Name: quantitative analysis of alternative pre-mrna splicing in mouse brain sections using rna in situ hybridization assay
Uploaded: 2018-08-26T13:00:00
Description: Watch this Scientific Journal Video about Quantitative Analysis of Alternative Pre-mRNA Splicing in Mouse Brain Sections Using RNA In Situ Hybridization Assay at JoVE.com

This work was supported by the American Heart Association [Grant-in-Aid 0365274B to H.L.], National Cancer Institute [GI SPORE P50CA150964 to Z.W.], National Institutes of Health [Office of Research Infrastructure Shared Instrumentation Grant S10RR031845 to the Light Microscopy Imaging Facility at Case Western Reserve University], and China Scholarship Council [to X.G.]. 
The authors thank Richard Lee in the Light Microscopy Imaging Core for his help with slide scanning.

All of the experiments described here that involve mice have been approved by the Case Western Reserve University Institutional Animal Care and Use Committee. The title of the protocol 2016-0068 (PI: Hua Lou) is &#8220;Role of alternative pre-mRNA splicing in vertebrate development&#8221;.
NOTE: Information of all of the equipment, reagents and supplies used in this protocol is included in Table of Materials.
1. Prepare Formalin Fixed Paraffin Embedde...

<ol>
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This communication reports the use of BaseScope RNA ISH to examine AS expression patterns in mouse brain sections. It is demonstrated that anti-sense exon-exon junction probes shorter than 50 nucleotides can target exon inclusion and skipping isoforms robustly and specifically. Furthermore, the resulting signals can be used to calculate PSI of an alternative exon.
A few variations were tested in the procedure. For example, frozen tissue sections generated by cryostat sectioning were tested and...

Alternative splicing (AS) is a common process that occurs during pre-mRNA maturation. In this process, an exon can be differentially included in mature mRNA. Thus, through AS, one gene can generate many mRNAs that code for different protein products. It is estimated that 92&#8211;94% of human genes undergo alternative splicing1,2. Abnormal alternative splicing patterns resulted from genetic mutations have been linked to a large number of diseases, including amyotrophic lateral sclerosis, myotonic dystrophy, and cancer3,4. It is thus crucial to investigate and better understand alternative splicing regulatory mechanisms in an attempt to find new treatments of human diseases.
AS is often regulated in a cell type-specific fashion. It is important to determine the AS expression pattern of a specific gene in a given biological system. However, this becomes complicated when a complex organ that contains many different types of cells, such as the brain or heart, is studied. In this case, an ideal choice of assay system is RNA in situ hybridization (ISH) using tissue sections so the AS expression pattern of a specific gene can be detected in many cell types simultaneously. Indeed, exon-specific probes have been used to assess expression levels of an alternative exon5,6,7. However, this approach is not well suited for AS pattern analysis for the following reasons. First, conventional ISH methods usually use probes longer than 300 bp, while the average size of vertebrate internal exons (not first or last exon) is 170 nucleotides8,9. Second, when an exon-specific probe is used to examine the splicing pattern of an internal alternative exon, the only mRNA isoform detected by the probe is the one that contains the exon, while the mRNA isoform without the exon cannot be detected. Thus, calculation of the percent spliced in (PSI) value for the alternative exon is complicated. Furthermore, conventional fluorescent ISH often combines ISH with immunostaining, which reduces the detection efficiency and robustness. For example, in a study that investigated the stress-induced splicing isoform switching of the acetylcholinesterase (AChE) mRNA, digoxigenin was incorporated into the ISH probe and detected using anti-digoxigenin antibody. Alternatively, biotin-labeled probe was detected by an alkaline phosphatase/streptavidin conjugate and a substrate for alkaline phosphatase10. Neither method uses any amplification strategy to increase the sensitivity of detection. As a result, it is challenging to detect mRNA transcripts that are expressed at low levels. Thus, a simpler and more robust ISH assay system is needed to analyze AS expression patterns in situ.
BaseScope was recently developed based on the platform of RNAscope, a well-established and widely used ISH assay system. Both assay systems employ a target-specific amplification technology that increases the sensitivity of detection11,12. What distinguishes one from the other is the length of the target sequence, which is as short as 50 nucleotides for BaseScope, and 300&#8211;1,000 nucleotides for RNAscope. Thus, it is possible to design probes that target exon-exon junctions to detect specific alternative mRNA isoforms. In the current study, a procedure was established to examine AS expression patterns of neurofibromatosis type 1 (Nf1) exon 23a, an alternative exon extensively studied in the same laboratory13,14,15,16,17, in mouse brain sections. The results demonstrate that BaseScope is an ideal system to study expression patterns of Nf1 exon 23a in situ. As this assay system can be adapted to analyze AS expression patterns of many alternative exons, it represents a powerful new tool in the studies of AS.

