Figure 4. The effect of denervation on the growth of the tiny limb staged regenerate.

(A) Dorsal root ganglia (DRGs) 3, 4, and 5 (green dots) are located lateral to the spinal column and their nerve bundles (green lines) feed into the forelimbs. Limbs were amputated and permitted to regenerate to the early tiny limb stage, at which point, either a mock, partial (1/3 = DRG 5 or 2/3 = DRGs 4 and 5), or full denervation (represented) was performed by severing (blue line) and removing sections of the nerve bundles. Limbs were collected 4 days post denervation, and growth rate (B), cell proliferation (C), cell death (D), and cell size (E) were analyzed for limbs with mock denervations (n = 6), 1/3 denervations (n = 5), 2/3 denervations (n = 5), and full denervations (n = 6). The color of the bars in panels C–E refers to the color of the bars in panel B. Error bars = SEM. p-Values calculated by ANOVA and the Tukey post hoc test. * = p < 0.05 ** = p < 0.005.

Figure 4—figure supplement 1. Impact of denervation on the growth characteristics of the late tiny limb (LTL) staged regenerate.

Amputated limbs were permitted to regenerate to the late tiny limb stage, at which point they underwent either a mock denervation (dark gray, n = 5) or a full denervation (white, n = 5). The limbs were collected and analyzed 4 days post denervation for growth rate (A), cell proliferation (B), cell death (C), and cell size (D) as previously described. Error bars = SEM. p-Values calculated by paired t-test. ** = p < 0.005 *** = p < 0.0005.