Isolating and Validating Fibroblast-like Cells from the Skeletal Muscle of the Siamese Crocodile (Crocodylus siamensis)

The isolation of fibroblast-like cells from crocodile skeletal muscle provides a valuable platform for studies in comparative physiology, reptilian biology, regenerative medicine, and tissue engineering. In this article, we present an optimized protocol for isolating and characterizing fibroblast-like cells derived from the embryonic skeletal muscle of the Siamese crocodile (Crocodylus siamensis). The procedure improved cell yields and viability while maintaining phenotypic and genetic stability. Dorsal and tail skeletal muscle tissue was cultured in flasks pre-coated with collagen. The cells attached and began migrating from the explants within one day. Optimal culture conditions were achieved using Dulbecco’s Modified Eagle Medium/Nutrient Mixture F-12 or Minimum Essential Medium Alpha supplemented with 10% fetal bovine serum, 2% crocodile serum, and growth-promoting factors, incubated at 28 °C without CO2. These conditions supported a shorter population doubling time and enhanced cell proliferation. The established cells displayed a spindle-shaped fibroblastic morphology, expressed the fibroblast-specific marker fibronectin, and maintained a stable karyotype through passage 20. The cell line remained stable and proliferative for at least 30 passages under standard culture conditions. Our study established the first standardized fibroblast-like cell line derived from C. siamensis, thus providing a foundation for future studies in reptilian physiology, cytogenetics, and regenerative biotechnology.