<table>
	<tbody>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Hybridization Oven</td>
			<td>Advanced Cell Diagnostics</td>
			<td>241000ACD</td>
			<td></td>
		</tr>
		<tr>
			<td>Humidity Control Tray (with lid)</td>
			<td>Advanced Cell Diagnostics</td>
			<td>310012</td>
			<td></td>
		</tr>
		<tr>
			<td>Stain Rack</td>
			<td>Advanced Cell Diagnostics</td>
			<td>310017</td>
			<td></td>
		</tr>
		<tr>
			<td>Hot plate</td>
			<td>Fisher Scientific</td>
			<td>1160049SH</td>
			<td></td>
		</tr>
		<tr>
			<td>Imperial III General Purpose Incubator</td>
			<td>Lab-Line</td>
			<td>302</td>
			<td></td>
		</tr>
		<tr>
			<td>Slide Scanner</td>
			<td>Leica</td>
			<td>SCN400</td>
			<td></td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Pretreatment kit</td>
			<td>Advanced Cell Diagnostics</td>
			<td>322381</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrogen Peroxide</td>
			<td>Advanced Cell Diagnostics</td>
			<td>2000899</td>
			<td></td>
		</tr>
		<tr>
			<td>Protease III*</td>
			<td>Advanced Cell Diagnostics</td>
			<td>2000901</td>
			<td></td>
		</tr>
		<tr>
			<td>10X Target Retrieval</td>
			<td>Advanced Cell Diagnostics</td>
			<td>2002555</td>
			<td></td>
		</tr>
		<tr>
			<td>BaseScope Detection Reagent Kit</td>
			<td>Advanced Cell Diagnostics</td>
			<td>332910</td>
			<td></td>
		</tr>
		<tr>
			<td>AMP 0</td>
			<td>Advanced Cell Diagnostics</td>
			<td>2001814</td>
			<td></td>
		</tr>
		<tr>
			<td>AMP 1</td>
			<td>Advanced Cell Diagnostics</td>
			<td>2001815</td>
			<td></td>
		</tr>
		<tr>
			<td>AMP 2</td>
			<td>Advanced Cell Diagnostics</td>
			<td>2001816</td>
			<td></td>
		</tr>
		<tr>
			<td>AMP 3</td>
			<td>Advanced Cell Diagnostics</td>
			<td>2001817</td>
			<td></td>
		</tr>
		<tr>
			<td>AMP 4</td>
			<td>Advanced Cell Diagnostics</td>
			<td>16229B</td>
			<td></td>
		</tr>
		<tr>
			<td>AMP 5-RED</td>
			<td>Advanced Cell Diagnostics</td>
			<td>16229C</td>
			<td></td>
		</tr>
		<tr>
			<td>AMP 6-RED</td>
			<td>Advanced Cell Diagnostics</td>
			<td>2001820</td>
			<td></td>
		</tr>
		<tr>
			<td>Fast RED-A</td>
			<td>Advanced Cell Diagnostics</td>
			<td>2001821</td>
			<td></td>
		</tr>
		<tr>
			<td>Fast RED-B</td>
			<td>Advanced Cell Diagnostics</td>
			<td>16230F</td>
			<td></td>
		</tr>
		<tr>
			<td>50X Wash Buffer</td>
			<td>Advanced Cell Diagnostics</td>
			<td>310091</td>
			<td></td>
		</tr>
		<tr>
			<td>Negative Control Probe- Mouse DapB-1ZZ</td>
			<td>Advanced Cell Diagnostics</td>
			<td>701021</td>
			<td></td>
		</tr>
		<tr>
			<td>Positive Control Probe- Mouse (Mm)-PPIB-1ZZ</td>
			<td>Advanced Cell Diagnostics</td>
			<td>701081</td>
			<td></td>
		</tr>
		<tr>
			<td>Control slide-mouse 3T3 cell pellet</td>
			<td>Advanced Cell Diagnostics</td>
			<td>310045</td>
			<td></td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Other supplies</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Humidifying Paper</td>
			<td>Advanced Cell Diagnostics</td>
			<td>310015</td>
			<td></td>
		</tr>
		<tr>
			<td>Washing Rack</td>
			<td>American Master Tech Scientific</td>
			<td>9837976</td>
			<td></td>
		</tr>
		<tr>
			<td>Washing Dishes</td>
			<td>American Master Tech Scientific</td>
			<td>LWS20WH</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrophobic Barrier Pen</td>
			<td>Vector Laboratory</td>
			<td>H-4000</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass Slides</td>
			<td>Fisher Scientific</td>
			<td>12-550-15</td>
			<td></td>
		</tr>
		<tr>
			<td>Cover Glass, 24 x 50 mm</td>
			<td>Fisher Scientific</td>
			<td>12--545-F</td>
			<td></td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Chemicals</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ammonium hydroxide</td>
			<td>Fisher Scientific</td>
			<td>002689</td>
			<td></td>
		</tr>
		<tr>
			<td>100% ethanol (EtOH)</td>
			<td>Decon Labs</td>
			<td>2805</td>
			<td></td>
		</tr>
		<tr>
			<td>formalde solution</td>
			<td>Fisher Scientific</td>
			<td>SF94-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Hematoxylin I</td>
			<td>American Master Tech Scientific</td>
			<td>17012359</td>
			<td></td>
		</tr>
		<tr>
			<td>Mounting Medium</td>
			<td>Vector Labs</td>
			<td>H-5000</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylene</td>
			<td>Fisher Scientific</td>
			<td>173942</td>
			<td></td>
		</tr>
	</tbody>
</table>

