SUBCHRONIC EFFECTS OF DIFLUBENZURON ON THE MALE GONADS OF ZEBRAFISH (Danio rerio): A MORPHOFUNCTIONAL AND MOLECULAR APPROACH

• Grant number: 25/15091-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2026
• End date: December 31, 2026
• Field of knowledge: Biological Sciences - Morphology
• Principal Investigator: Bruno Fiorelini Pereira
• Grantee: Gustavo Franco de Albuquerque
• Host Institution: Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF). Universidade Federal de São Paulo (UNIFESP). Campus Diadema. Diadema , SP, Brazil
• Associated research grant: 22/03094-5 - Project Zebratox: toxicological screening of larvicides of public and veterinary health importance, AP.PNGP.PI

Abstract

Emerging contaminants, such as insect growth regulators, have garnered increasing attention due to their risks to non-target organisms, particularly in aquatic environments. Diflubenzuron (DFB), widely used in urban, agricultural, and veterinary practices, is one such compound, although its effects on fish reproductive biology remain poorly understood. The zebrafish (Danio rerio) is widely recognized as a valuable experimental model in ecotoxicological studies, due to its high anatomical, physiological, and developmental homology with higher vertebrates, as well as its ecological relevance in aquatic ecosystems. In this context, the present project aims to investigate the subchronic effects of DFB exposure on reproductive parameters in male D. rerio. The animals will be exposed to increasing concentrations of the insecticide (0.025; 0.0625; 0.125; 0.250; 0.500; and 1.00 mg/L), and brain and testis samples will be analyzed for potential morphological and functional alterations. The hypothalamic-pituitary-testicular (HPT) axis will be assessed based on the gene expression of selected target genes. At the same time, the testes will be examined using histological and morphometric techniques to evaluate the stages of spermatogenesis and identify potential histopathological changes. The results are expected to contribute to a better understanding of DFB's impacts on reproductive parameters in non-target species, provide scientific support for revising regulatory guidelines, and promote safer practices for using this compound. Furthermore, this study seeks to reinforce the importance of the zebrafish as a key model organism in environmental risk assessment of emerging chemical contaminants.