Name: tick artificial membrane feeding for ixodes scapularis
Uploaded: 2022-11-30T14:00:00
Description: Watch this Scientific Journal Video about Tick Artificial Membrane Feeding for Ixodes scapularis at JoVE.com

1. Preparing the tick membrane chamber
<ol>
	<li>Prepare a flat, non-porous surface such as a plane of glass or ceramic-coated metal base of an arm stand by wiping it down with 70% ethanol and then cover it with a single layer of plastic wrap, making sure that the plastic wrap is flat and without bubbles or wrinkles (see Figure 1A).</li>
	<li>Tape down 100% rayon lens cleaning paper to the prepared surface. Ensure it is flat and slightly taut with tape across all four side...

<ol>
	<li>Rosenberg, 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=Vital+signs:+trends+in+reported+vectorborne+disease+cases+-+United+States+and+territories,+2004-2016.">Vital signs: trends in reported vectorborne disease cases - United States and territories, 2004-2016.</a> Morbidity and Mortality Weekly Report. 67 (17), 496-501 (2018).</li><li>Busch, J. D., 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=Widespread+movement+of+invasive+cattle+fever+ticks+(Rhipicephalus+microplus)+in+southern+Texas+leads+to+shared+local+infestations+on+cattle+and+deer.">Widespread movement of invasive cattle fever ticks (Rhipicephalus microplus) in southern Texas leads to shared local infestations on cattle and deer.</a> Parasites &amp; Vectors. 7, 188 (2014).</li><li>S&#252;ss, J., Klaus, C., Gerstengarbe, F. W., Werner, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+makes+ticks+tick?+Climate+change,+ticks,+and+tick-borne+diseases.">What makes ticks tick? Climate change, ticks, and tick-borne diseases.</a> Journal of Travel Medicine. 15 (1), 39-45 (2008).</li><li>Gray, J. S., Dautel, H., Estrada-Pe&#241;a, A., Kahl, O., Lindgren, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+climate+change+on+ticks+and+tick-borne+diseases+in+Europe.">Effects of climate change on ticks and tick-borne diseases in Europe.</a> Interdisciplinary Perspectives on Infectious Diseases. 2009, 593232 (2009).</li><li>Sonenshine, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Biology of Ticks. , (1991).</li><li>Schwan, T. G., Piesman, J., Golde, W. T., Dolan, M. C., Rosa, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+an+outer+surface+protein+on+Borrelia+burgdorferi+during+tick+feeding.">Induction of an outer surface protein on Borrelia burgdorferi during tick feeding.</a> Proceedings of the National Academy of Sciences. 92 (7), 2909-2913 (1995).</li><li>Massung, R. F., Priestley, R. A., Miller, N. J., Mather, T. N., Levin, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inability+of+a+variant+strain+of+Anaplasma+phagocytophilum+to+infect+mice.">Inability of a variant strain of Anaplasma phagocytophilum to infect mice.</a> The Journal of Infectious Diseases. 188 (11), 1757-1763 (2003).</li><li>Koci, J., Bernard, Q., Yang, X., Pal, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Borrelia+burgdorferi+surface+protein+Lmp1+facilitates+pathogen+dissemination+through+ticks+as+studied+by+an+artificial+membrane+feeding+system.">Borrelia burgdorferi surface protein Lmp1 facilitates pathogen dissemination through ticks as studied by an artificial membrane feeding system.</a> Scientific Reports. 8 (1), 1910 (2018).</li><li>Levin, M. L., Schumacher, L. B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Manual+for+maintenance+of+multi-host+ixodid+ticks+in+the+laboratory.">Manual for maintenance of multi-host ixodid ticks in the laboratory.</a> Experimental and Applied Acarology. 70 (3), 343-367 (2016).</li><li>Hart, T., Yang, X., Pal, U., Lin, Y. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+Lyme+borreliae+proteins+promoting+vertebrate+host+blood-specific+spirochete+survival+in+Ixodes+scapularis+nymphs+using+artificial+feeding+chambers.">Identification of Lyme borreliae proteins promoting vertebrate host blood-specific spirochete survival in Ixodes scapularis nymphs using artificial feeding chambers.</a> Ticks and Tick-Borne Diseases. 9 (5), 1057-1063 (2018).</li><li>Hart, T. M., 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=Host+tropism+determination+by+convergent+evolution+of+immunological+evasion+in+the+Lyme+disease+system.">Host tropism determination by convergent evolution of immunological evasion in the Lyme disease system.</a> PLoS Pathogens. 17 (7), (2021).</li><li>Bernard, Q., 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=Plasticity+in+early+immune+evasion+strategies+of+a+bacterial+pathogen.">Plasticity in early immune evasion strategies of a bacterial pathogen.