This work is supported by a Canadian Health Research Institute (CIHR) Team Grant to Dr. Bolduc (co-PI) and Dr. Guy Rouleau (PI). We would like to thank Dr. Oksana Suchowersky, Dr. Kathryn Todd, the members of the University of Alberta fly club and Dr. Clayton Dickson for help in development of the method and statistical analysis.

Research on Drosophila melanogaster was in compliance with the University of Alberta&#8217;s research guidelines.
1. Fly Collection
<ol>
	<li>Collect 20 flies using CO2 (g) anesthetization and place in a 25 mm x 95 mm collection vial containing food.</li>
	<li>Store vials containing flies horizontally to avoid trapping flies in any liquids that may accumulate in the bottom the vial.</li>
	<li>Incubate flies for at least 21 hr&#160;at 22 &#176;C at 45% humidity in an incubator for approximately for 15 hr. Set the incubator with a 12 hr&#160;light : dark cycle.</li>
</ol>
2. Climbing Assay
<ol>
	<li>The following morning, transfer 20 flies from a single vial into a 250 ml glass graduated cylinder. Mark the position of the cylinder to keep it constant everyday. Use one glass cylinder per genotype to prevent cross contamination between the genotypes. Wash at the end of each experiment and rotate them between genotypes.
	<ol>
		<li>Conduct the experiments in ambient light (or red light if there is a potential defect in vision) at temperature and humidity of 22 &#176;C and 40% respectively. To avoid circadian rhythm confound, always perform experiments at the same time of day.</li>
	</ol>
	</li>
	<li>Seal the top of cylinder with a barrier film (wax film) to prevent the escape of any flies (Figure 2).</li>
	<li>Set up the video camera on a tripod. Focus camera on the 190 ml line of the 250 ml graduated cylinder (17.5 cm).</li>
	<li>Count the number of dead flies at the bottom of the cylinder and in the food vials. Record this number as the mortality.</li>
	<li>Very lightly tap the cylinder against a closed cell foam pad repeatedly with enough force to displace the flies to the inner bottom surface. Tap 5 - 10 times while using the other hand to press record on the camera.</li>
	<li>Press the &#8220;Record&#8221; button on the camera.</li>
	<li>Start the video camera recording and tap the cylinder six times in a distinct non-rhythmic pattern.</li>
	<li>Conduct each trial for 2 min from the time the flies are last tapped and record the number of flies crossing the height of 17.5 cm (190 ml) at each time point chosen (quantify every 10 sec). Note: The ml marking on the cylinder will vary from one cylinder model to another depending on diameter. To avoid error, measure the height on each cylinder used.</li>
	<li>Once the trial has ended, dispose of flies in 95% ethanol.</li>
	<li>Repeat steps 2.1 to 2.9 until all the replicates have been tested with fresh flies every time. 
	Note: Although 5 replicates may be enough with a mutation having a strong effect on locomotion, 10 biological replicates of 20 flies (200 flies) is recommended to detect smaller differences.</li>
	<li>Upon completion of the experiment, wash the cylinders in the lab dishwasher and dry O/N to be re-used.</li>
</ol>
3. Analysis
<ol>
	<li>Analyze videos of each fly trial. Each 10 sec, record the total number of flies that pass the target line.
	<ol>
		<li>If a fly climbs back down or falls, record that fly as -1 and count the next fly to cross the target line as the same number as the fly that climbed back down or fell. For example, if the 15th fly falls below the target line, the next fly to cross the line (the 16th fly) is considered the 15th fly and not the 16th.</li>
	</ol>
	</li>
	<li>Subtract the mortality from the total number of flies (20) to obtain the number of flies that remain in the trial. At each time point, obtain the fraction of flies above the target line.</li>
	<li>Plot each percentage at each time point (see Figure 3).</li>
	<li>Analyze the performance at the 120 sec data point and perform student t-test when 2 groups are present or ANOVA and a post-test for multiple comparisons (with Bonferroni modification for planned and Tukey for unplanned comparisons). The Kolmogorov-Smirnov tests17 is also performed to ascertain normality and equal variance but also to compare the distributions of the mutant group to the control.</li>
	<li>To present the data over aging, plot the percentage of flies climbing at 120 sec with flies of different ages (2 days, 1 week, 2 weeks) to see if there is a progressive deficit (Figure 4).</li>
</ol>

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S., Tully, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Excess+protein+synthesis+in+Drosophila+fragile+X+mutants+impairs+long-term+memory.">Excess protein synthesis in Drosophila fragile X mutants impairs long-term memory.</a> Nature neuroscience. 11, 1143-1145 (2008).</li><li>McBride, S. 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=Pharmacological+rescue+of+synaptic+plasticity,+courtship+behavior,+and+mushroom+body+defects+in+a+Drosophila+model+of+fragile+X+syndrome.">Pharmacological rescue of synaptic plasticity, courtship behavior, and mushroom body defects in a Drosophila model of fragile X syndrome.</a> Neuron. 45, 753-764 (2005).</li><li>Parker, L., Padilla, M., Du, Y., Dong, K., Tanouye, M. 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The authors have nothing to disclose.

Drosophila has already proven to be an excellent model in Parkinson&#8217;s disease14 and other neurodegenerative conditions1,2. In addition to the genetic tools available in Drosophila, its genome is highly conserved for genes involved in neurological disorders19. The advent of genome wide genetic screening methods (including whole exome sequencing) is likely to continue to provide a larger list of candidate genes associated with human movement disorders. The developmen...

Devastating neurodegenerative disorders such as Parkinson&#8217;s disease, amyotrophic lateral sclerosis, and hereditary spastic paraplegia are increasingly recognized. Unfortunately, most of these neurodegenerative disorders are still without treatments. The widespread clinical use of genome-wide, unbiased genetic tests such as whole exome sequencing has led to an increasing number of genes being implicated in human locomotive disorders. Despite this progress, the pathological progression from early to late stages, remains elusive in these disorders. Drosophila provides one with the genetic tools for studying gene requirement in a controlled spatial and temporal manner. In addition, Drosophila has proven useful in screening drugs for neurological conditions such as Parkinson&#8217;s1, Alzheimer&#8217;s2, intellectual disability3,4 and epilepsy5,6 among others. Our aim was to develop a cost effective and reliable assay that would allow high throughput analysis that would still be sensitive enough to detect small changes in motor performance.
There are several assays used to quantify the effects of genetic mutation and/or environmental condition on Drosophila climbing behavior. Most of the assays capitalize on the natural tendency of flies to climb, known as negative geotaxis, or the climbing assay. Benzer7 suggested in 1967 that the counter-current apparatus used for the study of phototaxis could also be used to study gravitaxis. Since then, Ganetsky8 and many others9-12 have built on the initial assay. The principle is to place a known number of flies in a vial and tap the vial strongly against a hard surface, causing the flies to fall to the bottom of the vial. As it is an innate behavior, the flies will attempt to climb to the top of the vial, opposed to gravity. This assay is quantitative and measures how many flies have climbed past a marker on the vial during an allotted time period. Measurement of speed instead of total number of flies climbing has become a reliable parameter and shown defects in cases where the number of flies criteria was not significant13.
The climbing assay has proven useful in the study of many neurodegenerative disorders including Parkinson&#8217;s disease14. However, we noted that locomotive defects may not be detectable at time where neurodegeneration is already seen in pathological studies14. Thus, use of the traditional assay may limit the ability to study the early stages of disease pathogenesis. The appearance of locomotive defects during later stages of pathology may reflect a disease whose progression is too advanced for complete rescue.
This raises a potential issue with the sensitivity of the traditional climbing assay. The potential inability of the traditional climbing assay to detect mild locomotive defects can be attributed to the height to which the flies are required to climb. The traditional assay15,16 measures the number of flies to successfully climb over a height of 2 to 5 cm in 10 to 20 sec.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Drosophila stocks</td>
			<td></td>
			<td></td>
			<td>The stocks are selected depending on the experiments. The temperature and humidity in the room and in the incubator must be controled and consistent to avoid flies being too staticky or too wet.</td>
		</tr>
		<tr>
			<td>Video camera</td>
			<td></td>
			<td></td>
			<td>Any digital camcorder will do. Make sure they can focus on close object.</td>
		</tr>
		<tr>
			<td>Graduated cylinder</td>
			<td>Kimble</td>
			<td>20028W</td>
			<td>Different models of graduated cylinder may have different diameter. It is therefore imporant to measure the height.</td>
		</tr>
		<tr>
			<td>computer</td>
			<td></td>
			<td></td>
			<td>Any model will do. We used the computer to monitor the climbing of the flies and record the number of flies at each time point</td>
		</tr>
	</tbody>
</table>

