Fig. 1

Transverse section of hindlimb thigh muscles in different tadpole stages. Abbreviations: a G26; b G36; c G37; d G41; e G41; f G42; g G45; h G46. The rectangle represents two streams of myogenous cells. VM, vastus medialis muscle; MS, musculi semimenbranosus; AM, adductor magnus muscle; GM, gracilis major; VL, vastus lateralis muscle; BF, biceps femoris muscle; Sa, sartorius; Se, semitendinosus; GMi, gracilis minor; RF, rectus femoris muscle; AL, adductor longus. MC, myogenous cell; MT, myotube; P-MF, primary myofiber; S-MF, secondary myofiber. F-, corresponding muscle groups in the future