Name: visualization of mitochondrial respiratory function using cytochrome c oxidase / succinate dehydrogenase (cox/sdh) double-labeling histochemistry
Uploaded: 2011-11-23T12:00:00
Description: Watch this Scientific Journal Video about Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase COX/SDH Double-labeling Histochemistry at JoVE.com

This work was supported by the National Institute of Aging (AG04418), National Institute on Drug Abuse, National Institute of Health-Karolinska Institutet Graduate Partnerships Program, Karolinska Institutet, Swedish Research Council, Swedish Brain Power, and Swedish Brain Foundation. Many thanks to Mattias Karlen and Dr. Giuseppe Coppotelli for creative support with Figure 1 and 2, respectively; Karin Pernold for technical assistance; and Drs. Barry J. Hoffer, Lars Olson, and Nils-G&ouml;ran Larsson for much helpful advice and discussion.

1. Tissue preparation for cryosectioning
<ol>
	<li>Sacrifice the animal by either cervical dislocation or decapitation, in accordance with available ethical permit.</li>
	<li>Quickly collect tissues of interest (e.g. brain), and rapidly freeze on dry ice (tissues may require freezing in isopentane or propane chilled with liquid nitrogen to obtain optimal morphology). Store tissues in aluminum foil at -80 &deg;C until ready to section.</li>
	<li>Embed frozen tissue in preparation for cryosectioning.</li>
	...

