Name: an experimental study on colorado potato beetle hibernation under natural conditions
Uploaded: 2023-11-17T13:00:00
Description: Watch this Scientific Journal Video about An Experimental Study on Colorado Potato Beetle Hibernation Under Natural Conditions at JoVE.com

We thank our colleagues Vladimir Shilo, Vera Morozov&#1072;, Ulyana Rotskaya, Olga Polenogova, and Oksana Tomilova for their help with organizing and execution of the field and laboratory procedures.
The research was supported by the Russian Science Foundation, project No. 22-14-00309.

1. Description of the cages for hibernation
NOTE: Depending on the aims of the experiment, the number of cages varies. Use at least three cages per sampling date. To estimate the number of beetles that will emerge, prepare at least three additional cages, which will not be taken out of the soil until spring.
<ol>
	<li>Use cages made of a rigid wooden frame with a size of 25&#160;&#215; 25&#160;&#215; 40 cm (L&#160;&#215; W&#160;&#215; H).</li>
	<li>To build a frame for the c...

<ol>
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L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+soil+moisture+on+overwintering+pupae+in+Spodopteraexigua+(Lepidoptera:+Noctuidae).">Effect of soil moisture on overwintering pupae in Spodopteraexigua (Lepidoptera: Noctuidae).</a> Applied Entomology and Zoology. 48, 365-371 (2013).</li><li>Hiiesaar, K., Metspalu, L., J&#245;udu, J., J&#245;gar, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Over-wintering+of+the+Colorado+potato+beetle+(Leptinotarsa+decemlineata+Say)+in+field+conditions+and+factors+affecting+its+population+density+in+Estonia.">Over-wintering of the Colorado potato beetle (Leptinotarsa decemlineata Say) in field conditions and factors affecting its population density in Estonia.</a> Agronomy Research. 4 (1), 21-30 (2006).</li><li>Yocum, G. D., Rinehart, J. P., Chirumamilla-Chapara, A., Larson, 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=Characterization+of+gene+expression+patterns+during+the+initiation+and+maintenance+phases+of+diapause+in+the+Colorado+potato+beetle,+Leptinotarsa+decemlineata.">Characterization of gene expression patterns during the initiation and maintenance phases of diapause in the Colorado potato beetle, Leptinotarsa decemlineata.</a> Journal of Insect Physiology. 55 (1), 32-39 (2009).</li><li>Yocum, G. D., Buckner, J. S., Fatland, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+of+internal+and+external+lipids+of+nondiapausing+and+diapause+initiation+phase+adult+Colorado+potato+beetles,+Leptinotarsa+decemlineata.">A comparison of internal and external lipids of nondiapausing and diapause initiation phase adult Colorado potato beetles, Leptinotarsa decemlineata.</a> Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology. 159 (3), 163-170 (2011).</li><li>Nikonorov, Y. M., Syrtlanova, L. A., Kitaev, K. A., Benkovskaya, G. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcription+activity+of+genes+involved+in+diapause+regulation+in+the+Colorado+Potato+beetle+and+its+change+under+a+fipronil+impact.">Transcription activity of genes involved in diapause regulation in the Colorado Potato beetle and its change under a fipronil impact.</a> Russian Journal of Genetics: Applied Research. 8, 80-86 (2018).</li><li>Govaere, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcriptome+and+proteome+analyses+to+investigate+the+molecular+underpinnings+of+cold+response+in+the+Colorado+potato+beetle,+Leptinotarsa+decemlineata.">Transcriptome and proteome analyses to investigate the molecular underpinnings of cold response in the Colorado potato beetle, Leptinotarsa decemlineata.</a> Cryobiology. 88, 54-63 (2019).</li><li>Lehmann, P., Westberg, M., Tang, P., Lindstr&#246;m, L., K&#228;kel&#228;, 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+diapause+lipidomes+of+three+closely+related+beetle+species+reveal+mechanisms+for+tolerating+energetic+and+cold+stress+in+high-latitude+seasonal+environments.">The diapause lipidomes of three closely related beetle species reveal mechanisms for tolerating energetic and cold stress in high-latitude seasonal environments.</a> Frontiers in Physiology. 