EpiGraph: an open-source platform to quantify epithelial organization

During development, cells must coordinate their differentiation with their growth and organization to form complex multicellular structures such as tissues and organs. Epithelia are packed assembles of cells that will originate the different tissues of the organism during embryogenesis. A big caveat for the analysis of the morphogenetic changes in epithelia is the lack of simple tools that enable the quantification of cell rearrangements. Here we present EpiGraph, an image analysis tool that quantifies epithelial organization. Our method combines computational geometry and graph theory to measure the degree of order of any packed tissue. EpiGraph goes beyond the traditional polygon distribution analysis, capturing other organizational traits that improve the characterization of epithelia. EpiGraph can objectively compare the rearrangements of epithelial cells during development and quantify how the global assemble is affected. Importantly, it has been implemented in the open-access platform FIJI. This makes EpiGraph very simple to use without any programming skills being required.