Localization of Nucleus Organizing Regions (NORs) in One-Cell Mouse Embryos and Oocytes by Fluorescence in situ Hybridization

Localization of Nucleus Organizing Regions (NORs) in One-Cell Mouse Embryos and Oocytes by... In mouse zygotes, ribosomal genes (rDNA) are transcriptionally silent and so-called “nucleolar precursor bodies” are present instead of typical nucleoli. However, the functional significance of these structures remains obscure. Specifically, it remains unknown whether structural association between the nucleolar precursor bodies and rDNA are maintained when rDNA synthesis is switched off. Here, we described the rDNA topology in one-cell mouse embryos and MII oocytes using fluorescence in situ hybridization and mouse rDNA probes. Our data suggest that in the pronuclei of one-cell embryos, rDNAs form rather compact clusters, whose number does not exceed that of nucleolus organizing chromosomes characteristic for the haploid set of mouse chromosomes. In zygotic pronuclei, not all nucleolar precursor bodies are associated with rDNA and not all rDNA repeats are attached to the nucleolar precursor bodies. Altogether, these data favor the idea that spatial interactions of nucleolus organizing chromosomes and nucleolar precursor bodies are not obligatory. We assume that associations between nucleolar precursor bodies and nucleolus organizing chromosomal regions are mediated by centromeric heterochromatin. The total numbers of silver stained nucleolus organizing chromosomes in CBA and C57BL mice are different. rDNA genes are unequally distributed among nucleolus organizing chromosomes and nucleolus organizing regions of sister chromatids. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Russian Journal of Developmental Biology Springer Journals

Localization of Nucleus Organizing Regions (NORs) in One-Cell Mouse Embryos and Oocytes by Fluorescence in situ Hybridization

Loading next page...
Kluwer Academic Publishers-Plenum Publishers
Copyright © 2004 by MAIK “Nauka/Interperiodica”
Life Sciences; Animal Anatomy / Morphology / Histology
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial