Taurine related pathways effect the potential domestication of wild Larimichthys crocea adapt to stress environment

Abstract

The large yellow croaker (Larimichthys crocea) was inherently sensitive and exhibited pronounced responses to external stimuli, which posed challenges for its domestication and breeding. The swim bladder, a sensory organ richly innervated with sympathetic and parasympathetic nerves, played a critical role in this process. However, the molecular mechanisms underlying the neural and physiological changes induced by domestication remained unclear. In this study, significant differences in metabolic profile and gene expression were identified in swim bladder when compared cultured and wild L. crocea, as well as in metabolic profile of liver. Taurine and hypotaurine metabolism were notably enriched in the swim bladder and liver. Taurine levels were significantly higher in the swim bladder of wild individuals, and after injection of taurine, gene expression levels of taurine synthesis in swim bladder were elevated, while taurine transport and metabolism genes in swim bladder and liver were also upregulated. In addition, taurine alterations were associated with differential expression of neuroregulatory genes. Swim bladder inflation and deflation resulted in varying degrees of reduction or deformation of the Nissl bodies and elevated expression of neural regulatory genes after pressure and noise exposure. Pressure and noise processing affected neural regulatory genes such as angpt2, lepr, foxm1 and sema3d. These genes showed minimal changes in expression during stress and noise processing, with noise having a greater impact on neural regulation in the brain. Taurine injection significantly increased expression of angpt2, lepr, foxm1 and sema3d under pressure stress but decreased them under noise stress. Conversely, notch1a, tmc1, colla1a, and mylpfa were consistently downregulated in the swim bladder and brain under both stress conditions. This study was the first to propose a swim bladder-brain axis regulating neural sensitivity in L. crocea, providing new insights into the molecular mechanisms through which domestication and aquaculture affected the neural responses of this species.