11, 576617 (2020).</li><li>Lebenzon, J. E., Torson, A. S., Sinclair, 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=Diapause+differentially+modulates+the+transcriptomes+of+fat+body+and+flight+muscle+in+the+Colorado+potato+beetle.">Diapause differentially modulates the transcriptomes of fat body and flight muscle in the Colorado potato beetle.</a> Comparative Biochemistry and Physiology Part D: Genomics and Proteomics. 40, 100906 (2021).</li><li>Lashomb, J. H., Ng, Y. S., Ghidiu, G., Green, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Description+of+spring+emergence+by+the+Colorado+potato+beetle,+Leptinotarsa+decemlineata+(Say)+(Coleoptera:+Chrysomelidae),+in+New+Jersey.">Description of spring emergence by the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), in New Jersey.</a> Environmental entomology. 13 (3), 907-910 (1984).</li><li>Cantwell, G. E., Cantelo, W. W., Schroder, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Beauveria+bassiana+on+underground+stages+of+the+Colorado+potato+beetle,+Leptinotarsa+decemlineata+(Coleoptera:+Chrysomelidae).">Effect of Beauveria bassiana on underground stages of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae).</a> The Great Lakes Entomologist. 19 (2), 6 (1986).</li><li>Fedorko, A., Bajan, C., Kmitowa, K., Wojciehowska, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effectiveness+of+the+use+of+selected+microorganisms+to+control+the+Colorado+beetle+during+hibernation.">Effectiveness of the use of selected microorganisms to control the Colorado beetle during hibernation.</a> Ecological Studies. 3 (2), 127-134 (1977).</li><li>Gaugler, R., Costa, S. D., Lashomb, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stability+and+efficacy+of+Beauveria+bassiana+soil+inoculations.">Stability and efficacy of Beauveria bassiana soil inoculations.</a> Environmental Entomology. 18 (3), 412-417 (1989).</li><li>Bajan, C., Kmitowa, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contribution+of+entomopathogenic+fungi+to+the+natural+winter+reduction+of+Colorado+beetle+adults.">Contribution of entomopathogenic fungi to the natural winter reduction of Colorado beetle adults.</a> Polish Ecological Studies. 3 (2), 107-114 (1977).</li><li>Milner, M., Kung, K. S., Wyman, J. A., Feldman, J., Nordheim, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhancing+overwintering+mortality+of+Colorado+potato+beetle+(Coleoptera:+Chrysomelidae)+by+manipulating+the+temperature+of+its+diapause+habitat.">Enhancing overwintering mortality of Colorado potato beetle (Coleoptera: Chrysomelidae) by manipulating the temperature of its diapause habitat.</a> Journal of Economic Entomology. 85 (5), 1701-1708 (1992).</li><li>Do&#287;an, C., 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=Characterization+of+calcium+signaling+proteins+from+the+fat+body+of+the+Colorado+Potato+Beetle,+Leptinotarsa+decemlineata+(Coleoptera:+Chrysomelidae):+Implications+for+diapause+and+lipid+metabolism.">Characterization of calcium signaling proteins from the fat body of the Colorado Potato Beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae): Implications for diapause and lipid metabolism.</a> Insect Biochemistry and Molecular Biology. 133, 103549 (2021).</li><li>Benkovskaya, G. V., Udalov, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Colorado+potato+beetle+investigations+in+the+south+Urals.">Colorado potato beetle investigations in the south Urals.</a> Nova Science Publishers. , (2011).</li><li>Short, C. A., Hahn, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fat+enough+for+the+winter?+Does+nutritional+status+affect+diapause.">Fat enough for the winter? Does nutritional status affect diapause.</a> Journal of Insect Physiology. , 104488 (2023).</li><li>McDonald, J. R., Bale, J. S., Walters, K. F. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-temperature+mortality+and+overwintering+of+the+western+flower+thrips+Frankliniella+occidentalis+(Thysanoptera:+Thripidae).">Low-temperature mortality and overwintering of the western flower thrips Frankliniella occidentalis (Thysanoptera: Thripidae).</a> Bulletin of Entomological Research. 87 (5), 497-505 (1997).</li></ol>

This study shows that the proposed method for studying the overwintering of CPBs enables us to obtain a sufficient number of insects in different periods of hibernation. The success of the presented technique depends on several independent factors, the most important of which is weather conditions. In a cold, snowless winter, the soil may freeze to the entire depth of the cage. In this case, the risk of death of all beetles goes up significantly18. The survival of the beetle depends on a combinati...

The Colorado potato beetle Leptinotarsa decemlineata Say (CPB) is an important pest of Solanaceae plants, predominantly potato Solanum tuberosum L. The geographic range of this species is more than 16 million km2 and constantly expands1. The CPB has facultative winter diapause, and hibernation is obligatory in the temperate zone. The diapause is induced by a short-day photoperiod and modulated by temperature1. These beetles overwinter in the adult stage by burrowing into soil. With increasing latitudes, the duration of the hibernation period extends. In the temperate zone, especially on northern territories of its range, the overwintering lasts up to 9 months: from August-September until May-June (Noskov et al., personal observations). During this period, the CPB-just like any other insect in the temperate zone-is exposed to unfavorable winter conditions and must increase its cold tolerance. At the same time, contact of the beetles with soil increases the risk of infection by various opportunistic and pathogenic microorganisms2. Therefore, these beetles need to maintain a certain level of immune-system activity during hibernation, which is also energetically costly. Nonetheless, even if the insect survives an infection, the disease may reduce its cold hardiness3. It should be noted that low temperature is not the only reason for winter mortality of the CPB. An important role is also played by the lack of oxygen, and under some conditions, it could be the main factor of winter mortality4,5.
It is known that natural winter mortality of the CPB can be very high, reaching 100% in clay loam soils6. Thus, overwintering is one of the most crucial periods in the CPB life cycle. Nevertheless, data on the physiology, immune-system activity, survival, and other parameters of CPB hibernation under natural conditions are still limited. There are studies on differential gene expression and various physiological parameters in CPB adults during the diapause and in response to cold shock7,8,9,10,11,12; however, these analyses have mainly been carried out by induction of diapause or cold stress under laboratory conditions without natural fluctuations of temperature, humidity, and native pathogen load. Nonetheless, research on the physiology of these beetles collected by excavation from soil under natural conditions is important. Different aspects of CPB overwintering under natural conditions were actively studied in the 1970s-1980s13,14,15,16,17,18. On the other hand, these studies did not involve CPB excavation from the soil in winter. In addition, a technique for controlled hibernation of the CPB and a description of the cages are not provided in detail. Thus, investigation into the physiology of CPBs overwintering in natural settings is needed19.
The aim of this study was to develop and test a method for controlled hibernation of CPB adults under natural conditions. The proposed method allows to obtain a desired number of CPB individuals for microbiological, immunological, and other assays during hibernation under field conditions of a continental climate. This method can be adapted and applied to other insect species overwintering in soil under snow.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Agar-agar bacteriological purified</td>
			<td>diaGene</td>
			<td>1806.5000</td>
			<td></td>
		</tr>
		<tr>
			<td>Bile Esculin Agar</td>
			<td>HiMedia</td>
			<td>M972</td>
			<td></td>
		</tr>
		<tr>
			<td>Endo Agar&#160;</td>
			<td>HiMedia</td>
			<td>M029</td>
			<td></td>
		</tr>
		<tr>
			<td>Glucose monohydrate-D</td>
			<td>PanReac Applichem</td>
			<td>143140.1000&#934;</td>
			<td></td>
		</tr>
		<tr>
			<td>Lactic acid&#160;</td>
			<td>PanReac Applichem</td>
			<td>141034.1211</td>
			<td></td>
		</tr>
		<tr>
			<td>Luria-Bertani liquid medium</td>
			<td>HiMedia</td>
			<td>G009</td>
			<td></td>
		</tr>
		<tr>
			<td>15 ml conical centrifuge tubes</td>
			<td>Axygen</td>
			<td>SCT-15ML-25-S</td>
			<td></td>
		</tr>
		<tr>
			<td>Peptone</td>
			<td>FBIS SRCAMB</td>
			<td>M<img alt="Equation 1" src="/files/ftp_upload/65862/65862eq01v2.jpg" style="margin: auto;" />030/O61</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline</td>
			<td>Medigen</td>
			<td>PBS500</td>
			<td></td>
		</tr>
		<tr>
			<td>Temperatutre and humidity datalogger Ecklerk-M-11</td>
			<td>Relsib</td>
			<td></td>
			<td>Waterproof datalogger</td>
		</tr>
	</tbody>
</table>

an experimental study on colorado potato beetle hibernation under natural conditions

One of the major pests of potato Solanum tuberosum L. in the temperate zone is the insect Colorado potato beetle (CPB). Most studies on the immunity and diseases of the CPB are conducted during active feeding stages. Nonetheless, there are fewer studies on resting stages, although these beetles spend most of their life cycle in a state of winter diapause (hibernation). In this work, a method for investigating CPB hibernation under natural conditions was developed and tested, offering an opportunity to collect a sufficient number of individuals in winter. In this article, CPB survival was assessed, and infectious agents at different stages of hibernation were identified. CPB mortality increased during the hibernation, reaching a maximum in April-May. Entomopathogenic fungi (Beauveria, Isaria, and Lecanicillium) and bacteria Bacillus, Sphingobacterium, Peribacillus, Pseudomonas, and Serratia were isolated&#160;from the dead insects. The survival rate of the beetles for the entire hibernation period was 61%. No frozen or desiccated beetles were found, indicating the success of the presented method.

The results below on overwintering CPBs show soil temperature, survival, and infections.
Soil temperature dynamics. 
Temperatures below zero in the cages at a depth of 30 cm were registered from the end of November to the beginning of April (Figure 1). The average temperature during this period was minus 3.3 &#177; 0.1 &#176;C (mean &#177; standard error). The lowest recorded temperature was minus 7.9 &#176;C in mid-February.
<p class="jo...

Watch this Scientific Journal Video about An Experimental Study on Colorado Potato Beetle Hibernation Under Natural Conditions at JoVE.com

An Experimental Study on Colorado Potato Beetle Hibernation Under Natural Conditions

Here we present a method for studying Colorado potato beetle hibernation under the natural conditions of the temperate zone as well as a technique for collecting beetles in winter. This method allows to obtain a desired number of overwintering individuals for various analyses at any stage of hibernation.

One of the major pests of potato Solanum tuberosum L. in the temperate zone is the insect Colorado potato beetle (CPB). Most studies on the immunity and ...

The Colorado potato beetle is one of the most serious pests of potato in temperate zone. Studies of the immunity and pathogenesis of this pest are mainly carried out at the active stage. However, in temperate zone, this pest spend most of its lifecycle in a state of hibernation.In this study, we present a method for hibernation of Colorado potato beetle and a technique for collecting beetles in winter. The main advantage of this method is that it allows obtaining any number of overwintering individuals for virus analysis at any period of hibernation. Use cages made of a rigid wooden frame with a size of 25 by 25 by 40 centimeters.To build a frame for the cage, use wooden slats at least two centimeters thick and four centimeters wide. Cover the inside of the cage with a stainless steel mesh with a size of no larger than five by three millimeters. Fix the mesh with a wood stapler.Line the inside of the cage with a black synthetic geotextile with a density of 60 grams per square meter. Tightly attach a tube of synthetic translucent breathable fabric, approximately 60 centimeters high to the top of the cage. Cross and fix two strong ropes to the bottom of the cage to pull it out from the soil when needed.Dig a hole in the soil 40 centimeters deep. Lay dry grass or hay onto the hole. Place the cage inside so that the hay or dry grass is between the cage's walls and the soil.Fill the cages up with soil from the same potato field where the insects are collected. Install waterproof temperature and humidity data loggers into the cages at required depths. Plant potato seedlings inside the cage three to four weeks prior to beetle introduction and water them moderately.Fix a tube of synthetic fabric vertically to a stick of any material installed on the outside of the cage. Manually collect adult beetles in the pesticide-free potato fields toward the end of potato vegetation. Keep the collected beetles in 20 liter plastic buckets containing potato tops for feeding the insects before placing in the cages.Cover the buckets with a breathable fabric. Place no more than 200 individuals of the beetles onto the potato plants covered by the synthetic fabric mesh. When the potato tops are consumed, add fresh ones set in a plastic jar containing water and change the potato tops daily afterwards.Once all the beetles burrowed into the soil for overwintering, untie the tube of synthetic fabric from the stick and lay the fabric down. Remove the snow above the surface of the cage. Loosen the cage on each side with a strong shovel.Pull the cage out the soil using ropes. Bring the cage to the lab. Remove the soil from the cage in small portions, carefully break up large pieces of soil and isolate beetles using tweezers.Separate live beetles from cadavers. Live, healthy beetles compact soil around them forming an air cavity, a so-called cradle, and therefore are easily separated from the soil. Beetles killed by fungi are mummified or have visible mycelium on the surface.Bacterially decomposing insects are dark. Sift the soil through a sieve to make sure all the beetles are isolated and not damaged. Place cadavers with symptoms of a fungal infection or bacterial decomposition in an individual sterile Falcon tube for future identification.Store live beetles in a refrigerator at a temperature of 2 degrees Celsius until analysis in closed ventilated containers containing a damp cotton ball. To collect hemolymph, make a puncture in the lateral part of the abdomen under aorta with an insulin needle. To isolate the gut, cut off the head capsule, squeeze out all the contents into a Petri dish with phosphate buffer.Separate the gut and cleanse it from fat and Malpighian vessels. Separate a desired section of the gut, such as the foregut, midgut or hindgut. To isolate the fat body, separate it from the other tissues after the isolation of the gut.To isolate entomopathogenic fungi from the cadavers, put the mummified cadavers into a sterile humidity chamber. Use aerial conidia or sclerotia from the internal contents of the beetles for plating on Sabouraud dextrose agar with 0.4%lactic acid. Isolate bacteria from the cadavers with symptoms of bacterial decay.Cut off a beetle's head, squeeze out the internal contents and collect into tubes for subsequent plating on media for bacteria. Temperatures below zero in the cages at a depth of 30 centimeters, were registered from the end of November to the beginning of April. The average temperature during this period was 3.3 0.1 Celsius.The lowest registered temperature was 7.9 Celsius in mid-February. Insect mortality increased during the hibernation and reached a maximum in spring before the emergence. The initial number of beetles was 2, 000, of which 1, 470 individuals survived.Thus, the survival rate of the beetles during the hibernation was 61%An analysis of 530 cadavers showed that during the hibernation period 53%of them were characterized by symptoms of bacterial decomposition and 25%were characterized by symptoms of fungal infection. Beauveria dominated among the isolated cultures of entomopathogenic fungi. Metarhizium, Cordyceps and Lecanicillium were much less common.Among the bacteria isolated from the cadavers with symptoms of bacterial decomposition, species belonging to genera Bacillus, Sphingobacterium, Peribacillus, Pseudomonas, Serratia, Rahnella and Glutamicibacter were identified. Using this method can solve the problem of obtaining Colorado potato beetles from the field in winter. It allows getting as much individuals as you need with the low mortality rate of the insects.The study of various aspects of the beetles hibernation is important from both fundamental and applied points of view for improving approach to the control of this pest. And of course, this technique can be adapted for other insect species overwintering in the soil.

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Testing Visual Sensitivity to the Speed and Direction of Motion in Lizards

Testing visual sensitivity in any species provides basic information regarding behaviour, evolution, and ecology. However, testing specific features of the visual system provide more empirical evidence for functional applications. Investigation into the sensory system provides information about the sensory capacity, learning and memory ability, and establishes known baseline behaviour in which to gauge deviations (Burghardt, 1977). However, unlike mammalian or avian systems, testing for learning and memory in a reptile species is difficult. Furthermore, using an operant paradigm as a psychophysical measure of sensory ability is likewise as difficult. Historically, reptilian species have responded poorly to conditioning trials because of issues related to motivation, physiology, metabolism, and basic biological characteristics. Here, I demonstrate an operant paradigm used a novel model lizard species, the Jacky dragon (Amphibolurus muricatus) and describe how to test peripheral sensitivity to salient speed and motion characteristics. This method uses an innovative approach to assessing learning and sensory capacity in lizards. I employ the use of random-dot kinematograms (RDKs) to measure sensitivity to speed, and manipulate the level of signal strength by changing the proportion of dots moving in a coherent direction. RDKs do not represent a biologically meaningful stimulus, engages the visual system, and is a classic psychophysical tool used to measure sensitivity in humans and other animals. Here, RDKs are displayed to lizards using three video playback systems. Lizards are to select the direction (left or right) in which they perceive dots to be moving. Selection of the appropriate direction is reinforced by biologically important prey stimuli, simulated by computer-animated invertebrates.

Testing visual sensitivity in lizards using an operant conditioning paradigm that employs video playback of random-dot kinematograms and computer-generated invertebrates.

Testing visual sensitivity in any species provides basic information regarding behaviour, evolution, and ecology. However, testing specific features of ...

Computer-Generated Animal Model Stimuli

Communication between animals is diverse and complex. Animals may communicate using auditory, seismic, chemosensory, electrical, or visual signals. In particular, understanding the constraints on visual signal design for communication has been of great interest. Traditional methods for investigating animal interactions have used basic observational techniques, staged encounters, or physical manipulation of morphology. Less intrusive methods have tried to simulate conspecifics using crude playback tools, such as mirrors, still images, or models. As technology has become more advanced, video playback has emerged as another tool in which to examine visual communication (Rosenthal, 2000). However, to move one step further, the application of computer-animation now allows researchers to specifically isolate critical components necessary to elicit social responses from conspecifics, and manipulate these features to control interactions. Here, I provide detail on how to create an animation using the Jacky dragon as a model, but this process may be adaptable for other species. In building the animation, I elected to use Lightwave  3D to alter object morphology, add texture, install bones, and provide comparable weight shading that prevents exaggerated movement. The animation is then matched to select motor patterns to replicate critical movement features. Finally, the sequence must rendered into an individual clip for presentation. Although there are other adaptable techniques, this particular method had been demonstrated to be effective in eliciting both conspicuous and social responses in staged interactions.

Computer-generated stimuli using the Jacky dragon as a model.

Communication between animals is diverse and complex. Animals may communicate using auditory, seismic, chemosensory, electrical, or visual signals. In ...