quantitative analysis of alternative pre-mrna splicing in mouse brain sections using rna in situ hybridization assay

Alternative splicing (AS) occurs in more than 90% of human genes. The expression pattern of an alternatively spliced exon is often regulated in a cell type-specific fashion. AS expression patterns are typically analyzed by RT-PCR and RNA-seq using RNA samples isolated from a population of cells. In situ examination of AS expression patterns for a particular biological structure can be carried out by RNA in situ hybridization (ISH) using exon-specific probes. However, this particular use of ISH has been limited because alternative exons are generally too short to design exon-specific probes. In this report, the use of BaseScope, a recently developed technology that employs short antisense oligonucleotides in RNA ISH, is described to analyze AS expression patterns in mouse brain sections. Exon 23a of neurofibromatosis type 1 (Nf1) is used as an example to illustrate that short exon-exon junction probes exhibit robust hybridization signals with high specificity in RNA ISH analysis on mouse brain sections. More importantly, signals detected with exon inclusion- and skipping-specific probes can be used to reliably calculate the percent spliced in values of Nf1 exon 23a expression in different anatomical areas of a mouse brain. The experimental protocol and calculation method for AS analysis are presented. The results indicate that BaseScope provides a powerful new tool to assess AS expression patterns in situ.

BaseScope ISH was carried out using three mouse strains: CD1 wild type mice, C57BL/6J wild type mice, and Nf123aIN/23aIN mutant mice in the C57BL/6J background, in which exon 23a is included in all cell types as a result of engineered splice site mutations14,15.
As a first step, the ISH assay system was tested using company provided reagents: slides t...

Watch this Scientific Journal Video about Quantitative Analysis of Alternative Pre-mRNA Splicing in Mouse Brain Sections Using RNA In Situ Hybridization Assay at JoVE.com

Quantitative Analysis of Alternative Pre-mRNA Splicing in Mouse Brain Sections Using RNA In Situ Hybridization Assay

An in situ hybridization (ISH) protocol that uses short antisense oligonucleotides to detect alternative pre-mRNA splicing patterns in mouse brain sections is described.

Quantitative Analysis of Alternative Pre-mRNA Splicing in Mouse Brain Sections Using RNA In Situ Hybridization Assay

Alternative splicing (AS) occurs in more than 90% of human genes. The expression pattern of an alternatively spliced exon is often regulated in a cell ...

