecting needle to carefully open one end of the pupal shell under a stereomicroscope (Figure 4).</li>
		<li>Hold the other end by hand and find the wasp embryos. Use a dissecting needle to transfer embryos from the surface of the L. sericata pupa tissue to a sterile cell strainer with phosphate-buffered saline (PBS)14. 
		NOTE: Older L. sericata pupae should be used for parasitism because the dry L. sericata pupa tissue is easier to transfer embryos. In order to ensure the smooth transfer of eggs from the L. sericata pupa tissue surface, try to be careful not to puncture the tissue when the dissecting needle opens the pupal case so that the interstitial fluid does not flow out.</li>
	</ol>
	</li>
	<li>Place 20-30 embryos on a cell strainer and wash them evenly with 1,000 &#181;L of 10% commercial sodium hypochlorite solution (see Table of Materials), followed by another wash with 1,000 &#181;L of 1x sterile PBS. Then, wash once with 1,000 &#181;L of 70% ethanol solution and wash three times with 1,000 &#181;L of 1x sterile PBS.</li>
	<li>First, place a 5 mm diameter polypropylene mesh sheet (see Table of Materials) that has been pre-wetted with 1x PBS into a 24-well plate. Then, using a sterilized small brush, gently brush the wasp embryos on the cell strainer onto the polypropylene mesh sheet. This can be done for all four wells in a vertical column of the 24-well plate.</li>
</ol>
3. Germ-free wasp rearing
<ol>
	<li>Add 50 &#181;L of NRM to each well in a laminar flow hood. To maintain a humid environment for growth, add 1 mL of sterile water between each well in the 24-well plate. A small beaker containing 30 mL of sterile water can also be placed in the 5 L sterile plastic box with the 24-well plate.
	<ol>
		<li>Throughout the entire experiment, keep the sterile plastic box and the 24-well plate in a climate chamber at a constant temperature of 25 &#177; 2 &#176;C and under constant light.</li>
	</ol>
	</li>
	<li>Before transferring and adding NRM every day, thaw the frozen NRM on a laminar flow bench. In a sterile environment, use alcohol-disinfected tweezers to transfer the polypropylene mesh with larvae on it from one well to another. Lastly, add 50 &#181;L of NRM that has been equilibrated to room temperature (Figure 3B). Repeat the above operations every day until pupae are observed. 
	NOTE: With the development of wasps, the amount of NRM should be increased appropriately to ensure that the germ-free wasps have sufficient nutrition. For example, the fourth instar larvae were supplied with 60 to 70 &#181;L of NRM. Since different developmental stages may coexist in the same well, use a sterilized brush to transfer out the pupae. Add a small amount of NRM to the remaining larvae. Use aseptic techniques to avoid microbial invasion and pollution.</li>
	<li>After feeding for 9 to 11 days, more than 80% of the larvae develop into white or yellow pupae. At this time, move the filter to a clean well plate and stop adding culture medium to wait for eclosion.</li>
</ol>