</a> Proceedings of the National Academy of Sciences. 115 (16), 3788-3797 (2018).</li><li>Pierce, A. E., Pierce, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+note+on+the+cultivation+of+Boophilus+microplus+(Canestrini,+1887)+(Ixodidae:+Acarina)+on+the+embyonated+hen+egg.">A note on the cultivation of Boophilus microplus (Canestrini, 1887) (Ixodidae: Acarina) on the embyonated hen egg.</a> Australian Veterinary Journal. 32 (6), 144-146 (1956).</li><li>Doube, B. M., Kemp, D. H. <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,+relative+humidity+and+host+factors+on+the+attachment+and+survival+of+Boophilus+microplus+(Canestrini)+larvae+to+skin+slices.">The influence of temperature, relative humidity and host factors on the attachment and survival of Boophilus microplus (Canestrini) larvae to skin slices.</a> International Journal for Parasitology. 9 (5), 449-454 (1979).</li><li>Kr&#246;ber, T., Guerin, P. 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+in+vitro+feeding+assay+to+test+acaricides+for+control+of+hard+ticks.">An in vitro feeding assay to test acaricides for control of hard ticks.</a> Pest Management Science. 63 (1), 17-22 (2007).</li><li>Kuhnert, F., Diehl, P. A., Guerin, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+life-cycle+of+the+bont+tick+Amblyomma+hebraeum+in+vitro.">The life-cycle of the bont tick Amblyomma hebraeum in vitro.</a> International Journal for Parasitology. 25 (8), 887-896 (1995).</li><li>Kr&#246;ber, T., Guerin, P. M. <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+feeding+assays+for+hard+ticks.">In vitro feeding assays for hard ticks.</a> Trends in Parasitology. 23 (9), 445-449 (2007).</li><li>Andrade, J. J., Xu, G., Rich, S. 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+silicone+membrane+for+in+vitro+feeding+of+Ixodes+scapularis+(Ixodida:+Ixodidae).">A silicone membrane for in vitro feeding of Ixodes scapularis (Ixodida: Ixodidae).</a> Journal of Medical Entomology. 51 (4), 878-879 (2014).</li><li>Oliver, J. D., 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=Infection+of+immature+Ixodes+scapularis+(Acari:+Ixodidae)+by+membrane+feeding.">Infection of immature Ixodes scapularis (Acari: Ixodidae) by membrane feeding.</a> Journal of Medical Entomology. 53 (2), 409-415 (2016).</li><li>Oliver, J. D., 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=Growth+dynamics+and+antibiotic+elimination+of+symbiotic+Rickettsia+buchneri+in+the+tick+Ixodes+scapularis+(Acari:+Ixodidae).">Growth dynamics and antibiotic elimination of symbiotic Rickettsia buchneri in the tick Ixodes scapularis (Acari: Ixodidae).</a> Applied and Environmental Microbiology. 87 (3), (2021).</li><li>Graham, E. E., Poland, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficacy+of+Fluon+conditioning+for+capturing+cerambycid+beetles+in+different+trap+designs+and+persistence+on+panel+traps+over+time.">Efficacy of Fluon conditioning for capturing cerambycid beetles in different trap designs and persistence on panel traps over time.</a> Journal of Economic Entomology. 105 (2), 395-401 (2012).</li><li>Munderloh, U. G., Liu, Y., Wang, M., Chen, C., Kurtti, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Establishment,+maintenance+and+description+of+cell+lines+from+the+tick+Ixodes+scapularis.">Establishment, maintenance and description of cell lines from the tick Ixodes scapularis.</a> Journal of Parasitology. 80 (4), 533-543 (1994).</li><li>Lehane, 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=Prevalence+of+single+and+coinfections+of+human+pathogens+in+Ixodes+ticks+from+five+geographical+regions+in+the+United+States,+2013-2019.">Prevalence of single and coinfections of human pathogens in Ixodes ticks from five geographical regions in the United States, 2013-2019.</a> Ticks and Tick-Borne Diseases. 12 (2), (2021).</li><li>Gonz&#225;lez, J., Bickerton, M., Toledo, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+artificial+membrane+feeding+for+ixodid+ticks.">Applications of artificial membrane feeding for ixodid ticks.</a> Acta Tropica. 215, (2021).</li><li>Kr&#243;l, N., 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=Evaluating+transmission+paths+for+three+different+Bartonella+spp.+in+Ixodes+ricinus+ticks+using+artificial+feeding.">Evaluating transmission paths for three different Bartonella spp. in Ixodes ricinus ticks using artificial feeding.</a> Microorganisms. 9 (5), 901 (2021).</li><li>Anderson, J. F., Magnarelli, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biology+of+ticks.">Biology of ticks.</a> Infectious Disease Clinics of North America. 22 (2), 195-215 (2008).</li></ol>

