Name: production of nurr-1 specific polyclonal antibodies free of cross-reactivity against its close homologs, nor1 and nur77
Uploaded: 2015-08-17T14:00:00
Description: Watch this Scientific Journal Video about Production of Nurr-1 Specific Polyclonal Antibodies Free of Cross-reactivity Against Its Close Homologs, Nor1 and Nur77 at JoVE.com

This work was supported by NIH grants (NS070577 and NS084869).

Note: The composition of all solutions cited below can be found in the Materials/Equipment Table.
1. Protein A Column Antibody Purification
<ol>
	<li>Equilibrate a protein A spin column and all required buffers to room temperature for 15 min prior to starting the procedure.</li>
	<li>Dilute the immune serum 1:1 with Protein A IgG Binding Buffer. (5 ml of serum is recommended).</li>
	<li>Gently tap a protein A spin column on the bench top to dislodge any resin that may be lodged in the cap. R...

<ol>
	<li>Hawk, J. D., Abel, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+NR4A+transcription+factors+in+memory+formation.">The role of NR4A transcription factors in memory formation.</a> Brain Res. Bull. 85 (1-2), 21-29 (2011).</li><li>Law, S. W., Conneely, O. M., DeMayo, F. J., O'Malley, B. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+a+new+brain-specific+transcription+factor,+NURR1.">Identification of a new brain-specific transcription factor, NURR1.</a> Mol. Endocrinol. 6 (12), 2129-2135 (1992).</li><li>Zetterstr&#246;m, R. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dopamine+neuron+agenesis+in+Nurr1-deficient+mice.">Dopamine neuron agenesis in Nurr1-deficient mice.</a> Science. 276 (5310), 248-250 (1997).</li><li>Kadkhodaei, 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=Nurr1+is+required+for+maintenance+of+maturing+and+adult+midbrain+dopamine+neurons.">Nurr1 is required for maintenance of maturing and adult midbrain dopamine neurons.</a> J. Neurosci. 29 (50), 15923-15932 (2009).</li><li>Decressac, M., Volakakis, N., Bj&#246;rklund, A., Perlmann, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NURR1+in+Parkinson+disease--from+pathogenesis+to+therapeutic+potential.">NURR1 in Parkinson disease--from pathogenesis to therapeutic potential.</a> Nat Rev Neurol. 9 (11), 629-636 (2013).</li><li>Pe&#241;a de Ortiz, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hippocampal+Expression+of+the+Orphan+Nuclear+Receptor+Gene+hzf-3/nurr1+during+Spatial+Discrimination+Learning.">Hippocampal Expression of the Orphan Nuclear Receptor Gene hzf-3/nurr1 during Spatial Discrimination Learning.</a> Neurobiol Learn Mem. 74 (2), 161-175 (2000).</li><li>Vecsey, C. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histone+deacetylase+inhibitors+enhance+memory+and+synaptic+plasticity+via+CREB:CBP-dependent+transcriptional+activation.">Histone deacetylase inhibitors enhance memory and synaptic plasticity via CREB:CBP-dependent transcriptional activation.</a> J. Neurosci. 27 (23), 6128-6140 (2007).</li><li>Col&#243;n-Cesario, W. 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=Knockdown+of+Nurr1+in+the+rat+hippocampus:+implications+to+spatial+discrimination+learning+and+memory.">Knockdown of Nurr1 in the rat hippocampus: implications to spatial discrimination learning and memory.</a> Learn Mem. 13 (6), 734-744 (2006).</li><li>McQuown, S. 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=HDAC3+is+a+critical+negative+regulator+of+long-term+memory+formation.">HDAC3 is a critical negative regulator of long-term memory formation.</a> J. Neurosci. 31 (2), 764-774 (2011).</li><li>Hawk, J. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NR4A+nuclear+receptors+support+memory+enhancement+by+histone+deacetylase+inhibitors.">NR4A nuclear receptors support memory enhancement by histone deacetylase inhibitors.</a> J. Clin. Invest. 122 (10), 3593-3602 (2012).</li><li>Bridi, M. S., Abel, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+NR4A+orphan+nuclear+receptors+mediate+transcription-dependent+hippocampal+synaptic+plasticity.">The NR4A orphan nuclear receptors mediate transcription-dependent hippocampal synaptic plasticity.</a> Neurobiol Learn Mem. 105, 151-158 (2013).</li><li>Gill, S. C., von Hippel, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calculation+of+protein+extinction+coefficients+from+amino+acid+sequence+data.">Calculation of protein extinction coefficients from amino acid sequence data.</a> Anal. Biochem. 182 (2), 319-326 (1989).</li><li>Smith, P. K., 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=Measurement+of+protein+using+bicinchoninic+acid.">Measurement of protein using bicinchoninic acid.</a> Anal. Biochem. 150 (1), 76-85 (1985).</li><li>Zetterstr&#246;m, R. H., Williams, R., Perlmann, T., Olson, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+expression+of+the+immediate+early+transcription+factors+Nurr1+and+NGFI-B+suggests+a+gene+regulatory+role+in+several+brain+regions+including+the+nigrostriatal+dopamine+system.">Cellular expression of the immediate early transcription factors Nurr1 and NGFI-B suggests a gene regulatory role in several brain regions including the nigrostriatal dopamine system.</a> Brain Res. Mol. Brain Res. 41 (1-2), 111-120 (1996).</li><li>Xiao, Q., Castillo, S. O., Nikodem, V. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distribution+of+messenger+RNAs+for+the+orphan+nuclear+receptors+Nurr1+and+Nur77+(NGFI-B)+in+adult+rat+brain+using+in+situ+hybridization.">Distribution of messenger RNAs for the orphan nuclear receptors Nurr1 and Nur77 (NGFI-B) in adult rat brain using in situ hybridization.</a> Neuroscience. 75 (1), 221-230 (1996).</li></ol>