Rearing Germ-Free Nasonia Wasps

<ol>
	<li>Diviccaro, 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=Exploring+the+impact+of+the+microbiome+on+neuroactive+steroid+levels+in+germ-free+animals.">Exploring the impact of the microbiome on neuroactive steroid levels in germ-free animals.</a> International Journal of Molecular Sciences. 22 (22), 12551 (2021).</li><li>Pang, X., 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=Inter-species+transplantation+of+gut+microbiota+from+human+to+pigs.">Inter-species transplantation of gut microbiota from human to pigs.</a> The ISME Journal. 1 (2), 156-162 (2007).</li><li>Uzbay, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Germ-free+animal+experiments+in+the+gut+microbiota+studies.">Germ-free animal experiments in the gut microbiota studies.</a> Current Opinion in Pharmacology. 49, 6-10 (2019).</li><li>Zhu, Z., Liu, Y., Hu, H., Wang, G. -. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nasonia-microbiome+associations:+a+model+for+evolutionary+hologenomics+research.">Nasonia-microbiome associations: a model for evolutionary hologenomics research.</a> Trends in Parasitology. 39 (2), 101-112 (2022).</li><li>Li, J., Wei, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Establishment+of+an+efficient+germ-free+animal+system+to+support+functional+microbiome+research.">Establishment of an efficient germ-free animal system to support functional microbiome research.</a> Science China Life Sciences. 62 (10), 1400-1403 (2019).</li><li>Wang, G. H., 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=Changes+in+microbiome+confer+multigenerational+host+resistance+after+sub-toxic+pesticide+exposure.">Changes in microbiome confer multigenerational host resistance after sub-toxic pesticide exposure.</a> Cell Host Microbe. 27 (2), 213-224 (2020).</li><li>Wang, G. H., Dittmer, J., Douglas, B., Huang, L., Brucker, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coadaptation+between+host+genome+and+microbiome+under+long-term+xenobiotic-induced+selection.">Coadaptation between host genome and microbiome under long-term xenobiotic-induced selection.</a> Science Advances. 7 (19), (2021).</li><li>Dittmer, J., Brucker, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=When+your+host+shuts+down:+larval+diapause+impacts+host-microbiome+interactions+in+Nasonia+vitripennis.">When your host shuts down: larval diapause impacts host-microbiome interactions in Nasonia vitripennis.</a> Microbiome. 9 (1), 85 (2021).</li><li>Dittmer, 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=Disentangling+a+holobiont-recent+advances+and+perspectives+in+Nasonia+wasps.">Disentangling a holobiont-recent advances and perspectives in Nasonia wasps.</a> Frontiers in Microbiology. 7, 1478 (2016).</li><li>Brooks, A. W., Kohl, K. D., Brucker, R. M., van Opstal, E. J., Bordenstein, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phylosymbiosis:+relationships+and+functional+effects+of+microbial+communities+across+host+evolutionary+history.">Phylosymbiosis: relationships and functional effects of microbial communities across host evolutionary history.</a> PLoS Biology. 14 (11), e2000225 (2016).</li><li>Heavner, 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=Partial+venom+gland+transcriptome+of+a+Drosophila+parasitoid+wasp,+Leptopilina+heterotoma,+reveals+novel+and+shared+bioactive+profiles+with+stinging+Hymenoptera.">Partial venom gland transcriptome of a Drosophila parasitoid wasp, Leptopilina heterotoma, reveals novel and shared bioactive profiles with stinging Hymenoptera.</a> Gene. 526 (2), 195-204 (2013).</li><li>Brucker, R. M., Bordenstein, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+cultivation+of+the+hymenoptera+genetic+model,+Nasonia.">In vitro cultivation of the hymenoptera genetic model, Nasonia.</a> PLoS One. 7 (12), e51269 (2012).</li><li>Shropshire, J. D., van Opstal, E. J., Bordenstein, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+optimized+approach+to+germ-free+rearing+in+the+jewel+wasp+Nasonia.">An optimized approach to germ-free rearing in the jewel wasp Nasonia.</a> PeerJ. 4, e2316 (2016).</li><li>Wang, G. H., Brucker, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+optimized+method+for+Nasonia+germ-free+rearing.">An optimized method for Nasonia germ-free rearing.</a> Scientific Reports. 12 (1), 219 (2022).</li><li>Brucker, R. M., Bordenstein, S. 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+hologenomic+basis+of+speciation:+gut+bacteria+cause+hybrid+lethality+in+the+genus+Nasonia.">The hologenomic basis of speciation: gut bacteria cause hybrid lethality in the genus Nasonia.</a> Science. 341 (6146), 667-669 (2013).</li><li>Fontaine, C. 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=How+free+of+germs+is+germ-free?+Detection+of+bacterial+contamination+in+a+germ+free+mouse+unit.">How free of germs is germ-free? Detection of bacterial contamination in a germ free mouse unit.</a> Gut Microbes. 6 (4), 225-233 (2015).</li><li>Mazmanian, S. K., Liu, C. H., Tzianabos, A. O., Kasper, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+immunomodulatory+molecule+of+symbiotic+bacteria+directs+maturation+of+the+host+immune+system.">An immunomodulatory molecule of symbiotic bacteria directs maturation of the host immune system.</a> Cell. 122 (1), 107-118 (2005).</li><li>Weersma, R. K., Zhernakova, A., Fu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interaction+between+drugs+and+the+gut+microbiome.">Interaction between drugs and the gut microbiome.</a> Gut. 69 (8), 1510-1519 (2020).</li></ol>

The authors have nothing to disclose.

With the application of high-throughput detection technologies such as genomics and metabolomics, researchers have gradually realized that there is huge genetic diversity and metabolic complexity in the gut microbiota16. These symbiotic bacteria are closely related to various physiological or pathological states, such as host nutritional metabolism, tumors, immunity, and aging through complex interactions with the host17. However, the research related to the network of the ...

