Figure 8. Neurons lose the ability to regulate allometric growth in the neural-modified accessory limb model (NM-ALM).

(A) Dorsal root ganglia (DRGs) from large (~14 cm, n = 12) and small (~7 cm, n = 16) GFP+ animals were grafted into wound sites on host animals (~14 cm) followed by mid-bud blastemas from (~7 cm) donor animals. (B) If the ability to regulate size is autonomous to the DRGs, the DRGs from large animals will produce larger ectopic limbs than those from small animals. If size regulation is not autonomous, there will be no difference in ectopic limb size between grafts supplied by large or small animal DRGs. (C) The ectopic limb lengths were the same size at 0 day post graft (DPG) and remained the same throughout regeneration (135 DPG). Error bars = SEM. p-Values calculated by t-tests. (D) GFP+ innervation abundance was quantified in transverse sections of the ectopic limbs, showing significantly more nerve area (mm²) in the NM-ALMs grafted with DRGs from large donors compared to small donors (n = 5). Error bars = SEM. p-value = 0.0079, calculated by Mann-Whitney test.