Artificial membrane feeding of ticks provides a useful tool for a variety of experimental procedures, but is not likely to replace animal feeding for all applications. Maintaining large colonies of ticks at all life stages without animal feeding is generally untenable. Instead, the artificial feeding system is valuable for other purposes such as infecting ticks with pathogens not supported by model hosts, evaluating the impacts of controlled dosages of compounds or microorganisms on the ticks in a simplified feeding envi...

Tick-borne diseases strongly impact the health of humans and animals across the world, being responsible for more than two-thirds of all vector-associated illness in the USA from 2004 to 20161. Additionally, case numbers have been growing in recent years, with more people and livestock being affected by ticks and their associated diseases2,3. While there are likely numerous causes for the upward trend in case numbers, the changing climate is an important factor3,4. The predicted ongoing increase in the number of tick-borne disease cases underlines the need to develop new tools to investigate the relationships between ticks and the pathogens they transmit.
It is known that ticks undergo changes in physiology and gene expression during feeding and that these changes play a role in pathogen transmission5,6. It may be difficult to perform studies that examine the effects of full and partial feeding on pathogen transmission and acquisition using animal models, particularly in situations where rodent models are not susceptible to infection by a particular pathogen. For example, Anaplasma phagocytophilum Variant-1 strain is naturally transmitted between Ixodes scapularis and deer but is unable to infect mice, complicating tick infection in the lab7. Artificial feeding systems can also be applied to help study pathogens such as Borrelia burgdorferi via the use of transgenic mutants that have gene deletions that inhibit transmission or infection8. Using an artificial feeding system helps researchers isolate the genes&#39; role by allowing infection or transmission to only occur on the tick&#39;s side, thereby isolating any host response that may confound such studies.
Similarly, some life stages of ticks involved in disease and animal transmission may not be induced to feed on common laboratory model species. Ixodes scapularis females, for example, must be fed on larger animals, typically rabbits9. While often accessible for laboratory experimentation, the administrative and husbandry requirements of using rabbits exceeds those of small rodents and may be prohibitive for some laboratories. Other tick species, particularly those of veterinary concern, must be fed on cattle or other large animals that are not practical to use in most laboratories. In vitro feeding and infection methods, such as artificial membrane feeding, provide alternatives to using large or exotic host animals.
Additionally, the use of an artificial feeding system allows certain analyses that may not be possible with traditional animal feeding methods. One such example is that, by separating the blood source from the feeding mechanism, examination of the role that different hosts&#39; blood may have in B. burgdorferi transmission becomes possible10. This examination of host blood and the role blood itself plays in the absence of the host immune response is an important factor in being able to understand pathogen transmission cycles and one that artificial feeding systems are able to help answer11. It also becomes possible to quantify the exact transmission numbers of a pathogen during a feed rather than just examining transmission success and establishment in a host8,12.
Some of the first artificial feeding membranes made for hard ticks were made out of animal skins or animal-derived membranes in the 1950s and 1960s13,14. Due to the biological nature of these membranes, there were problems with both the production of new membranes and shelf life. In the 1990s, fully artificial membranes were developed that utilized a backing of netting, paper, or fabric with silicone impregnation15,16. Silicone was ideal as its physical properties mimic skin&#39;s stretchiness and slight tackiness, along with its bio-inherent nature. Building on this, Krober and Guerin, whose work this technique was based on, described a silicone-impregnated rayon membrane feeding technique for the artificial feeding of I. ricinus17.
Refinement of the methods for I. scapularis, a closely related species, has led to notable differences in the hardness of silicone used in membrane impregnation, the recipe for membrane production, dimensions of the chamber, and the attachment stimulant. While the refinements reported in this study have resulted in similar membrane characteristics as those reported by Andrade et al., who also developed a silicone-based membrane based on Krober and Guerin for use in I. scapularis, there is a difference in the silicone impregnation steps, which allows the flexibility to utilize this protocol for immature life stages of I. scapularis15,18. This study also describes additions and technical alterations based on repeated use of this method, best practices that result in a successful feed, and troubleshooting of problems that may arise. This method has been used to feed all active life stages, infect ticks with pathogenic bacteria, and expose ticks to multiple dosages of antibiotics19,20. While the artificial membrane feeding method shown is for I. scapularis, this method is readily adaptable to other species of ticks with minor modifications in membrane thickness.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>00-10 Hardness Silicone</td>
			<td>Smooth-On</td>
			<td>Ecoflex 00-10</td>
			<td>Trial size from Smooth-On Store</td>
		</tr>
		<tr>
			<td>00-50 Hardness Silicone</td>
			<td>Smooth-On</td>
			<td>Ecoflex 00-50</td>
			<td>Trial size from Smooth-On Store</td>
		</tr>
		<tr>
			<td>30 Hardness Silicone</td>
			<td>Smooth-On</td>
			<td>Mold Star 30</td>
			<td>Trial size from Smooth-On Store</td>
		</tr>
		<tr>
			<td>6-well cell culture plates</td>
			<td>Corning Incorporated</td>
			<td>3516</td>
			<td></td>
		</tr>
		<tr>
			<td>Adenosine triphosphate (ATP)</td>
			<td>Millipore Sigma</td>
			<td>A1852-1VL</td>
			<td>Used to make an aqueous solution of 3 mM ATP that has been filter sterlized via 0.2 micometer filter</td>
		</tr>
		<tr>
			<td>Bovine blood</td>
			<td>HemoStat</td>
			<td>DBB500</td>
			<td>Mechanically defibrinated; 500 mL is usually sufficient for one experiment</td>
		</tr>
		<tr>
			<td>Clingwrap</td>
			<td>Fisherbrand</td>
			<td>22-305654&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter Paper</td>
			<td>Fisherbrand</td>
			<td>09-790-2C</td>
			<td>Autoclave and let cool before using. Can use Fine quality instead of medium too</td>
		</tr>
		<tr>
			<td>Fluon (aqueous polytetrafluoroethylene)</td>
			<td>Bioquip</td>
			<td>2871</td>
			<td>Available from other sources such as https://canada-ant-colony.com/products/fluon-ptfe-10ml</td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Millipore Sigma</td>
			<td>G8270-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Hexane</td>
			<td>Millipore Sigma</td>
			<td>139386-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Lens paper</td>
			<td>Fisherbrand</td>
			<td>11-995</td>
			<td>100% rayon</td>
		</tr>
		<tr>
			<td>Nystatin &#160;</td>
			<td>Gold Biotechnology</td>
			<td>N-750-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Parafilm</td>
			<td>Fisherbrand</td>
			<td>S37440&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin/streptomycin/fungizone</td>
			<td>Gibco</td>
			<td>15240-096</td>
			<td>Or equivalent generic with concentration as follows (10,000 units/mL of penicillin, 10,000 &#181;g/mL of streptomycin, and 25 &#181;g/mL of Amphotericin B)</td>
		</tr>
		<tr>
			<td>Phagostimulant</td>
			<td>Made in House</td>
			<td></td>
			<td>Collected from prior tick feeds</td>
		</tr>
		<tr>
			<td>Polycarbonate Pipe</td>
			<td>McMaster-Carr</td>
			<td>8585K204&#160;</td>
			<td>Cut to 45 mm length, 1.25 inch outer diameter, 1 inch inner diameter. Cutting requires a chop saw grinding wheel.</td>
		</tr>
		<tr>
			<td>Rubber O-rings</td>
			<td>McMaster-Carr</td>
			<td>9452K38&#160;</td>
			<td>5 mm thick, 1.25 inch inner diameter</td>
		</tr>
		<tr>
			<td>Soft touch forceps</td>
			<td>VWR</td>
			<td>470315-238&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Super glue</td>
			<td></td>
			<td></td>
			<td>cyanoacrylate glue</td>
		</tr>
		<tr>
			<td>Unryu paper&#160;</td>
			<td>Art supply stores</td>
			<td></td>
			<td>mulberry fiber 10 g/m2. Purchased at Wet Paint art supply store, St. Paul, MN, USA</td>
		</tr>
	</tbody>
</table>