Interview: HIV-1 Proviral DNA Excision Using an Evolved Recombinase

HIV-1 integrates into the host chromosome of infected cells and persists as a provirus flanked by long terminal repeats. Current treatment strategies primarily target virus enzymes or virus-cell fusion, suppressing the viral life cycle without eradicating the infection. Since the integrated provirus is not targeted by these approaches, new resistant strains of HIV-1 may emerge. Here, we report that the engineered recombinase Tre (see Molecular evolution of the Tre recombinase , Buchholz, F., Max Planck Institute for Cell Biology and Genetics, Dresden) efficiently excises integrated HIV-1 proviral DNA from the genome of infected cells. We produced loxLTR containing viral pseudotypes and infected HeLa cells to examine whether Tre recombinase can excise the provirus from the genome of HIV-1 infected human cells. A virus particle-releasing cell line was cloned and transfected with a plasmid expressing Tre or with a parental control vector. Recombinase activity and virus production were monitored. All assays demonstrated the efficient deletion of the provirus from infected cells without visible cytotoxic effects. These results serve as proof of principle that it is possible to evolve a recombinase to specifically target an HIV-1 LTR and that this recombinase is capable of excising the HIV-1 provirus from the genome of HIV-1-infected human cells.
Before an engineered recombinase could enter the therapeutic arena, however, significant obstacles need to be overcome. Among the most critical issues, that we face, are an efficient and safe delivery to targeted cells and the absence of side effects.

Current HIV-1 strategies act to suppress the viral life cycle but do not effectively eradicate infection. Here, we demonstrate that an engineered recombinase can efficiently excise integrated HIV-1 proviral DNA from the genome of infected cells.

HIV-1 integrates into the host chromosome of infected cells and persists as a provirus flanked by long terminal repeats. Current treatment strategies ...

Using Unfixed, Frozen Tissues to Study Natural Mucin Distribution

Mucins are complex and heavily glycosylated O-linked glycoproteins, which contain more than 70% carbohydrate by weight1-3. Secreted mucins, produced by goblet cells and the gastric mucosa, provide the scaffold for a micrometers-thick mucus layer that lines the epithelia of the gut and respiratory tract3,4. In addition to mucins, mucus layers also contain antimicrobial peptides, cytokines, and immunoglobulins5-9. The mucus layer is an important part of host innate immunity, and forms the first line of defense against invading microorganisms8,10-12. As such, the mucus is subject to numerous interactions with microbes, both pathogens and symbionts, and secreted mucins form an important interface for these interactions. The study of such biological interactions usually involves histological methods for tissue collection and staining. The two most commonly used histological methods for tissue collection and preservation in the clinic and in research laboratories are: formalin fixation followed by paraffin embedding, and tissue freezing, followed by embedding in cryo-protectant media.
Paraffin-embedded tissue samples produce sections with optimal qualities for histological visualization including clarity and well-defined morphology. However, during the paraffin embedding process a number of epitopes become altered and in order to study these epitopes, tissue sections have to be further processed with one of many epitope retrieval methods13. Secreted mucins and lipids are extracted from the tissue during the paraffin-embedding clearing step, which requires prolong incubation with organic solvents (xylene or Citrisolv). Therefore this approach is sub-optimal for studies focusing on the nature and distribution of mucins and mucus in vivo.
In contrast, freezing tissues in Optimal Cutting Temperature (OCT) embedding medium avoids dehydration and clearing of the sample, and maintains the sample hydration. This allows for better preservation of the hydrated mucus layer, and thus permits the study of the numerous roles of mucins in epithelial biology. As this method requires minimal processing of the tissue, the tissue is preserved in a more natural state. Therefore frozen tissues sections do not require any additional processing prior to staining and can be readily analyzed using immunohistochemistry methods.
We demonstrate the preservation of micrometers-thick secreted mucus layer in frozen colon samples. This layer is drastically reduced when the same tissues are embedded in paraffin. We also demonstrate immunofluorescence staining of glycan epitopes presented on mucins using plant lectins. The advantage of this approach is that it does not require the use of special fixatives and allows utilizing frozen tissues that may already be preserved in the laboratory.

Unfixed frozen tissue samples embedded in Optimal Cutting Temperature medium (OCT) can be used to study natural distribution and glycosylation of secreted mucus. In this approach tissue processing is minimal and the natural presentation of glycolipids, mucins and glycan-epitopes is preserved. Tissue sections can be analyzed by immunohistochemistry using fluorescence or chromogenic detection.

Mucins are complex and heavily glycosylated O-linked glycoproteins, which contain more than 70% carbohydrate by weight1-3. Secreted mucins, produced by ...

High-throughput Image Analysis of Tumor Spheroids: A User-friendly Software Application to Measure the Size of Spheroids Automatically and Accurately

