mTOR promotes zebrafish larvae fin regeneration through regulating macrophages activation and CaM-mTOR-dnm1l axis
To investigate the functional and mechanistic roles of mTOR in zebrafish larvae fin regeneration, we firstly examined the spatiotemporal expression of mTOR in larvae fin and established a mTOR knockout (mTOR-KO)  transgenic fish line using CRISPER / Cas9 gene editing technology. Moreover, mTOR was essential for the activation of macrophages, which is a key factor in maintaining the regenerative repair process. We also demonstrated that mTOR knockdown attenuated the proliferative capacity of bud embryo cell during the regenerative phase, while cell apoptosis was not affected. RNA-sequence analysis showed changes in mitochondrial function and dnm1l was identified as the main regulatory factor during the fin regeneration stage. We further suggested that mTOR may promote mitochondrial fission to support bud embryo cell regeneration via CaM-mTOR-dnm1l axis. Overall design: Sequencing samples for the micro-transcriptome were obtained from tail fin tissues regenerated for 24 h. Fifty regenerated tail fins were extracted for each sample from the control and experimental groups treated with 1 uM Rapamycin. Each group had 3 biological replicates and samples were lysed using Trizol. Sequencing technology was provided by UNIKAWA Biotechnology Co.Ltd (Hangzhou, China).