Stepwise in vitro induction of human somitic mesoderm and its derivatives

Abstract Our understanding of human somitogenesis is limited and largely based on insights gained from model organisms. Pluripotent stem cell-based in vitro approaches aiming to recapitulate distinct aspects of this core developmental process have recently been reported, including our recent paper on the in vitro recapitulation of the human segmentation clock1. Here we describe in detail our stepwise induction protocol of presomitic mesoderm (PSM), somitic mesoderm (SM), and its two major derivatives, sclerotome (SCL) and dermomyotome (DM) from human induced pluripotent stem cells (iPSCs). We further briefly address the subsequent molecular and functional analysis of these in vitro induced human mesodermal lineages and cell-types.