quantitative analysis of climbing defects in a drosophila model of neurodegenerative disorders

Locomotive defects resulting from neurodegenerative disorders can be a late onset symptom of disease, following years of subclinical degeneration, and thus current therapeutic treatment strategies are not curative. Through the use of whole exome sequencing, an increasing number of genes have been identified to play a role in human locomotion. Despite identifying these genes, it is not known how these genes are crucial to normal locomotive functioning. Therefore, a reliable assay, which utilizes model organisms to elucidate the role of these genes in order to identify novel targets of therapeutic interest, is needed more than ever. We have designed a sensitized version of the negative geotaxis assay that allows for the detection of milder defects earlier and has the ability to evaluate these defects over time. The assay is performed in a glass graduated cylinder, which is sealed with a wax barrier film. By increasing the threshold distance to be climbed to 17.5 cm and increasing the experiment duration to 2 min&#160;we have observed a greater sensitivity in detecting mild mobility dysfunctions. The assay is cost effective and does not require extensive training to obtain highly reproducible results. This makes it an excellent technique for screening candidate drugs in Drosophila mutants with locomotion defects.

Climbing is a strong and reproducible behavior. Indeed, one day old wild-type flies reach the target distance climbing performance rapidly (25 - 30 sec). Mutant flies present a range of performance from mild (or delayed) to complete inability to climb to the target. We illustrate this here with two different mutant alleles. The first one is a severe allele of the gene spastin caused by a complete deletion of the spastin gene (spas5.75) 18. In this line (spas5.75 with TM6b) one day old fli...

Watch this Scientific Journal Video about Quantitative Analysis of Climbing Defects in a Drosophila Model of Neurodegenerative Disorders at JoVE.com

Quantitative Analysis of Climbing Defects in a Drosophila Model of Neurodegenerative Disorders

We present an optimized inexpensive and reliable negative geotaxis assay in Drosophila melanogaster as a model for neurodegenerative disorders. Being more sensitive to mild locomotor defects, this assay will help screen for potential genetic interactions and drug targets.

Locomotive defects resulting from neurodegenerative disorders can be a late onset symptom of disease, following years of subclinical degeneration, and ...

quantitative-analysis-climbing-defects-drosophila-model

Research

JoVE Journal

Neuroscience

18.5K Views.  University of Alberta. We present an optimized inexpensive and reliable negative geotaxis assay in Drosophila melanogaster as a model for neurodegenerative disorders. Being more sensitive to mild locomotor defects, this assay will help screen for potential genetic interactions and drug targets. 

