Diego Nazario-Martínez¹, Joseph Torres-Cruz¹, Alana Rivera², Julian Maldonado², Dina Bracho ², Laura Vicente-Rodríguez¹, Mark W. Miller²

¹Department of Biology, University of Puerto Rico at Cayey

²Department of Anatomy and Neurobiology, Institute of Neurobiology, University of Puerto Rico, Medical Sciences Campus

Introduction: Schistosomiasis is a disease that affects approximately 240 million people annually, with over 90% of cases estimated to occur in Africa. The most common form of infection is intestinal schistosomiasis, which is caused by the parasite Schistosomiasis mansoni. The life cycle of this trematode relies exclusively on freshwater snails from the Biomphalaria genus as intermediate hosts. Once the snail becomes infected, S. mansoni larvae transform into cercariae, the infectious form for humans. Intermediate hosts undergo significant changes in metabolism, neuronal activity, and other physiological processes that support the parasite’s development. Several studies have shown that snail neuropeptides play a role in initiating and facilitating these changes. However, the specific functions of individual neuropeptides in these processes remain unclear. This study aims to investigate the expression of allatotropin in the central nervous system (CNS) of Biomphalaria glabrata, given its known role in promoting muscle stimulation and inhibiting ion transportation, both of which are crucial for the parasite’s development.

Methods: We employed in situ hybridization to localize the mRNA of allatotropin within the snail’s CNS and subsequently conducted immunohistochemistry to co-localize the presence of the neuropeptide.

Results: The results demonstrate that allatotropin is expressed in all eleven ganglia within specific neuronal clusters.

Conclusion: Future work will involve nerve tracing to gain a better understanding of the pattern of allatotropin expression in the periphery.  The findings of this study will contribute to a clearer understanding of the role of neuropeptides in the development of the parasite, potentially offering novel strategies for parasitic control by targeting the neuropeptide system.

Acknowledgements: We thank Dr. M. W. Miller for his mentoring and laboratory provision/assistance. We also acknowledge the contribution of Dr. Dina Bracho and Julian Maldonado for the confocal images.