A Myt1 family transcription factor defines neuronal fate by repressing non-neuronal genes

Cellular differentiation requires both activation of target cell programs and repression of non-target cell programs. Transcriptional repressors such as RE1-silencing transcription factor (REST) and Hairy/Enhancer of Split (Hes) repress neuronal genes in non-neuronal cells. However, it is unknown whether transcriptional repressors of non-neuronal genes in neuronal precursors are required to specify neuronal fate during development. The Myt1 family of zinc finger transcription factors contributes to fibroblast to neuron reprogramming in vitro by repressing Notch signaling. Here, we show that ztf-11 (Zinc-finger Transcription Factor-11), the sole Caenorhabditis elegans Myt1 homolog, is required for neurogenesis in multiple neuronal lineages, including an in vivo developmental epithelial-to-neuronal transdifferentiation event. ztf-11 is exclusively expressed in all neuronal precursors with remarkable specificity at single cell resolution. Loss of ztf-11 leads to upregulation of non-neuronal genes and reduced neurogenesis. Ectopic expression of ztf-11 in epidermal lineages is sufficient to produce additional neurons. Our genetic and genomic experiments show that ZTF-11 indeed functions as a transcriptional repressor to suppress the activation of non-neuronal genes in neurons; however, it does not function via repression of Notch signaling. Instead, ZTF-11 binds to the MuvBco-repressor complex, which we show is also required for neurogenesis. These results dovetail with ability of Myt1l (Myt1-like) to drive neuronal transdifferentiation in vitro in vertebrate systems. Together, we identified an evolutionarily conserved mechanism to specify neuronal cell fate by repressing non-neuronal genes. Overall design: 4 biological replicates each under 2 experemental conditions (ztf-11 KD and negative control) were used for total of 8 samples

8

Lee J, Taylor CA, Barnes KM, Shen A, Stewart EV, Chen A, Xiang YK, Bao Z, Shen K