The success of this protocol relies on the availability of pure proteins for characterization of the antibodies raised against a specific member of the protein family of interest. There is no need to purify the antibodies using protein A/G until it is clearly established that there are significant cross-reactivities by ELISA and Western blotting.
As stated in the text, it is important to avoid suspending the protein(s) to be cross-linked to the column in an amine-containing buffer such as Tris...

The transcription factor Nurr1 and its homologs (Nur77 and Nor1) belong to the nuclear receptor subfamily 4A (NR4A)1. They are also orphan receptors because their endogenous ligands are not identified yet. Nurr1 was first cloned in 1992 and although known to be expressed in the brain2, its essential role for development and maintenance of midbrain dopamine neurons was revealed by knockout mouse studies3. In addition, its important role for maintenance of midbrain dopamine neurons was recently demonstrated by a conditional knockout study4. Due to these elegant studies showing Nurr1&#8217;s critical roles for midbrain dopamine neurons, many subsequent studies have largely focused on the midbrain dopamine neurons and dopamine-related neurodegenerative disorder, Parkinson&#8217;s disease (PD)5.
Notably, Nurr1 is expressed not only in the midbrain dopamine (mDA) neurons, but also in diverse brain areas2, suggesting that it may have functional roles in many non-DA areas, which is strongly supported by more recent studies showing that Nurr1 plays important roles in various brain functions. For examples, it was shown that memory-inducing activities such as learning, or other hippocampus-dependent tasks result in up-regulation of Nurr1 expression in the hippocampus6,7. In addition, knock down of Nurr1 expression in the hippocampus was sufficient to impair long-term memory and/or synaptic plasticity8-11, strongly suggesting that Nurr1 plays diverse roles in many brain areas. Thus, to further understand the cell-type-specific and subcellular expression of Nurr1, it is desirable to use Nurr1-specific antibodies, which do not exhibit any cross-reactivity to its homologs Nur77 or Nor1. This paper describes a pre-adsorption protocol to generate Nurr1-specific antibodies and present additional data showing its specificity.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Purified Ligand Binding Domain from Nurr1, Nor 1 and Nur77</td>
			<td></td>
			<td></td>
			<td>Column Storage solution</td>
		</tr>
		<tr>
			<td>AminoLink Coupling Resin and Kit</td>
			<td>Thermo Scientific</td>
			<td>44890</td>
			<td></td>
		</tr>
		<tr>
			<td>Protein A spin column</td>
			<td>Thermo Scientific</td>
			<td>89978</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Phosphate-Buffered Saline</td>
			<td>Corning</td>
