Meeting Abstract
During embryogenesis, animal embryos often transition from a sphere of cells to a pill-shaped stage as they elongate along the anterior-posterior axis. This process of axial elongation is deeply conserved amongst Bilateria, occurring before divergent morphologies arise in embryogenesis. Yet, the cellular and molecular mechanisms that control it are not well-understood among a large and morphologically diverse branch of animals, the Spiralia (including annelids, molluscs, nemerteans). We are using the slipper snail Crepidula fornicata as a representative spiralian to study the mechanisms controlling axial elongation. A common hypothesis for axial elongation among spiralians involves differential proliferation on the dorsal side of the embryo. However, this was not observed in Crepidula fornicata. Instead, we hypothesize that cellular re-arrangement is primarily responsible for axial elongation. To better understand the molecular basis for axial elongation in Crepidula fornicata, pathways involved in early development were inhibited and it was found that inhibition of the JNK pathway resulted in a noticeable phenotype. Since previous work has shown that JNK interacts with the non-canonical Wnt pathway to regulate morphogenesis in different model organisms, including Drosophila and Xenopus, expression patterns for genes involved in the non-canonical Wnt pathway were obtained through in situ hybridization. Through studying axial elongation in this new gastropod model, we hope to contribute to understanding early development by characterizing morphogenetic processes not observed in more traditional model organisms.
