Djcoronin controls the AP axis polarity through Wnt signaling pathway during planarian regeneration

Planarians have whole body regeneration ability and are model animals for the study of regeneration and development. Coronin is an actin binding protein involved in a variety of cellular processes. However, the precise role of coronins in tissue regeneration remains unclear. In this study, we found that Djcoronin exhibited a concentration gradient expression pattern throughout the worm and was highly expressed in the newly formed tail region after amputation. We used RNA interference to knockdown Djcoronin and found that loss of Djcoronin function affected tail regeneration, characterized by nervous system defects and a two-headed phenotype, while having no significant effect on head regeneration. Importantly, knockdown of Djcoronin downregulated the expression of β-catenin and posterior Wnt genes, accompanied with the reversal of the head-tail polarity. Moreover, treatment with Wnt agonist 1 significantly alleviated the regeneration and polarity defects caused by Djcoronin knockdown. In conclusion, our study suggests that Djcoronin is an important regulator of polarity maintenance that contributes to AP polarity regulation via the Wnt/β-catenin signaling pathway.