<ol>
	<li>Larsson, N. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Somatic+mitochondrial+DNA+mutations+in+mammalian+aging.">Somatic mitochondrial DNA mutations in mammalian aging.</a> Annu. Rev. Biochem. 79, 683-706 (2010).</li><li>Cottrell, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+mitochondrial+DNA+mutations+in+disease+and+aging.">Role of mitochondrial DNA mutations in disease and aging.</a> Ann. NY Acad. Sci. 908, 199-207 (2000).</li><li>Harman, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+biologic+clock:+the+mitochondria.">The biologic clock: the mitochondria.</a> J. Am. Geriatr. Soc. 20, 145-147 (1972).</li><li>Wallace, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+genetics+-+a+paradigm+for+aging+and+degenerative+diseases.">Mitochondrial genetics - a paradigm for aging and degenerative diseases.</a> Science. 256, 628-632 (1992).</li><li>Trifunovic, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Premature+ageing+in+mice+expressing+defective+mitochondrial+DNA+polymerase.">Premature ageing in mice expressing defective mitochondrial DNA polymerase.</a> Nature. 429, 417-423 (2004).</li><li>Ameur, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultra-deep+sequencing+of+mouse+mitochondrial+DNA:+mutational+patterns+and+their+origins.">Ultra-deep sequencing of mouse mitochondrial DNA: mutational patterns and their origins.</a> PLoS Genet. 7, e1002028-e1002028 (2011).</li><li>Safdar, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endurance+exercise+rescues+progeroid+aging+and+induces+systemic+mitochondrial+rejuvenation+in+mtDNA+mutator+mice.">Endurance exercise rescues progeroid aging and induces systemic mitochondrial rejuvenation in mtDNA mutator mice.</a> Proc. Natl. Acad. Sci. U. S. A. 108, 4135-4140 (2011).</li><li>DiMauro, S., Bonilla, E., Zeviani, M., Nakagawa, M., DeVivo, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+myopathies.">Mitochondrial myopathies.</a> Ann. Neurol. 17, 521-538 (1985).</li><li>Old, S. L., Johnson, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+of+microphotometric+assay+of+succinate+dehydrogenase+and+cytochrome+c+oxidase+activities+for+use+on+human+skeletal+muscle.">Methods of microphotometric assay of succinate dehydrogenase and cytochrome c oxidase activities for use on human skeletal muscle.</a> Histochem. J. 21, 545-555 (1989).</li><li>Chaturvedi, R. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impaired+PGC-1alpha+function+in+muscle+in+Huntington's+disease.">Impaired PGC-1alpha function in muscle in Huntington's disease.</a> Hum. Mol. Genet. 18, 3048-3065 (2009).</li><li>Edgar, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Random+point+mutations+with+major+effects+on+protein-coding+genes+are+the+driving+force+behind+premature+aging+in+mtDNA+mutator+mice.">Random point mutations with major effects on protein-coding genes are the driving force behind premature aging in mtDNA mutator mice.</a> Cell. Metab. 10, 131-138 (2009).</li><li>Ross, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+brain+lactate+is+a+hallmark+of+aging+and+caused+by+a+shift+in+the+lactate+dehydrogenase+A/B+ratio.">High brain lactate is a hallmark of aging and caused by a shift in the lactate dehydrogenase A/B ratio.</a> Proc. Natl. Acad. Sci. U. S. A. 107, 20087-20092 (2010).</li><li>Crugnola, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+respiratory+chain+dysfunction+in+muscle+from+patients+with+amyotrophic+lateral+sclerosis.">Mitochondrial respiratory chain dysfunction in muscle from patients with amyotrophic lateral sclerosis.</a> Arch. Neurol. 67, 849-854 (2010).</li><li>Nonaka, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Muscle+pathology+in+cytochrome+c+oxidase+deficiency.">Muscle pathology in cytochrome c oxidase deficiency.</a> Acta. Neuropathol. 77, 152-160 (1988).</li><li>DiMauro, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+encephalomyopathies.">Mitochondrial encephalomyopathies.</a> Neurol. Clin. 8, 483-506 (1990).</li><li>Bonilla, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+morphological+approaches+to+the+study+of+mitochondrial+encephalomyopathies.">New morphological approaches to the study of mitochondrial encephalomyopathies.</a> Brain. Pathol. 2, 113-119 (1992).</li><li>Brierley, E. J., Johnson, M. A., Lightowlers, R. N., James, O. F., Turnbull, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+mitochondrial+DNA+mutations+in+human+aging:+implications+for+the+central+nervous+system+and+muscle.">Role of mitochondrial DNA mutations in human aging: implications for the central nervous system and muscle.