Meeting Abstract
Dorsal-ventral patterning in bilaterians is controlled by the highly conserved BMP signaling pathway. Morphogenic gradients of BMP signaling and their modulators control the specification of cell fates along the dorsoventral (DV) axis. In the cnidarian Nematostella vectensis, BMP signaling genes are expressed asymmetrically on one side of the directive axis, opposite the side of asymmetric Hox gene expression. Using CRISPR/Cas9 we have produced gene knockouts in F 0 populations of key Hox and BMP signaling genes. Knockout animals show asymmetric morphological defects, such as improper formation of tentacles and endodermal structures. In addition, we assessed the spatial and temporal patterns of asymmetrically expressed genes in knockout animals by in-situ hybridization. The data generated allowed us to generate preliminary gene regulatory networks of bmp and hox gene interactions. We show that BMP signaling initially sets up the directive axis, and that proper morphological patterning is controlled by interactions of Hox genes. We propose that the DV axis in bilaterians is homologous to the directive axis of cnidarians, and is set up using conserved signaling pathways, and gene regulatory networks.