Video: Quantitative Analysis of Climbing Defects in a Drosophila Model of Neurodegenerative Disorders

Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system1. Most of these diseases, including Alzheimer's, Parkinson's and Huntington's disease are characterized by age-dependent deterioration in learning and memory functions and movement coordination2. Here we use behavioral assays, including the negative geotaxis assay3 and the aversive phototaxic suppression assay (APS assay)4,5, to show that some of the behavior characteristics associated with human neurodegeneration can be recapitulated in flies. In the negative geotaxis assay, the natural tendency of flies to move against gravity when agitated is utilized to study genes or conditions that may hinder locomotor capacities. In the APS assay, the learning and memory functions are tested in positively-phototactic flies trained to associate light with aversive bitter taste and hence avoid this otherwise natural tendency to move toward light. Testing these trained flies 6 hours post-training is used to assess memory functions. Using these assays, the contribution of any genetic or environmental factors toward developing neurodegeneration can be easily studied in flies.

Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Behavior assays for measuring locomotor functions, learning, and memory abilities in Drosophila.

Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system1. Most of ...

In Vivo Forward Genetic Screen to Identify Novel Neuroprotective Genes in Drosophila melanogaster

There is much to understand about the onset and progression of neurodegenerative diseases, including the underlying genes responsible. Forward genetic screening using chemical mutagens is a useful strategy for mapping mutant phenotypes to genes among Drosophila and other model organisms that share conserved cellular pathways with humans. If the mutated gene of interest is not lethal in early developmental stages of flies, a climbing assay can be conducted to screen for phenotypic indicators of decreased brain functioning, such as low climbing rates. Subsequently, secondary histological analysis of brain tissue can be performed in order to verify the neuroprotective function of the gene by scoring neurodegeneration phenotypes. Gene mapping strategies include meiotic and deficiency mapping that rely on these same assays can be followed by DNA sequencing to identify possible nucleotide changes in the gene of interest.

In Vivo Forward Genetic Screen to Identify Novel Neuroprotective Genes in Drosophila melanogaster

We present a protocol using a forward genetic approach to screen for mutants exhibiting neurodegeneration in Drosophila melanogaster. It incorporates a climbing assay, histology analysis, gene mapping and DNA sequencing to ultimately identify novel genes related to the process of neuroprotection.

There is much to understand about the onset and progression of neurodegenerative diseases, including the underlying genes responsible. Forward genetic ...

Genetics

An Automated Rapid Iterative Negative Geotaxis Assay for Analyzing Adult Climbing Behavior in a Drosophila Model of Neurodegeneration

Neurodegenerative diseases are frequently associated with a progressive loss of movement ability, reduced life span, and age-dependent neurodegeneration. To understand the mechanism of these cellular events, and their causal relationships with each other, Drosophila melanogaster, with its sophisticated genetic tools and diverse behavioral features, are used as disease models for assessing neurodegenerative phenotypes. Here we describe a high-throughput method to analyze Drosophila adult negative geotaxis behavior, as an indication for possible motor defects associated with neurodegeneration. An automated machine is designed and developed to drive fly synchronization using an initial electric impulse, later allowing the recording of negative geotaxis behavior over a course of secs to mins. Images from the digitally recorded video are then processed with the self-designed RflyDetection software for statistical data manipulation. Different from the manually controlled negative geotaxis assay based on single fly, this precise, fast, and high-throughput protocol allows data acquisition from more than hundreds of flies simultaneously, providing an efficient approach to advance our understanding in the underlying mechanism of locomotor deficits associated with neurodegeneration.

An Automated Rapid Iterative Negative Geotaxis Assay for Analyzing Adult Climbing Behavior in a Drosophila Model of Neurodegeneration

This step-by-step protocol analyzes Drosophila negative geotaxis behavior using an automated multi-cylinder system that hosts hundreds of flies and synchronizes their action by an electric motor. Upon synchronization, fly negative geotaxis behavior is assayed, digitally recorded, and analyzed using the self-designed RflyDetection software.

Neurodegenerative diseases are frequently associated with a progressive loss of movement ability, reduced life span, and age-dependent neurodegeneration. ...

