Functional characterization of the natterin gene loc795232 in CRISPR/Cas9 mutant zebrafish: impact on post-embryonic larval morphogenesis and metabolism

• Grant number: 25/09570-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Carla Lima da Silva
• Grantee: Manuela Jacobina de Sá
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated research grant: 13/07467-1 - CeTICS - Center of Toxins, Immune-Response and Cell Signaling, AP.CEPID

Abstract

The venom of the Thalassophryne nattereri fish (VTn) contains a protein family called Natterin, responsible for symptoms such as pain, edema, and necrosis in humans. This family includes four orthologs (Natterin-1 to -4) with similar structures, containing a DM9/DM9 domain at the N-terminal and an Aerolysin domain at the C-terminal, the latter being associated with pore formation. Subsequently, 859 natterin-like genes were identified across 331 species, including vertebrates such as fish, reptiles, and birds, but absent in mammals. Notably, zebrafish (Danio rerio) possesses 10 natterin-like genes, including the protein NP_001013322.1 (encoded by aep-1), whose octameric structure and immune defense function have been characterized. Previously, we focused on the loc795232 gene, which encodes the XP_017212453.1 protein with high similarity to the Aerolysin domain of aep-1, to study its role in development. CRISPR/Cas9-mediated gene depletion of loc795232 in zebrafish caused severe embryonic developmental abnormalities, including: curved body and deformed head; lack of pigmentation and swim bladder; pericardial edema and enlarged yolk sac; 50% premature mortality, with survivors exhibiting cardiac dysfunction and locomotor hyperactivity. These results demonstrate that Natterin-like plays a crucial role in zebrafish morphogenesis and pave the way for future investigations into potential metabolic effects. In this study, our objective is to investigate the function of the natterin-like loc795232 gene in late-stage larval zebrafish embryonic development and metabolism, using CRISPR/Cas9 technology to generate knockout (KO) mutants and evaluate the resulting phenotypes. (AU)