Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Plant Cell. 2009 Jul;21(7):1929-39. doi: 10.1105/tpc.109.066662. Epub 2009 Jul 14.

Reactivation of an inactive centromere reveals epigenetic and structural components for centromere specification in maize.

Author information

  • 1Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211-7400, USA.

Abstract

Stable maize (Zea mays) chromosomes were recovered from an unstable dicentric containing large and small versions of the B chromosome centromere. In the stable chromosome, the smaller centromere had become inactivated. This inactive centromere can be inherited from one generation to the next attached to the active version and loses all known cytological and molecular properties of active centromeres. When separated from the active centromere by intrachromosomal recombination, the inactive centromere can be reactivated. The reactivated centromere regains the molecular attributes of activity in anaphase I of meiosis. When two copies of the dicentric chromosome with one active and one inactive centromere are present, homologous chromosome pairing reduces the frequency of intrachromosomal recombination and thus decreases, but does not eliminate, the reactivation of inactive centromeres. These findings indicate an epigenetic component to centromere specification in that centromere inactivation can be directed by joining two centromeres in opposition. These findings also indicate a structural aspect to centromere specification revealed by the gain of activity at the site of the previously inactive sequences.

Comment in

PMID:
19602622
[PubMed - indexed for MEDLINE]
PMCID:
PMC2729603
Free PMC Article

Images from this publication.See all images (7)Free text

Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire Icon for PubMed Central
    Write to the Help Desk