title: Changes in testicular leydig cells and in plasma testosterone levels among seasonally breeding rock hyrax.
mesh_terms: D000818:Animals; D001947:Breeding; D004721:Endoplasmic Reticulum / Q000033:anatomy & histology*; D007985:Leydig Cells / Q000166:cytology*; D008297:Male; D008322:Mammals; D008854:Microscopy, Electron; D009929:Organ Size; D012669:Seminal Vesicles / Q000033:anatomy & histology; D012726:Sexual Behavior, Animal; D013737:Testis / Q000033:anatomy & histology* / Q000166:cytology / Q000601:surgery; D013739:Testosterone / Q000097:blood
chemical_list: D013739:Testosterone