Epigenetic factors coordinate intestinal development

Intestinal epithelium development depends on epigenetic modifications, but whether that is also the case for other intestinal tract cell types remains unclear. We found that functional loss of a DNA methylation machinery component,ubiquitin-like protein containing PHD and RING finger domains 1 (uhrf1),leads to reduced enteric neuron number, changes in neuronal morphology, and severe intestinal smooth muscle disruption. Genetic chimeras revealed that Uhrf1 functions both cell-autonomously in enteric neuron progenitors and cell-non-autonomously in surrounding intestinal cells. Uhrf1 recruits the DNA methyltransferase Dnmt1 to unmethylated DNA during replication. Dnmt1 is also expressed in enteric neuron and smooth muscle progenitors.dnmt1mutants show a strong reduction in enteric neuron number and disrupted intestinal smooth muscle. Becausednmt1;uhrf1double mutants have a similar phenotype todnmt1anduhrf1single mutants, Dnmt1 and Uhrf1 must function together during enteric neuron and intestinal muscle development. This work shows that genes controlling epigenetic modifications are important in coordinating intestinal tract development, provides the first demonstration that these genes are important in ENS development, and advancesuhrf1anddnmt1as potential new Hirschsprung disease candidates.SummaryThis work provides evidence that DNA methylation factors are important in all cell types that contribute to development of a functional intestine.