We are interested in the development of the vertebrate limb using avian and mouse embryos as experimental models. The aim of our research is to uncover molecular signals which regulate the diffe rentiation of skeletal progenitors and also to provide information about limb morphogenesis. Genesidentified by different molecular strategies are functionally analyzed through gain-of- and lossof-function experiments. Gain-of-function experiments are performed through the overexpression of the selected genes employing viral infections or plasmid electroporation. Loss-of-function experiments are made with short hairpin RNAi or CRISPR-Cas9 approaches. Our major research field is the formation of the digits. During this process mesodermal progenitors of the embryonic limb bud follow two alternative fates: in the future digit regions, mesodermal cells aggregate and differentiate into cartilage, joints and fibrous tissues such as tendons or ligaments; in the interdigital regions, cells do not condense and instead undergo massive cell death. The goal of these studies is to obtain information of relevance in regenerative medicine to direct the differentiation of stem cells into skeletal tissues and to provide basic information about the mechanisms
accounting for programmed cell death.