Behavior

Assessing Neurodegenerative Phenotypes in Drosophila Dopaminergic Neurons by Climbing Assays and Whole Brain Immunostaining

Drosophila melanogaster is a valuable model organism to study aging and pathological degenerative processes in the nervous system. The advantages of the fly as an experimental system include its genetic tractability, short life span and the possibility to observe and quantitatively analyze complex behaviors. The expression of disease-linked genes in specific neuronal populations of the Drosophila brain, can be used to model human neurodegenerative diseases such as Parkinson's and Alzheimer's 5.
Dopaminergic (DA) neurons are among the most vulnerable neuronal populations in the aging human brain. In Parkinson's disease (PD), the most common neurodegenerative movement disorder, the accelerated loss of DA neurons leads to a progressive and irreversible decline in locomotor function. In addition to age and exposure to environmental toxins, loss of DA neurons is exacerbated by specific mutations in the coding or promoter regions of several genes. The identification of such PD-associated alleles provides the experimental basis for the use of Drosophila as a model to study neurodegeneration of DA neurons in vivo. For example, the expression of the PD-linked human &alpha;-synuclein gene in Drosophila DA neurons recapitulates some features of the human disease, e.g. progressive loss of DA neurons and declining locomotor function 2. Accordingly, this model has been successfully used to identify potential therapeutic targets in PD 8.
Here we describe two assays that have commonly been used to study age-dependent neurodegeneration of DA neurons in Drosophila: a climbing assay based on the startle-induced negative geotaxis response and tyrosine hydroxylase immunostaining of whole adult brain mounts to monitor the number of DA neurons at different ages. In both cases, in vivo expression of UAS transgenes specifically in DA neurons can be achieved by using a tyrosine hydroxylase (TH) promoter-Gal4 driver line 3, 10.

Assessing Neurodegenerative Phenotypes in Drosophila Dopaminergic Neurons by Climbing Assays and Whole Brain Immunostaining

Here we describe two assays that have been established to study age-dependent neurodegeneration of dopaminergic (DA) neurons in Drosophila: the climbing/startle-induced negative geotaxis assay which allows to study the functional effects of DA neurons degeneration and the tyrosine hydroxylase immunostaining which is used to identify and count DA neurons in whole brain mounts.

Drosophila melanogaster is a valuable model organism to study aging and pathological degenerative processes in the nervous system. The advantages of the ...

A Simple Technique to Assay Locomotor Activity in Drosophila

Drosophila melanogaster is an ideal model organism for studying various diseases due to its abundance of advanced genetic manipulation techniques and diverse behavioral features. Identifying behavioral deficiency in animal models is a crucial measure of disease severity, for example, in neurodegenerative diseases where patients often experience impairments in motor function. However, with the availability of various systems to track and assess motor deficits in fly models, such as drug-treated or transgenic individuals, an economical and user-friendly system for precise evaluation from multiple angles is still lacking. A method based on the AnimalTracker application programming interface (API) is developed here, which is compatible with the Fiji image processing program, to systematically evaluate the movement activities of both adult and larval individuals from recorded video, thus allowing for the analysis of their tracking behavior. This method requires only a high-definition camera and a computer peripheral hardware integration to record and analyze behavior, making it an affordable and effective approach for screening fly models with transgenic or environmental behavioral deficiencies. Examples of behavioral tests using pharmacologically treated flies are given to show how the techniques can detect behavioral changes in both adult flies and larvae in a highly repeatable manner.

A Simple Technique to Assay Locomotor Activity in Drosophila

The present protocol assesses the locomotor activity of Drosophila by tracking and analyzing the movement of flies in a hand-made arena using open-source software Fiji, compatible with plugins to segment pixels of each frame based on high-definition video recording to calculate parameters of speed, distance, etc.

Drosophila melanogaster is an ideal model organism for studying various diseases due to its abundance of advanced genetic manipulation techniques and ...