This method can help answer key questions in the field of alternative pre-mRNA splicing. Specifically it provides a robustly, sensitive assay system to examine alternative splicing patterns in situ in tissue slices. With this method, alternative splicing can be analyzed simultaneously in many subtypes that are contained in complex biological structures such as a mouse brain.The main advantage of this technique is that it uses shock anti-static exon junction probes in mRNA in situ hybridization to produce isoform specific hybridization signals. Building signal amplification technology increases the sensitivity of the detection to provide robust hybridization signals. The signals detected was exon inclusion escaping specific probes that are used to calculate the percentage splice in vitals at different anatomical areas of a mouse brain.In this study NF1 exon 23a is used as an example to illustrate the use of the assay system. However, the system can be adapted to analysis expression patterns of many alternative exons. To start mouse brain section D paraffinization, fill two washing dishes with 250 milliliters of xylene.And another two with 250 milliliters of 100%ethanol inside a fume hood. Insert the tissue slides into a washing rack. Next, place the washing rack in a xylene containing dish and incubate for five minutes while moving the rack up and down at least three times and repeat with the second xylene dish.Then place the rack in an ethanol containing dish and incubate for two minutes with the same up and down movements and then repeat with the second ethanol dish. To dry the slides, move the rack from the second ethanol dish and place it inside an incubator at 60 degrees Celsius for five minutes. Use a hydrophobic barrier pen to draw a 0.75 inch by 0.75 inch barrier around the tissue section and air dry for three minutes at room temperature.Turn on the hybridization oven and set the temperature at 40 degrees Celsius. After completely wetting humidifying paper with distilled water, place it in a humidity control tray. Then insert the humidity control tray into the hybridization oven.After placing the dried slides on a bench, completely cover the tissue sections on each slide with five to eight drops of hydrogen peroxide solution. Incubate for 10 minutes at room temperature. Tap the slides on an absorbent paper, one at a time to remove the hydrogen peroxide solution and insert the slides into a washing rack.Immerse the rack in a washing dish containing water while moving it up and down three to five times to wash the slides. Fill a one liter glass beaker placed on a hot plate with 700 milliliters of 1X target removal treatment and cover it with foil. Insert a thermometer through the foil cover and turn on the hot plate, set on high temperature for 10 to 15 minutes.Once the temperature of the retrieval reagent reaches 98 degrees Celsius, set the hot plate at low temperature to maintain a mild boiling condition. Next, carefully remove the foil and place the rack inside the beaker. Cover the beaker with foil and incubate for 15 minutes.Use forceps to transfer the rack from the beaker to a washing dish containing 200 milliliters of distilled water and incubate for 15 seconds. After 15 seconds place the rack in a washing dish containing 100%ethanol and incubate for three minutes. Remove the rack from the dish and dry at 60 degrees Celsius for 10 minutes.After placing the slides on a stain rack, cover the tissue sections with five drops of protease 3 per slide. Carefully place the rack in the humidity control tray and insert the tray into the hybridization oven and incubate at 40 degrees Celsius for 30 minutes. After removing the rack from the tray, tap the slides to remove excess liquid and insert them into a washing rack.Place the rack into a washing dish containing distilled water and move the rack up and down three to five times to wash the slides. To prepare for in situ hybridization, incubate the probes and AMP reagents at room temperature for 30 minutes. Insert the humidity control tray into the hybridization oven and set at 40 degrees Celsius.For probe hybridization, remove the slides from the washing rack and tap them to remove excess liquid. Place the slides on a stain rack. Use a pencil to label the slides with the probe name.Place three adjacently cut brain tissue slides to be hybridized with three different neural fiber mitosis type one probes together. Because there are very different isoform specific probes, I use adjacently cut tissue sections. It is critical that these sections are treated exactly the same in hybridization, amplification, and signal detection steps to ensure the accuracy of the percentage splice in calculation.Cover the tissue sections with four drops of probe per section, one slide at a time to prevent drying out of the sections. Then place the stain rack in the humidity control tray and insert it into the 40 degrees Celsius oven for two hours. Next, place a washing rack in a washing dish filled with 200 milliliters of 1X wash buffer.Then tap each slide, one at a time on a paper towel to remove excess liquid. And immediately insert each slide into the washing rack. Incubate at room temperature for two minutes in a dish filled with fresh wash buffer while moving the rack up and down three to five times and then repeat the wash in a new dish.For signal amplification, tap each slide to remove excess wash buffer and place them on a stain rack. Cover the tissue section on each slide with four drops of AMP zero reagent. Next, place the rack in the humidity control tray, insert the tray into the oven and incubate at 40 degrees Celsius for 30 minutes.Wash the slide twice with wash buffer as previously done in this experiment. Repeat the signal amplification step with AMP reagents one through six as described in the text protocol and wash the slides after each step. For signal detection, remove excess wash buffer from the slides by tapping and place them on a stain rack.Next, mix two microliters of fast red B with 120 microliters of fast red A in a micro centrifuge tube. Add the solution to the tissue sections on each slide to fully cover them. Place the stain rack in the humidity control tray, cover the tray and incubate for 10 minutes at room temperature.Then remove the solution and insert the slides into a washing rack. Place the rack in a washing dish containing tap water to wash the slides and repeat the wash. After the second wash, tap on an absorbent paper to remove excess water.Next, place the rack in a dish containing 50%hematoxylin staining solution. Move the rack up and down several times. And incubate for two minutes at room temperature.Transfer the rack to a washing dish containing tap water. Move the rack up and down five times and repeat the wash until the slides become clear, while tissue sections remain purple. Then transfer the rack to a dish containing 0.02%ammonia water.Move the rack up and down two to four times until the sections turn blue. Wash the slides with tap water three to five times in the staining dish. Next, place the rack inside an incubator and incubate for 15 minutes at 60 degrees Celsius to dry the slides.When completely dry, add one drop of mounting medium on each slide to cover the slice. Then, carefully place a 24 by 50 millimeter coverslip over the tissue sections on each slide. After air drying the slides for 30 minutes at room temperature, proceed with data collection.To calculate the percent spliced in or PSI value for exon 23a, the number of cells and dots in three sub-regions of cortex, and hippocampus CA3 are counted. RNA in situ hybridization assay is performed in brain sections of CD1 wild type mice using three different NF1 specific probes. Red punctate dots observed in the cortex and hippocampus sections, indicate positive signals by NF1 total, inclusion specific, and skipping specific probes.The ISH signals from the three probes are then counted and used to calculate PSI. RNA in situ hybridization assay is performed in the cortex of C57 black 6J wild type mice and C57 black 6J mutant mice in which exon 23a is included in all cell types. Red punctate dots observed in the cortex of C57 black 6J wild type mice, indicate positive signals by NF1 total, inclusion specific, and skipping specific probes.In C57 black 6J mutant mice, similar signals are obtained by NF1 total and inclusion specific probes. However, no signal is detected when skipping specific probe is used, indicating that two probes targeting exon inclusion or skipping are highly specific. Because multi-color labeling on the same tissue slides is not yet available for this procedure, different probes are used on the different tissue slides.To obtain the accurate percent splicing values, it's important to use adjacently cut slides and treating slides in the exact same way throughout this procedure. Complementing this procedure are the measures like immunohistochemistry, can be performed to answer additional questions regarding the localization and function of differentially expressed splicing isoforms.

