High- and low-throughput scoring of fat mass and body fat distribution in C. elegans.
Fat accumulation is a complex phenotype affected by factors such as neuroendocrine signaling, feeding, activity, and reproductive output. Accordingly, the most informative screens for genes and compounds affecting fat accumulation would be those carried out in whole living animals. Caenorhabditis elegans is a well-established and effective model organism, especially for biological processes that involve organ systems and multicellular interactions, such as metabolism. Every cell in the transparent body of C. elegans is visible under a light microscope. Consequently, an accessible and reliable method to visualize worm lipid-droplet fat depots would make C. elegans the only metazoan in which genes affecting not only fat mass but also body fat distribution could be assessed at a genome-wide scale. Here we present a radical improvement in oil red O worm staining together with high-throughput image-based phenotyping. The three-step sample preparation method is robust, formaldehyde-free, and inexpensive, and requires only 15min of hands-on time to process a 96-well plate. Together with our free and user-friendly automated image analysis package, this method enables C. elegans sample preparation and phenotype scoring at a scale that is compatible with genome-wide screens. Thus we present a feasible approach to small-scale phenotyping and large-scale screening for genetic and/or chemical perturbations that lead to alterations in fat quantity and distribution in whole animals.
Centre for Image Analysis and Science for Life Laboratory, Uppsala University, Uppsala, Sweden; Imaging Platform, Broad Institute of Harvard and MIT, Cambridge, MA, USA. Electronic address: carolina@cb.uu.se.
Carolina
C
Wählby
Massachusetts General Hospital, Boston, MA, USA.
Annie Lee
AL
Conery
Imaging Platform, Broad Institute of Harvard and MIT, Cambridge, MA, USA.
Mark-Anthony
MA
Bray
Imaging Platform, Broad Institute of Harvard and MIT, Cambridge, MA, USA.
Lee
L
Kamentsky
Massachusetts General Hospital, Boston, MA, USA.
Jonah
J
Larkins-Ford
Imaging Platform, Broad Institute of Harvard and MIT, Cambridge, MA, USA.
Katherine L
KL
Sokolnicki
Imaging Platform, Broad Institute of Harvard and MIT, Cambridge, MA, USA.
Matthew
M
Veneskey
Department of Biology, University of Virginia, Charlottesville, VA, USA.
Kerry
K
Michaels
Imaging Platform, Broad Institute of Harvard and MIT, Cambridge, MA, USA.
Anne E
AE
Carpenter
Department of Biology, University of Virginia, Charlottesville, VA, USA. Electronic address: ejorourke@virginia.edu.
Eyleen J
EJ
O'Rourke
D000818:Animals; D050218:Body Fat Distribution; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development; D016678:Genome; D057166:High-Throughput Screening Assays; D050356:Lipid Metabolism / Q000235:genetics*; D023421:Models, Animal; D009765:Obesity / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype
Body fat distribution; C. elegans; Fat mass; High-content screening; Lipid; Obesity