Meeting Abstract

99.3  Monday, Jan. 6 14:00  Investigating the emergence of the matrix protein fibronectin in the urochordate Ciona intestinalis FAMIGLIETTI, A.*; SEGADE, F. ; DAVIDSON, B.; Swarthmore College; Swarthmore College; Swarthmore College afamigl1@gmail.com

The glycoprotein fibronectin (FN) is a major instructive molecule in the extracellular matrix (ECM) of vertebrates that contains three domains: fibronectin type 1 (FN1), type 2 (FN2), and type 3 (FN3). FN performs many cellular functions including mediation of cell movement, proliferation, and differentiation by binding to receptors on the cell surface (Tucker and Chiquet-Ehrismann, 2008). A recent analysis of the fully sequenced FN gene in the urochordate Ciona intestinalis shows a characteristic “vertebrate-like” arrangement of FN domains that is not found in other invertebrates. In order to investigate the expression pattern of this gene, we fused the intergenic region upstream of Fn to a GFP reporter. The reporter construct was electroporated into Ciona embryos and expression was evaluated at various developmental stages. Our findings indicate that the FN enhancer drives expression predominantly in the notochord lineage, beginning at early tailbud stage (~9.5H after fertilization). Further studies of the Ciona FN protein may provide insight into the ancestral role of FN in the shared tunicate/vertebrate ancestor. We plan to next knockdown Fn expression through RNAi interference in order to determine any potential effect on Ciona development.