Abstract: The hybrid is a high-quality triploid hybrid obtained by distantly crossing female Ctenopharyngodon idella with a male Xenocypris davidi Bleeker, which has advantages including tender flesh and strong stress resistance. Myostatin (Mstn) is a key negative regulator of muscle development and growth in animals, and its structure and expression hold significant importance in fishery production. To explore the gene sequence and expression level of Mstn, the Mstn gene sequences of the hybrid fish and its parents were cloned by molecular cloning method for analysis and comparison in this study. The results indicate that: the cDNA sequence of the Mstn gene of hybrid fish was 1 242 bp long, and its sequence was identical to the sequences of Ctenopharyngodon idella and Xenocypris davidi Bleeker, with a nucleotide homology of up to 100%. Fluorescent quantitative analysis revealed that the Mstn gene is expressed in the muscle, liver, and gills of all three species, with the highest expression level in the muscle of the hybrid fish, the highest in the gills of Ctenopharyngodon idella, and the highest in the liver of Xenocypris davidi Bleeker. The findings of this thesis not only enrich the genetic information on the Mstn gene of the hybrid fish, but also provide fundamental data for research on muscle growth and development and offer a new approach for hybrid breeding of Ctenopharyngodon idella.
Keywords: distant hybridization; hybrid fish; myostatin; fish muscles; growth and development
（Acta Laser Biology Sinica, 2026, 35(3): 262-269）