ABS 117: Characterizing the Role of the Arthropod Somatostatin AstCC in Drosophila melanogaster Adult Ecdysis

Maya Lall ¹ , Tho Nguyen ¹ , PhD; Benjamin White, PhD ¹

¹ Section on Neural Function, National Institute of Mental Health, NIH, Bethesda, MD

Van Wickle (2025) Volume 1, ABS 117

Introduction: Ecdysis, the process of shedding an exoskeleton, is necessary for fly development. Neural networks controlling ecdysis use neuropeptides to regulate behavior. This research was part of a larger project on neural function, using Drosophila as a model organism. The two neuropeptides studied were Bursicon (Burs) and Allatostatin double C (AstCC), which are co-expressed in Bursicon neurons. It is known that Burs controls cuticle tanning and wing expansion, so the purpose of this research was to determine the role of AstCC in ecdysis. The expression pattern of AstCC in Bursicon neurons was investigated by dissecting stage L3 larvae brains, immunostaining with an anti-AstCC antibody, and scanning with a confocal microscope. In addition, wing expansion deficits in the AstCC knockdown line were genetically screened using the GAL4/UAS system with a Burs-Gal4 driver. Genetic screening of wing expansion deficits was also performed in three AstCC-receptor mutant lines: R1 null, R2 null, and R1&R2 deficiency. Confocal microscopy confirmed the expression of AstCC in Bursicon neurons. Using the AstCC knockdown line, a correlation was found between reduced levels of AstCC in Bursicon neurons and wing expansion deficits. These results indicated that AstCC is important in adult ecdysis. Lastly, wing expansion deficits were found in all three AstCC-receptor mutant lines compared to the wildtype, indicating that R1 and R2 are both involved in wing expansion.