tick artificial membrane feeding for ixodes scapularis

Ticks and their associated diseases are an important topic of study due to their public health and veterinary burden. However, the feeding requirements of ticks during both study and rearing can limit experimental questions or the ability of labs to research ticks and their associated pathogens. An artificial membrane feeding system can reduce these problems and open up new avenues of research that may not have been possible with traditional animal feeding systems. This study describes an artificial membrane feeding system that has been refined for feeding and engorgement success for all Ixodes scapularis life stages. Moreover, the artificial membrane feeding system described in this study can be modified for use with other tick species through simple refinement of the desired membrane thickness. The benefits of an artificial membrane feeding system are counterbalanced by the labor intensiveness of the system, the additional environmental factors that may impact feeding success, and the need to refine the technique for each new species and life stage of ticks.

A successful feeding depends on whether a partial or full engorgement is desired. Successfully fed I. scapularis turn a shade of gunmetal grey for adults and detach on their own from the membrane. However, if they are at least pea-sized, they may be detached from the membrane when finishing up the feeding. For immature stages of I. scapularis, the size for fully engorged ticks varies, and because, unlike adults, they do not exhibit a color change, detachment is the best way to determine if a tick is ful...

Watch this Scientific Journal Video about Tick Artificial Membrane Feeding for Ixodes scapularis at JoVE.com

Tick Artificial Membrane Feeding for Ixodes scapularis

Presented here is a method to blood feed ticks in vitro via an artificial membrane system to allow for partial or full engorgement of a variety of tick life stages.

Tick Artificial Membrane Feeding for Ixodes scapularis

Ticks and their associated diseases are an important topic of study due to their public health and veterinary burden. However, the feeding requirements of ...

