Stamatia Gioftsidi and Takuto Hayashi from Mourikis’ team discovered how Pax7-expressing hindlimb cells are multipotent and generate non-myogenic lineages persisting into adulthood
Postnatal Pax7-expressing limb cells are multipotent and generate non-myogenic lineages that persist into adulthood
Developmental Cell – September 2026
Stamatia Gioftsidi, Takuto Hayashi and the Muscle Stem Cells-Niche Interaction lab, headed by Philippos Mourikis report in Developmental Cell a previously unrecognised multipotency of postnatal Pax7+ cells, which is manifested by the production of diverse non-myogenic lineages, including a subpopulation of fibro-adipogenic progenitors, termed Pax7-FAPs.
Using a combination of in vivo lineage tracing and single-cell technologies, this work demonstrates that Pax7+ progenitor cells are not restricted to a single lineage during postnatal limb muscle development. By mapping cellular trajectories of Pax7+ stem cells during postnatal development, the authors identified a non-myogenic population that they named Pax7FAPs, as they have a fibrogenic molecular identity. Furthermore, they showed that Notch activation signalled Pax7+ cells toward a fibrogenic identity at the expense of myogenesis. In addition, Pax7+ cells multipotency declines with age, but perinatally-derived Pax7FAPs can be found in adult muscle.
Those findings indicate that Pax7-derived non-myogenic cells contribute to the cellular architecture of muscle from early postnatal stages through adulthood, helping understanding tissue development during postnatal muscle growth.