</a> Ann. Neurol. 43, 217-223 (1998).</li><li>Borthwick, G. M., Johnson, M. A., Ince, P. G., Shaw, P. J., Turnbull, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+enzyme+activity+in+amyotrophic+lateral+sclerosis:+implications+for+the+role+of+mitochondria+in+neuronal+cell+death.">Mitochondrial enzyme activity in amyotrophic lateral sclerosis: implications for the role of mitochondria in neuronal cell death.</a> Ann. Neurol. 46, 787-790 (1999).</li><li>Gellerich, F. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+respiratory+rates+and+activities+of+respiratory+chain+complexes+correlate+linearly+with+heteroplasmy+of+deleted+mtDNA+without+threshold+and+independently+of+deletion+size.">Mitochondrial respiratory rates and activities of respiratory chain complexes correlate linearly with heteroplasmy of deleted mtDNA without threshold and independently of deletion size.</a> Biochim. Biophys. Acta. 1556, 41-52 (2002).</li><li>Larsson, N. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+transcription+factor+A+is+necessary+for+mtDNA+maintenance+and+embryogenesis+in+mice.">Mitochondrial transcription factor A is necessary for mtDNA maintenance and embryogenesis in mice.</a> Nat. Genet. 18, 231-236 (1998).</li><li>Ekstrand, M. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progressive+parkinsonism+in+mice+with+respiratory-chain-deficient+dopamine+neurons.">Progressive parkinsonism in mice with respiratory-chain-deficient dopamine neurons.</a> Proc. Natl. Acad. Sci. U. S. A. 104, 1325-1330 (2007).</li><li>Seligman, A. M., Karnovsky, M. J., Wasserkrug, H. L., Hanker, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nondroplet+ultrastructural+demonstration+of+cytochrome+oxidase+activity+with+a+polymerizing+osmiophilic+reagent,+diaminobenzidine+(DAB).">Nondroplet ultrastructural demonstration of cytochrome oxidase activity with a polymerizing osmiophilic reagent, diaminobenzidine (DAB).</a> J. Cell. Biol. 38, 1-14 (1968).</li><li>Dubowitz, V., Brooke, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Muscle+Biopsy:+A+Modern+Approach.">Muscle Biopsy: A Modern Approach.</a> , (1973).</li><li>Cottrell, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytochrome+c+oxidase+deficient+cells+accumulate+in+the+hippocampus+and+choroid+plexus+with+age.">Cytochrome c oxidase deficient cells accumulate in the hippocampus and choroid plexus with age.</a> Neurobiol. Aging. 22, 265-272 (2001).</li><li>Blanco, C. E., Sieck, G. C., Edgerton, V. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+histochemical+determination+of+succinic+dehydrogenase+activity+in+skeletal+muscle+fibres.">Quantitative histochemical determination of succinic dehydrogenase activity in skeletal muscle fibres.</a> Histochem. J. 20, 230-243 (1988).</li><li>Moraes, C. T., Ricci, E., Bonilla, E., DiMauro, S., Schon, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+mitochondrial+tRNA(Leu(UUR))+mutation+in+mitochondrial+encephalomyopathy,+lactic+acidosis,+and+strokelike+episodes+(MELAS):+genetic,+biochemical,+and+morphological+correlations+in+skeletal+muscle.">The mitochondrial tRNA(Leu(UUR)) mutation in mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS): genetic, biochemical, and morphological correlations in skeletal muscle.</a> Am. J. Hum. Genet. 50, 934-949 (1992).</li><li>Petruzzella, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extremely+high+levels+of+mutant+mtDNAs+co-localize+with+cytochrome+c+oxidase-negative+ragged-red+fibers+in+patients+harboring+a+point+mutation+at+nt+3243.">Extremely high levels of mutant mtDNAs co-localize with cytochrome c oxidase-negative ragged-red fibers in patients harboring a point mutation at nt 3243.</a> Hum. Mol. Genet. 3, 449-454 (1994).</li><li>Tulinius, M. H., Holme, E., Kristiansson, B., Larsson, N. G., Oldfors, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+encephalomyopathies+in+childhood.+I.+Biochemical+and+morphologic+investigations.">Mitochondrial encephalomyopathies in childhood. I. Biochemical and morphologic investigations.</a> J. Pediatr. 119, 242-250 (1991).</li><li>Haas, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+in-depth+evaluation+of+suspected+mitochondrial+disease.">The in-depth evaluation of suspected mitochondrial disease.</a> Mol. Genet. Metab. 94, 16-37 (2008).</li></ol>

