Muscle growth in teleost fish is regulated by factors utilizing the activin II B receptor.

The activin type IIB receptor (Acvr2b) is the cell surface receptor for multiple transforming growth factor β (TGF-β) superfamily ligands, several of which regulate muscle growth in mammals. To investigate the role of the Acvr2b signaling pathway in the growth and development of skeletal muscle in teleost fish, transgenic rainbow trout (RBT; Oncorhynchus mykiss) expressing a truncated form of the acvr2b-2a (acvr2b(▵)) in muscle tissue were produced. High levels of acvr2b(▵) expression were detected in the majority of P1 transgenic fish.