An ancient neurotrophin code in zebrafish; the Runx/Cbfβ complex specifies the fate switch from TrkB+ to TrkC+ nociceptors and sensory receptor expression

Abstract

The somatosensory system is a critical interface to the environment. It contains a highly diverse group of sensory neurons that are responsible for sensing touch, temperature, pain, and proprioception. The Runx transcription factors have been identified as key factors in generating some somatosensory neuron diversity. However, it is not well understood how these factors function. This work establishes the functional significance of the zebrafish somatosensory system by focusing on the nociceptive ion channel TRPV1 and explores the interaction of the Runx transcription factors with their cofactor Cbfβ during somatosensory neuron development. This work demonstrates that Cbfβ is an obligate cofactor for the Runx transcription factors and is required for somatosensory neuron specification, suggests that Runx1 and Runx3 perform the same function in fish, and uncovers an ancient neurotrophin code in zebrafish.