While artificial membrane feeding has been done before, our protocol is simpler to set up and adaptable to other tick species with some modifications. The main advantage of artificial membrane feeding is that it allows for exposure to pathogens and treatments that may not be feasible via animal feeding. This artificial membrane feeding system can be applied to other arthropod species with some testing for ideal phagostimulants and modifications on ideal membrane thickness.Producing the correct membrane thickness requires some practice. Be sure to use a micrometer to measure the thickness at several locations on the membrane. Benjamin Cull, a postdoc in our laboratory will help me to demonstrate the procedure.To begin, wipe down a flat, non-porous surface such as a pane of glass or ceramic coated metal base of an arm stand with 70%ethanol and then cover it with a single layer of plastic wrap. Make sure the plastic wrap is flat and without bubbles or wrinkles. Tape down 100%rayon lens cleaning paper to the prepared surface.Ensure it is flat and slightly taut with tape across all four sides of the paper. Prepare the 0010 hardness silicone mixture by measuring out five milliliters of each part of the silicone kit into a disposable container. Lightly mix the two liquids and add 1.5 milliliters of hexane.Continue mixing until the mixture is homogenous and thoroughly mixed. Use a small squeegee to distribute the silicone mix over the lens paper and allow it to stand for one minute to ensure that the silicone has soaked into the lens paper. Steadily, scrape the excess silicone to the side with the squeegee using a small amount of downward pressure.Perform a second pass with the squeegee without exerting the downward pressure to remove any lines of silicone and produce a smooth layer. For larvae only, dip the top of the feeding chamber into Fluon fluoropolymer resin several times, allowing it to dry between applications to produce a consistent layer. Leave the membrane to cure for at least 24 hours in a dust-free environment such as a closed chemical or biosafety cabinet.Next, mix equal parts of silicone mix A and B to prepare the 30 hardness silicone mixture to attach the chambers to the membrane. Dip the polycarbonate chambers about a quarter of an inch into the silicone mixture and then place them on the membrane sheet, taking care not to overlap any of the tapes. Allow the attaching silicone to cure for at least 24 hours.Using a scalpel, carefully cut the membrane around each of the attached chambers, trimming down the edges so that it can fit smoothly into a well of the six well plate without much scraping on the sides. Allow sufficient material outside the chamber to maximize the addition of the membrane. Cut a small piece of the leftover membrane from each corner and the center of the membrane sheet.Remove the plastic wrap from each piece and measure the pieces with a micrometer to determine the average membrane thickness. Place the feeding chambers along with one O-ring per chamber into a glass beaker to be autoclaved at 121 degrees Celsius for at least 20 minutes to sterilize. Allow the chambers to cool before using them.After taking out the pre-prepared, autoclaved membrane chambers and placing the O-ring around them, fill each chamber with enough 70%ethanol to cover the membrane. Let it sit in a six well plate for five minutes and then look for any leaks between the chamber and membrane and in the membrane itself. Empty out the ethanol from the chambers and then let it air dry inside a biosafety cabinet or laminar flow hood.To heat and activate the complement in the blood, heat it at 56 degrees Celsius for 40 minutes and supplement mechanically defibrillated bovine blood with two grams per liter of glucose. Once the membrane is dry, apply around 20 microliters of phagostimulant to the inside of the chamber and tilt the chamber to spread it around the surface. When the phagostimulant is dry, quickly add the ticks to the chamber with either a brush or forceps.Seal the top with parafilm as the heat from the water bath can cause it to rip. Then add five milliliters of the heat and activated blood per well or chamber into a conical tube and place it in the water bath set at 36 degrees Celsius. Add five microliters of three millimolar ATP and 50 microliters of 100X stock of penicillin streptomycin fungizone per five milliliters of blood to the tube and transfer 4.5 milliliters of the blood into a well of a six well plate.Gently place the chamber into the well, adjusting the O-ring height on the chamber so that the membrane sits in the blood, but the blood level around the side does not overtop the well. Then place the well into the blood at an angle to avoid air bubble formation between the blood and the membrane. Place the lid of the six well plate on top of the feeding chambers.Put the six well plate with chambers into the prepared 34 degrees Celsius water bath and the lid. Add five microliters of three millimolar ATP and 50 microliters of 100X stock of penicillin streptomycin fungizone per well to the blood tube and transfer 4.5 milliliters of blood into a well of a fresh six well plate as shown earlier. Take out the six well plate with the tick chamber from the water bath and remove the chamber from the well.Rinse the outside of the chamber and membrane with 10 milliliters of sterilized 1X PBS to remove the blood. Using autoclaved filter paper, gently dab dry the membrane and chamber to remove the excess PBS. If there is a lot of condensation inside the chamber, dab dry the wet spots with autoclaved filter paper before sealing it with fresh parafilm.Then replace the parafilm on the top of the chamber. Place the tick chamber into the new six well plate with fresh blood, adjusting the O-ring height if needed. Repeat these steps for each chamber on the plate.Finally, place the lid of the six well plate over the top of the chambers and move the new six well plate back into the 34 degrees Celsius water bath. An ongoing feed with partially engorged ixodes scapularis nymphs is shown here. The black or brown dots around the attachment sites are the frost that can be collected during and after the feed to make the phagostimulant.Partially engorged ixodes scapularis nymphs are seen attached to the membrane. A husk of the engorged larvae mold can also be seen here. The tick engorgement numbers and egg mass weights are presented in this table.Larval and nymphal engorgement experimental conditions had deer organ homogenate added to the blood in addition to the supplements used in this technique. Here, successful engorgement was defined as either engorged ticks that successfully molted to the next live stage or engorged females that successfully laid eggs. It takes practice to get acceptable thickness when applying silicone to the lens paper so it is always important to measure the thickness of the membrane before use.Membrane feeding can expose ticks to pathogens or antibiotics. The effects of these on aspects of tick biology such as molting success, egg laying and survival can be assessed post feed.

tick-artificial-membrane-feeding-for-ixodes-scapularis

Research

JoVE Journal

Biology

Testing Nicotine Tolerance in Aphids Using an Artificial Diet Experiment

Plants may upregulate the production of many different seconday metabolites in response to insect feeding. One of these metabolites, nicotine, is well know to have insecticidal properties. One response of tobacco plants to herbivory, or being gnawed upon by insects, is to increase the production of this neurotoxic alkaloid. Here, we will demonstrate how to set up an experiment to address this question of whether a tobacco-adapted strain of the green peach aphid, Myzus persicae, can tolerate higher levels of nicotine than the a strain of this insect that does not infest tobacco in the field.