Germ-free animals are animals that have no detectable living microorganisms and parasites1. Germ-free embryos can be obtained by dissecting the mother under aseptic conditions and subsequently raised in barrier systems2. Such animals can be used to study the effects of microorganisms on animals, such as on the intestinal microbiota, immune system, and metabolism1. With certain technical means, many insects and even mammals can be rendered sterile3,4. Germ-free animals have a unique role and have been widely used in various aspects of microbiology research5. For example, the use of germ-free Nasonia wasps has revealed that microorganisms can help hosts adapt to new environments under long-term exogenous environmental stress6,7.
Nasonia parasitoids are small parasitic wasps that inject their eggs into the pupae of flies4. There are four known species of Nasonia, including Nasonia vitripennis, Nasonia longicornis, Nasonia giraulti, and Nasonia oneida8. N. vitripennis can be found worldwide, while the other three species have limited ranges in North America4. Nasonia parasitoid wasps are regarded as ideal model insects because of their characteristics, such as easy cultivation, short reproduction cycle, sequenced genome, and long term diapause8,9. They can be used to study various aspects of insect evolution, genetics, development, behavior, and symbiosis10. Moreover, Nasonia parasitoid wasps can also help control harmful flies in agriculture and disease11. The successful establishment of a sterile insect system involves two major steps: (1) sterilization of the embryos and (2) provision of sterile food to the larvae in vitro. In order to obtain sterile food, Brucker and Bordenstein12 developed Nasonia rearing medium (NRMv1) in 2012 by using chemicals such as antibiotics, bleach, and fetal bovine serum to kill bacteria12. However, the chemical sterilization method resulted in low survival and eclosion rates of N. vitripennis13. Then, in 2016, Shropshire et al. developed NRMv2 by using a filter sterilization method instead of a chemical sterilization method to eliminate the hazards of antibiotics and other substances, and optimized the breeding process13. Unfortunately, this method still has some disadvantages, such as the challenges associated with preparing and using the medium, as well as the risks of drowning, underfeeding, or dehydration for the embryos, larvae, and closed pupae14. Wang and Brucker14 recently improved the Nasonia rearing media version 3 (NRMv3) and the germ-free rearing version 2 (GFRv2) protocols. These improvements reduced the cost and media consumption. However, the NRMv3 has a very short storage time and is highly susceptible to contamination.
Building on NRMv3, the NRM preparation tool storage method and nutrient ratio were optimized in this study. This methodological refinement facilitates using N. vitripennis as a model for microbiome studies. Compared with the NRMv3 developed by Wang et al.14, the improved tool for squeezing Sarcophaga bullata pupa, one of the NRM raw materials, greatly enhances the production efficiency of S. bullata pupa tissue fluid compared with the 60 mL syringe with a bottom hole used by Wang et al.14. We adjusted the nutrient ratio of NRM, which led to a certain increase in the survival rate of germ-free Nasonia wasps without affecting their development time. In addition, the NRM was packed into small-capacity centrifuge tubes (1.5 mL) and frozen in a -20 &#176;C refrigerator to extend the storage time. It is worth noting that while we used the housefly Lucilia sericata as the host and source for NRM preparation, this protocol can likely be adapted for other Nasonia hosts that are available in the laboratory.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.22 Sterile vacuum filter</td>
			<td>NEST</td>
			<td>331011</td>
			<td></td>
		</tr>
		<tr>
			<td>10% SodiumHypochlorite</td>
			<td>LIRCON</td>
			<td>XB-84BS-1</td>
			<td></td>
		</tr>
		<tr>
			<td>1x PBS solution</td>
			<td>Solarbio</td>
			<td>P1020</td>
			<td></td>
		</tr>
		<tr>
			<td>200 mesh nylon net</td>
			<td>BIOBYING</td>
			<td>BY-378Z</td>
			<td></td>
		</tr>
		<tr>
			<td>24&#160;well-plate</td>
			<td>NEST</td>
			<td>702001</td>
			<td></td>
		</tr>
		<tr>
			<td>8, 1.2, 0.8, and 0.45 &#181;m filters</td>
			<td>Shanghai Xingya Purification Material Factory</td>
			<td>HN-AA-JT-10079</td>
			<td></td>
		</tr>
		<tr>
			<td>Absolute ethyl alcohol</td>
			<td>Macklin</td>
			<td>E809057-500ml</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell Strainer</td>
			<td>BIOLOGIX</td>
			<td>15-1100</td>
			<td></td>
		</tr>
		<tr>
			<td>Commercial Drosophila Medium</td>
			<td>Boer</td>
			<td>B645446-500ml</td>
			<td></td>
		</tr>
		<tr>
			<td>Dissecting needle</td>
			<td>Bioroyee</td>
			<td>17-9140</td>
			<td></td>
		</tr>
		<tr>
			<td>Garlic press</td>
			<td>Taobao</td>
			<td>No Catalog numbers</td>
			<td>Purchase on Taobao</td>
		</tr>
		<tr>
			<td>Lucillia sericata pupae</td>
			<td>Hefei Dayuan Biotechnology Co., Ltd.</td>
			<td>No Catalog numbers</td>
			<td>Purchase on Taobao</td>
		</tr>
		<tr>
			<td>Small writing brush</td>
			<td>Cestidur</td>
			<td>BL0508</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereoscope</td>
			<td>SOPTOP</td>
			<td>RX50</td>
			<td></td>
		</tr>
		<tr>
			<td>Tweezers</td>
			<td>SALMART</td>
			<td>A109001-56</td>
			<td></td>
		</tr>
	</tbody>
</table>

