ELife Assessment: Touch Receptor End-Organ Innervation and Function Require Sensory Neuron Expression of the Transcription Factor Meis2

The study identifies the transcription factor Meis2 as a crucial regulator of low-threshold mechanoreceptors (LTMRs) in mice, which are responsible for touch sensation. The deletion of Meis2 in postmitotic dorsal root ganglia (DRG) neurons leads to changes in gene expression, targeting errors, altered sensory neuron responses, and reduced sensitivity to light touch in mutant animals. The research also found that Meis2 is necessary for normal end-organ innervation and specifically for SA-LTMR morphology and function only in the glabrous skin. Inactivation of the Meis2 gene compromised Merkel cell innervation in the glabrous skin and increased the vibration threshold of slowly adapting mechanoreceptors (SAMs). However, this was not observed in the hairy skin. The study concluded that Meis2 is necessary for Merkel cell innervation in the glabrous skin and for the structure and function of RA-LTMRs.