|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 3, 437-444, Copyright © 1968 by Company of Biologists
Submitted on November 8, 1967
1 Department of Zoology, The University, St Andrews, Fife, Scotland
The ovaries of newly metamorphosed Xenopus females contain oocytes in all stages of early meiotic prophase. In pachytene nuclei extrachromosomal nucleolar DNA appears in the form of a thin cap covering one side of the nucleus. During pachytene this cap of DNA enlarges to occupy half the nucleus. After pachytene the nucleus grows rapidly and the cap of DNA disperses into numerous tiny granules which become scattered throughout the nucleoplasm. Autoradiographs of cells which have been incubated with [3H]thymidine, and microspectrophotometric measurements of the Feulgen dye contents of nuclei in various stages of meiosis, show that the extrachromosomal nucleolar DNA is synthesized during the pachytene and immediate post-pachytene stages. Microspectrophotometric comparison of the Feulgen dye contents of post-pachytene nuclei in which the DNA cap has dispersed, and similarly prepared mouse liver nuclei, show that the post-pachytene nuclei have about 30 µµg of extrachromosomal pachytene nucleolar DNA. In [3H]thymidine autoradiographs early pachytene nuclei are less heavily labelled than late pachytene and early diplotene nuclei. Consequently it is proposed that primary replicas of the chromosomal nucleolar organizer undergo a series of post-detachment replications.
Submitted on November 8, 1967
This article has been cited by other articles:
|
|
 |
|
  B Trask, G van den Engh, J Landegent, N. in de Wal, and M van der Ploeg Detection of DNA sequences in nuclei in suspension by in situ hybridization and dual beam flow cytometry Science, December 20, 1985; 230(4732): 1401 - 1403. [Abstract] [PDF]
|
|
|
|
 |
|
 A. P. Bird A Study of Early Events in Ribosomal Gene Amplification Cold Spring Harb Symp Quant Biol, January 1, 1978; 42(0): 1179 - 1183. [Abstract] [PDF]
|
|
|
|
|
|
D. Hourcade, D. Dressler, and J. Wolfson The Nucleolus and the Rolling Circle Cold Spring Harb Symp Quant Biol, January 1, 1974; 38(0): 537 - 550. [Abstract] [PDF]
|
|
