In Vivo Living Imaging Of Mitochondrial Transport In Zebrafish Axonal Regeneration

Mitochondria,play an essential role in neurons,not only produce energy,balance redox reactions,but also regulate calcium homeostasis.Considering the complex structure and various morphology of neurons,the appropriate distribution and movement of mitochondria in neurons are vital for neuronal functioning.Up to now,in vivo imaging of mitochondrial dynamics in spinal cord of vertebrate models,remains limited.To address this weakness,we developed a new model which can study mitochondrial dynamics in vivo in zebrafish Mauthner cells.Using single-cell electroporation with GAL4-UAS system,we focused on axonal mitochondria.To ensure this new model is suitable for studying mitochondrial transport,we proved nocodazole could disrupt mitochondrial trafficking.Additionally,we found axons of Mauthner cells have the regenerative capabilities after laser axotomy.Thus,this situation provided our opportunities to study relationship between mitochondrial transport and axonal regeneration.According to our preliminary results,it is demonstrated that mitochondrial transport could be affected by axonal injury,and there are an improving proportion of moving mitochondria in axons which have a strong ability of regeneration.Finally,we attempted to convert eGFP-transgenic zebrafish lines into lines expressing mito-DsRed2 or DsRed2 from the same locus.To sum up,our method is useful for characterizing mitochondrial transport in axonal regeneration of the CNS in vivo.