Formation,transport, and storage of ribonucleic acid containing structures in oocytes of Acheta domesticus (Orthoptera)

Summary Oocyte development of Acheta domesticus was investigated morphologically and cytochemically. The studies demonstrated a size decrease and final disappearance of a large extrachromosomal DNA body in the nuclei as the cells proceeded through the diplotene stage of meiosis. The body was surrounded by fascicles of RNA containing material. This material remained within the nuclei in individual packets after the DNA body was no longer detectable. An active nucleo-cytoplasmic migration of RNA was seen prior to the disappearance of the DNA body. After the disappearance of the body very little migration was detected. Evidence was presented to demonstrate the ribosomal nature of this migratory RNA. The RNA packets remaining in nuclei of cells arrested in the diplotene stage of oogenesis functioned as storage depots for ribosomal RNA.The authors acknowledge the technical assistance of Miss Agnes Cralley. Dr. D. Ammermann, Zoologisches Institut, Tübingen, W. Germany, provided the animals used in this study. — This work was supported in part by a Health Research Services Foundation Grant No. J-1 and in part by U.S.P.H.S. Grant No. 7-FZCA-23,971-O1A1.