Name: creating and applying a reference to facilitate the discussion and classification of proteins in a diverse group
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Description: Watch this Scientific Journal Video about Creating and Applying a Reference to Facilitate the Discussion and Classification of Proteins in a Diverse Group at JoVE.com

Ongoing tardigrade antimicrobial peptide research is supported by intramural funding from the Midwestern University Office of Research and Sponsored Programs (ORSP). The ORSP had no role in study design, data collection, analysis, interpretation, or manuscript preparation.

1. Determine the Defining Features of the Protein Group of Interest
<ol>
	<li>Consult previous publications to determine if there is a consensus regarding the features that are necessary to be considered part of the group. Take note of any inconsistencies or differences in opinion between research groups, and include characteristics that may serve to differentiate one subgroup from another.</li>
	<li>If previous literature does not address defining characteristics, use sequences that are considered representative of th...

<ol>
	<li>Matsuyama, K., Natori, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+of+Three+Antibacterial+Proteins+from+the+Culture+Medium+of+NIH-Sape-4,+an+Embryonic+Cell+Line+of+Sarcophaga+peregrina.">Purification of Three Antibacterial Proteins from the Culture Medium of NIH-Sape-4, an Embryonic Cell Line of Sarcophaga peregrina.</a> J Biol Chem. 263 (32), 17112-17116 (1988).</li><li>Lambert, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insect+immunity:+Isolation+from+immune+blood+of+the+dipteran+Phormia+terranovae.+of+two+insect+antibacterial+peptides+with+sequence+homology+to+rabbit+lung+macrophage+bactericidal+peptides.">Insect immunity: Isolation from immune blood of the dipteran Phormia terranovae. of two insect antibacterial peptides with sequence homology to rabbit lung macrophage bactericidal peptides.</a> PNAS. 86 (262-266), (1989).</li><li>Dimarcq, J. -. L., Bulet, P., Hetru, C., Hoffmann, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cysteine-rich+antimicrobial+peptides+in+invertebrates.">Cysteine-rich antimicrobial peptides in invertebrates.</a> Biopolymers. 47, 465-477 (1998).</li><li>Shafee, T. M. A., Lay, F. T., Hulett, M. D., Anderson, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Defensins+Consist+of+Two+Independent,+Convergent+Protein+Superfamilies.">The Defensins Consist of Two Independent, Convergent Protein Superfamilies.</a> Mol Biol Evol. 33 (9), 2345-2356 (2016).</li><li>Zhu, S., Gao, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nematode-derived+drosomycin-type+antifungal+peptdies+provide+evidence+for+plant-to-ecdysozoan+horizontal+transfer+of+a+disease+resistance+gene.">Nematode-derived drosomycin-type antifungal peptdies provide evidence for plant-to-ecdysozoan horizontal transfer of a disease resistance gene.</a> Nat Commun. 5, (2014).</li><li>Zhu, S., Gao, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolutionary+origin+of+b-defensins.">Evolutionary origin of b-defensins.</a> Dev. Comp. Immunol. 39, 79-84 (2013).</li><li>Bonmatin, J. -. 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=Two-dimensional+1H+NMR+study+of+recombinant+insect+defensin+A+in+water:+Resonance+assignments,+secondary+structure+and+global+folding.">Two-dimensional 1H NMR study of recombinant insect defensin A in water: Resonance assignments, secondary structure and global folding.</a> J Biomol NMR. 2 (3), 235-256 (1992).</li><li>Cornet, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Refined+three-dimensional+solution+structure+of+insect+defensin+A.">Refined three-dimensional solution structure of insect defensin A.</a> Structure. 3 (5), 435-448 (1995).</li><li>Murzin, A. G., Brenner, S. E., Hubbard, T., Chothia, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SCOP:+a+structural+classification+of+proteins+database+for+the+investigations+of+sequences+and+structures.">SCOP: a structural classification of proteins database for the investigations of sequences and structures.