The snail family member worniu is continuously required in neuroblasts to prevent Elav-Induced premature differentiation

摘要

Snail family transcription factors are best known for regulating epithelial-mesenchymal transition (EMT). The Drosophila Snail family member Worniu is specifically transcribed in neural progenitors (neuroblasts) throughout their lifespan, and worniu mutants show defects in neuroblast delamination (a form of EMT). However, the role of Worniu in neuroblasts beyond their formation is unknown. We performed RNA-seq on worniu mutant larval neuroblasts and observed reduced cell-cycle transcripts and increased neural differentiation transcripts. Consistent with these genomic data, worniu mutant neuroblasts showed a striking delay in prophase/metaphase transition by live imaging and increased levels of the conserved neuronal differentiation splicing factor Elav. Reducing Elav levels significantly suppressed the worniu mutant phenotype. We conclude that Worniu is continuously required in neuroblasts to maintain self-renewal by promoting cell-cycle progression and inhibiting premature differentiation. Continuous expression of the Drosophila Snail family gene Woniu is required for neuroblast maintenance. Lai et al. analyze worniu mutant larval neuroblasts by RNA-seq and demonstrate that Worniu maintains neuroblast self-renewal by preventing Prospero-mediated cell-cycle arrest and by controlling the level of splicing factor Elav to inhibit premature differentiation.