The increasing number of applications of three-dimensional (3D) tumor spheroids as an in vitro model for drug discovery requires their adaptation to large-scale screening formats in every step of a drug screen, including large-scale image analysis. Currently there is no ready-to-use and free image analysis software to meet this large-scale format. Most existing methods involve manually drawing the length and width of the imaged 3D spheroids, which is a tedious and time-consuming process. This study presents a high-throughput image analysis software application &#8211; SpheroidSizer, which measures the major and minor axial length of the imaged 3D tumor spheroids automatically and accurately; calculates the volume of each individual 3D tumor spheroid; then outputs the results in two different forms in spreadsheets for easy manipulations in the subsequent data analysis. The main advantage of this software is its powerful image analysis application that is adapted for large numbers of images. It provides high-throughput computation and quality-control workflow. The estimated time to process 1,000 images is about 15 min&#160;on a minimally configured laptop, or around 1 min&#160;on a multi-core performance workstation. The graphical user interface (GUI) is also designed for easy quality control, and users can manually override the computer results. The key method used in this software is adapted from the active contour algorithm, also known as Snakes, which is especially suitable for images with uneven illumination and noisy background that often plagues automated imaging processing in high-throughput screens. The complimentary &#8220;Manual Initialize&#8221; and &#8220;Hand Draw&#8221; tools provide the flexibility to SpheroidSizer in dealing with various types of spheroids and diverse quality images. This high-throughput image analysis software remarkably reduces labor and speeds up the analysis process. Implementing this software is beneficial for 3D tumor spheroids to become a routine in vitro model for drug screens in industry and academia.

We present a high-throughput image analysis software application to measure the size of three-dimensional tumor spheroids imaged with bright-field microscopy. This application provides a fast and effective way to examine the effects of therapeutic drugs on spheroids, which is beneficial for researchers who wish to use spheroids in drug screens.

The increasing number of applications of three-dimensional (3D) tumor spheroids as an in vitro model for drug discovery requires their adaptation to ...

Applications of the Single-probe: Mass Spectrometry Imaging and Single Cell Analysis under Ambient Conditions

Mass spectrometry imaging (MSI) and in-situ single cell mass spectrometry (SCMS) analysis under ambient conditions are two emerging fields with great potential for the detailed mass spectrometry (MS) analysis of biomolecules from biological samples. The single-probe, a miniaturized device with integrated sampling and ionization capabilities, is capable of performing both ambient MSI and in-situ SCMS analysis. For ambient MSI, the single-probe uses surface micro-extraction to continually conduct MS analysis of the sample, and this technique allows the creation of MS images with high spatial resolution (8.5 &#181;m) from biological samples such as mouse brain and kidney sections. Ambient MSI has the advantage that little to no sample preparation is needed before the analysis, which reduces the amount of potential artifacts present in data acquisition and allows a more representative analysis of the sample to be acquired. For in-situ SCMS, the single-probe tip can be directly inserted into live eukaryotic cells such as HeLa cells, due to the small sampling tip size (&lt; 10 &#181;m), and this technique is capable of detecting a wide range of metabolites inside individual cells at near real-time. SCMS enables a greater sensitivity and accuracy of chemical information to be acquired at the single cell level, which could improve our understanding of biological processes at a more fundamental level than previously possible. The single-probe device can be potentially coupled with a variety of mass spectrometers for broad ranges of MSI and SCMS studies.

Here, we present protocols to perform both ambient mass spectrometry imaging (MSI) of tissues and in-situ live single cell MS (SCMS) analysis using the single-probe, which is a miniaturized multifunctional device for MS analysis.

Mass spectrometry imaging (MSI) and in-situ single cell mass spectrometry (SCMS) analysis under ambient conditions are two emerging fields with great ...

Experimental Protocol for Using Drosophila As an Invertebrate Model System for Toxicity Testing in the Laboratory

Emergent properties and external factors (population-level and ecosystem-level interactions, in particular) play important roles in mediating ecologically-important endpoints, though they are rarely considered in toxicological studies. D. melanogaster is emerging as a toxicology model for the behavioral, neurological, and genetic impacts of toxicants, to name a few. More importantly, species in the genus Drosophila can be utilized as a model system for an integrative framework approach to incorporate emergent properties and answer ecologically-relevant questions in&#160;toxicology research. The aim of this paper is to provide a protocol for exposing species in the genus Drosophila to pollutants to be used as a model system for a range of phenotypic outputs and ecologically-relevant questions. More specifically, this protocol can be used to 1) link multiple biological levels of organization and understand the impact of toxicants on both individual- and population-level fitness; 2) test the impact of toxicants at different stages of developmental exposure; 3) test multigenerational and evolutionary implications of pollutants; and 4) test multiple contaminants and stressors simultaneously.

Experimental Protocol for Using Drosophila As an Invertebrate Model System for Toxicity Testing in the Laboratory

In this paper, we provide a detailed protocol for exposing species in the genus Drosophila to pollutants with the goal of studying the impact of exposure on a range of phenotypic outputs at different developmental stages and for more than one generation.

Emergent properties and external factors (population-level and ecosystem-level interactions, in particular) play important roles in mediating ...

