Project description:Adult zebrafish have the ability to recover from spinal cord injury and exhibit re-growth of descending axons from the brainstem to the spinal cord. We performed gene expression analysis using microarray to find damage-induced genes after spinal cord injury, which shows that Sox11b mRNA is up-regulated at 11 days after injury. However, the functional relevance of Sox11b for regeneration is not known. Here, we report that the up-regulation of Sox11b mRNA after spinal cord injury is mainly localized in ependymal cells lining the central canal and in newly differentiating neuronal precursors or immature neurons. Using an in vivo morpholino-based gene knockout approach, we demonstrate that Sox11b is essential for locomotor recovery after spinal cord injury. In the injured spinal cord, expression of the neural stem cell associated gene, Nestin, and the proneural gene Ascl1a (Mash1a), which are involved in the self-renewal and cell fate specification of endogenous neural stem cells, respectively, is regulated by Sox11b. Our data indicate that Sox11b promotes neuronal determination of endogenous stem cells and regenerative neurogenesis after spinal cord injury in the adult zebrafish. Enhancing Sox11b expression to promote proliferation and neurogenic determination of endogenous neural stem cells after injury may be a promising strategy in restorative therapy after spinal cord injury in mammals. Spinal cord injury or control sham injury was performed on adult zebrafish. After 4, 12, or 264 hrs, a 5 mm segment of spinal cord was dissected and processed (as a pool from 5 animals) in three replicate groups for each time point and treatment.
Project description:Adult zebrafish have the ability to recover from spinal cord injury and exhibit re-growth of descending axons from the brainstem to the spinal cord. We performed gene expression analysis using microarray to find damage-induced genes after spinal cord injury, which shows that Sox11b mRNA is up-regulated at 11 days after injury. However, the functional relevance of Sox11b for regeneration is not known. Here, we report that the up-regulation of Sox11b mRNA after spinal cord injury is mainly localized in ependymal cells lining the central canal and in newly differentiating neuronal precursors or immature neurons. Using an in vivo morpholino-based gene knockout approach, we demonstrate that Sox11b is essential for locomotor recovery after spinal cord injury. In the injured spinal cord, expression of the neural stem cell associated gene, Nestin, and the proneural gene Ascl1a (Mash1a), which are involved in the self-renewal and cell fate specification of endogenous neural stem cells, respectively, is regulated by Sox11b. Our data indicate that Sox11b promotes neuronal determination of endogenous stem cells and regenerative neurogenesis after spinal cord injury in the adult zebrafish. Enhancing Sox11b expression to promote proliferation and neurogenic determination of endogenous neural stem cells after injury may be a promising strategy in restorative therapy after spinal cord injury in mammals.
Project description:In the embryonic spinal cord, cardinal populations of interneurons (INs) diversify into specialized subsets and migrate to defined locations within the spinal parenchyma.However, the factors that control IN diversification and migration remain almost totally unknown. We demonstrate with that Onecut proteins regulate the diversification and the migration of V2 INs in the spinal parenchyma. To identify genes downstream of Onecut transcription factors that may contribute to V2 interneuron differentiation and distribution, we performed a microarray comparison of control and of OC-deficient spinal cord transcriptome at e11.5, namely at the stage when significant numbers of V2 cells have been generated and are initiating migration
Project description:The goals of this study is to compare transcriptome profiles (RNA-seq) of zebrafish V2a interneurons with regrown axon and those without regrown axon in the spinal segments rostral to the lesion after spinal cord injury. For purification of V2a interneurons with regrown axon, the fluorescent tracer Rhodamine Dextran (RD) was retrogradely applied to Tg(Chx10:GFP) fish at three or eight weeks post injury. Spinal cord segments rostral to the lesion site was collected from 20 fish at 3- or 8 wpi, and corresponding spinal cord segments from 20 uninjured fish were collected as control material. GFP+/RD+ and GFP+/RD- cells were FAC-sorted and subjected to RNA-sequencing. Total RNA was isolated using SMART-SeqTM v4 UltraTM Low Input RNA Kit for Sequencing (Clontech). Sequencing libraries (N=5-6) were generated using NEBNext UltraTM RNA Library Prep Kit for Illumina following the manufacturer’s instructions (NEB). We mapped about 40-80 million sequence reads per sample to the zebrafish genome and identified 42,370 transcripts in the zebrafish V2a interneurons in the spinal cord. Our study represents the detailed analysis of transcriptomes of zebrafish V2a interneurons with regrown axon and those without regrown axon in the spinal segments rostral to the lesion after spinal cord injury.