			<td>21-031-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>96 well Flate-bottom plates, High Flange, 330&#956;L</td>
			<td>Thermo Scientific</td>
			<td>3455</td>
			<td></td>
		</tr>
		<tr>
			<td>10% Normal Goat Serum</td>
			<td>KPL</td>
			<td>50-675-69</td>
			<td></td>
		</tr>
		<tr>
			<td>Milk Diluent/ Blocking Concentrate&#160;</td>
			<td>KPL</td>
			<td>50-82-01</td>
			<td></td>
		</tr>
		<tr>
			<td>IgG Elution Buffer</td>
			<td>Thermo Scientific</td>
			<td>21004</td>
			<td></td>
		</tr>
		<tr>
			<td>UltraPure 1 M Tris-HCI Buffer, pH 7.5</td>
			<td>Life Technologies</td>
			<td>15567-&#173;&#8208;027</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro BCA Protein Assay Kit</td>
			<td>Thermo Scientific</td>
			<td>23235</td>
			<td></td>
		</tr>
		<tr>
			<td>Horse Radish Peroxidase conjugated Goat anti-Rabbit IgG (H+L)</td>
			<td>Thermo Scientific</td>
			<td>31460</td>
			<td></td>
		</tr>
		<tr>
			<td>Ni-NTA Resin</td>
			<td>Thermo Scientific</td>
			<td>88221</td>
			<td></td>
		</tr>
		<tr>
			<td>3, 3&#39;, 5, 5&#39; Tetramethylbenzydine</td>
			<td>Thermo Scientific</td>
			<td>34028</td>
			<td></td>
		</tr>
		<tr>
			<td>2N H2SO4</td>
			<td>Macron Fine Chemicals</td>
			<td>H381 05</td>
			<td></td>
		</tr>
		<tr>
			<td>Protein A IgG Binding Buffer</td>
			<td>Thermo Scientific</td>
			<td>21001</td>
			<td></td>
		</tr>
		<tr>
			<td>IgG Elution Buffer</td>
			<td>Thermo Scientific</td>
			<td>21004</td>
			<td></td>
		</tr>
		<tr>
			<td>Neutralization Buffer</td>
			<td></td>
			<td></td>
			<td>1M Tris-&#173;&#8208;HCl pH 8.5</td>
		</tr>
		<tr>
			<td>Column Storage solution</td>
			<td></td>
			<td></td>
			<td>Phosphate Buffered Saline containing 0.02% sodium azide</td>
		</tr>
		<tr>
			<td>Spectra/Por 7 pre-treated dialysis tubing</td>
			<td>Spectrum Labs</td>
			<td>132128</td>
			<td></td>
		</tr>
		<tr>
			<td>10 ml Disposable columns</td>
			<td>Thermo Scientific</td>
			<td>29924</td>
			<td></td>
		</tr>
		<tr>
			<td>AminoLink Coupling Buffer</td>
			<td></td>
			<td></td>
			<td>0.1M sodium phosphate, 0.05% NaN3, pH 7.0</td>
		</tr>
		<tr>
			<td>Quenching buffer</td>
			<td></td>
			<td></td>
			<td>1M Tris. HCI, 0.05% NaN3, pH 
			7.4</td>
		</tr>
		<tr>
			<td>Wash Solution</td>
			<td></td>
			<td></td>
			<td>1M NaCl, 0.05% NaN3</td>
		</tr>
		<tr>
			<td>ELISA Blocking buffer</td>
			<td></td>
			<td></td>
			<td>1% Normal Horse serum (NHS), 1% Normal Goat Serum (NGS) in 1X KPL milk diluent</td>
		</tr>
		<tr>
			<td>Storage Solution</td>
			<td></td>
			<td></td>
			<td>PBS pH 7.4 containing 0.02% sodium azide</td>
		</tr>
		<tr>
			<td>Micropipettes: 10 &#956;l; 20 &#956;l; 200 &#956;l; 1000 &#956;l</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

production of nurr-1 specific polyclonal antibodies free of cross-reactivity against its close homologs, nor1 and nur77