optimizing the rearing procedure of germ-free wasps

Aseptic rearing technology is a method of culturing insects under sterile or almost sterile conditions, which can effectively eliminate the influence of external microorganisms on insect microbiota and thus promote the rapid development of insect microbiota research. Nasonia (wasp genus) is a parasitic wasp insect that has many advantages, such as a short lifespan, high genetic variation, easy operation, etc., and is widely used as an insect model system. Unlike antibiotic treatment, which can only reduce the number of microorganisms in animals, aseptic rearing techniques can control both the composition and quantity of microorganisms in animals, further facilitating the study of host-microbe interactions. However, previous versions of Nasonia rearing medium (NRM) have some defects and problems, such as a complex and time-consuming preparation process, easy contamination by bacteria or fungi, and short storage time. Therefore, this study solves these problems by optimizing the tools used in the NRM preparation process, storage conditions, and component ratios. The optimized medium could allow storage at -20 &#176;C for at least 3 months and eliminate the possibility of NRM contamination during feeding sterile wasps. This further improves the survival rate and health level of aseptic Nasonia, which is important for using Nasonia as a model for microbial research.

The preparation efficiency of NRM was greatly improved by improving the preparation tools. In addition, the problem of NRM pollution in the feeding process was eliminated by optimizing the strategy and preservation method. At the same time, the adjusted NRM had a more suitable nutritional ratio for the growth and development of germ-free wasps with L. sericata as hosts. The survival rate of germ-free wasps from larvae to pupae was significantly improved compared to germ-free wasps reared with NRMv3 using GFRv2 (...

Watch this Scientific Journal Video about Optimizing the Rearing Procedure of Germ-Free Wasps at JoVE.com

Author Spotlight: Optimizing the Rearing Procedure of Germ-Free Wasps  

Nasonia wasp embryos were dissected from Lucillia sericata pupae after parasitization for 12-24 h and washed with alcohol and 10% sodium hypochlorite solution to obtain germ-free embryos. After rearing the germ-free embryos&#160;and supplying them with Nasonia rearing medium to grow and develop in vitro, germ-free Nasonia adults were obtained.

Optimizing the Rearing Procedure of Germ-Free Wasps

Aseptic rearing technology is a method of culturing insects under sterile or almost sterile conditions, which can effectively eliminate the influence of ...

optimizing-the-rearing-procedure-of-germ-free-wasps

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2.2K Views.  Chinese Academy of Sciences. Nasonia wasp embryos were dissected from Lucillia sericata pupae after parasitization for 12-24 h and washed with alcohol and 10% sodium hypochlorite solution to obtain germ-free embryos. After rearing the germ-free embryos and supplying them with Nasonia rearing medium to grow and develop in vitro, germ-free Nasonia adults were obtained.

Video: Author Spotlight: Optimizing the Rearing Procedure of Germ-Free Wasps  

Protocol for Mosquito Rearing (A. gambiae)

This protocol describes mosquito rearing in the insectary. The insectary rooms are maintained at 28&deg;C and ~80% humidity, with a 12 hr. day/night cycle. For this procedure, you'll need mosquito cages, 10% sterile sucrose solution, paper towels, beaker, whatman filter paper, glass feeders, human blood and serum, water bath, parafilm, distilled water, clean plastic trays, mosquito food (described below), mosquito net to cover the trays, vacuum, and a collection chamber to collect adults.

