Neural induction in mouse embryonic stem cells by co-culturing with chicken somites.

The role of paraxial mesoderm or the somites in decision of ectoderm to acquire the neuroepithelial fate and its subsequent diversification to functional neural subtypes especially in mammalians is obscure. Here we report, for the first time, the influence of the co-culture of alginate bead-encapsulated somites isolated from chick embryos on neural differentiation in mouse embryonic stem cells-derived embryoid bodies (EBs). Using a combination of morphology, immunofluorescence, flow cytometry, semiquantitative, and conventional RT-PCR techniques, we show that the somites induce rosette structures and weakly enhance neural differentiation and neural markers in a dose-dependent manner in comparison to the control group, but its effect is lower than retinoic acid treatment of EBs. By liquid chromatography-mass spectrometry, it was revealed that somitic cells synthesized and released retinoids into the medium. However, no effective influence of somitic co-culture on rostrocaudal or dorsoventral patterning is seen. Therefore, like amphibians, somites have a modest neural-inducing activity in amniotes.