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JoVE Journal

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Cell Biology

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Unit 1

Transcription: DNA to RNA

SCIENTISTS IN ACTION

Engineering Artificial Factors to Specifically Manipulate Alternative Splicing in Human Cells

The processing of most eukaryotic RNAs is mediated by RNA Binding Proteins (RBPs) with modular configurations, including an RNA recognition module, which specifically binds the pre-mRNA target and an effector domain. Previously, we have taken advantage of the unique RNA binding mode of the PUF domain in human Pumilio 1 to generate a programmable RNA binding scaffold, which was used to engineer various artificial RBPs to manipulate RNA metabolism. Here, a detailed protocol is described to construct Engineered Splicing Factors (ESFs) that are specifically designed to modulate the alternative splicing of target genes. The protocol includes how to design and construct a customized PUF scaffold for a specific RNA target, how to construct an ESF expression plasmid by fusing a designer PUF domain and an effector domain, and how to use ESFs to manipulate the splicing of target genes. In the representative results of this method, we have also described the common assays of ESF activities using splicing reporters, the application of ESF in cultured human cells, and the subsequent effect of splicing changes. By following the detailed protocols in this report, it is possible to design and generate ESFs for the regulation of different types of Alternative Splicing (AS), providing a new strategy to study splicing regulation and the function of different splicing isoforms. Moreover, by fusing different functional domains with a designed PUF domain, researchers can engineer artificial factors that target specific RNAs to manipulate various steps of RNA processing.

This report describes a bioengineering method to design and construct novel Artificial Splicing Factors (ASFs) that specifically modulate the splicing of target genes in mammalian cells. This method can be further expanded to engineer various artificial factors to manipulate other aspects of RNA metabolism.

The processing of most eukaryotic RNAs is mediated by RNA Binding Proteins (RBPs) with modular configurations, including an RNA recognition module, which ...

Rearing and Double-stranded RNA-mediated Gene Knockdown in the Hide Beetle, Dermestes maculatus

Advances in genomics have raised the possibility of probing biodiversity at an unprecedented scale. However, sequence alone will not be informative without tools to study gene function. The development and sharing of detailed protocols for the establishment of new model systems in laboratories, and for tools to carry out functional studies, is thus crucial for leveraging the power of genomics. Coleoptera (beetles) are the largest clade of insects and occupy virtually all types of habitats on the planet. In addition to providing ideal models for fundamental research, studies of beetles can have impacts on pest control as they are often pests of households, agriculture, and food industries. Detailed protocols for rearing and maintenance of D. maculatus laboratory colonies and for carrying out dsRNA-mediated interference in D. maculatus are presented. Both embryonic and parental RNAi procedures-including apparatus set up, preparation, injection, and post-injection recovery-are described. Methods are also presented for analyzing embryonic phenotypes, including viability, patterning defects in hatched larvae, and cuticle preparations for unhatched larvae. These assays, together with in situ hybridization and immunostaining for molecular markers, make D. maculatus an accessible model system for basic and applied research. They further provide useful information for establishing procedures in other emerging insect model systems.

Rearing and Double-stranded RNA-mediated Gene Knockdown in the Hide Beetle, Dermestes maculatus

Here, we present protocols for rearing an intermediate-germ beetle, Dermestes maculatus (D. maculatus) in the lab. We also share protocols for embryonic and parental RNAi and methods for analyzing embryonic phenotypes to study gene function in this species.

Advances in genomics have raised the possibility of probing biodiversity at an unprecedented scale. However, sequence alone will not be informative ...

