A vagal neural crest specific enhancer for establishing transgenic mouse models

Abstract

The enteric nervous system (ENS) is originated from the vagal neural crest (VNC) but the sacral neural crest (SNC) also has some contribution. Cell ablation and transplantation studies in avian species showed that the VNC colonizes the entire gut in a rostrocaudal direction while the SNC colonizes only the hindgut. However, the coordination of neural crest migration and the molecular control of their differentiation into specific cell types are not clearly known. We have identified a VNC specific enhancer element from the mouse Hoxb3 gene, b3-IIIa, which could direct lacZ reporter gene expression in the ENS of transgenic mice. When crossed with the mega- colon mutant Dom, the hybrid mutant displayed an absence of lacZ marked cells in the hindgut, further confirming the specificity of this enhancer in the ENS. To allow further studies of genes required for normal ENS development by conditional gene targeting, we generated IIIa-cre transgenic mouse lines using the VNC enhancer. Tissue specificity and efficiency of the cre recombinase was assess by crossing the IIIa-cre transgenic mice with the Z/AP reporter mouse line.