Protocol for Mosquito Rearing A. gambiae

This video illustrates the general techniques used to rear Anopheles gambiae in the laboratory. The methods for caring for laboratory mosquitoes are demonstrated through all stages of the organism's life cycle from larvae to pupae to blood-feeding adults.

This protocol describes mosquito rearing in the insectary. The insectary rooms are maintained at 28&deg;C and ~80% humidity, with a 12 hr. day/night ...

Murine Renal Transplantation Procedure

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell et al over 30 years ago (1) and refined by Zhang et al years later (2), few people in the world have mastered this procedure. In our laboratory we have successfully performed 1200 orthotopic kidney transplantations with &gt; 90% survival rate. The key points for success include stringent control of reperfusion injury, bleeding and thrombosis, both during the procedure and post-transplantation, and use of 10-0 instead of 11-0 suture for anastomoses.
Post-operative care and treatment of the recipient is extremely important to transplant success and evaluation. All renal graft recipients receive antibiotics in the form of an injection of penicillin immediately post-transplant and sulfatrim in the drinking water continually. Overall animal health is evaluated daily and whole blood creatinine analyses are performed routinely with a portable I-STAT machine to assess graft function.

Renal transplantation in mice is a technically challenging procedure that requires careful post-operative care and treatment for success.

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell ...

Bioluminescence Imaging of Heme Oxygenase-1 Upregulation in the Gua Sha Procedure

Gua Sha is a traditional Chinese folk therapy that employs skin scraping to cause subcutaneous microvascular blood extravasation and bruises. The protocol for bioluminescent optical imaging of HO-1-luciferase transgenic mice reported in this manuscript provides a rapid in vivo assay of the upregulation of the heme oxygenase-1 (HO-1) gene expression in response to the Gua Sha procedure. HO-1 has long been known to provide cytoprotection against oxidative stress. The upregulation of HO-1, assessed by the bioluminescence output, is thought to represent an antioxidative response to circulating hemoglobin products released by Gua Sha. Gua Sha was administered by repeated strokes of a smooth spoon edge over lubricated skin on the back or other targeted body part of the transgenic mouse until petechiae (splinter hemorrhages) or ecchymosis (bruises) indicative of extravasation of blood from subcutaneous capillaries was observed. After Gua Sha, bioluminescence imaging sessions were carried out daily for several days to follow the dynamics of HO-1 expression in multiple internal organs.

Gua Sha, traditional Chinese therapeutic skin scraping, causes subcutaneous microvascular blood extravasation. We report a protocol of bioluminescence imaging of HO-1-luciferase transgenic mice to demonstrate that Gua Sha upregulates heme oxygenase-1 (HO-1) in multiple organs.

Gua Sha is a traditional Chinese folk therapy that employs skin scraping to cause subcutaneous microvascular blood extravasation and bruises. The protocol ...

An Optimized Protocol for Rearing Fopius arisanus, a Parasitoid of Tephritid Fruit Flies

Fopius arisanus (Sonan) is an important parasitoid of Tephritid fruit flies for at least two reasons. First, it is the one of only three opiine parasitoids known to infect the host during the egg stage1. Second, it has a wide range of potential fruit fly hosts. Perhaps due to its life history, F. arisanus has been a successfully used for biological control of fruit flies in multiple tropical regions2-4. One impediment to the wide use of F. arisanus for fruit fly control is that it is difficult to establish a stable laboratory colony5-9. Despite this difficulty, in the 1990s USDA researchers developed a reliable method to maintain laboratory populations of F. arisanus10-12. There is significant interest in F. arisanus biology13,14, especially regarding its ability to colonize a wide variety of Tephritid hosts14-17; interest is especially driven by the alarming spread of Bactrocera fruit fly pests to new continents in the last decade18. Further research on F. arisanus and additional deployments of this species as a biological control agent will benefit from optimizations and improvements of rearing methods. In this protocol and associated video article we describe an optimized method for rearing F. arisanus based on a previously described approach12. The method we describe here allows rearing of F. arisanus in a small scale without the use of fruit, using materials available in tropical regions around the world and with relatively low manual labor requirements.

