Immunohistochemical localization of leptin in different tissues of Chinese alligator: A, adipocyte; B, gastric gland (GG) of the stomach; C, lamina propria of the intestine; D, interstitial cell (IC) of the testis; E, supporting cell (SC), spermatogonium (SP), primary spermatocyte (PS), secondary spermatocyte (SS), and spermatid (S) of the testis. Magnification: A, B, C = X400; D, E = X200.