morphoHeart: a novel quantitative tool to perform integrated 3D morphometric analyses of heart and ECM morphology during embryonic development

Abstract

SummaryHeart development involves the complex structural remodelling of a linear heart tube into an asymmetrically looped and ballooned organ. Previous studies have associated regional expansion of extracellular matrix (ECM) space with tissue morphogenesis during development. We have developedmorphoHeart, an 3D image tissue segmentation and morphometry software which delivers the first integrated 3D visualisation and multiparametric analysis of both heart and ECM morphology in live embryos.morphoHeartreveals that the ECM undergoes regional dynamic expansion and reduction during cardiac development, concomitant with chamber-specific morphological maturation. We usemorphoHeartto demonstrate that regionalised ECM expansion driven by the ECM crosslinker Hapln1a promotes atrial lumen expansion during heart development. Finally, we have developed a GUI that allows the morphometric analysis tools ofmorphoHeartto be applied toz-stack images of any fluorescently-labelled tissue.