Quantification of cki-1 promoter activity during PHso1-to-PHD remodeling in Caenorhabditis elegans.

Cyclin-dependent kinase inhibitor ( cki-1 ) is associated with cell cycle arrest and cellular quiescence. In Caenorhabditis elegans , glia-to-neuron transdifferentiation of the phasmid socket 1 (PHso1) glia into the phasmid D (PHD) neuron has been previously described across larval stages. Here, we report the post-hatching timeline of PHso1-to-PHD remodeling within L4 substages, including the loss of glial socket morphology and the acquisition of neuronal features well into adulthood. We find that cki-1 expression decreases across L4 substages between 40-50 hours post-hatching in males, while cki-1 remains robustly expressed in hermaphrodite PHso1 cells. Across L3, L4, and adulthood, PHso1 cell proportions change consistently.