SICB Division of Evolutionary Developmental Biology (DEDB)

DEDB Researchers Database Entry

Danielle Liubicich

The role of Hox genes in crustacean appendage specialization
Crustaceans are among the most morphologically diverse organisms in the animal kingdom. Although these animals display extraordinary diversity in appendage specialization and body regionalization, they utilize patterning mechanisms conserved among all arthropods. Arthropods use Hox genes to pattern the anterior-posterior body axis and establish regional identity. Altering the expression patterns of Hox genes can result in gross morphological changes as one body region assumes the identity of another. In crustaceans, expression of a particular Hox gene, Ultrabithorax (Ubx), correlates with the type of appendage that develops in the trunk region. Trunk segments without Ubx develop modified appendages called maxillipeds that are used for feeding rather than locomotion. My research in Dr. Nipam H. Patel's lab at the University of California, Berkeley, characterizes the role of Ubx (in blue above) and the additional Hox genes, Antennapedia (Antp), and Sex combs reduced (Scr) (in red above), in appendage specialization in the amphipod crustacean, Parhyale hawaiensis. By changing the expression patterns of these Hox genes (Scr, Antp, Ubx) and assessing appendage morphology in Parhyale, I may be able to determine whether shifting Hox gene expression is a potential mechanism by which crustacean appendage diversity evolved.