In this video and assay is demonstrated that tests the tolerance of nicotine to two types of aphids one that infests tobacco plants in the field and one that does not.

Plants may upregulate the production of many different seconday metabolites in response to insect feeding. One of these metabolites, nicotine, is well ...

Preparation of Artificial Bilayers for Electrophysiology Experiments

Planar lipid bilayers, also called artificial lipid bilayers, allow you to study ion-conducting channels in a well-defined environment. These bilayers can be used for many different studies, such as the characterization of membrane-active peptides, the reconstitution of ion channels or investigations on how changes in lipid bilayer properties alter the function of bilayer-spanning channels.  Here, we show how to form a planar bilayer and how to isolate small patches from the bilayer, and in a second video  will also demonstrate a procedure for using gramicidin channels to determine changes in lipid bilayer elastic properties.   We also demonstrate the individual steps needed to prepare the bilayer chamber, the electrodes and how to test that the bilayer is suitable for single-channel measurements.

Planar lipid bilayers, also called artificial lipid bilayers, allow you to study ion-conducting channels in a well-defined environment. Here, we demonstrate the individual steps needed to prepare the bilayer chamber, the electrodes and how to test that the bilayer is suitable for single-channel measurements.

Planar lipid bilayers, also called artificial lipid bilayers, allow you to study ion-conducting channels in a well-defined environment. These bilayers can ...

Crystallizing Membrane Proteins for Structure Determination using Lipidic Mesophases

A detailed protocol for crystallizing membrane proteins by using lipidic mesophases is described. This method has variously been referred to as the lipidic cubic phase or in meso method. The method has been shown to be quite versatile in that it has been used to solve X-ray crystallographic structures of prokaryotic and eukaryotic proteins, proteins that are monomeric, homo- and hetero-multimeric, chromophore-containing and chromophore-free, and alpha-helical and beta-barrel proteins. Recent successes using in meso crystallization are the human engineered beta2-adrenergic and adenosine A2a G protein-coupled receptors. Protocols are presented for reconstituting the membrane protein into the monoolein-based mesophase, and for setting up crystallizations in the manual mode. Additional steps in the overall process, such as crystal harvesting, are to be addressed in future video articles. The time required to prepare the protein-loaded mesophase and to set up a crystallization plate manually is about one hour.

Herein is described the procedure implemented in the Caffrey Membrane Structural and Functional Biology Group to set up manually crystallization trials of membrane proteins in lipidic mesophases.

A detailed protocol for crystallizing membrane proteins by using lipidic mesophases is described. This method has variously been referred to as the ...

Use of a Robot for High-throughput Crystallization of Membrane Proteins in Lipidic Mesophases

Structure-function studies of membrane proteins greatly benefit from having available high-resolution 3-D structures of the type provided through macromolecular X-ray crystallography (MX). An essential ingredient of MX is a steady supply of ideally diffraction-quality crystals. The in meso or lipidic cubic phase (LCP) method for crystallizing membrane proteins is one of several methods available for crystallizing membrane proteins. It makes use of a bicontinuous mesophase in which to grow crystals. As a method, it has had some spectacular successes of late and has attracted much attention with many research groups now interested in using it. One of the challenges associated with the method is that the hosting mesophase is extremely viscous and sticky, reminiscent of a thick toothpaste. Thus, dispensing it manually in a reproducible manner in small volumes into crystallization wells requires skill, patience and a steady hand. A protocol for doing just that was developed in the Membrane Structural &amp; Functional Biology (MS&amp;FB) Group1-3. JoVE video articles describing the method are available1,4. 
The manual approach for setting up in meso trials has distinct advantages with specialty applications, such as crystal optimization and derivatization. It does however suffer from being a low throughput method. Here, we demonstrate a protocol for performing in meso crystallization trials robotically. A robot offers the advantages of speed, accuracy, precision, miniaturization and being able to work continuously for extended periods under what could be regarded as hostile conditions such as in the dark, in a reducing atmosphere or at low or high temperatures. An in meso robot, when used properly, can greatly improve the productivity of membrane protein structure and function research by facilitating crystallization which is one of the slow steps in the overall structure determination pipeline. 
In this video article, we demonstrate the use of three commercially available robots that can dispense the viscous and sticky mesophase integral to in meso crystallogenesis. The first robot was developed in the MS&amp;FB Group5,6. The other two have recently become available and are included here for completeness.	
An overview of the protocol covered in this article is presented in Figure 1. All manipulations were performed at room temperature (~20 &deg;C) under ambient conditions.

Herein is described a robotic approach to high-throughput crystallization of membrane proteins in lipidic mesophases for use in structure determination using macromolecular X-ray crystallography. Three robots capable of handling the viscous and sticky protein-laden mesophase integral to the method are introduced.

Structure-function studies of membrane proteins greatly benefit from having available high-resolution 3-D structures of the type provided through ...