</a> J Mol Biol. 247, 536-540 (1995).</li><li>Sillitoe, I., 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=CATH:+comprehensive+structural+and+functional+annotations+for+genome+sequences.">CATH: comprehensive structural and functional annotations for genome sequences.</a> Nucleic Acids Res. 43, 376-381 (2015).</li><li>Lam, S. 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=Gene3D:+expanding+the+utility+of+domain+assignments.">Gene3D: expanding the utility of domain assignments.</a> Nucleic Acids Res. 44, 404-409 (2016).</li><li>Tarr, D. E. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Establishing+a+reference+array+for+the+CS-ab+superfamily+of+defensive+peptides.">Establishing a reference array for the CS-ab superfamily of defensive peptides.</a> BMC Res Notes. 9, 490 (2016).</li><li>Shafee, T. M. A., Robinson, A. J., van der Weerden, N., Anderson, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+homology+guided+alignment+of+cysteine+rich+proteins.">Structural homology guided alignment of cysteine rich proteins.</a> SpringerPlus. 5 (27), (2016).</li><li>Altschul, S. F., Gish, W., Miller, W., Myers, E. W., Lipman, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basic+Local+Alignment+Search+Tool.">Basic Local Alignment Search Tool.</a> J Mol Biol. 215 (3), 403-410 (1990).</li><li>Duckert, P., Brunak, S., Blom, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prediction+of+proprotein+convertase+cleavage+sites.">Prediction of proprotein convertase cleavage sites.</a> Protein Eng Des Sel. 17 (1), 107-112 (2004).</li><li>Petersen, T. N., Brunak, S., von Heijne, G., Nielsen, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SignalP+4.0:discriminating+signal+peptides+from+transmembrane+regions.">SignalP 4.0:discriminating signal peptides from transmembrane regions.</a> Nat Methods. 8, 785-786 (2011).</li><li>Kobayashi, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cysteine-stabilized+a-helix:+A+common+structural+motif+of+ion-channel+blocking+neurotoxic+peptides.">The cysteine-stabilized a-helix: A common structural motif of ion-channel blocking neurotoxic peptides.</a> Biopolymers. 31, 1213-1220 (1991).</li><li>Gao, B., del Carmen Rodriguez, M., Lanz-Mendoza, H., Zhu, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=AdDLP,+a+bacterial+defensin-like+peptide,+exhibits+anti-Plasmodium.+activity.">AdDLP, a bacterial defensin-like peptide, exhibits anti-Plasmodium. activity.</a> Biochem Biophys Res Commun. 387, 393-398 (2009).</li><li>Tamura, K., Stecher, G., Peterson, D., Filipski, A., Kumar, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MEGA6:+Molecular+Evolutionary+Genetics+Analysis.">MEGA6: Molecular Evolutionary Genetics Analysis.</a> Mol Biol Evol. 30 (12), 2725-2729 (2013).</li><li>Edgar, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MUSCLE:+multiple+sequence+alignment+with+high+accuracy+and+high+throughput.">MUSCLE: multiple sequence alignment with high accuracy and high throughput.</a> Nucleic Acids Res. 32 (5), 1792-1797 (2004).</li><li>Ronquist, F., Huelsenbeck, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MrBayes+3:+Bayesian+phylogenetic+inference+under+mixed+models.">MrBayes 3: Bayesian phylogenetic inference under mixed models.</a> Bioinformatics. 19 (12), 1572-1574 (2003).</li><li>Altschul, S. F., 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=Gapped+BLAST+and+PSI-BLAST:+a+new+generation+of+protein+database+search+programs.">Gapped BLAST and PSI-BLAST: a new generation of protein database search programs.</a> Nucleic Acids Res. 25 (17), 3389-3402 (1997).</li><li>Zhang, Z., 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=Protein+sequence+similarity+searches+using+patterns+as+seeds.">Protein sequence similarity searches using patterns as seeds.</a> Nucleic Acids Res. 26 (17), 3986-3990 (1998).</li></ol>