High Resolution Fluorescent In Situ Hybridization in Drosophila Embryos and Tissues Using Tyramide Signal Amplification

In our efforts to determine the patterns of expression and subcellular localization of Drosophila RNAs on a genome-wide basis, and in a variety of tissues, we have developed numerous modifications and improvements to our original fluorescent in situ hybridization (FISH) protocol. To facilitate throughput and cost effectiveness, all steps, from probe generation to signal detection, are performed using exon 96-well microtiter plates. Digoxygenin (DIG)-labelled antisense RNA probes are produced using either cDNA clones or genomic DNA as templates. After tissue fixation and permeabilization, probes are hybridized to transcripts of interest and then detected using a succession of anti-DIG antibody conjugated to biotin, streptavidin conjugated to horseradish peroxidase (HRP) and fluorescently conjugated tyramide, which in the presence of HRP, produces a highly reactive intermediate that binds to electron dense regions of immediately adjacent proteins. These amplification and localization steps produce a robust and highly localized signal that facilitates both cellular and subcellular transcript localization. The protocols provided have been optimized to produce highly specific signals in a variety of tissues and developmental stages. References are also provided for additional variations that allow the simultaneous detection of multiple transcripts, or transcripts and proteins, at the same time.

High Resolution Fluorescent In Situ Hybridization in Drosophila Embryos and Tissues Using Tyramide Signal Amplification

The described RNA in situ hybridization protocol allows the detection of RNA in whole Drosophila embryos or dissected tissues. Using 96-well microtiter plates and tyramide signal amplification, transcripts can be detected at high resolution, sensitivity, and throughput, and at a relatively low cost.

In our efforts to determine the patterns of expression and subcellular localization of Drosophila RNAs on a genome-wide basis, and in a variety of ...

Visualization of Microbiota in Tick Guts by Whole-mount In Situ Hybridization

Infectious diseases transmitted by arthropod vectors continue to pose a significant threat to human health worldwide. The pathogens causing these diseases, do not exist in isolation when they colonize the vector; rather, they likely engage in interactions with resident microorganisms in the gut lumen. The vector microbiota has been demonstrated to play an important role in pathogen transmission for several vector-borne diseases. Whether resident bacteria in the gut of the Ixodes scapularis tick, the vector of several human pathogens including Borrelia burgdorferi, influence tick transmission of pathogens is not determined. We require methods for characterizing the composition of the bacteria associated with the tick gut to facilitate a better understanding of potential interspecies interactions in the tick gut. Using whole-mount in situ hybridization to visualize RNA transcripts associated with particular bacterial species allows for the collection of qualitative data regarding the abundance and distribution of the microbiota in intact tissue. This technique can be used to examine changes in the gut microbiota milieu over the course of tick feeding and can also be applied to analyze expression of tick genes. Staining of whole tick guts yield information about the gross spatial distribution of target RNA in the tissue without the need for three-dimensional reconstruction and is less affected by environmental contamination, which often confounds the sequencing-based methods frequently used to study complex microbial communities. Overall, this technique is a valuable tool that can be used to better understand vector-pathogen-microbiota interactions and their role in disease transmission.

Visualization of Microbiota in Tick Guts by Whole-mount In Situ Hybridization

Here, we present a protocol to spatially and temporally assess the presence of viable microbiota in tick guts using a modified whole-mount in situ hybridization approach.

Infectious diseases transmitted by arthropod vectors continue to pose a significant threat to human health worldwide. The pathogens causing these ...

Single Molecule Fluorescence In Situ Hybridization (smFISH) Analysis in Budding Yeast Vegetative Growth and Meiosis

Single molecule fluorescence in situ hybridization (smFISH) is a powerful technique to study gene expression in single cells due to its ability to detect and count individual RNA molecules. Complementary to deep sequencing-based methods, smFISH provides information about the cell-to-cell variation in transcript abundance and the subcellular localization of a given RNA. Recently, we have used smFISH to study the expression of the gene&#160;NDC80&#160;during meiosis in budding yeast, in which two transcript isoforms exist and the short transcript isoform has its entire sequence shared with the long isoform. To confidently identify each transcript isoform, we optimized known smFISH protocols and obtained high consistency and quality of smFISH data for the samples acquired during budding yeast meiosis. Here, we describe this optimized protocol, the criteria that we use to determine whether high quality of smFISH data is obtained, and some tips for implementing this protocol in&#160;other yeast strains and growth conditions.

Single Molecule Fluorescence In Situ Hybridization smFISH Analysis in Budding Yeast Vegetative Growth and Meiosis

This single molecule fluorescence in situ hybridization protocol is optimized to quantify the number of RNA molecules in budding yeast during vegetative growth and meiosis.

Single molecule fluorescence in situ hybridization (smFISH) is a powerful technique to study gene expression in single cells due to its ability to detect ...

