Meeting Abstract
Bilaterians have known axis-patterning genes with interaction gradients and feedback loops that establish the dorsal-ventral and anterior-posterior axis. The bilaterality of animals likely evolved in the last common ancestor of cnidarians and their sister group, the bilaterians, which have been shown to have a primary and secondary axis. Past studies have shown asymmetric expression of conserved bilaterian axis specification genes along the body axis of the cnidarian model organism Nematostella vectensis. We used CRISPR/Cas9 gene editing via embryo microinjections to knock out ten asymmetrically expressed genes of interest, related to BMP signaling and Hox genes. We successfully established F0 populations of knockout animals, noted abnormal morphology in late planula and early polyp stages via fluorescent antibody staining, and observed disorganized and missing axes via in-situ hybridization of 13 axis marker genes in the knockout animals. We thus propose a new model for axis specification in N. vectensis via regulation by inhibition and promotion based on the altered expression patterns of the axis patterning genes in the knockout animals presented in this study.
