Cell and Tissue Journal

Abstract Aim: The somites are epithelial blocks of mesodermal cells differentiating to sclerotome and dermomyotome and notochord or axial mesoderm plays a major role in somitic cell differentiation to sclerotome. This study was aimed to evaluate the role of the notochord in sclerotomal differentiation of the somites in vitro. Material and Methods: In this experimental study, isolated notochords from chick embryo were encapsulated in alginate beads and co-cultured with somites for six days. In control group, the somites were cultured alone. Newly isolated and non-cultured somites were considered as somites on day 0. Eventually, morphology of cultured somitic cells was evaluated by inverted microscope and then RT-PCR method was used to analyze the sclerotomal and dermomyotomal gene expression profile. Results: In comparison with control group, the somitic cells co-cultured with notochord had highly differentiation potential and showed mesenchymal morphology with numerous slender processes. Gene expression profile of co-cultured somitic cells indicated upregulation of Pax1 and BMP4 and downregulation of MyoD, presenting sclerotomal cell characteristics. Conclusion: Embryonic notochord can induce in vitro sclerotomal differentiation in somites through upregulation of genes involving in this differentiation.