Tissue-specific miRNA Expression Profiling in Mouse Heart Sections Using In Situ Hybridization

micro-RNAs (miRNAs) are single-stranded RNA transcripts that bind to messenger RNAs (mRNAs) and inhibit their translation or promote their degradation. To date, miRNAs have been implicated in a large number of biological and disease processes, which has signified the need for the reliable detection methods of miRNA transcripts. Here, we describe a detailed protocol for digoxigenin-labeled (DIG) Locked Nucleic Acid (LNA) probe-based miRNA detection, combined with protein immunostaining on mouse heart sections. First, we performed an in situ hybridization technique using the probe to identify miRNA-182 expression in heart sections from control and cardiac hypertrophy mice. Next, we performed immunostaining for cardiac Troponin T (cTnT) protein, on the same sections, to co-localize miRNA-182 with the cardiomyocyte cells. Using this protocol, we were able to detect miRNA-182 through an alkaline phosphatase based colorimetric assay, and cTnT through fluorescent staining. This protocol can be used to detect the expression of any miRNA of interest through DIG-labeled LNA probes, and relevant protein expression on mouse heart tissue sections.

Tissue-specific miRNA Expression Profiling in Mouse Heart Sections Using In Situ Hybridization

micro-RNAs (miRNAs) are short and highly homologous RNA sequences, serving as post-transcriptional regulators of messenger RNAs (mRNAs). Current miRNA detection methods vary in sensitivity and specificity. We describe a protocol that combines in situ hybridization and immunostaining for concurrent detection of miRNA and protein molecules on mouse heart tissue sections.

micro-RNAs (miRNAs) are single-stranded RNA transcripts that bind to messenger RNAs (mRNAs) and inhibit their translation or promote their degradation. To ...

Using In Vitro and In-cell SHAPE to Investigate Small Molecule Induced Pre-mRNA Structural Changes

In the process of drug development of RNA-targeting small molecules, elucidating the structural changes upon their interactions with target RNA sequences is desired. We herein provide a detailed in vitro and in-cell selective 2&#39;-hydroxyl acylation analyzed by primer extension (SHAPE) protocol to study the RNA structural change in the presence of an experimental drug for spinal muscular atrophy (SMA), survival of motor neuron (SMN)-C2, and in exon 7 of the pre-mRNA of the SMN2 gene. In in vitro SHAPE, an RNA sequence of 140 nucleotides containing SMN2 exon 7 is transcribed by T7 RNA polymerase, folded in the presence of SMN-C2, and subsequently modified by a mild 2&#39;-OH acylation reagent, 2-methylnicotinic acid imidazolide (NAI). This 2&#39;-OH-NAI adduct is further probed by a 32P-labeled primer extension and resolved by polyacrylamide gel electrophoresis (PAGE). Conversely, 2&#39;-OH acylation in in-cell SHAPE takes place in situ with SMN-C2 bound cellular RNA in living cells. The pre-mRNA sequence of exon 7 in the SMN2 gene, along with SHAPE-induced mutations in the primer extension, was then amplified by PCR and subject to next-generation sequencing. Comparing the two methodologies, in vitro SHAPE is a more cost-effective method and does not require computational power to visualize results. However, the in vitro SHAPE-derived RNA model sometimes deviates from the secondary structure in a cellular context, likely due to the loss of all interactions with RNA-binding proteins. In-cell SHAPE does not need a radioactive material workplace and yields a more accurate RNA secondary structure in the cellular context. Furthermore, in-cell SHAPE is usually applicable for a larger range of RNA sequences (~1,000 nucleotides) by utilizing next-generation sequencing, compared to in vitro SHAPE (~200 nucleotides) that usually relies on PAGE analysis. In case of exon 7 in SMN2 pre-mRNA, the in vitro and in-cell SHAPE derived RNA models are similar to each other.

Detailed protocols for both in vitro and in-cell selective 2&#39;-hydroxyl acylation analyzed by primer extension (SHAPE) experiments to determine the secondary structure of pre-mRNA sequences of interest in the presence of an RNA-targeting small molecule are presented in this article.

In the process of drug development of RNA-targeting small molecules, elucidating the structural changes upon their interactions with target RNA sequences ...

Use of Single Molecule Fluorescent In Situ Hybridization (SM-FISH) to Quantify and Localize mRNAs in Murine Oocytes

