Abstract
This study investigated muscle quality differences between wild-type (WT) and yellow-mutant (YM) Triplophysa siluroides. Texture analysis showed WT T. siluroides had significantly greater hardness, gumminess, and resilience than YM. Histological and biochemical analyses ruled out myofiber diameter/density as drivers, instead identifying reduced collagen in YM as key, as confirmed by Picrosirius red staining, collagen quantification, and transmission electron microscopy. Transcriptomic and proteomic analyses revealed that TGF-β/BMP pathway suppression in YM resulted in downregulation of core molecules (e.g., BMP2 and SMAD1), collagen-related genes (e.g., COL1A1a and COL1A1b), and ECM-related genes (e.g., TNC and FN1), potentially influencing collagen synthesis and ECM homeostasis. Notably, melanin gene TYRP1 was also downregulated in YM T. siluroides, suggesting a link between pathway suppression, muscle quality alteration, and body pigmentation. The potential role of the BMP2-SMAD1-TYRP1 axis in the association between muscle quality and body colour provides novel mechanistic insights, offering molecular targets for the breeding of T. siluroides with superior commercial traits.