The criteria for naming a protein within a group should be clear, but this is not always the case. Sequences that have the CS-&#945;&#946; fold have been studied in many labs using a variety of organisms, resulting in different systems of nomenclature, as well as varying levels of characterization. Attempting to impose a completely new nomenclature is not reasonable and would result in a great deal of confusion when consulting previous literature. A reference numbering system can be used in addition to the name of a prot...

A protein&#39;s name should reflect is characteristics and relationship to other proteins. Unfortunately, names are generally assigned at the time of discovery and, as research continues, the understanding of the larger context may change. This can lead to multiple names if a protein was independently identified by more than one lab, to changes in nomenclature or in the characteristics thought to be definitive when assigning the name, and to the name no longer sufficiently differentiating the protein from others.
Invertebrate defensins provide a good example of degeneration in nomenclature and classification. The first invertebrate defensins were reported from insects, and the name &#34;insect defensin&#34; was proposed based on the perceived homology to mammalian defensins1,2. The term defensin is still used, even though it is now clear that invertebrate and mammalian defensins do not share a common ancestor3,4. Depending on the species, an invertebrate &#34;defensin&#34; may have six or eight cysteines (that form three or four disulfide bonds) and a variety of antimicrobial activities. To complicate the situation, proteins with the same characteristics as defensins are not always called &#34;defensins,&#34; such as the recently identified cremycins from Caenorhabditis remanei5. In addition, invertebrate big defensins are more likely to be evolutionarily related to vertebrate &#946;-defensins than to other invertebrate defensins6. Despite this, researchers sometimes rely on the name &#34;defensin&#34; when determining which sequences should be included in analyses.
Structural studies revealed the similarity between insect defensins and scorpion toxins7, and the CS-&#945;&#946; fold was subsequently established as the defining structural characteristic of insect defensins8. This fold defines the scorpion toxin-like (CS-&#945;&#946;) superfamily in the Structural Classification of Proteins (SCOP) database9, which currently includes five families: insect defensins, short-chain scorpion toxins, long-chain scorpion toxins, MGD-1 (from a mollusk), and plant defensins. This superfamily is synonymous with the recently described cis-defensins4 and Superfamily 3.30.30.10 in the CATH/Gene 3D database10,11. Studies from a variety of invertebrate taxa, plants, and fungi show that the names of proteins that contain this fold are not clearly related to cysteine number or bonding pattern, antimicrobial activity, or evolutionary history12.
The lack of consistency and clear criteria make it challenging to name and classify newly-identified sequences in this superfamily. A major obstacle to comparing proteins in this superfamily is that cysteines are numbered with respect to each individual sequence (the first cysteine in each sequence is C1), with no way to account for the structural role. This means that only sequences with the same number of cysteines can be compared. There is little sequence conservation other than the cysteines forming the CS-&#945;&#946; fold, which makes alignments and phylogenetic analyses difficult. By developing a numbering system that prioritizes structural features, superfamily sequences can be more easily compared and aligned. Conserved features, as well as those defining subgroups, can be visualized quickly, and new sequences can be more easily placed into the appropriate context.
This paper uses a spreadsheet software (e.g., Excel) to generate a reference numbering system for the CS-&#945;&#946; superfamily. It shows how this clarifies comparisons between sequences and applies it to new CS-&#945;&#946; sequences identified from tardigrades. Using the CS-&#945;&#946; superfamily as an example, the protocol was written to provide guidance when using sequences of interest; however, it is not intended to be specific to this superfamily or to cysteine-rich sequences. This method will likely be most useful for groups of proteins that have been researched independently in divergent taxa and/or have little overall sequence homology, with discrete characteristics that may not be easily recognized by molecular analysis software. This method requires some a priori decisions regarding important features, so it will be of limited utility if no important features have been identified. The primary goal is to show how a simple visualization of the sequence relationships can be achieved. This can then be used to inform sequence alignment and analysis, but if alignment and analysis are the primary goals, a barcode method would be a suitable alternative that has more capacity for automation13. The current method displays the features of each peptide in a linear form, so it will not be helpful for the direct visualization of 3D structure.

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			<td height="42" style="width:216px;height:42px;">BLAST webpage</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td style="width:167px;">https://blast.ncbi.nlm.nih.gov/Blast.cgi</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:216px;height:21px;">EditSeq (Lasergene suite)</td>
			<td style="width:71px;">DNASTAR</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">https://www.dnastar.com/t-allproducts.aspx</td>
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			<td height="21" style="width:216px;height:21px;">Excel 2013</td>
			<td style="width:71px;">Microsoft</td>
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			<td style="width:167px;"></td>
		</tr>
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			<td height="63" style="width:216px;height:63px;">FigTree</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td style="width:167px;">&#160;http://tree.bio.ed.ac.uk/software/figtree/</td>
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			<td height="21" style="width:216px;height:21px;">MEGA</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td>www.megasoftware.net</td>
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			<td height="42" style="width:216px;height:42px;">MrBayes</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td style="width:167px;">http://mrbayes.sourceforge.net/</td>
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			<td height="42" style="width:216px;height:42px;">SCOP database</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td style="width:167px;">http://scop.mrc-lmb.cam.ac.uk/scop/</td>
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creating and applying a reference to facilitate the discussion and classification of proteins in a diverse group

Related proteins that have been studied in different labs using varying organisms may lack a uniform system of nomenclature and classification, making it difficult to discuss the group as a whole and to place new sequences into the appropriate context. Developing a reference that prioritizes important sequence features related to structure and/or activity can be used in addition to established names to add some coherency to a diverse group of proteins. This paper uses the cysteine-stabilized alpha-helix (CS-&#945;&#946;) superfamily as an example to show how a reference generated in&#160;spreadsheet software can clarify relationships between existing proteins in the superfamily, as well as facilitate the addition of new sequences. It also shows how the reference can help to refine sequence alignments generated in commonly used software, which impacts the validity of phylogenetic analyses. The use of a reference will likely be most helpful for protein groups that include highly divergent sequences from a broad spectrum of taxa, with features that are not adequately captured by molecular analyses.

