The Molecular Evolution of Hedgehog in Stolidobranchia Ascidians

Abstract

Ascidians are highly studied in evolution and development because they have a tiny chordate tadpole larva. As a sister clade to vertebrates, ascidian research has lead to greater understanding of the molecular roles of developmental genes in vertebrates. However, recent research on a Phlebobranchia ascidian Ciona intestinalis indicates that the developmental gene hedgehog (hh) may have undergone a duplication independent to the hh duplications in vertebrates (Hudson, et al. 2011). To investigate this hypothesis, more research is needed on the other ascidian clade, Stolibranchia. In this study we strived to use maximum-likelihood analysis to compare the evolution of hh in Stolidobranchia and Phleobranchia ascidians. Future research will investigate the different developmental roles of hh in Stolidobranchia and Phlebobranchia ascidians.