Presenter(s): Vithika Goyal — Marine Biology
Co-Presenter(s): Micah Woods
Faculty Mentor(s): Hope Healey, William Cresko
Session: (In-Person) Poster Presentation
The fibroblast growth factor (fgf) signaling pathway is essential to vertebrate craniofacial development. Alterations in fgf receptors and ligands can lead to craniofacial disorders. While deleterious effects are observed in response to pathway mutations in many vertebrates, syngnathid fishes (pipefishes, seahorses, seadragons) have lost several of these genes (fgf3, fgf4, and others). Syngnathids have also evolved unique craniofacial features, such as an elongated snout, important to suction feeding, and absence of teeth. Since fgf3 and fgf4 are involved in craniofacial development, it is possible that their loss in syngnathids is related to the family’s unique faces. Our lab is investigating the developmental impact of the loss of fgf3 and 4 in syngnathids. To establish the ancestral expression patterns of fgf genes, we studied stickleback fishes due to their recent divergence from syngnathids. Using in situ hybridization, we assessed the spatial localization of fgf expression in stickleback embryos through development. Embryos were imaged and fgf/fgfrs staining patterns were compared to zebrafish. We observed expression of fgfr1a and fgf3 in the pharyngeal arches of stickleback embryos, paralleling zebrafish. Understanding the ancestral expression patterns of genes in the fgf signaling pathway reveals the deep conservation of the fgf signaling pathway in stickleback and provides opportunities for better interpreting the impact of the losses of these genes in syngnathids.