Ultrastructural Study of Uromastyx aegyptia Skeletal Muscles

ABSTRACf. The present study was concerned with the ultrastructure of the mandibular externus of the jaw and the tail skeletal muscles of U. aegyptia. Results obtained revealed differences in general morphology between the two muscles. The sarcoplasmic reticulum, T-system, and large deposits of glycogen granules, were encountered in the jaw muscle. However, the SR are not well developed. In contrast, indistinct glycogen granules, sarcoplasmic reticulum and T -system are the main features of the tail muscles. Furthermoce, the jaw muscle demonstrated a typical sarcomere with parallel striation but no indication of M-line. Results showed that although the properties and details of the fine strlicture of the two muscles studied varied, the fllftdamental struct"re was typical vertebrate Skeletal muscle. Experiments on physiological and biochemical aspects should be obtained to arrive to a final conclusion about the type of muscle.