The nuclear receptor subfamily 4 (NR4A) is composed of 3 related proteins sharing a DNA binding domain (DBD) and a ligand-binding domain (LBD). The nuclear receptor related 1 protein (Nurr1 or NR4A2) plays a key role in the maintenance of the dopaminergic system. Dopamine dysfunctions associated with the Nurr1 gene include Parkinson&#8217;s disease, schizophrenia and manic depression among others. Furthermore, recent evidence indicates that Nurr1 is also expressed in other brain areas such as the hippocampus and plays critical roles for learning and memory. The other members of the family are nerve growth factor IB (Nur77 or NR4A1) and neuron-derived orphan receptor 1 (NOR1 or NR4A3). To help investigate the precise functional roles of Nurr1 in dopaminergic and other brain region-related neuronal dysfunctions antibodies devoid of cross-reactivities against Nur77 and NOR1 were needed. Since the proteins are more divergent in their LBDs than in their DNA binding domains immunization with purified LBDs should yield antibodies specific for Nurr1 with minimal reactivities against Nur77 and/or NOR1. Although anti-Nurr1 antibodies were successfully generated these showed significant immunoreactivity against the other members of the family. Affinity chromatography over immobilized Protein A followed by pre-adsorption against immobilized Nur77 and NOR1 LBDs yielded Nurr1 specific antibodies free of cross-reactivity. Here, we selectively target antibodies against a specific member of a highly conserved family of proteins by immunizing animals with their most divergent regions followed by removing cross reactive antibodies by pre-adsorption. The goal of the protocol is to increase polyclonal antibodies specificity through pre-adsorption against cross-reactive antigens.

A comparison of Protein A column purified Nurr1-specific antibodies with Protein A purified anti-Nurr1 antibodies followed by passage through Nur77 LBD and Nor1 LBD columns is shown in Figure 1. As can be seen, Protein A-purified Nurr1 antibody exhibited a strong binding to Nurr1 LBD. However, it also showed significant binding to Nur77 LBD and to Nor1 LBD. When Protein A-purified Nurr1 antibodies were further purified against Nur77 LBD and Nor1 LBD, the final affinity purified Nurr1 antibodies exhibited...

Watch this Scientific Journal Video about Production of Nurr-1 Specific Polyclonal Antibodies Free of Cross-reactivity Against Its Close Homologs, Nor1 and Nur77 at JoVE.com

Production of Nurr-1 Specific Polyclonal Antibodies Free of Cross-reactivity Against Its Close Homologs, Nor1 and Nur77

Here, we selectively target antibodies against a specific member of a highly conserved family of proteins by immunizing animals with their most divergent regions followed by removing cross reactive antibodies by pre-adsorption.

The nuclear receptor subfamily 4 (NR4A) is composed of 3 related proteins sharing a DNA binding domain (DBD) and a ligand-binding domain (LBD). The ...

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Biology

Principles of Site-Specific Recombinase (SSR) Technology

Site-specific recombinase (SSR) technology allows the manipulation of gene structure to explore gene function and has become an integral tool of molecular biology. Site-specific recombinases are proteins that bind to distinct DNA target sequences. The Cre/lox system was first described in bacteriophages during the 1980's. Cre recombinase is a Type I topoisomerase that catalyzes site-specific recombination of DNA between two loxP (locus of X-over P1) sites. The Cre/lox system does not require any cofactors. LoxP sequences contain distinct binding sites for Cre recombinases that surround a directional core sequence where recombination and rearrangement takes place. When cells contain loxP sites and express the Cre recombinase, a recombination event occurs. Double-stranded DNA is cut at both loxP sites by the Cre recombinase, rearranged, and ligated ("scissors and glue"). Products of the recombination event depend on the relative orientation of the asymmetric sequences.
SSR technology is frequently used as a tool to explore gene function. Here the gene of interest is flanked with Cre target sites loxP ("floxed"). Animals are then crossed with animals expressing the Cre recombinase under the control of a tissue-specific promoter. In tissues that express the Cre recombinase it binds to target sequences and excises the floxed gene. Controlled gene deletion allows the investigation of gene function in specific tissues and at distinct time points. Analysis of gene function employing SSR technology --- conditional mutagenesis -- has significant advantages over traditional knock-outs where gene deletion is frequently lethal.