Mass Histology to Quantify Neurodegeneration in Drosophila

Progressive neurodegenerative diseases like Alzheimer&#39;s disease (AD) or Parkinson&#39;s disease (PD) are an increasing threat to human health worldwide. Although mammalian models have provided important insights into the underlying mechanisms of pathogenicity, the complexity of mammalian systems together with their high costs are limiting their use. Therefore, the simple but well-established Drosophila model-system&#160;provides an alternative for investigating the molecular pathways that are affected in these diseases. Besides behavioral deficits, neurodegenerative diseases are characterized by histological phenotypes such as neuronal death and axonopathy. To quantify neuronal degeneration and to determine how it is affected by genetic and environmental factors, we use a histological approach that is based on measuring the vacuoles in adult fly brains. To minimize the effects of systematic error and to directly compare sections from control and experimental flies in one preparation, we use the &#39;collar&#39; method for paraffin sections. Neurodegeneration is then assessed by measuring the size and/or number of vacuoles that have developed in the fly brain. This can either be done by focusing on a specific region of interest or by analyzing the entire brain by obtaining serial sections that span the complete head. Therefore, this method allows one to measure not only severe degeneration but also relatively mild phenotypes that are only detectable in a few sections, as occurs during normal aging.

Mass Histology to Quantify Neurodegeneration in Drosophila

Drosophila is widely used as a model system to study neurodegeneration. This protocol describes a method by which degeneration, as determined by vacuole formation in the brain, can be quantified. It also minimizes effects due to the experimental procedure by processing and sectioning control and experimental flies as one sample.

Progressive neurodegenerative diseases like Alzheimer&#39;s disease (AD) or Parkinson&#39;s disease (PD) are an increasing threat to human health ...

Quantitative Analysis of Neuronal Dendritic Arborization Complexity in Drosophila

Dendrites are the branched projections of a neuron, and dendritic morphology reflects synaptic organization during the development of the nervous system. Drosophila larval neuronal dendritic arborization (da) is an ideal model for studying morphogenesis of neural dendrites and gene function in the development of nervous system. There are four classes of da neurons. Class IV is the most complex with a branching pattern that covers almost the entire area of the larval body wall. We have previously characterized the effect of silencing the Drosophila ortholog of SOX5 on class IV neuronal dendritic arborization complexity (NDAC) using four parameters: the length of dendrites, the surface area of dendrite coverage, the total number of branches, and the branching structure. This protocol presents the workflow of NDAC quantitative analysis, consisting of larval dissection, confocal microscopy, and image analysis procedures using ImageJ software. Further insight into da neuronal development and its underlying mechanisms will improve the understanding of neuronal function and provide clues about the fundamental causes of neurological and neurodevelopmental disorders.

Quantitative Analysis of Neuronal Dendritic Arborization Complexity in Drosophila

This protocol focuses on quantitative analysis of neuronal dendritic arborization complexity (NDAC) in Drosophila, which can be used for studies of dendritic morphogenesis.

Dendrites are the branched projections of a neuron, and dendritic morphology reflects synaptic organization during the development of the nervous system. ...

Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ

With the rising prevalence of neurodegenerative diseases, it is increasingly important to understand the underlying pathophysiology that leads to neuronal dysfunction and loss. Fluorescence-based imaging tools and technologies enable unprecedented analysis of subcellular neurobiological processes, yet there is still a need for unbiased, reproducible, and accessible approaches for extracting quantifiable data from imaging studies. We have developed a simple and adaptable workflow to extract quantitative data from fluorescence-based imaging studies using Drosophila models of neurodegeneration. Specifically, we describe an easy-to-follow, semi-automated approach using Fiji/ImageJ to analyze two cellular processes: first, we quantify protein aggregate content and profile in the Drosophila optic lobe using fluorescent-tagged mutant huntingtin proteins; and second, we assess autophagy-lysosome flux in the Drosophila visual system with ratiometric-based quantification of a tandem fluorescent reporter of autophagy. Importantly, the protocol outlined here includes a semi-automated segmentation step to ensure all fluorescent structures are analyzed to minimize selection bias and to increase resolution of subtle comparisons. This approach can be extended for the analysis of other cell biological structures and processes implicated in neurodegeneration, such as proteinaceous puncta (stress granules and synaptic complexes), as well as membrane-bound compartments (mitochondria and membrane trafficking vesicles). This method provides a standardized, yet adaptable reference point for image analysis and quantification, and could facilitate reliability and reproducibility across the field, and ultimately enhance mechanistic understanding of neurodegeneration.

Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ

We have developed a simple and adaptable workflow to extract quantitative data from fluorescence-imaging-based cell biological studies of protein aggregation and autophagic flux in the central nervous system of Drosophila models of neurodegeneration.

With the rising prevalence of neurodegenerative diseases, it is increasingly important to understand the underlying pathophysiology that leads to neuronal ...

Purification of Transcripts and Metabolites from Drosophila Heads

For the last decade, we have tried to understand the molecular and cellular mechanisms of neuronal degeneration using Drosophila as a model organism. Although fruit flies provide obvious experimental advantages, research on neurodegenerative diseases has mostly relied on traditional techniques, including genetic interaction, histology, immunofluorescence, and protein biochemistry. These techniques are effective for mechanistic, hypothesis-driven studies, which lead to a detailed understanding of the role of single genes in well-defined biological problems. However, neurodegenerative diseases are highly complex and affect multiple cellular organelles and processes over time. The advent of new technologies and the omics age provides a unique opportunity to understand the global cellular perturbations underlying complex diseases. Flexible model organisms such as Drosophila are ideal for adapting these new technologies because of their strong annotation and high tractability. One challenge with these small animals, though, is the purification of enough informational molecules (DNA, mRNA, protein, metabolites) from highly relevant tissues such as fly brains. Other challenges consist of collecting large numbers of flies for experimental replicates (critical for statistical robustness) and developing consistent procedures for the purification of high-quality biological material. Here, we describe the procedures for collecting thousands of fly heads and the extraction of transcripts and metabolites to understand how global changes in gene expression and metabolism contribute to neurodegenerative diseases. These procedures are easily scalable and can be applied to the study of proteomic and epigenomic contributions to disease.

Purification of Transcripts and Metabolites from Drosophila Heads

We describe here the procedures for the extraction and purification of mRNA and metabolites from Drosophila heads. We are applying these techniques to better understand the cellular perturbations underlying neuronal degeneration. These methodologies can be easily scaled and adapted for other "omic" projects.

For the last decade, we have tried to understand the molecular and cellular mechanisms of neuronal degeneration using Drosophila as a model organism. ...

Biology

Visualizing Synaptic Degeneration in Adult Drosophila in Association with Neurodegeneration

Drosophila serves as a useful model for assessing synaptic structure and function associated with neurodegenerative diseases. While much work has focused on neuromuscular junctions (NMJs) in Drosophila larvae, assessing synaptic integrity in adult Drosophila has received much less attention. Here we provide a straightforward method for dissection of the dorsal longitudinal muscles (DLMs), which are required for flight ability. In addition to flight as a behavioral readout, this dissection allows for the both DLM synapses and muscle tissue to be amenable to structural analysis using fluorescently labeled antibodies for synaptic markers or proteins of interest. This protocol allows for the evaluation of the structural integrity of synapses in adult Drosophila during aging to model the progressive, age-dependent nature of most neurodegenerative diseases.

Visualizing Synaptic Degeneration in Adult Drosophila in Association with Neurodegeneration

The goal of this procedure is to dissect the dorsal longitudinal muscle (DLM) tissue to assess the structural integrity of DLM neuromuscular junctions (NMJs) in neurodegenerative disease models using Drosophila melanogaster.

Drosophila serves as a useful model for assessing synaptic structure and function associated with neurodegenerative diseases. While much work has focused ...