Abstract
Background: The unique feeding behavior of Siniperca chuatsi (S. chuatsi), which exclusively consumes live fry and rejects dead fry, severely limits the development of its aquaculture industry. This rejection of dead fry likely stems from an aversion to necromones (death-associated odors). Although a subset of trace amine-associated receptors (TAARs) containing key conserved residues (Asp3.32 and/or Asp5.42) are implicated in detecting amine-related odors, the taar gene members in S. chuatsi and their responsiveness to necromones remain unexplored. Results: In this study, we found that the aversion of S. chuatsi to dead prey is associated with necromones. Furthermore, we identified 68 taar family members in the S. chuatsi genome, distributed across six chromosomes, with 36 tandem duplication events generating 54 duplicated genes. Phylogenetic analysis classified taars into two classes, Class I and Class III, with a total of eight subfamilies. Synteny analysis revealed low synteny between the taars of S. chuatsi and Dicentrarchus labrax, with only 12 pairs of genes showing syntenic relationships. Protein sequence analysis demonstrated that taars contain amine recognition sites, N-glycosylation, and conserved cysteine structures, with high conservation and purifying selection observed within subfamilies. Subcellular localization revealed that TAARs are localized to the cell membrane and nucleus. Transcriptome data indicated that 61 taars are expressed in the olfactory epithelium, while only 19 are expressed in the brain. The response of representative taars to putrescine and cadaverine was divergent when comparing olfactory and brain tissues. Conclusions: This study systematically identified the taar gene family in S. chuatsi, analyzing their evolutionary relationships, protein structures, subcellular localization, expression profiles in olfactory and brain tissues, and the response of selected TAARs to necromones (cadaverine and putrescine). This work establishes a foundation for further investigation into TAAR-mediated death odor recognition in S. chuatsi.