BMP signaling in wing development: A critical perspective on quantitative image analysis.
Bone Morphogenetic Proteins (BMPs) are critical for pattern formation in many animals. In numerous tissues, BMPs become distributed in spatially non-uniform profiles. The gradients of signaling activity can be detected by a number of biological assays involving fluorescence microscopy. Quantitative analyses of BMP gradients are powerful tools to investigate the regulation of BMP signaling pathways during development. These approaches rely heavily on images as spatial representations of BMP activity levels, using them to infer signaling distributions that inform on regulatory mechanisms. In this perspective, we discuss current imaging assays and normalization methods used to quantify BMP activity profiles with a focus on the Drosophila wing primordium. We find that normalization tends to lower the number of samples required to establish statistical significance between profiles in controls and experiments, but the increased resolvability comes with a cost. Each normalization strategy makes implicit assumptions about the biology that impacts our interpretation of the data. We examine the tradeoffs for normalizing versus not normalizing, and discuss their impacts on experimental design and the interpretation of resultant data.
School of Life Sciences, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las Vegas, NV 89154-4004, USA.
Alexander
A
Brooks
Wei
W
Dou
Xiaoying
X
Yang
Tara
T
Brosnan
Michael
M
Pargett
Laurel A
LA
Raftery
David M
DM
Umulis
D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D003198:Computer Simulation; D004305:Dose-Response Relationship, Drug; D029721:Drosophila Proteins / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster / Q000378:metabolism; D005456:Fluorescent Dyes / Q000494:pharmacology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008856:Microscopy, Fluorescence / Q000379:methods; D008954:Models, Biological; D015233:Models, Statistical; D008962:Models, Theoretical; D015398:Signal Transduction; D012984:Software; D014921:Wings, Animal / Q000254:growth & development / Q000378:metabolism*
D019485:Bone Morphogenetic Proteins; D029721:Drosophila Proteins; D005456:Fluorescent Dyes; C064196:dpp protein, Drosophila