Current methods routinely used to quantify mRNA in oocytes and embryos include digital reverse-transcription polymerase chain reaction (dPCR), quantitative, real-time RT-PCR (RT-qPCR) and RNA sequencing. When these techniques are performed using a single oocyte or embryo, low-copy mRNAs are not reliably detected. To overcome this problem, oocytes or embryos can be pooled together for analysis; however, this often leads to high variability amongst samples. In this protocol, we describe the use of fluorescence in situ hybridization (FISH) using branched DNA chemistry. This technique identifies the spatial pattern of mRNAs in individual cells. When the technique is coupled with Spot Finding and Tracking&#160;computer software, the abundance of mRNAs in the cell can also be quantified. Using this technique, there is reduced variability within an experimental group and fewer oocytes and embryos are required to detect significant differences between experimental groups. Commercially available branched-DNA SM-FISH kits have been optimized to detect mRNAs in sectioned tissues or adherent cells on slides. However, oocytes do not effectively adhere to slides and some reagents in the kit were too harsh resulting in oocyte lysis. To prevent this lysis, several modifications were made to the FISH kit. Specifically, oocyte permeabilization and wash&#160;buffers designed for the immunofluorescence of oocytes and embryos replaced the proprietary buffers. The permeabilization, washes, and incubations with probes and amplifier were performed in 6-well plates and oocytes were placed on slides at the end of the protocol using mounting media. These modifications were able to overcome the limitations of the commercially available kit, in particular, the oocyte lysis. To accurately and reproducibly count the number of mRNAs in individual oocytes, computer software was used. Together, this protocol represents an alternative to PCR and sequencing to compare the expression of specific transcripts in single cells.

Use of Single Molecule Fluorescent In Situ Hybridization SM-FISH to Quantify and Localize mRNAs in Murine Oocytes

To reproducibly count the numbers of mRNAs in individual oocytes, single molecule RNA fluorescence in situ hybridization (RNA-FISH) was optimized for non-adherent cells. Oocytes were collected, hybridized with the transcript specific probes, and quantified using an image quantification software.

Current methods routinely used to quantify mRNA in oocytes and embryos include digital reverse-transcription polymerase chain reaction (dPCR), ...

Chromogenic In Situ Hybridization as a Tool for HPV-Related Head and Neck Cancer Diagnosis

Human papillomavirus (HPV) infection is a major risk factor for a subtype of oropharyngeal squamous cell carcinoma (OPSCC), which tends to be associated with a better outcome than alcohol- and tobacco-related OPSCC. Chromogenic in situ hybridization (CISH) of HPV viral RNA could allow the semiquantitative evaluation of viral transcripts of the oncogenic proteins E6 and E7 and an in situ visualization with a good spatial resolution. This technique allows the diagnosis of an active infection with the visualization of HPV transcription in the tumoral HPV-infected cells. An advantage of this technique is the avoidance of contamination from nonneoplastic HPV-infected cells adjacent to the tumor. Overall, its good diagnosis performances have it considered to be the gold standard for active HPV infection identification. Since E6 and E7 viral protein interaction with cell proteins pRb and p53 is mandatory for cell transformation, HPV RNA CISH is functionally relevant and acutely reflects active oncogenic HPV infection. This technique is clinically relevant as well since &#34;low&#34; or &#34;high&#34; HPV transcription levels helped the identification of two prognosis groups among HPV-related p16-positive head and neck cancer patients. Here we present the protocol for manual HPV RNA CISH performed on formalin-fixed paraffin-embedded (FFPE) slides with a kit obtained from the manufacturer. Instead of chromogenic revelation, RNA in situ hybridization may also be performed with fluorescent revelation (RNA FISH). It may also be combined with conventional immunostaining.

Human papillomavirus (HPV) RNA chromogenic in situ hybridization is considered to be one of the gold standards for active human papillomavirus infection detection within tumors. It allows the visualization of HPV E6-E7 mRNA expression with localization and semiquantitative evaluation of its signal.

Human papillomavirus (HPV) infection is a major risk factor for a subtype of oropharyngeal squamous cell carcinoma (OPSCC), which tends to be associated ...

An Assay for Quantifying Protein-RNA Binding in Bacteria

In the initiation step of protein translation, the ribosome binds to the initiation region of the mRNA. Translation initiation can be blocked by binding of an RNA binding protein (RBP) to the initiation region of the mRNA, which interferes with ribosome binding. In the presented method, we utilize this blocking phenomenon to quantify the binding affinity of RBPs to their cognate and non-cognate binding sites. To do this, we insert a test binding site in the initiation region of a reporter mRNA and induce the expression of the test RBP. In the case of RBP-RNA binding, we observed a sigmoidal repression of the reporter expression as a function of RBP concentration. In the case of no-affinity or very low affinity between binding site and RBP, no significant repression was observed. The method is carried out in live bacterial cells, and does not require expensive or sophisticated machinery. It is useful for quantifying and comparing between the binding affinities of different RBPs that are functional in bacteria to a set of designed binding sites. This method may be inappropriate for binding sites with high structural complexity. This is due to the possibility of repression of ribosomal initiation by complex mRNA structure in the absence of RBP, which would result in lower basal reporter gene expression, and thus less-observable reporter repression upon RBP binding.

In this method, we quantify the binding affinity of RNA binding proteins (RBPs) to cognate and non-cognate binding sites using a simple, live, reporter assay in bacterial cells. The assay is based on repression of a reporter gene.

In the initiation step of protein translation, the ribosome binds to the initiation region of the mRNA. Translation initiation can be blocked by binding ...