Groups of sequences in the CS-&#945;&#946; superfamily reported in the literature are shown in Figure 4. The cysteine pairings based on the numbering for each sequence suggest five basic groups (Table 1, middle column). Group 1 has six cysteines that from three disulfide bonds and includes sequences from insects, arachnids, mollusks, nematodes, and fungi. Groups 2, 3, and 4 have 8 cysteines that form four disulfide bonds. Group 2 includes ins...

Watch this Scientific Journal Video about Creating and Applying a Reference to Facilitate the Discussion and Classification of Proteins in a Diverse Group at JoVE.com

Creating and Applying a Reference to Facilitate the Discussion and Classification of Proteins in a Diverse Group

The goal of this protocol is to develop a reference for divergent proteins in a group that lacks coherent criteria for nomenclature and classification. This reference will facilitate analyses and discussion of the group as a whole and can be used in addition to established names.

Related proteins that have been studied in different labs using varying organisms may lack a uniform system of nomenclature and classification, making it ...

The overall goal of this procedure is to use standard spreadsheet software to develop a reference for divergent proteins in a group that lacks coherent criteria for nomenclature and classification. This method can help clarify relationships between related proteins that have confusing or inconsistent nomenclature, such as the cysteine-stabilized alpha-beta superfamily of defensive peptides that includes invertebrate defenses. The main advantage of this technique is that it provides a simple visual representation of the proteins of interest.To begin, identify the defining characteristics of the protein group of interest. For example, the CS alpha-beta fold in the solution structure of insect defense and aid from phormia terraenovae defines the CS alpha-beta superfamily. This fold also includes a smaller motif called the cysteine-stabilized helix, which is identified by CXXXC upstream of a CXC.The four cysteines form two disulfide bonds. To complete the CS alpha-beta motif, a third disulfide bond is formed by an additional pair of cysteines. Ultimately it is critical to know at least some important features related to the structure or function of the protein.Without this, there is no basis for generating a reference. Now, enter these defining features into a spreadsheet. Use columns for the conserved features and to represent the spaces between these features.Keep the columns wide enough to fit numbers, and give them a consistent width. In the rows, describe the sequences. To indicate a sequence as a feature, fill in the feature box with color, using the fill function.Then, to indicate the spacing between the features, enter the number of amino acids in the box between. Now, add representative sequences that have been previously established as members of the group based on structural databases and published results. As needed, add features that are likely to define a subgroup of sequences, such as an extra cysteine.If features are missing from a given sequence, leave the box unfilled and combine it with boxes representing intervening amino acids. To do this, us the Merge and Center function. Once representative sequences have been entered, identify groups of clearly related sequences.Then, summarize the characteristics of these groups. When the number of amino acids between features varies, use a hyphen to indicate a range or slashes to indicate a few specific numbers. As needed, creatively annotate features that may be relevant or aren't common enough to include in the reference.For example, since cysteines are important in the superfamily, the presence of additional cysteines can be labeled. Sometimes, when adding newly identified sequences to the spreadsheet, the sequences of one species fall into several different groups of the superfamily, such as for tardigrades. Once completed, the rows of the spreadsheet can then be sorted to highlight variation within a species, or variation in between taxonomic groups.This demonstration uses the freely available MEGA 6 software. However, other software can be used similarly. To start a new alignment, select Edit/Build Alignment under the Align tab.Then select Create a new alignment, in the box that appears and click OK.Then select Protein. Now, select Insert Sequence from File, in the Edit menu, to import the sequences. The sequences must be in FASTA format.Background colors reflecting different amino acid types are shown by default and can be turned off with a toggle, under the Display menu. Once all the sequences are entered, click the flexing arm icon and then Align Protein to align the sequences using the muscle algorithm. If the message, Nothing selected for alignment.Select all? pops up, choose OK.Some parameters can be changed in the pop-up window, but for this demonstration, the defaults will suffice. Now, check the alignment based on the important features of the protein superfamily.The top bar shows an asterisk in any position in which the amino acid is completely conserved. The initial alignment identifies three of the four conserved cysteines. One sequence is clearly misaligned.To fix a misaligned sequence, highlight the dashes and press the Delete key without accidentally deleting amino acids. Then, move the amino acids into their proper alignment by adding spaces. After aligning the sequence manually, note that the last cysteine of the CXXXC motif is conserved throughout the alignment.Manual adjustment is often necessary to prioritize the most important features of the sequences. The spreadsheet alignment of the previously established CS alpha-beta superfamily revealed five basic patterns of bond formation. The newly identified tardigrade sequences fell into the complete spectrum of these patterns.Next, phylogenetic analyses were used to examine how this group of proteins may have evolved. However, the sequences are generally short and highly divergent. Thus, the resulting trees were poorly resolved and offered little insight.The multiple sequence alignment was optimized using the reference, but there was still poor resolution in the maximum likelihood analysis and in the Bayesian phylogenetic analysis. Most clades had only low levels of support. However, five small groups were supported in at least one of the two trees.Sequences with different cysteine numbers within a taxonomical group may be more closely related than sequences with the same pattern from different groups. After watching this video, you should have a good understanding of how to use spreadsheet software to generate a simple visualization of important protein characteristics. While attempting this procedure, it's important to remember that determining the most relevant characteristics for the group of proteins is often an iterative process, and revision of the reference will likely be necessary.New sequences can always be added to a spreadsheet, and it is easy to have multiple versions allowing for new features to be added that may be useful for classification and analysis. Although the spreadsheet alignment allows easy visualization of structural and functional features, other methods like phylogenetic analysis can be performed to provide additional insight into evolutionary relationships.