Harvesting and Cryo-cooling Crystals of Membrane Proteins Grown in Lipidic Mesophases for Structure Determination by Macromolecular Crystallography

An important route to understanding how proteins function at a mechanistic level is to have the structure of the target protein available, ideally at atomic resolution. Presently, there is only one way to capture such information as applied to integral membrane proteins (Figure 1), and the complexes they form, and that method is macromolecular X-ray crystallography (MX). To do MX diffraction quality crystals are needed which, in the case of membrane proteins, do not form readily. A method for crystallizing membrane proteins that involves the use of lipidic mesophases, specifically the cubic and sponge phases1-5, has gained considerable attention of late due to the successes it has had in the G protein-coupled receptor field6-21 (<a href="http://www.mpdb.tcd.ie" target="_blank">www.mpdb.tcd.ie</a>). However, the method, henceforth referred to as the in meso or lipidic cubic phase method, comes with its own technical challenges. These arise, in part, due to the generally viscous and sticky nature of the lipidic mesophase in which the crystals, which are often micro-crystals, grow. Manipulating crystals becomes difficult as a result and particularly so during harvesting22,23. Problems arise too at the step that precedes harvesting which requires that the glass sandwich plates in which the crystals grow (Figure 2)24,25 are opened to expose the mesophase bolus, and the crystals therein, for harvesting, cryo-cooling and eventual X-ray diffraction data collection.
The cubic and sponge mesophase variants (Figure 3) from which crystals must be harvested have profoundly different rheologies4,26. The cubic phase is viscous and sticky akin to a thick toothpaste. By contrast, the sponge phase is more fluid with a distinct tendency to flow. Accordingly, different approaches for opening crystallization wells containing crystals growing in the cubic and the sponge phase are called for as indeed different methods are required for harvesting crystals from the two mesophase types. Protocols for doing just that have been refined and implemented in the Membrane Structural and Functional Biology (MS&amp;FB) Group, and are described in detail in this JoVE article (Figure 4). Examples are given of situations where crystals are successfully harvested and cryo-cooled. We also provide examples of cases where problems arise that lead to the irretrievable loss of crystals and describe how these problems can be avoided. In this article the Viewer is provided with step-by-step instructions for opening glass sandwich crystallization wells, for harvesting and for cryo-cooling crystals of membrane proteins growing in cubic and in sponge phases.

Herein is described procedures implemented in the Caffrey Membrane Structural and Functional Biology Group to harvest and cryo-cool membrane protein crystals grown in lipidic cubic and sponge phases for use in structure determination using macromolecular X-ray crystallography.

An important route to understanding how proteins function at a mechanistic level is to have the structure of the target protein available, ideally at ...

Microperfusion Technique to Investigate Regulation of Microvessel Permeability in Rat Mesentery

Experiments to measure the permeability properties of individually perfused microvessels provide a bridge between investigation of molecular and cellular mechanisms regulating vascular permeability in cultured endothelial cell monolayers and the functional exchange properties of whole microvascular beds. A method to cannulate and perfuse venular microvessels of rat mesentery and measure the hydraulic conductivity of the microvessel wall is described. The main equipment needed includes an intravital microscope with a large modified stage that supports micromanipulators to position three different microtools: (1) a beveled glass micropipette to cannulate and perfuse the microvessel; (2) a glass micro-occluder to transiently block perfusion and enable measurement of transvascular water flow movement at a measured hydrostatic pressure, and (3) a blunt glass rod to stabilize the mesenteric tissue at the site of cannulation. The modified Landis micro-occlusion technique uses red cells suspended in the artificial perfusate as markers of transvascular fluid movement, and also enables repeated measurements of these flows as experimental conditions are changed and hydrostatic and colloid osmotic pressure difference across the microvessels are carefully controlled. Measurements of hydraulic conductivity first using a control perfusate, then after re-cannulation of the same microvessel with the test perfusates enable paired comparisons of the microvessel response under these well-controlled conditions. Attempts to extend the method to microvessels in the mesentery of mice with genetic modifications expected to modify vascular permeability were severely limited because of the absence of long straight and unbranched microvessels in the mouse mesentery, but the recent availability of the rats with similar genetic modifications using the CRISPR/Cas9 technology is expected to open new areas of investigation where the methods described herein can be applied.

The modified Landis technique enables paired measurement of the hydraulic conductivity of individual microvessels in the mesentery of normal and genetically modified rats under control and test conditions using microperfusion techniques. It provides a convenient method to evaluate mechanisms that regulate microvessel permeability and transvascular exchange under physiological conditions.

Experiments to measure the permeability properties of individually perfused microvessels provide a bridge between investigation of molecular and cellular ...

