Meeting Abstract

21.3  Tuesday, Jan. 4  SoxE genes and the role of neural crest in cartilage evolution and development MCCAULEY, David W; University of Oklahoma dwmccauley@ou.edu

Neural crest cells give rise to many vertebrate-specific structures. These cells arise during development along the dorsal aspect of the neural tube, undergo an epithelial to mesenchymal transition whereupon they migrate along defined pathways and subsequently differentiate into many tissues including craniofacial cartilage and bone, pigment cells, peripheral neurons and glia. Lampreys are a relict group of jawless fishes that diverged early in vertebrate evolution and are useful for understanding the evolution of vertebrate developmental processes. Lampreys possess a cartilaginous branchial skeleton derived from the neural crest. We have recently described development of the branchial skeleton using a newly-developed imaging technique and have shown that differentiation of the lamprey branchial basket cartilage depends on the expression of multiple SoxE transcription factors instead of a single SoxE gene (Sox9) gene as in other vertebrates; three lamprey SoxE homologs are expressed in the migratory neural crest and in presumptive chondrocytes. We have examined changes in the expression patterns of SoxE genes and other neural crest related genes following morpholino antisense oligonucleotide knockdown. Our results suggest a neural crest gene regulatory network already present during early vertebrate evolution plays a key role in differentiation of the chondrogenic neural crest.