Principles of Site-Specific Recombinase SSR Technology

The advent of site-specific recombinase (SSR) technology and the Cre/lox system has led to numerous advances in molecular biology, and has proven itself as a valuable tool for assessing gene function in transgenic animals. This interview discusses the mechanism of site specific recombination by Cyclization recombinase (Cre) and how the use of this enzyme has led to the development of conditional mutagenesis, which has significant advantages over traditional knock out strategies.

Site-specific recombinase (SSR) technology allows the manipulation of gene structure to explore gene function and has become an integral tool of molecular ...

Operant Learning of Drosophila at the Torque Meter

For experiments at the torque meter, flies are kept on standard fly medium at 25&deg;C and 60% humidity with a 12hr light/12hr dark regime. A standardized breeding regime assures proper larval density and age-matched cohorts. Cold-anesthetized flies are glued with head and thorax to a triangle-shaped hook the day before the experiment. Attached to the torque meter via a clamp, the fly's intended flight maneuvers are measured as the angular momentum around its vertical body axis. The fly is placed in the center of a cylindrical panorama to accomplish stationary flight. An analog to digital converter card feeds the yaw torque signal into a computer which stores the trace for later analysis. The computer also controls a variety of stimuli which can be brought under the fly's control by closing the feedback loop between these stimuli and the yaw torque trace. Punishment is achieved by applying heat from an adjustable infrared laser.

Measuring the yaw torque of tethered Drosophila with the torque meter allows the neuroscientist exquisite control of the stimulus situation of the experimental animal. Together with the unique genetic tools available in the fruit fly, this paradigm is used for a wide variety of neurobiological research.

For experiments at the torque meter, flies are kept on standard fly medium at 25&deg;C and 60% humidity with a 12hr light/12hr dark regime. A standardized ...

In vivo Ca2+- Imaging of Mushroom Body Neurons During Olfactory Learning in the Honey Bee

The in vivo and semi-in vivo preparation for Calcium imaging has been developed in our lab by Joerges, K&uuml;ttner and Galizia over ten years ago, to measure odor evoked activity in the antennal lobe1. From then on, it has been continuously refined and applied to different neuropiles in the bee brain. Here, we describe the preparation currently used in the lab to measure activity in mushroom body neurons using a dextran coupled calcium-sensitive dye (Fura-2). We retrogradely stain mushroom body neurons by injecting dye into their axons or soma region. We focus on reducing the invasiveness, to achieve a preparation in which it is still possible to train the bee using PER conditioning. We are able to monitor and quantify the behavioral response by recording electro-myograms from the muscle which controls the PER (M17)2.
After the physiological experiment the imaged structures are investigated in greater detail using confocal scanning microscopy to address the identity of the neurons.

In vivo Ca2+- Imaging of Mushroom Body Neurons During Olfactory Learning in the Honey Bee

Bees can be conditioned in an appetitive olfactory learning paradigm (PER-conditioning). Using odors as stimuli, we established a method in which behavior is recorded while simultaneously Calcium Imaging is used to measure odor evoked activity in mushroom body neurons in vivo.

The in vivo and semi-in vivo preparation for Calcium imaging has been developed in our lab by Joerges, K&uuml;ttner and Galizia over ten years ago, to ...

