Role of Wnt/ β-Catenin signaling in neural crest development

Abstract

The neural crest is a transient population of migratory cells unique to vertebrate development. It consists of neural crest stem cell (NSCS). Stem cells are able to self- renew, meaning they can go through numerous cycles of cell division while maintaining the undifferentiated state. Additionally, they are able to give rise to multiple cell types, an ability referred to as multipotency. The population of NCSC emigrates from the dorsal neural tube shortly after neural tube closure, migrates through the body along distinct pathways, and populates different target sites where they give rise to a wide array of cell types. Derivatives of the neural crest include sensory and autonomic neurons as well as glia of the peripheral nervous system, chromaffin cells of the adrenal glands, pigment cells in the skin, or bone and cartilage of the head. Several extracellular growth factors as well as intracellular cues have been identified to influence the fate of NCSC. Among the signaling cascades playing an important role in neural crest development is the Wnt/ β-Catenin pathway. Canonical Wnt/ β-Catenin signaling is involved in many processes throughout embryonic development and in adult tissue homeostasis. It plays multiple roles in neural crest development. First, it is necessary for induction of the neural crest at the neural plate border. Additionally, together with bone morphogenic protein (BMP) growth factors, it is able to maintain NCSC in an undifferentiated state. Furthermore, Wnt signaling is involved in generation of the sensory and melanocyte lineages. The function of Wnt/ β-Catenin signaling in sensory and melanocyte lineage formation will be the subject of this thesis