Related Experiment Video
Updated: Aug 20, 2026

Meiotic Spindle Assessment in Mouse Oocytes by siRNA-mediated Silencing
Published on: October 11, 2015
Silencing of unsynapsed meiotic chromosomes in the mouse
James M A Turner1, Shantha K Mahadevaiah, Oscar Fernandez-Capetillo
1Division of Stem Cell Research and Developmental Genetics, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK. jturner@nimr.mrc.ac.uk <jturner@nimr.mrc.ac.uk>
Abstract:
In Neurospora, DNA unpaired in meiosis both is silenced and induces silencing of all DNA homologous to it. This process, called meiotic silencing by unpaired DNA, is thought to protect the host genome from invasion by transposable elements. We now show that silencing of unpaired (unsynapsed) chromosome regions also takes place in the mouse during both male and female meiosis. The tumor suppressor protein BRCA1 is implicated in this silencing, mirroring its role in the meiotic silencing of the X and Y chromosomes in normal male meiosis. These findings impact on the interpretation of the relationship between synaptic errors and sterility in mammals and extend our understanding of the biology of Brca1.
Related Concept Videos
Meiosis II
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
Meiosis II
In-vitro Mutagenesis
Meiosis vs. Mitosis
Before the start of mitosis and meiosis I, the cell synthesizes DNA, resulting in two homologous copies of each chromosome. DNA synthesis is...
Meiosis I
Prophase I is the most extended and complex step of meiosis I characterized by synapsis, chromosome pairing, and recombination of the homologous chromosomes. This process is facilitated by a proteinaceous structure called the...
X-Inactivation

