Transient grb10a Knockdown Permanently Alters Growth, Cardiometabolic Phenotype and the Transcriptome in Danio rerio

Embryonic growth trajectory is a risk factor for chronic metabolic and cardiovascular disorder. Grb10 is a negative regulator of the main pathways driving embryonic growth. This study investigates the long-term cardiometabolic consequences and transcriptomic profiles of transient disruption of grb10a expression in Danio rerio. Knockdown was associated with increased embryonic growth (+7%) and metabolic rate (+25%), and decreased heart rate (- 50%) in early life. Juvenile growth and respiratory rate were also elevated (+30% and 7-fold increase respectively). The transcriptome was permanently remodelled by this transient disruption, with dysregulation of multiple growth, cardiac, and metabolic pathways. Phenotypic alteration persisted into adulthood, resulting in a leaner body with elevated skeletal and cardiac muscle content and aerobic scope (43%). This study not only confirms for the first time that transient disruption of a single gene can result in permanent transcriptomic remodelling but correlates this remodelling with persistent alterations to the adult cardiometabolic phenotype.