Figure 2: HIF-1 positively regulates axon regeneration.
From: Axotomy-induced HIF-serotonin signalling axis promotes axon regeneration in C. elegans
(a) Induction of Ptph-1::gfp expression in D-type motor neurons by laser surgery. Expression of fluorescent proteins in D-type motor neurons 30 min after laser surgery is shown. A schematic representation of D-type motor neurons is shown on the bottom. Arrowheads and arrows indicate axons and cell bodies of D-type neurons with (white) or without (blue) laser surgery, respectively. D-type neurons are visualized by mCherry under control of the unc-47 promoter. Cell bodies of D-type neurons are magnified (blue boxes). Scale bar=20 μm. (b) Percentages of animals expressing tph-1. Induction of Ptph-1::gfp expression in D-type motor neurons with (+) or without (−) laser surgery was assayed as described in Methods section. Twenty neurons were examined for each condition. Error bars indicate 95% CI. ***P<0.001; *P<0.05 (Fisher’s exact test, two-tailed, n=20). (c) Regeneration of D-type motor neurons. Percentages of axons that initiated regeneration 24 h after laser surgery are shown. Error bars indicate 95% CI. ***P<0.001; *P<0.05 (Fisher’s exact test, two-tailed, n≥50). (d) Regeneration of PLM sensory motor neurons. Lengths of PLM regrowth at 24 h after laser surgery are shown. Error bars indicate s.e.m. ***P<0.001 (n≥30; unpaired t-test, two-tailed, unequal variances). CI, confidence interval.
