Meeting Abstract

P1.130  Friday, Jan. 4  The topology of Hox gene networks during limb morphogenesis of the crustacean Parhyale hawaiensis BRUCE, HS*; EISEN, MB; PATEL, MB; University of California, Berkeley; University of California, Berkeley; University of California, Berkeley hbruce@berkeley.edu

Generating a multicellular animal from a single-celled zygote requires the coordinated spatiotemporal expression of thousands of genes. Members of the Hox family of transcription factors, expressed in different domains along the anterior-posterior axis of Bilaterian embryos, are well known for their role in determining regional identity. The Hox proteins, however, only regulate the process as transcription factors; it is the hundreds of downstream genes they mobilize that physically construct the embryo. This downstream network that builds each unique region of an embryo is largely a black box. The goal of my project is to systematically identify the genes regulated by Hox proteins in a model crustacean, Parhyale hawaiensis, and to begin to dissect their role in segment construction and evolution. I will generate expression profiles from individual segments from single embryos at time points throughout appendage morphogenesis, using Illumina’s Tru-Seq platform. This will give me snapshots of only those genes associated with each appendage type, and at progressive stages of morphogenesis. By comparing and contrasting this set of time- and segment-specific expression profiles, I will generate candidate genes with which to perform follow-up functional studies. One question I will address is whether maxillipeds, feeding appendages that evolved independently in at least two crustacean lineages, have co-opted the same genetic pathways to arrive at a similar morphology. This work will provide a detailed picture of the molecular network that connects Hox genes to the structures they pattern in a crustacean model organism, which is necessary for a holistic understanding of morphogenesis and morphological evolution.