University of Kentucky
Automated Image Analysis of Electron Micrographs of Structurally Compromised Striated Muscle
Institution
University of Kentucky
Faculty Advisor/ Mentor
Karyn Esser; Kenneth Campbell
Abstract
Striated (skeletal and cardiac) muscle is a highly organized and conserved tissue with a molecular structure comprised of bundles of actin (thin filaments) and myosin (thick filaments). We have observed that skeletal muscle from two genetically modified murine models showing disrupted circadian rhythms (Bmal knockout and ClockΔ19), exhibit significant muscle weakness defined by a reduction in specific tension. Electron micrographs (EMs) of crosssections from adult gastrocnemius in these mice reveal obvious divergences from the normal hexagonal arrangement of thin filaments around thick filaments. The goal of this project was to develop a tool for the high-throughput analysis of myofilament architecture. Image processing software written in MATLAB identifies myofilaments in EMs of muscle cross-sections as intensity peaks in the gray-scale image. Filaments are categorized as thick or thin depending on the cross-sectional area of the peaks after thresholding. Structural properties, such as the ratio ofthin to thick filaments, the distance to closest neighbors, the angular distribution and the diameter of filaments will be determined for different muscle samples. This quantitative analysis should lead to improved understanding of structure-function relationships in striated muscle.
Automated Image Analysis of Electron Micrographs of Structurally Compromised Striated Muscle
Striated (skeletal and cardiac) muscle is a highly organized and conserved tissue with a molecular structure comprised of bundles of actin (thin filaments) and myosin (thick filaments). We have observed that skeletal muscle from two genetically modified murine models showing disrupted circadian rhythms (Bmal knockout and ClockΔ19), exhibit significant muscle weakness defined by a reduction in specific tension. Electron micrographs (EMs) of crosssections from adult gastrocnemius in these mice reveal obvious divergences from the normal hexagonal arrangement of thin filaments around thick filaments. The goal of this project was to develop a tool for the high-throughput analysis of myofilament architecture. Image processing software written in MATLAB identifies myofilaments in EMs of muscle cross-sections as intensity peaks in the gray-scale image. Filaments are categorized as thick or thin depending on the cross-sectional area of the peaks after thresholding. Structural properties, such as the ratio ofthin to thick filaments, the distance to closest neighbors, the angular distribution and the diameter of filaments will be determined for different muscle samples. This quantitative analysis should lead to improved understanding of structure-function relationships in striated muscle.