✍🏼 Panpan Zhu, Pengfei Zheng, Xinlong Kong, Shuo Wang, Muqing Cao, Chengtian Zhao

🏠 Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China

📑 EMBO Rep (2022)

Abstract
Spinal cord injury (SCI) can cause long‐lasting disability in mammals due to the lack of axonal regrowth together with the inability to reinitiate spinal neurogenesis at the injury site. Deciphering the mechanisms that regulate the proliferation and differentiation of neural progenitor cells is critical for understanding spinal neurogenesis after injury. Compared with mammals, zebrafish show a remarkable capability of spinal cord regeneration. Here, we show that Rassf7a, a member of the Ras‐association domain family, promotes spinal cord regeneration after injury. Zebrafish larvae harboring a rassf7a mutation show spinal cord regeneration and spinal neurogenesis defects. Live imaging shows abnormal asymmetric neurogenic divisions and spindle orientation defects in mutant neural progenitor cells. In line with this, the expression of rassf7a is enriched in neural progenitor cells. Subcellular analysis shows that Rassf7a localizes to the centrosome and is essential for cell cycle progression. Our data indicate a role for Rassf7a in modulating spindle orientation and the proliferation of neural progenitor cells after spinal cord injury.

How the WOLF was used in this study
In this study, the WOLF G2 cell sorter was used to isolate defined neural cell populations from zebrafish spinal cords for downstream gene expression analysis. Following spinal cord injury, trunks from transgenic zebrafish larvae expressing GFP under neuronal  or neural progenitor promoters were enzymatically dissociated into single-cell suspensions. GFP-positive cells were then purified by FACS using the WOLF G2 at gentle, low-pressure conditions, and with a BD FACSAria II used in parallel for comparison.