Surviving climate change: prospecting cold temperature resistance biomarkers in fish circulating microRNAome

• Grant number: 24/07174-9
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2025
• End date: March 31, 2027
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Danillo Pinhal
• Grantee: Danillo Pinhal
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated researchers: Alexandre Wagner Silva Hilsdorf ; Bastian Fromm ; Caio Augusto Perazza ; Eduardo Bierhals Blodorn ; Leandro Silva Nunes ; Luiz Augusto Bovolenta ; Rafael Vilhena Reis Neto ; Vinicius Farias Campos ; Waldir Heinrichs Caldas

Abstract

Amidst global climate changes, understanding the genetic mechanisms of cold tolerance can bring significant gains to aquaculture. As ectothermic organisms, fish are sensitive to extreme temperature fluctuations due to the strong influence of the environment on their physiological functions. Currently, there are no commercially available genetic or epigenetic markers capable of selecting a cold-tolerant fish lineage. Although the acclimatization of different lineages to temperate regions has sought to mitigate this constraint through "wintering" processes, such measures are palliative and increase production costs. Extracellular circulating microRNAs (c-miRNAs) have been scarcely explored in aquaculture as biomarkers for fish responses to climate change, especially regarding tolerance to exposure to low temperatures. Additionally, studies on the circulating miRNA profile in fish body fluids are scarce, and there are no data available for Neotropical species. We propose to identify and characterize the total set of c-miRNAs present in the blood plasma and epidermal mucus of tambaqui (Colossoma macropomum) and Nile tilapia (Oreochromis niloticus) after acute and gradual exposure to low temperatures. Candidate c-miRNAs as biomarkers will be identified in tolerant animals through high-throughput sequencing, characterized by bioinformatics, and validated by real-time quantitative PCR (qPCR). Genes negatively correlated with the expression profiles of c-miRNAs will be used for functional enrichment and regulatory network construction. We expect to map the positively modulated biological processes and molecular pathways in animals tolerant to exposure to low temperatures. The commercial availability of c-miRNAs as biomarkers capable of selecting a cold-tolerant fish lineage represents an innovative approach that could steer the development of sustainable and non-invasive aquaculture strategies aimed at ensuring the health and productivity of tilapia and tambaqui lineages. This could pave the way for new technologies and significant economic expansion of fish farms in the southeast and south of Brazil and other temperate climate regions worldwide. (AU)