biostudies-literatureKanno TYFoundation for the National Institutes of HealthFoundation for the National Institutes of Health (Foundation for the National Institutes of Health, Inc.)7824https://www.ebi.ac.uk/biostudies/studies/S-EPMC12371044biostudies-literatureUnknown16(1)The establishment of the vertebrate body plan is orchestrated by the organizer, a specialized group of cells with inductive properties that guide axial specification during early development. In avian embryos, organizer cells reside within Hensen's node, a transient structure located at the tip of the primitive streak. Despite its pivotal role during gastrulation, the cellular architecture of the Hensen's node remains poorly understood. Here, we show that Hensen's node is composed of two transcriptionally and functionally distinct organizer populations. In addition to anterior GSC-expressing cells associated with head induction, we identify a posterior population co-expressing organizer and mesodermal genes. These posterior cells exhibit trunk-inducing activity when transplanted into naïveNature communicationsChanges in cellular composition shape the inductive properties of Hensen's Node.PMC12371044DP2HD102043Rothstein MKanno TYSimoes-Costa MfalseChanges in cellular composition shape the inductive properties of Hensen's Node.The establishment of the vertebrate body plan is orchestrated by the organizer, a specialized group of cells with inductive properties that guide axial specification during early development. In avian embryos, organizer cells reside within Hensen's node, a transient structure located at the tip of the primitive streak. Despite its pivotal role during gastrulation, the cellular architecture of the Hensen's node remains poorly understood. Here, we show that Hensen's node is composed of two transcriptionally and functionally distinct organizer populations. In addition to anterior GSC-expressing cells associated with head induction, we identify a posterior population co-expressing organizer and mesodermal genes. These posterior cells exhibit trunk-inducing activity when transplanted into naïve2025-01-01T00:00:00Z2025 Aug2026-05-08T10:52:57.271Z2026-05-03T03:06:11.516ZS-EPMC123710444084154210.1038/s41467-025-63154-2