A Spectral Phasor Perspective in Zebrafish Muscle Development

Hyperspectral imaging provides the potential for assessing biochemical interactions in the zebrafish embryo in a label-free manner that extends beyond conventional morphological and molecular phenotyping. It takes advantage of the intrinsic wavelengths emitted or reflected from a sample without the need for extrinsic staining methods. The specific spectral signature from a sample can arise from chemical interactions, molecular bonds and macro-structural arrangements. A challenge in hyperspectral imaging is the large spectral data sets that result from acquiring a spectrum for every pixel within an image. Spectral Phasor offers an efficient representation of the spectral data as vectors in Fourier space, thereby condensing each spectrum into a single point in a 2-D plot. The Spectral Phasor has been successfully applied to hyperspectral data on protein samples, demonstrating changes in fluorescence signatures. This study proposes an application of Spectral Phasor to the zebrafish muscle development. The skeletal muscle system provides an attractive model for the proof-of-principle experiments in the implementation of Spectral Phasor. Skeletal muscle is a highly organized tissue with myofibrils as the functional unit that contributes to the repetitive segment of the myotome. The modularity of these units provides unique landmarks for anchoring the SP data. Our analysis of muscle suggest that SP can be used for staging the skeletal muscle development.