Fig. 5. Cl-runt transcription factor is a conserved regulator of acoel regeneration.

a Comparison of log₂FoldChange (log₂FC) in expression of orthologous genes at 3 vs 0 hpa between C. longifissura and H. miamia. Orthologs were identified using reciprocal BLAST. Differentially expressed genes at 3 hpa for H. miamia were obtained from ref. ³². b Expression of Cl-runt is evident only at 3 hpa at anterior wounds. Numbers represent animals in which the expression of Cl-runt is consistent with the figure, out of the total number of animals examined. c Morphological comparison between Cl-runt and control RNAi treated animals at 1 and 4 dpa. While Cl-runt RNAi tail fragments heal the wound, they neither form a blastema at 1 dpa nor regenerate head structures and eye spots, and have minimal tissue growth and shape changes. Arrow points at the regenerated head. d Expression of Cl-pc2, a neuronal marker, at 4 dpa in control and Cl-runt RNAi treated acoels. Neuronal ganglion is only present in control animals, whereas only distributed neurons are observed in Cl-runt RNAi treated animals. Arrowheads point at the regenerated lobes of the neuronal ganglion in the control RNAi animal. Numbers in (c, d) represent the animals that had regeneration phenotypes consistent with the images shown out of the total animals examined. Experiments were repeated twice (b, d) or three times (c) with similar results. Source data for (a) are provided as a Source Data file.