Co-immunoprecipitation Assay Using Endogenous Nuclear Proteins from Cells Cultured Under Hypoxic Conditions

Low oxygen levels (hypoxia) trigger a variety of adaptive responses with the Hypoxia-inducible factor 1 (HIF-1) complex acting as a master regulator. HIF-1 consists of a heterodimeric oxygen-regulated &#945; subunit (HIF-1&#945;) and constitutively expressed &#946; subunit (HIF-1&#946;) also known as aryl hydrocarbon receptor nuclear translocator (ARNT), regulating genes involved in diverse processes including angiogenesis, erythropoiesis and glycolysis. The identification of HIF-1 interacting proteins is key to the understanding of the hypoxia signaling pathway. Besides the regulation of HIF-1&#945; stability, hypoxia also triggers the nuclear translocation of many transcription factors including HIF-1&#945; and ARNT. Notably, most of the current methods used to study such protein-protein interactions (PPIs) are based on systems where protein levels are artificially increased through protein overexpression. Protein overexpression often leads to non-physiological results arising from temporal and spatial artifacts. Here we describe a modified co-immunoprecipitation protocol following hypoxia treatment using endogenous nuclear proteins, and as a proof of concept, to show the interaction between HIF-1&#945; and ARNT. In this protocol, the hypoxic cells were harvested under hypoxic conditions and the Dulbecco's Phosphate-Buffered Saline (DPBS) wash buffer was also pre-equilibrated to hypoxic conditions before usage to mitigate protein degradation or protein complex dissociation during reoxygenation. In addition, the nuclear fractions were subsequently extracted to concentrate and stabilize endogenous nuclear proteins and avoid possible spurious results often seen during protein overexpression. This protocol can be used to demonstrate endogenous and native interactions between transcription factors and transcriptional co-regulators under hypoxic conditions.

Here we describe a co-immunoprecipitation protocol to study protein-protein interactions between endogenous nuclear proteins under hypoxic conditions. This method is suitable for demonstration of the interactions between transcription factors and transcriptional co-regulators at hypoxia.

Low oxygen levels (hypoxia) trigger a variety of adaptive responses with the Hypoxia-inducible factor 1 (HIF-1) complex acting as a master regulator. ...

Field-Based Thermal Physiology Assay: Cold Shock Recovery under Ambient Conditions

Ecological physiology, particularly of ectotherms, is increasingly important in this changing world as it uses measures of species and environmental traits to explore the interactions between organisms and their surroundings to better understand their survival and fitness. Traditional thermal assays are costly in terms of time, money, and equipment and are therefore often limited to small sample sizes and few species. Presented here is a novel protocol that generates detailed data on individual behavior and physiology of large, volant, terrestrial insects, using the example of butterflies. This paper describes the methods of a cold shock recovery assay that can be performed in the field under ambient environmental conditions and does not require costly laboratory equipment. This method has been used to understand the response and recovery strategy to cold shock of tropical butterflies, generating individual level data across entire butterfly communities. These methods can be employed in both remote field settings and classrooms and can be used to generate ecologically relevant physiological data and as a teaching tool.

Here, a low-cost, accessible protocol is described to evaluate cold shock recovery of butterflies under ambient environmental conditions.

Ecological physiology, particularly of ectotherms, is increasingly important in this changing world as it uses measures of species and environmental ...

Tobacco Hornworm as an Insect Model System for Cannabinoid Pre-clinical Studies

With increased attention on cannabinoids in medicine, several mammalian model organisms have been used to elucidate their unknown pharmaceutical functions. However, many difficulties remain in mammalian research, which necessitates the development of non-mammalian model organisms for cannabinoid research. The authors suggest the tobacco hornworm Manduca sexta as a novel insect model system. This protocol provides information on preparing the artificial diet with varying amounts of cannabidiol (CBD), setting up a cultivation environment, and monitoring their physiological and behavioral changes in response to CBD treatment. Briefly, upon receiving hornworm eggs, the eggs were allowed 1-3 days at 25 &#176;C on a 12:12 light-dark cycle to hatch before being randomly distributed into control (wheat germ-based artificial diet; AD), vehicle (AD + 0.1% medium-chain triglyceride oil; MCT oil) and treatment groups (AD + 0.1% MCT + 1 mM or 2 mM of CBD). Once the media was prepared, 1st instar larvae were individually placed in a 50 mL test tube with a wooden skewer stick, and then the test tube was covered with a cheesecloth. Measurements were taken in 2-day intervals for physiological and behavioral responses to the CBD administration. This simple cultivation procedure allows researchers to test large specimens in a given experiment. Additionally, the relatively short life cycles enable researchers to study the impact of cannabinoid treatments over multiple generations of a homogenous population, allowing for data to support an experimental design in higher mammalian model organisms.

The present protocol provides instructional information for using tobacco hornworm Manduca sexta in cannabinoid research. The method described here includes all necessary supplies and protocols to monitor physiological and behavioral changes of the insect model in response to cannabidiol (CBD) treatment.