An Optimized Protocol for Rearing Fopius arisanus, a Parasitoid of Tephritid Fruit Flies

Fopius arisanus is an egg-larval parasitoid of Tephritid fruit flies that is successfully used in biological control of these important tropical pests. We describe here an optimized protocol for rearing F. arisanus on a small scale using readily available materials.

Fopius arisanus (Sonan) is an important parasitoid of Tephritid fruit flies for at least two reasons. First, it is the one of only three opiine ...

Test Samples for Optimizing STORM Super-Resolution Microscopy

STORM is a recently developed super-resolution microscopy technique with up to 10 times better resolution than standard fluorescence microscopy techniques. However, as the image is acquired in a very different way than normal, by building up an image molecule-by-molecule, there are some significant challenges for users in trying to optimize their image acquisition. In order to aid this process and gain more insight into how STORM works we present the preparation of 3 test samples and the methodology of acquiring and processing STORM super-resolution images with typical resolutions of between 30-50 nm. By combining the test samples with the use of the freely available rainSTORM processing software it is possible to obtain a great deal of information about image quality and resolution. Using these metrics it is then possible to optimize the imaging procedure from the optics, to sample preparation, dye choice, buffer conditions, and image acquisition settings. We also show examples of some common problems that result in poor image quality, such as lateral drift, where the sample moves during image acquisition and density related problems resulting in the 'mislocalization' phenomenon.

We describe the preparation of three test samples and how they can be used to optimize and assess the performance of STORM microscopes. Using these examples we show how to acquire raw data and then process it to acquire super-resolution images in cells of approximately 30-50 nm resolution.

STORM is a recently developed super-resolution microscopy technique with up to 10 times better resolution than standard fluorescence microscopy ...

Procedure to Evaluate the Efficiency of Flocculants for the Removal of Dispersed Particles from Plant Extracts

Plants are important to humans not only because they provide commodities such as food, feed and raw materials, but increasingly because they can be used as manufacturing platforms for added-value products such as biopharmaceuticals. In both cases, liquid plant extracts may need to be clarified to remove particulates. Optimal clarification reduces the costs of filtration and centrifugation by increasing capacity and longevity. This can be achieved by introducing charged polymers known as flocculants, which cross-link dispersed particles to facilitate solid-liquid separation. There are no mechanistic flocculation models for complex mixtures such as plant extracts so empirical models are used instead. Here a design-of-experiments procedure is described that allows the rapid screening of different flocculants, optimizing the clarification of plant extracts and significantly reducing turbidity. The resulting predictive models allow the identification of robust process conditions and sets of polymers with complementary properties, e.g. effective flocculation in extracts with specific conductivities. The results presented for tobacco leaf extracts can easily be adapted to other plant species or tissues and will thus facilitate the development of more cost-effective downstream processes for commodities and plant-derived pharmaceuticals.

The design-of-experiments procedure presented here allows the evaluation of different flocculants in terms of their ability to aggregate dispersed particles in plant extracts, thus reducing turbidity and the costs of downstream processing.

Plants are important to humans not only because they provide commodities such as food, feed and raw materials, but increasingly because they can be used ...

Laboratory Rearing of Stable Flies and Other Muscoid Diptera

Stable flies, Stomoxys calcitrans, are serious pests of livestock, humans, companion animals and wildlife worldwide. During the last 20+ years, changes in agronomic practices resulted in serious outbreaks of stable flies in several countries. These outbreaks disrupted livestock production and human recreation resulting in public demands for increasing research and management efforts for this pest. A simple and inexpensive procedure for rearing stable flies for laboratory studies is presented. The procedure uses locally available diet components, equipment and supplies. The procedure can be adapted for rearing other muscoid flies including face fly (Musca autumnalis), horn fly (Haematobia irritans), and house fly (Musca domestica). The procedure produces stable fly puparia averaging 12.5 mg and ~35% egg to adult survival. Approximately 3000 flies are produced in each pan.

A procedure for rearing stable flies (Stomoxys calcitrans) is presented. The procedure uses locally available materials for diet components, equipment and supplies.

Stable flies, Stomoxys calcitrans, are serious pests of livestock, humans, companion animals and wildlife worldwide. During the last 20+ years, changes in ...

