P18. Sox10 mutation affects enteric neural crest cell migration in a cell autonomous manner

Abstract

Enteric neural crest stem cells (eNCSCs) are a pluripotent, migratory cell population that gives rise to the enteric neurons and glia throughout the gastrointestinal tract. Sox10 is a transcription factor required for the maintenance of pluripotency and survival of eNCSCs during enteric nervous system (ENS) development. SOX10 mutations disrupt NCSCs development and result in Waardenburg–Hirschsprung (WS4) disease, which displays varying degrees of intestinal aganglionosis, pigmentation and hearing defects. To elucidate the role of Sox10 in migration of eNCSCs, and to understand how the impaired function contributes to gut aganglionosis, we generated a novel WS4 mouse mutant Sox10NGFP where EGFP reporter was fused to the N-terminal region of Sox10 . EGFP expression in Sox10NGFP mice recaptured the dynamics of Sox10 expression during development. Neurospheres of mutant eNCSCs exhibited reduced proliferation capability as demonstrated by BrdU incorporation assay. The mean size of mutant neurospheres was significantly reduced compared with wildtype control. Using time-lapse imaging, we found that migratory eNCSCs in Sox10NGFP/+ mutants displayed altered trajectories and reduced migration speed compared to Wnt1cre/ZEG control. Explant culture, assays that determine the advancement of eENCCs in normal/abnormal gut environment, indicated that migration defects in Sox10NGFP/+ mice occurred in a cell-autonomous manner. Together, these findings suggested that Sox10 mutation impaired the proliferation and migration capability of eNCSCs. The abnormal migration behavior of mutant eNCSCs restricted the colonization of eNCSC along the gut wall, and contributed to aganglionosis in mutant guts.