| An overarching goal in the study of neurobiology is to translate the capacity to perform an action to its underlying cellular and molecular mechanisms. As a result, nervous systems involved in central pattern generation have become well-studied models for the control of behavior. Amongst the most important model organisms for this field are the decapod crustaceans Cancer borealis (Jonah crab) and Homarus americanus (American lobster). Studies of these systems have defined our knowledge of the general principles of the organization and modulation of neural circuits, as well as garnered considerable clarity on crustacean physiology and behavior, including perception of sensory stimuli. However, this field has been stalled in its ability to use the full range of molecular technologies available. Both Homarus americanus and Cancer borealis currently lack a published genome or transcriptome, which limits the genetic resources available for use of approaches like qPCR, RNAi or CRISPR genome editing, and high-throughput sequencing (DNA-Seq, RNA-Seq, CHIP-Seq). My dissertation work established a de novo assembled transcriptome for Homarus americanus and defined differential gene expression across central nervous system and muscular tissues using RNA-Seq. This work also confirms the peptide proctolin as a circulating neuromodulator, concluding two decades of speculation and identifying its role in transcriptional regulation in nervous system tissues. The results of this work uncover links between proctolin and innate immunity, as well as thermoreception. We also identify possible candidate genes for thermoreception in homologs of thermosensory TRPA channels, and explore the behavioral component of thermoreception by establishing behavioral thermoregulation in C. borealis. Finally, transcriptome-wide profiles of the rhythmic pattern generating ganglia in Homarus americanus reveal candidates for neuronal genes that drive the production of motor output in these systems. Together, these studies offer important behavioral and genetic information into the field of crustacean neurobiology and lay the groundwork for an array of future studies ranging from characterization of thermoreception in nervous systems to the use of synthetic biology to construct neural networks. |