High-fat Feeding Paradigm for Larval Zebrafish: Feeding, Live Imaging, and Quantification of Food Intake

Zebrafish are emerging as a model of dietary lipid processing and metabolic disease. This protocol describes how to feed larval zebrafish a lipid-rich meal, which consists of an emulsion of chicken egg yolk liposomes created by sonicating egg yolk in embryo media. Detailed instructions are provided to screen larvae for egg yolk consumption so that larvae that fail to feed will not confound experimental results. The chicken egg yolk liposomes can be spiked with fluorescent lipid analogs, including fatty acids and cholesterol, enabling both systemic and subcellular visualization of dietary lipid processing. Several methods are described to mount larvae that are conducive to short- and long-term live imaging with both upright and inverted objectives at high and low magnification. Additionally presented is an assay to quantify larval food intake by extracting the lipids of larvae fed fluorescent lipid analogs, spotting the lipids on a thin layer chromatography plate, and quantifying the fluorescence. Finally, critical aspects of the procedures, important controls, options for modifying the protocols to address specific experimental questions, and potential limitations are discussed. These techniques can be applied not only to focused, hypothesis driven inquiries, but also to a variety of screens and live imaging techniques to study dietary lipid metabolism and the control of food intake.

Zebrafish are emerging as a valuable model of dietary lipid processing and metabolic disease. Described are protocols of lipid-rich larval feeds, live imaging of dietary fluorescent lipid analogs, and quantification of food intake. These techniques can be applied to a variety of screening, imaging, and hypothesis driven inquiry techniques.

Zebrafish are emerging as a model of dietary lipid processing and metabolic disease. This protocol describes how to feed larval zebrafish a lipid-rich ...

Ground State Depletion Super-resolution Imaging in Mammalian Cells

Advances in fluorescent microscopy and cell biology are intimately correlated, with the enhanced ability to visualize cellular events often leading to dramatic leaps in our understanding of how cells function. The development and availability of super-resolution microscopy has considerably extended the limits of optical resolution from ~250-20 nm. Biologists are no longer limited to describing molecular interactions in terms of colocalization within a diffraction limited area, rather it is now possible to visualize the dynamic interactions of individual molecules. Here, we outline a protocol for the visualization and quantification of cellular proteins by ground-state depletion microscopy&#160;for fixed cell imaging. We provide examples from two different membrane proteins, an element of the endoplasmic reticulum translocon, sec61&#946;, and a plasma membrane-localized voltage-gated L-type Ca2+ channel (CaV1.2). Discussed are the specific microscope parameters, fixation methods, photo-switching buffer formulation, and pitfalls and challenges of image processing.

This article outlines a protocol for the detection of one or more plasma and/or intracellular membrane proteins using Ground State Depletion (GSD) super-resolution microscopy in mammalian cells. Here, we discuss the benefits and considerations of using such approaches for the visualization and quantification of cellular proteins.

Advances in fluorescent microscopy and cell biology are intimately correlated, with the enhanced ability to visualize cellular events often leading to ...

A Versatile Model of Hard Tick Infestation on Laboratory Rabbits

The use of live animals in tick research is crucial for a variety of experimental purposes including the maintenance of hard tick colonies in the laboratory. In ticks, all developmental stages (except egg) are hematophagous, and acquiring a blood-meal when attached to their vertebrate hosts is essential for the successful completion of their life cycle. Here we demonstrate a simple method that uses easily openable capsules for feeding of hard ticks on rabbits. The advantages of the proposed method include its simplicity, short duration and most importantly versatile adjustment to the needs of specific experimental requirements. The method makes possible the use of multiple chambers (of various sizes) on the same animal, which permits feeding of multiple stages or different experimental groups while reducing the overall animal requirement. The non-irritating and easily accessible materials used minimizes discomfort to the animals, which can be easily recovered from an experiment and offered for adoption or reused if the ethical protocol allows it.

We have developed a simple and versatile system to feed hard ticks on laboratory rabbits. Our non-laborious protocol uses easily accessible materials and can be adjusted depending on the requirements of the various experimental settings. The method allows comfortable monitoring and/or sampling of ticks during the entire feeding period.

The use of live animals in tick research is crucial for a variety of experimental purposes including the maintenance of hard tick colonies in the ...

Plasmodium falciparum Gametocyte Culture and Mosquito Infection Through Artificial Membrane Feeding

Malaria remains one of the most important public health problems, causing significant morbidity and mortality. Malaria is a mosquito borne disease transmitted through an infectious bite from the female Anopheles mosquito. Malaria control will eventually rely on a multitude of approaches, which includes ways to block transmission to, through and from mosquitoes. To study mosquito stages of malaria parasites in the laboratory, we have optimized a protocol to culture highly infectious Plasmodium falciparum gametocytes, a parasite stage required for transmission from the human host to the mosquito vector. P. falciparum gametocytes mature through five morphologically distinct steps, which takes approximately 1-2 weeks. Gametocyte culture described in this protocol is completed in 15 days and are infectious to mosquitoes from days 15-18. These protocols were developed to maintain a continuous cycle of infection competent gametocytes and to maintain uninterrupted supply of mosquito stages of the parasite. Here, we describe the methodology of gametocyte culture and how to infect mosquitoes with these parasites using glass membrane feeders.

Plasmodium falciparum Gametocyte Culture and Mosquito Infection Through Artificial Membrane Feeding

Detailed investigations on mosquito stages of malaria parasites are critical to design effective transmission blocking strategies. This protocol demonstrates how to effectively culture infectious gametocytes and then feed these gametocytes to mosquitoes to generate mosquito stages of P. falciparum.