creating-applying-reference-to-facilitate-discussion-classification

Research

JoVE Journal

Behavior

The Crossmodal Congruency Task as a Means to Obtain an Objective Behavioral Measure in the Rubber Hand Illusion Paradigm

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden hand is touched. If the viewed and felt touches are given at the same time then this is sufficient to induce the compelling experience that the rubber hand is one's own hand. The RHI can be used to investigate exactly how the brain constructs distinct body representations for one's own body. Such representations are crucial for successful interactions with the external world. To obtain a subjective measure of the RHI, researchers typically ask participants to rate statements such as "I felt as if the rubber hand were my hand". Here we demonstrate how the crossmodal congruency task can be used to obtain an objective behavioral measure within this paradigm.
The variant of the crossmodal congruency task we employ involves the presentation of tactile targets and visual distractors. Targets and distractors are spatially congruent (i.e. same finger) on some trials and incongruent (i.e. different finger) on others. The difference in performance between incongruent and congruent trials - the crossmodal congruency effect (CCE) - indexes multisensory interactions. Importantly, the CCE is modulated both by viewing a hand as well as the synchrony of viewed and felt touch which are both crucial factors for the RHI.
The use of the crossmodal congruency task within the RHI paradigm has several advantages. It is a simple behavioral measure which can be repeated many times and which can be obtained during the illusion while participants view the artificial hand. Furthermore, this measure is not susceptible to observer and experimenter biases. The combination of the RHI paradigm with the crossmodal congruency task allows in particular for the investigation of multisensory processes which are critical for modulations of body representations as in the RHI.

We demonstrate how an objective measure can be employed in the widely employed rubber hand illusion paradigm. This measure is obtained by modifying the well-established crossmodal congruency task. This task allows the investigation of multisensory processes which are critical for modulations of body representations as in the rubber hand illusion.

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden ...

Using the Threat Probability Task to Assess Anxiety and Fear During Uncertain and Certain Threat

Fear of certain threat and anxiety about uncertain threat are distinct emotions with unique behavioral, cognitive-attentional, and neuroanatomical components. Both anxiety and fear can be studied in the laboratory by measuring the potentiation of the startle reflex. The startle reflex is a defensive reflex that is potentiated when an organism is threatened and the need for defense is high. The startle reflex is assessed via electromyography (EMG) in the orbicularis oculi muscle elicited by brief, intense, bursts of acoustic white noise (i.e., &#8220;startle probes&#8221;). Startle potentiation is calculated as the increase in startle response magnitude during presentation of sets of visual threat cues that signal delivery of mild electric shock relative to sets of matched cues that signal the absence of shock (no-threat cues). In the Threat Probability Task, fear is measured via startle potentiation to high probability (100% cue-contingent shock; certain) threat cues whereas anxiety is measured via startle potentiation to low probability (20% cue-contingent shock; uncertain) threat cues. Measurement of startle potentiation during the Threat Probability Task provides an objective and easily implemented alternative to assessment of negative affect via self-report or other methods (e.g., neuroimaging) that may be inappropriate or impractical for some researchers. Startle potentiation has been studied rigorously in both animals (e.g., rodents, non-human primates) and humans which facilitates animal-to-human translational research. Startle potentiation during certain and uncertain threat provides an objective measure of negative affective and distinct emotional states (fear, anxiety) to use in research on psychopathology, substance use/abuse and broadly in affective science. As such, it has been used extensively by clinical scientists interested in psychopathology etiology and by affective scientists interested in individual differences in emotion.

