Fig. 3

Roles of the different antler-lineage periosteum in antler development. a Antlerogenic periosteum (AP), the tissue for pedicle and first antler formation, note that deletion of the AP abrogates future pedicle and antler formation (arrow) and subcutaneous transplantation elsewhere on the deer body induces ectopic antler formation (arrowhead); b Pedicle periosteum (PP), the tissue for antler regeneration, note that deletion of the PP renders the PP-less pedicle failure of regenerating antlers (arrow) c Antler periosteum (AnP), the tissue for partial antler regeneration/antler tissue repair, note that a spike antler (arrow) is regenerated peripherally around an antler base created after the removal of the antler in its growth phase. d The spike antler remanent (arrow) after removing the spike antler, which reveals that the spike antler is regenerated from the AnP of the antler base