Fig. 6

Overexpression of amphiregulin disrupts limb regeneration. Axolotl limbs with no prior injuries were electroporated with either plasmid encoding GFP (control) or plasmids encoding GFP plus AREG. a Overview of experimental strategy. b-b”) Representative images of EGFP control limbs from 8 to 16 days post-amputation (dpa). Arrowheads denote amputation planes. c-c”) Representative images of areg mis-expressing limbs from 8 to 16 days post-amputation (dpa). Arrowheads denote amputation planes. d Quantification of blastema lengths in b–b” and c–c”. N = 24 animals for control and N = 23 animals for areg overexpression. e-g Representative images of control limbs and limbs exhibiting severe regenerative defects or no regeneration beyond the stylopodium following areg overexpression. e’–g’) Representative skeletal preparations of control limbs and limbs exhibiting severe regenerative defects or no regeneration beyond the stylopodium following areg overexpression. h Quantification of defects after control egfp and areg overexpression. The two groups exhibit significantly different morphologies (p < 0.01, Fisher’s exact test). N = 48 limbs for control and N = 46 limbs for areg overexpression