Potentiation of the startle reflex is measured via electromyography of the orbicularis oculi muscle during low (uncertain) and high (certain) probability electric shock threat in the Threat Probability Task. This provides an objective measure of distinct negative emotional states (fear/anxiety) for research on psychopathology, substance use/abuse, and broad affective science.

Fear of certain threat and anxiety about uncertain threat are distinct emotions with unique behavioral, cognitive-attentional, and neuroanatomical ...

The Modified Hole Board - Measuring Behavior, Cognition and Social Interaction in Mice and Rats

This protocol describes the modified hole board (mHB), which combines features from a traditional hole board and open field and is designed to measure multiple dimensions of unconditioned behavior in small laboratory mammals (e.g., mice, rats, tree shrews and small primates). This paradigm is a valuable alternative for the use of a behavioral test battery, since a broad behavioral spectrum of an animal&#8217;s behavioral profile can be investigated in one single test.
The apparatus consists of a box, representing the &#8216;protected&#8217; area, separated from a group compartment. A board, on which small cylinders are staggered in three lines, is placed in the center of the box, representing the &#8216;unprotected&#8217; area of the set-up. The cognitive abilities of the animals can be measured by baiting some cylinders on the board and measuring the working and reference memory. Other unconditioned behavior, such as activity-related-, anxiety-related- and social behavior, can be observed using this paradigm. Behavioral flexibility and the ability to habituate to a novel environment can additionally be observed by subjecting the animals to multiple trials in the mHB, revealing insight into the animals&#8217; adaptive capacities.
Due to testing order effects in a behavioral test battery, na&#239;ve animals should be used for each individual experiment. By testing multiple behavioral dimensions in a single paradigm and thereby circumventing this issue, the number of experimental animals used is reduced. Furthermore, by avoiding social isolation during testing and without the need to food deprive the animals, the mHB represents a behavioral test system, inducing if any, very low amount of stress.

This protocol describes the modified hole board, which is a behavioral test set-up that comprises the characteristics of an open field and a traditional hole board. This set-up enables the differential analysis of unconditioned behavior of small laboratory mammals as well as the analysis of cognitive abilities.

This protocol describes the modified hole board (mHB), which combines features from a traditional hole board and open field and is designed to measure ...

Applying Stereotactic Injection Technique to Study Genetic Effects on Animal Behaviors

Stereotactic injection is a useful technique to deliver high titer lentiviruses to targeted brain areas in mice. Lentiviruses can either overexpress or knockdown gene expression in a relatively focused region without significant damage to the brain tissue. After recovery, the injected mouse can be tested on various behavioral tasks such as the Open Field Test (OFT) and the Forced Swim Test (FST). The OFT is designed to assess locomotion and the anxious phenotype in mice by measuring the amount of time that a mouse spends in the center of a novel open field. A more anxious mouse will spend significantly less time in the center of the novel field compared to controls. The FST assesses the anti-depressive phenotype by quantifying the amount of time that mice spend immobile when placed into a bucket of water. A mouse with an anti-depressive phenotype will spend significantly less time immobile compared to control animals. The goal of this protocol is to use the stereotactic injection of a lentivirus in conjunction with behavioral tests to assess how genetic factors modulate animal behaviors.

Stereotactic injection of lentiviruses expressing cDNAs or shRNAs can modulate gene expression in specific brain areas of mice. Here, we present a protocol to combine stereotactic injections with behavioral tasks, such as the Open Field Test (OFT) and the Forced Swim Test (FST).

Stereotactic injection is a useful technique to deliver high titer lentiviruses to targeted brain areas in mice. Lentiviruses can either overexpress or ...

The Social Dimension of Stress: Experimental Manipulations of Social Support and Social Identity in the Trier Social Stress Test

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations supportive behavior of other people as well as positive social relationships can act as powerful resources to cope with stress. In order to study the interplay between these variables, this protocol describes two effective experimental manipulations of social relationships and supportive behavior in the laboratory. In the present article, these two manipulations are implemented in the Trier Social Stress Test (TSST)&#8212;a standard stress induction paradigm in which participants are subjected to a simulated job interview. More precisely, we propose (a) a manipulation of the relationship between different protagonists in the TSST by making a shared social identity salient and (b) a manipulation of the behavior of the TSST-selection committee, which acts either supportively or unsupportively. These two experimental manipulations are designed in a modular fashion and can be applied independently of each other but can also be combined. Moreover, these two manipulations can also be integrated into other stress protocols and into other standardized social interactions such as trust games, negotiation tasks, or other group tasks.