The combined COX/SDH histochemical method enables the visualization of cells with mitochondrial dysfunction. This technique, with early studies dating back to 1968, remains popular, with many considering it the "gold standard" for identifying mitochondrial diseases in patients14,19,26,27. It is now frequently used to investigate mtDNA mutation-driven aging and aging-related disorders 12,13,18,20,21,24. The COX/SDH double-labeling method is often used in parallel with other techniques to identify spe...

<table border="1">
<tr>
<td>Name of the reagent</td>
<td>Company</td>
<td>Catalogue number</td>
<td>Comments (optional)</td>
</tr>
<tr>
<td>Dry Ice</td>
<td>AGA Gas AB</td>
<td>block form</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Isopentane (2-methylbutane)</td>
<td>Sigma-Aldrich</td>
<td>277258 
 CAS: 78-78-4</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Cyrostat embedding solution</td>
<td>Sakura Finetek</td>
<td>Tissue Tek 4583</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Cryostat</td>
<td>Microm</td>
<td>Microm Model HM 500M</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Slides</td>
<td>Thermo Scientific</td>
<td>Super Frost Plus 
 Menzel Gl&auml;ser 
 J1800AMWZ</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Cover glasses 
 Borosilicate glass</td>
<td>VWR International</td>
<td>16004-098</td>
<td>24 x 50 mm</td>
</tr>
<tr>
<td>Filter Paper</td>
<td>Munktell Filter AB</td>
<td>Quality: 1350 
 Article Number: 242 001</td>
<td>430 x 430 mm</td>
</tr>
<tr>
<td>3,3&prime;-diaminobenzidine tetrahydrochloride (DAB)</td>
<td>Sigma-Aldrich</td>
<td>Sigma Liquid Substrate System, D7304</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Cytochrome c (Type III, from equine heart)</td>
<td>Sigma-Aldrich</td>
<td>C2506 
 CAS: 9007-43-6</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Bovine catalase (from liver)</td>
<td>Sigma-Aldrich</td>
<td>C9322 
 CAS: 9001-05-2</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Nitroblue tetrazolium (NBT)</td>
<td>Sigma-Aldrich</td>
<td>N6876 
 CAS: 298-83-9</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Sodium succinate</td>
<td>Sigma-Aldrich</td>
<td>S2378 
 CAS: 6106-21-4</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Phenazine methosulfate (PMS)</td>
<td>Sigma-Aldrich</td>
<td>P9625 
 CAS: 299-11-6</td>
<td>PMS is light sensitive. Shield from light.</td>
</tr>
<tr>
<td>Sodium azide</td>
<td>Sigma-Aldrich</td>
<td>S8032 
 CAS: 26628-22-8</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Xylene</td>
<td>VWR International</td>
<td>EM-XX0060-4 </td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Entellan</td>
<td>VWR International</td>
<td>100503-870</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Malonate 
 (Malonic acid)</td>
<td>Sigma-Aldrich</td>
<td>M1296 
 CAS: 141-82-2</td>
<td>&nbsp;</td>
</tr>
</table>

visualization of mitochondrial respiratory function using cytochrome c oxidase / succinate dehydrogenase (cox/sdh) double-labeling histochemistry

Mitochondrial DNA (mtDNA) defects are an important cause of disease and may underlie aging and aging-related alterations 1,2. The mitochondrial theory of aging suggests a role for mtDNA mutations, which can alter bioenergetics homeostasis and cellular function, in the aging process 3. A wealth of evidence has been compiled in support of this theory 1,4, an example being the mtDNA mutator mouse 5; however, the precise role of mtDNA damage in aging is not entirely understood 6,7.
Observing the activity of respiratory enzymes is a straightforward approach for investigating mitochondrial dysfunction. Complex IV, or cytochrome c oxidase (COX), is essential for mitochondrial function. The catalytic subunits of COX are encoded by mtDNA and are essential for assembly of the complex (Figure 1). Thus, proper synthesis and function are largely based on mtDNA integrity 2. Although other respiratory complexes could be investigated, Complexes IV and II are the most amenable to histochemical examination 8,9. Complex II, or succinate dehydrogenase (SDH), is entirely encoded by nuclear DNA (Figure 1), and its activity is typically not affected by impaired mtDNA, although an increase might indicate mitochondrial biogenesis 10-12. The impaired mtDNA observed in mitochondrial diseases, aging, and age-related diseases often leads to the presence of cells with low or absent COX activity 2,12-14. Although COX and SDH activities can be investigated individually, the sequential double-labeling method 15,16 has proved to be advantageous in locating cells with mitochondrial dysfunction 12,17-21.
Many of the optimal constitutions of the assay have been determined, such as substrate concentration, electron acceptors/donors, intermediate electron carriers, influence of pH, and reaction time 9,22,23. 3,3'-diaminobenzidine (DAB) is an effective and reliable electron donor 22. In cells with functioning COX, the brown indamine polymer product will localize in mitochondrial cristae and saturate cells 22. Those cells with dysfunctional COX will therefore not be saturated by the DAB product, allowing for the visualization of SDH activity by reduction of nitroblue tetrazolium (NBT), an electron acceptor, to a blue formazan end product 9,24. Cytochrome c and sodium succinate substrates are added to normalize endogenous levels between control and diseased/mutant tissues 9. Catalase is added as a precaution to avoid possible contaminating reactions from peroxidase activity 9,22. Phenazine methosulfate (PMS), an intermediate electron carrier, is used in conjunction with sodium azide, a respiratory chain inhibitor, to increase the formation of the final reaction products 9,25. Despite this information, some critical details affecting the result of this seemly straightforward assay, in addition to specificity controls and advances in the technique, have not yet been presented.

