Fig. 2

Trex1 is downregulated in the limb regenerative blastema of axolotl. (a) Axolotl limbs were amputated at the level of zeugopod and regeneration was observed at different stages of limb regeneration. (b) An increase in the expression of interleukin 6 (Il6) and interleukin 8 (Il8) was observed in the early stages of axolotl limb regeneration. Blastema from the regenerating limb was isolated within the first 96 h and then at three different stages of limb regeneration (early, medium and late bud). (c) 2′3′- cGAMP levels are elevated in the early bud of the regenerating axolotl limb. 2′3′-cGAMP concentrations were determined from the same axolotl regenerative blastema used for RNA isolation. (d) Gene expression analysis of the cGAS-STING pathway orthologs in axolotl indicate that Trex1 is downregulated during the stages of regeneration where cGAS activity is elevated. (e) Comparison of the cGAS-STING pathway in the spotted gar and axolotl. Variation between groups was assessed with a one-way ANOVA, with Tukey's post hoc analysis for pairwise comparison between groups. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001