Microtubule-Like Structures in Developing Oocytes of the Mongolian Gerbil (iMeriones unguiculatus/i)

摘要

Oocytes of sexually mature Mongolian gerbils, Meriones unguiculatus, of all stages of the estrous cycle were investigated electron-microscopically during foUiculogenesis. Oocytes of advanced stages of development contained numerous microtubule-like structures, which ran through the cytoplasm without any preference in direction. Initially they occurred in oocytes of secondary follicles. In the cross-section view they were either round showing an inner diameter of approximately 16 nm, or they were slightly triangle-shaped. Incomplete tubules were also present. The highest organization was found in oocytes of preovulatory follicles, whereas they vanished during atretic processes. A possible role of the tubules during the maturative growth of the oocyte is discussed.