Preparing and Rearing Axenic Insects with Tissue Cultured Seedlings for Host-Gut Microbiota Interaction Studies of the Leaf Beetle

Insect guts are colonized by diverse bacteria that can profoundly impact the host&#39;s physiological traits. Introducing a particular bacterial strain into an axenic insect is a powerful method to verify gut microbial function and elucidate the mechanisms underlying gut microbe-host interactions. Administering antibiotics or sterilizing egg surfaces are two commonly used methods to remove gut bacteria from insects. However, in addition to the potential adverse effects of antibiotics on insects, previous studies indicated that feeding antibiotics could not eliminate gut bacteria. Thus, germ-free artificial diets are generally employed to maintain axenic insects, which is a tedious and labor-intensive process that cannot fully resemble nutritional components in natural food. Described here is an efficient and simple protocol to prepare and maintain axenic larvae of a leaf beetle&#160;(Plagiodera versicolora). Specifically, surfaces of the beetle eggs were sterilized, following which germ-free poplar leaves were used to rear axenic larvae. The axenic status of the insects was further confirmed via culture-dependent and culture-independent assays. Collectively, by combining egg disinfection and germ-free cultivation, an efficient and convenient method was developed to obtain axenic P. versicolora, providing a readily transferable tool for other leaf-eating insects.

To obtain an axenic insect, its egg surface is sterilized, and the hatched larva is subsequently reared using axenic leaves. This method provides an efficient way for axenic insect preparation without administering antibiotics or developing an artificial diet, which can also be applied to other leaf-eating insects.

Insect guts are colonized by diverse bacteria that can profoundly impact the host&#39;s physiological traits. Introducing a particular bacterial strain ...

Methods for Rearing the Parasitoid Ganaspis brasiliensis, a Promising Biological Control Agent for the Invasive Drosophila suzukii

Native to East Asia, the spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), has established widely in the Americas, Europe, and parts of Africa over the last decade, becoming a devastating pest of various soft-skinned fruits in its invaded regions. Biological control, especially by means of self-perpetuating and specialized parasitoids, is expected to be a viable option for sustainable area-wide management of this highly mobile and polyphagous pest. Ganaspis brasiliensis Ihering (Hymenoptera: Figitidae) is a larval parasitoid that is widely distributed in East Asia, and has been found to be one of the most effective parasitoids of D. suzukii.
Following rigorous pre-introduction evaluations of its efficacy and potential non-target risks, one of the more host-specific genetic groups of this species (G1 G. brasiliensis) has been approved recently for introduction and field release in the United States and Italy. Another genetic group (G3 G. brasiliensis), which was also commonly found to attack D. suzukii in East Asia, may be considered for introduction in the near future. There is currently enormous interest in rearing G. brasiliensis for research or in mass-production for field release against D. suzukii. This protocol and associated video article describe effective rearing methods for this parasitoid, both on a small scale for research and a large scale for mass-production and field release. These methods may benefit further long-term research and use of this Asian-native parasitoid as a promising biological control agent for this global invasive pest.

Methods for Rearing the Parasitoid Ganaspis brasiliensis, a Promising Biological Control Agent for the Invasive Drosophila suzukii

Ganaspis brasiliensis-a larval parasitoid of Drosophila suzukii (a global invasive fruit crop pest)-has been approved or is considered for introduction into Europe and the United States for biological control of this pest. This article provides protocols for both small-scale and large-scale rearing of this parasitoid.

Native to East Asia, the spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), has established widely in the Americas, Europe, ...

Enhancing Survival and Development of Marmosets Using a Hand-Rearing Approach

Hand-Rearing Method for Infant Marmosets

The common marmoset (Callithrix jacchus) is a small and highly social New World monkey with high reproduction rates, which has been proven to be a compelling non-human primate model for biomedical and neuroscience research. Some females give birth to triplets; however, the parents cannot raise all of them. To save these infants, we have developed a hand-rearing method for raising newborn marmosets. In this protocol, we describe the formula of the food, the time for feeding, the configuration of the temperature and humidity, as well as the adaptation of the hand-reared infants to the colony environment. This hand-rearing method significantly increases the survival rate of marmoset infants (without hand-rearing: 45%; with hand-rearing: 86%) and provides the opportunity to study the development of marmoset infants with similar genetic backgrounds raised in different postnatal environments. As the method is practical and easy to use, we anticipate that it could also be applied to other labs working with common marmosets.

Author Spotlight: Marmoset Research - Scope and Challenges 

Here, we describe a hand-rearing method for raising infant marmosets in an animal incubator. This method greatly increases the survival rate of marmoset infants, which provides the opportunity to study the development of marmoset infants with similar genetic backgrounds raised in different postnatal environments.