Sequences associated with A chromosome centromeres are present throughout the maize B chromosome

Chromosoma. 2005 Feb;113(7):337-49. doi: 10.1007/s00412-004-0319-z. Epub 2004 Dec 7.

Abstract

Maize chromosome spreads containing the supernumerary B chromosome were hybridized with probes from various repetitive elements including CentC, CRM, and CentA, which have been localized to centromeric regions on the A chromosomes. Repetitive elements that are enriched or found exclusively near the centromeres of A chromosomes hybridized to many sites distinct from the centromere on the B chromosome. To examine whether these elements recruit kinetochore proteins at locations other than the canonical B centromere, cells were labeled with antibodies against CENH3, a key kinetochore protein. No labeling was detected outside the normal centromere and no evidence of B chromosome holocentromeric activity was observed. This finding suggests that, as in other higher eukaryotes, DNA sequence alone is insufficient to dictate kinetochore location in plants. Additionally, examination of the B centromere region in pachytene chromosomes revealed that the B-specific element ZmBs hybridizes to a much larger region than the site of hybridization of CentC, CRM, and CentA and the labeling by anti-CENH3 antibodies.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Centromere / genetics*
  • Chromosomes, Plant / genetics*
  • DNA, Plant
  • Genes, Plant*
  • In Situ Hybridization, Fluorescence
  • Kinetochores / metabolism*
  • Retroelements / genetics*
  • Sequence Analysis, DNA
  • Tandem Repeat Sequences / genetics
  • Zea mays / genetics*

Substances

  • DNA, Plant
  • Retroelements