Fig 2: Confocal representative images showing immunofluorescence staining for Kiss1R (AbKiss1R, green) in rat spermatozoa collected from epididymis caput (A–C) and cauda (D,E). DAPI (blue) was used to counterstain sperm cell nuclei. Scale bar: 5 µm (A–C); 7.5 µm (D–F).

Fig 3: Expression and localization of Kiss1R in rat epididymis. (A) Western blot for Kiss1R in spermatozoa free epididymis (Ep.) caput and cauda. (B) Schematic representation of cell types in epididymal epithelium, with Kiss1R immunoreactive cells in violet. 1: Myoid cells; 2: basal cells; 3: apical cells, 4: Halo cell, 5: principal cells, 6: clear cells, L: lumen, SPZ: spermatozoa. (C–G) Histological sections of caput epididymis; (H–L) Histological sections of causa epididymis. (C,H) Haematoxylin-eosin staining. (D–G), (I–L): immunohistochemistry analysis for Kiss1R. (G,L): controls of immunoreactions. Arrows indicate Kiss1R immunoreactive cells. Asterisk indicates statistically significant differences (p < 0.05).

Fig 4: GPR54 Protein Expression in the Testis of Different Stages of Rat Growth. (As shown in Fig. 5a, c, GPR54 protein increased abruptly in puberty and reached maturity level; exercise did not change the expression trend of GPR54; high-fat diet led to the sudden increase of GPR54 protein at pre- puberty, and the peak level decreased; exercise can partially improve the abnormal expression of GPR54 induced by high-fat diet.)

Fig 5: GPR54 mRNA expression in the testis of different stages of rats growth