Previous research on the social dimension of stress has focused on two important variables: social identity and social support. This protocol introduces an effective experimental manipulation of these two social variables and describes their implementation in a standard stress induction paradigm (Trier Social Stress Test).

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations ...

Psychophysical Tracking Method to Measure Taste Preferences in Children and Adults

The Monell two-series, forced-choice, paired-comparison tracking method provides a reliable measure of sweet taste preferences from childhood to adulthood. The method, which is identical for children, adolescents, and adults, is of short duration (&#60; 15 min), does not rely on sustained attention or place demands on memory (which would yield spurious age differences), and minimizes the impact of language development, making this method amenable to the cognitive limitations of pediatric populations. In this whole-mouth tasting method, subjects are asked to taste (without swallowing) pairs of solutions of different sucrose concentrations and to point to the solution they prefer. Each subsequent pair contains the participant&#39;s preceding preferred concentration and an adjacent stimulus concentration. The procedure continues until the subject chooses either a given concentration of sucrose when paired with both a higher and a lower concentration, or the highest or lowest concentration two consecutive times. Subjects are prevented from reaching response criteria on the basis of first or second position bias by the two-series design of the method, which counterbalances the order of solution presentation within each pair between the series (the weaker concentration is presented first in Series 1, second in Series 2). The geometric mean of the two sucrose concentrations chosen in Series 1 and 2 is an estimate of the participant&#39;s most preferred level of sucrose. Sucrose preference as determined with this laboratory-based measure has been shown to be associated with preference for sugars in foods and beverages and with taste receptor genotype, family history of alcoholism, and race/ethnicity, as well as depressive symptomatology among pediatric populations. The method has real-world relevance and has been applied to determine most preferred level of other tastes (e.g., salt), making it a valuable psychophysical tool.

Sweet taste has powerful hedonic appeal among people of all ages, particularly children. Described herein is a reliable and valid method that can be used to determine the level of sweetness most preferred, making it a valuable psychophysical tool for scientists.

The Monell two-series, forced-choice, paired-comparison tracking method provides a reliable measure of sweet taste preferences from childhood to ...

Behavioral Disturbances: An Innovative Approach to Monitor the Modulatory Effects of a Nutraceutical Diet

In dogs, diets are often used to modulate behavioral disturbances related to chronic anxiety and stress caused by intense and restless activity. However, the traditional ways to monitor behavioral changes in dogs are complicated and not efficient. In the current clinical evaluation, a new, simple monitoring system was used to assess the effectiveness of a specific diet in positively modulating the intense and restless activity of 24 dogs of different ages and breeds. This protocol describes how to easily and rapidly evaluate improvement in a set of symptoms related to generalized anxiety by using a specific sensor, a mobile phone app, a wireless router, and a computer. The results showed that dogs treated with specific diets showed significant improvement in the times spent active and at rest after 10 days (p &lt; 0.01 and p &lt; 0.05, respectively). These dogs also showed an overall significant improvement in clinical and behavioral symptoms. A specific sensor, along with its related hardware, was demonstrated to successfully monitor behavioral changes relating to movement in dogs.

We report a simple approach to evaluate the effectiveness of a specific diet in positively modulating the daily activity and clinical and behavioral symptoms of dogs with evident behavioral disturbances.

In dogs, diets are often used to modulate behavioral disturbances related to chronic anxiety and stress caused by intense and restless activity. However, ...

Using a Virtual Store As a Research Tool to Investigate Consumer In-store Behavior

People&#39;s responses to products and/or choice environments are crucial to understanding in-store consumer behaviors. Currently, there are various approaches (e.g., surveys or laboratory settings) to study in-store behaviors, but the external validity of these is limited by their poor capability to resemble realistic choice environments. In addition, building a real store to meet experimental conditions while controlling for undesirable effects is costly and highly difficult. A virtual store developed by virtual reality techniques potentially transcends these limitations by offering the simulation of a 3D virtual store environment in a realistic, flexible, and cost-efficient way. In particular, a virtual store interactively allows consumers (participants) to experience and interact with objects in a tightly controlled yet realistic setting. This paper presents the key elements of using a desktop virtual store to study in-store consumer behavior. Descriptions of the protocol steps to: 1) build the experimental store, 2) prepare the data management program, 3) run the virtual store experiment, and 4) organize and export data from the data management program are presented. The virtual store enables participants to navigate through the store, choose a product from alternatives, and select or return products. Moreover, consumer-related shopping behaviors (e.g., shopping time, walking speed, and number and type of products examined and bought) can also be collected. The protocol is illustrated with an example of a store layout experiment showing that shelf length and shelf orientation influence shopping- and movement-related behaviors. This demonstrates that the use of a virtual store facilitates the study of consumer responses. The virtual store can be especially helpful when examining factors that are costly or difficult to change in real life (e.g., overall store layout), products that are not presently available in the market, and routinized behaviors in familiar environments.

