Meeting Abstract

P2.122  Thursday, Jan. 5  Anatomy of the brain in the crustacean model system, Parhyale hawaiensis: sexual dimorphism and an examination of the amphipod hemi-ellipsoid body MORA-KEPFER, F*; SIASSIPOUR, AH; STUMP, J; BROWNE, WE; University of Miami, Coral Gables

Recent molecular phylogenetic inference places the lineage giving rise to insects squarely in a paraphyletic crustacean clade. This suggests that insects are derived crustaceans. A suite of morphological characters also supports the close relationship between crustaceans and insects including similarities in the basic architecture of the brain. In well-studied insects, the brain is subdivided from anterior to posterior into protocerebral (PC), deutocerebral (DC), and tritocerebral (TC) neuromeres. A similar, and presumably homologous, tripartite ground plan for the brain is shared with all arthropods including the amphipod crustacean Parhyale hawaiensis. Here, we characterize Parhyale brain morphology via serial section series. These serial sections are the basis for our 3D volume reconstruction of the brain. Our morphological data suggest similarities between the mushroom bodies of insects and the hemi-ellipsoid bodies of Parhyale. Additionally we examine sexual dimorphism between the antennal lobes of sexually mature adults In contrast to females, males have more robust antennae with numerous sensory pits, which may reflect differential neural development of the antennal lobes. We are using our morphological data to explore the potential relationship between structural plasticity of the brain and sexual dimorphism in antennal structures. Our results provide critical anatomical information required to understand the basic organization of the brain in the model crustacean Parhyale hawaiensis. This detailed neuroanatomical dataset will contribute to experiments aimed at exploring the interplay between sexual dimorphism and neural plasticity in crustaceans.