Meeting Abstract

P1-36   -   Characterization of Leucine Rich Repeat-Containing G Protein-Coupled Receptors (LGR) in Gecarcinus lateralis Paul, AU*; Kozma, MT; Mykles, DL; Colorado State University, Fort Collins, CO; Colorado State University, Fort Collins, CO; Colorado State University, Fort Collins, CO ayaka.paul@gmail.com

Molting is a vital cyclic process that drives growth and regeneration in crustaceans. Y-Organs (YO) are a pair of glands that synthesize ecdysteroids, which stimulate progression through the four stages of crustacean molt. YO transcriptome of blackback land crab, Gecarcinus lateralis has gene expression of five putative leucine-rich repeat containing G protein-coupled receptors (LGRs). LGRs belong to class A rhodopsin-like GPCRs that contain multiple regions of leucine rich repeats (LRR), low density lipoprotein motif (LDL), and a 7-transmembrane domain. LGRs are classified into three distinct types (A, B, C) based on the number of LRRs, structure of the hinge region, and presence of LDL motifs. Gene expression of LGRs, especially LGR2 and LGR3, in G. lateralis YO is of interest due to their role in other arthropods. LGR2 and its associated ligand, bursicon are involved in cuticle tanning and hardening, and wing expansion in insects. In green shore crabs, a surge of bursicon release coincides with ecdysis, suggesting LGR2 plays an important role in the molt cycle of crustaceans. In Drosophila, LGR3 is activated by the insulin-like peptide, Dilp8, which is secreted by damaged imaginal discs. Activation of LGR3 increases nitric oxide synthase, which reduces ecdysteroid synthesis, and halts metamorphosis until damaged imaginal discs are regenerated. A similar mechanism exists in decapod crustaceans where damage to regenerating limbs in early premolt delays molting to allow for synchronous limb regeneration. The characterization and function of LGRs in crustaceans is still largely unknown. Using phylogeny, the LGR superfamily in decapods was characterized. Gene expression analyses of LGRs in YO of G. lateralis across molt stages when appendages are damaged will improve our understanding of their role in molting. Support: NSF (IOS-1922701) and CSU Honors Program.