This paper describes the use of a desktop virtual store to create virtual shopping environments to investigate in-store consumer behavior. A description of the protocol to build and run experiments, example results from an experiment concerning store layout, and important considerations when conducting virtual store experiments are presented.

People&#39;s responses to products and/or choice environments are crucial to understanding in-store consumer behaviors. Currently, there are various ...

Using the FishSim Animation Toolchain to Investigate Fish Behavior: A Case Study on Mate-Choice Copying In Sailfin Mollies

Over the last decade, employing computer animations for animal behavior research has increased due to its ability to non-invasively manipulate the appearance and behavior of visual stimuli, compared to manipulating live animals. Here, we present the FishSim Animation Toolchain, a software framework developed to provide researchers with an easy-to-use method for implementing 3D computer animations in behavioral experiments with fish. The toolchain offers templates to create virtual 3D stimuli of five different fish species. Stimuli are customizable in both appearance and size, based on photographs taken of live fish. Multiple stimuli can be animated by recording swimming paths in a virtual environment using a video game controller. To increase standardization of the simulated behavior, the prerecorded swimming path may be replayed with different stimuli. Multiple animations can later be organized into playlists and presented on monitors during experiments with live fish.
In a case study with sailfin mollies (Poecilia latipinna), we provide a protocol on how to conduct a mate-choice copying experiment with FishSim. We utilized this method to create and animate virtual males and virtual model females, and then presented these to live focal females in a binary choice experiment. Our results demonstrate that computer animation may be used to simulate virtual fish in a mate-choice copying experiment to investigate the role of female gravid spots as an indication of quality for a model female in mate-choice copying.
Applying this method is not limited to mate-choice copying experiments but can be used in various experimental designs. Still, its usability depends on the visual capabilities of the study species and first needs validation. Overall, computer animations offer a high degree of control and standardization in experiments and bear the potential to &#39;reduce&#39; and &#39;replace&#39; live stimulus animals as well as to &#39;refine&#39; experimental procedures.

Using the FishSim Animation Toolchain to Investigate Fish Behavior: A Case Study on Mate-Choice Copying In Sailfin Mollies

Using the novel FishSim Animation Toolchain, we present a protocol for non-invasive visual manipulation of public information in the context of mate-choice copying in sailfin mollies. FishSim Animation Toolchain provides an easy-to-use framework for the design, animation and presentation of computer-animated fish stimuli for behavioral experiments with live test fish.

Over the last decade, employing computer animations for animal behavior research has increased due to its ability to non-invasively manipulate the ...

Applying an eMASS Customization Program as a Research Tool to Evaluate Consumer Benefits

As many scholars and practitioners study personalization and relationship marketing, it is important to provide personalization such as mass customization through marketing technology. The purpose of this study is to examine how to conduct consumer research using an online survey and analysis of data. This study examines consumers&#39;&#160;perceived benefits while customizing a product as well as emotional product attachment, attitudes toward a customization program, and loyalty intentions in the context of online retailing. In addition, this study investigates how consumer responses are different based on individual characteristics such as fashion innovativeness. An online survey company in South Korea recruited 290 female apparel shoppers who purchased apparel online. To enhance external validity, this study used an existing retail website with a well-established mass customization program. After completing the customization program, participants complete the online questionnaire. Structural equation modeling (SEM) and latent mean analyses (LMAs) are then performed for analyses. This study stresses the importance of testing measurement invariance for mean comparisons. Before the SEM and LMA, this study follows the hierarchy of invariance tests (configural invariance test, metric invariance test, and scalar invariance test), which are not considered by traditional approaches such as ANOVA. These statistical analyses provide applicability of the invariance test procedures and LMA to consumer behaviors. The conclusions of mean differences have integrity and validity because they are guided by a sophisticated statistical procedure to ensure measurement invariance.

Presented here is a protocol to examine consumer responses toward mass customization in the context of online retailing. The protocol details the online survey procedure and how to analyze data using structural equation modeling and group differences using latent mean analyses.

As many scholars and practitioners study personalization and relationship marketing, it is important to provide personalization such as mass customization ...