Watch this Scientific Journal Video about Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase COX/SDH Double-labeling Histochemistry at JoVE.com

Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase COX/SDH Double-labeling Histochemistry

The cytochrome c oxidase/sodium dehydrogenase (COX/SDH) double-labeling method allows for direct visualization of mitochondrial respiratory enzyme deficiencies in fresh-frozen tissue sections. This is a straightforward histochemical technique and is useful in investigating mitochondrial diseases, aging, and aging-related disorders.

Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase (COX/SDH) Double-labeling Histochemistry

Mitochondrial DNA (mtDNA) defects are an important cause of disease and may underlie aging and aging-related alterations 1,2. The mitochondrial theory of ...

Research

JoVE Journal

Biology

Generation of Stable Transgenic C. elegans Using Microinjection

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1.  The plasmid DNA rearranges to ...

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Apoptosis, or programmed cell death, is a conserved and highly regulated pathway by which cells die1.  Apoptosis can be triggered when cells encounter a ...

The ex vivo Isolated Skeletal Microvessel Preparation for Investigation of Vascular Reactivity

The ex vivo Isolated Skeletal Microvessel Preparation for Investigation of Vascular Reactivity

The isolated  microvessel preparation is an ex vivo preparation that allows for examination of the different contributions of  factors that control vessel ...

Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes

The protein kinase C (PKC) family of isozymes is involved in numerous physiological and pathological processes. Our recent data demonstrate that PKC ...

Analysis of Gene Function and Visualization of Cilia-Generated Fluid Flow in Kupffer's Vesicle

Internal organs such as the  heart, brain, and gut develop left-right (LR) asymmetries that are critical for  their normal functions1. Motile cilia are ...

Visualization of Craniofacial Development in the sox10: kaede Transgenic Zebrafish Line Using Time-lapse Confocal Microscopy

Vertebrate palatogenesis is a highly choreographed and complex developmental process, which involves migration of cranial neural crest (CNC) cells, ...

Large-scale Gene Knockdown in C. elegans Using dsRNA Feeding Libraries to Generate Robust Loss-of-function Phenotypes

Large-scale Gene Knockdown in C. elegans Using dsRNA Feeding Libraries to Generate Robust Loss-of-function Phenotypes

RNA interference by feeding worms bacteria expressing dsRNAs has been a useful tool to assess gene function in C. elegans. While this strategy works well ...

Measuring Respiratory Function in Mice Using Unrestrained Whole-body Plethysmography

Respiratory dysfunction is one of the leading causes of morbidity and mortality in the world and the rates of mortality continue to rise. Quantitative ...

Experimental Approaches to Study Mitochondrial Localization and Function of a Nuclear Cell Cycle Kinase, Cdk1

Although mitochondria possess their own transcriptional machinery, merely 1% of mitochondrial proteins are synthesized inside the organelle. The ...

High-resolution Respirometry to Assess Mitochondrial Function in Permeabilized and Intact Cells

A high-resolution oxygraph is a device for measuring cellular oxygen consumption in a closed-chamber system with very high resolution and sensitivity in ...