CONICET | Buscador de Institutos y Recursos Humanos

During embryonic development, the vertebral elements are formed from the sclerotome cells as they migrate from somites to the periphery of the neural tube and notochord, where they proliferate and differentiate into bone and cartilage tissue. In most vertebrates, the vertebral column (VC) has a highly conserved structural plan. However, in anurans, the architecture of the VC diverges widely from this plan and is characterized by a great reduction in the number of vertebrae. Currently, the cellular and molecular events involved in the establishment of this divergent body plan are unknown, so we find that it would be important to study the genes involved in the formation of this organ. UNCX is a transcription factor that is expressed in the somites and sclerotome. Studies carried out in mouse showed that loss of function of this gene causes severe malformations in VC. In a previous work carried out in our laboratory, a cDNA of uncx on Xenopus laevis anuran was cloned and characterized and we found that it corresponds to a gene encoding a smaller protein in comparison with other vertebrates. Considering this feature, we found it interesting to analyse the role of the uncx gene during the development of the sclerotomal tissue in anurans. In this work, we cloned the uncx gene of X. tropicalis and carried out comparative studies with the protein sequence of different vertebrates, finding that the smaller size of uncx in X. laevis is an exclusive characteristic of this species. Additionally, we conducted experiments of gain- and loss-of-function of uncx through embryo microinjection with an mRNA corresponding to an inducible chimeric protein and a specific antisense morpholino for this gene. We found that uncx regulates sclerotome development and that it is required for the proper formation of the anteroposterior axis.