Autonomously Bioluminescent Mammalian Cells for Continuous and Real-time Monitoring of Cytotoxicity

Mammalian cell-based in vitro assays have been widely employed as alternatives to animal testing for toxicological studies but have been limited due to the high monetary and time costs of parallel sample preparation that are necessitated due to the destructive nature of firefly luciferase-based screening methods. This video describes the utilization of autonomously bioluminescent mammalian cells, which do not require the destructive addition of a luciferin substrate, as an inexpensive and facile method for monitoring the cytotoxic effects of a compound of interest. Mammalian cells stably expressing the full bacterial bioluminescence (luxCDABEfrp) gene cassette autonomously produce an optical signal that peaks at 490 nm without the addition of an expensive and possibly interfering luciferin substrate, excitation by an external energy source, or destruction of the sample that is traditionally performed during optical imaging procedures. This independence from external stimulation places the burden for maintaining the bioluminescent reaction solely on the cell, meaning that the resultant signal is only detected during active metabolism. This characteristic makes the lux-expressing cell line an excellent candidate for use as a biosentinel against cytotoxic effects because changes in bioluminescent production are indicative of adverse effects on cellular growth and metabolism. Similarly, the autonomous nature and lack of required sample destruction permits repeated imaging of the same sample in real-time throughout the period of toxicant exposure and can be performed across multiple samples using existing imaging equipment in an automated fashion.

Mammalian cells expressing the bacterial bioluminescence gene cassette (lux) produce light autonomously. The resulting bioluminescent dynamics upon chemical exposure have been demonstrated to reflect the treatment effects on cellular growth and metabolism, making these cells an inexpensive, continuous, real-time toxicity screening tool that can easily be adapted for high-throughput automation.

Mammalian  cell-based in vitro assays have been  widely employed as alternatives to animal testing for toxicological studies but  have been limited due to ...

Design and Analysis of Temperature Preference Behavior and its Circadian Rhythm in Drosophila

The circadian clock regulates many aspects of life, including sleep, locomotor activity, and body temperature (BTR) rhythms1,2. We recently identified a novel Drosophila circadian output, called the temperature preference rhythm (TPR), in which the preferred temperature in flies rises during the day and falls during the night 3. Surprisingly, the TPR and locomotor activity are controlled through distinct circadian neurons3. Drosophila locomotor activity is a well&#160;known circadian behavioral output and has provided strong contributions to the discovery of many conserved mammalian circadian clock genes and mechanisms4. Therefore, understanding TPR will lead to the identification of hitherto unknown molecular and cellular circadian mechanisms. Here, we describe how to perform and analyze the TPR assay. This technique not only allows for dissecting the molecular and neural mechanisms of TPR, but also provides new insights into the fundamental mechanisms of the brain functions that integrate different environmental signals and regulate animal behaviors. Furthermore, our recently published data suggest that the fly TPR shares features with the mammalian BTR3. Drosophila are ectotherms, in which the body temperature is typically behaviorally regulated. Therefore, TPR is a strategy used to generate a rhythmic body temperature in these flies5-8. We believe that further exploration of Drosophila TPR will facilitate the characterization of the mechanisms underlying body temperature control in animals.

Design and Analysis of Temperature Preference Behavior and its Circadian Rhythm in Drosophila

We recently identified a novel Drosophila circadian output, temperature preference rhythm (TPR), in which the preferred temperature in flies rises during the day and falls during the night. TPR is regulated independently from another circadian output, locomotor activity. Here&#160;we describe the design and analysis of TPR in Drosophila.

The circadian clock regulates many aspects of life, including sleep, locomotor activity, and body temperature (BTR) rhythms1,2. We recently identified a ...

Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System

The canonical set of amino acids leads to an exceptionally wide range of protein functionality. Nevertheless, the set of residues still imposes limitations on potential protein applications. The incorporation of noncanonical amino acids can enlarge this scope. There are two complementary approaches for the incorporation of noncanonical amino acids. For site-specific incorporation, in addition to the endogenous canonical translational machineries, an orthogonal aminoacyl-tRNA-synthetase-tRNA pair must be provided that does not interact with the canonical ones. Consequently, a codon that is not assigned to a canonical amino acid, usually a stop codon, is also required. This genetic code expansion enables the incorporation of a noncanonical amino acid at a single, given site within the protein. The here presented work describes residue-specific incorporation where the genetic code is reassigned within the endogenous translational system. The translation machinery accepts the noncanonical amino acid as a surrogate to incorporate it at canonically prescribed locations, i.e., all occurrences of a canonical amino acid in the protein are replaced by the noncanonical one. The incorporation of noncanonical amino acids can change the protein structure, causing considerably modified physical and chemical properties. Noncanonical amino acid analogs often act as cell growth inhibitors for expression hosts since they modify endogenous proteins, limiting in vivo protein production. In vivo incorporation of toxic noncanonical amino acids into proteins remains particularly challenging. Here, a cell-free approach for a complete replacement of L-arginine by the noncanonical amino acid L-canavanine is presented. It circumvents the inherent difficulties of in vivo expression. Additionally, a protocol to prepare target proteins for mass spectral analysis is included. It is shown that L-lysine can be replaced by L-hydroxy-lysine, albeit with lower efficiency. In principle, any noncanonical amino acid analog can be incorporated using the presented method as long as the endogenous in vitro translation system recognizes it.

Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System

An easy-to-use, cell-free expression protocol for the residue-specific incorporation of noncanonical amino acid analogs into proteins, including downstream analysis, is presented for medical, pharmaceutic, structural and functional studies.

The canonical set of amino acids leads to an exceptionally wide range of protein functionality. Nevertheless, the set of residues still imposes ...

Use of Anti-phospho-girdin Antibodies to Visualize Intestinal Tuft Cells in Free-Floating Mouse Jejunum Cryosections

The actin binding protein girdin is a cytosolic protein that is required for actin remodeling to trigger cell migration in various tissues. Girdin is phosphorylated by both receptor and non-receptor tyrosine kinases at tyrosine 1798. Omori et al. developed site- and phosphorylation status-specific antibodies against human girdin at tyrosine-1798 (pY1798), which specifically bind to phosphorylated tyrosine-1798, but not to unphosphorylated tyrosine-1798. pY1798 antibodies have been used to specifically label tuft cells (TCs) that are present in mammalian gastrointestinal tissues, but the function of these cells is unclear. This protocol allows the robust visualization of TCs in the jejunum using pY1798 antibodies and immunofluorescence. To ensure successful and simple TC visualization, this protocol includes two histological techniques: production of free-floating cryosections from gelatin-filled jejunum tissue, and low-temperature antigen retrieval at 50 &#176;C for 3 h. Filling the jejunum with gelatin maintains the shape of free-floating sections throughout the staining procedure, whereas low-temperature antigen retrieval ensures robust signals from TCs. Successful use of this protocol results in pY1798 staining of TCs distributed from villus tip to crypt. Stained TCs have a spool-shaped soma and fluorescent signals condense at the lumenal tip, which corresponds to the protruding &#39;tuft.&#39;&#160;Phalloidin staining colocalized with pY1798-positive TCs at the thickened brush border, and corresponds to a rootlet mass extending from the TC tuft. This protocol could be used to examine TCs in human biopsy samples collected with gastrointestinal endoscopes. Furthermore, TCs were recently reported to accumulate following parasite infection in mice, suggesting that this protocol could have applications for diagnosis of parasite infections in the human gut.

Kuga et al. discovered that phosphorylation-status specific antibodies against the actin binding protein girdin phosphorylated at tyrosine 1798 (pY1798) can be used to label tuft cells (TCs). This protocol allows robust visualization of TCs using immunofluorescent staining of free-floating jejunum cryosections with pY1798 antibodies.

The actin binding protein girdin is a cytosolic protein that is required for actin remodeling to trigger cell migration in various tissues. Girdin is ...

Agrobacterium-Mediated Genetic Transformation, Transgenic Production, and Its Application for the Study of Male Reproductive Development in Rice

Male sterility is an important agronomic trait for hybrid seed production that is usually characterized by functional defects in male reproductive organs/gametes. Recent advances in CRISPR-Cas9 genome editing technology allow for high editing efficacy and timesaving knockout mutations of endogenous candidate genes at specific sites. Additionally, Agrobacterium-mediated genetic transformation of rice is also a key method for gene modification, which has been widely adopted by many public and private laboratories. In this study, we applied CRISPR-Cas9 genome editing tools and successfully generated three male sterile mutant lines by targeted genome editing of OsABCG15 in a japonica cultivar. We used a modified Agrobacterium-mediated rice transformation method that could provide excellent means of genetic emasculation for hybrid seed production in rice. Transgenic plants can be obtained within 2&#8211;3 months and homozygous transformants were screened by genotyping using PCR amplification and Sanger sequencing. Basic phenotypic characterization of the male sterile homozygous line was performed by microscopic observation of the rice male reproductive organs, pollen viability analysis by iodine potassium iodide (I2-KI) staining semi-thin cross-sectioning of developing anthers.

Agrobacterium-Mediated Genetic Transformation, Transgenic Production, and Its Application for the Study of Male Reproductive Development in Rice

This work describes the use of CRISPR-Cas9 genome editing technology to knockout endogenous gene OsABCG15 followed by a modified Agrobacterium-mediated transformation protocol to produce a stable male-sterile line in rice.

Male sterility is an important agronomic trait for hybrid seed production that is usually characterized by functional defects in male reproductive ...

A Simple Dry Sectioning Method for Obtaining Whole-Seed-Sized Resin Section and Its Applications

The morphology, size and quantity of cells, starch granules&#160;and protein bodies in seed determine the weight and quality of seed. They are significantly different among different regions of seed. In order to view the morphologies of cells, starch granules and protein bodies clearly, and quantitatively analyze their morphology parameters accurately, the whole-seed-sized section is needed. Though the whole-seed-sized paraffin section can investigate the accumulation of storage materials in seeds, it is very difficult to quantitatively analyze the morphology parameters of cells and storage materials due to the low resolution of the thick section. The thin resin section has high resolution, but the routine resin sectioning method is not suitable to prepare the whole-seed-sized section of mature seeds with a large volume and high starch content. In this study, we present a simple dry sectioning method for preparing the whole-seed-sized resin section. The technique can prepare the cross and longitudinal whole-seed-sized sections of developing, mature, germinated, and cooked seeds embedded in LR White resin, even for large seeds with high starch content. The whole-seed-sized section can be stained with fluorescent brightener 28, iodine, and Coomassie brilliant blue R250 to specifically exhibit the morphology of cells, starch granules, and protein bodies clearly, respectively. The image obtained can also be analyzed quantitatively to show the morphology parameters of cells, starch granules, and protein bodies in different regions of seed.

This technique allows for the fast and simple preparation of whole-seed-sized resin section for the observation and analysis of cells, starch granules, and protein bodies in different regions of the seed.

The morphology, size and quantity of cells, starch granules&#160;and protein bodies in seed determine the weight and quality of seed. They are ...

Rapid, Affordable, and Uncomplicated Production of Bacterial Cell-free Lysate

Cell-free gene expression offers the power of biology without the complications of a living organism. Although many such gene expression systems exist, most are quite expensive to buy and/or require special equipment and finely honed expertise to produce effectively. This protocol describes a method to produce bacterial cell-free lysate that supports high levels of gene expression, using only standard laboratory equipment and requiring minimal processing. The method uses an Escherichia coli strain producing an endolysin that does not affect growth, but which efficiently lyses a harvested cell pellet following a simple freeze-thaw cycle. The only further processing required is a brief incubation followed by centrifugation to clear the autolysate of cellular debris. Dynamic gene circuits can be achieved through heterologous expression of the ClpX protease in the cells before harvesting. An E. coli strain lacking the lacZ gene can be used for high-sensitivity, cell-free biosensing applications using a colorimetric or fluorescent readout. The entire protocol requires as few as 8-9 hours, with only 1-2 hours of hands-on labor from inoculation to completion. By reducing the cost and time to obtain cell-free lysate, this method should increase the affordability of cell-free gene expression for various applications.

This protocol describes a rapid and simple method to produce bacterial lysate for cell-free gene expression, using an engineered strain of Escherichia coli and requiring only standard laboratory equipment.

Cell-free gene expression offers the power of biology without the complications of a living organism. Although many such gene expression systems exist, ...