Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/18/1998
Publication Date: N/A
Technical Abstract: A maize (Zea maize L.) chromosome 9 addition line of oat (Avena sativa L.) was used as a source of DNA to isolate cosmid clones from the centromeric region of this maize chromosome. Characterization of cloned DNA segments revealed that the maize centromeric region is composed of different families of dispersed and tandemly organized repetitive elements including a novel family of tandem repeats, termed CentC elements, in addition to CentA and other previously identified maize retroelements like Huck and Prem2. Fluorescence in situ hybridization revealed that CentC and CentA elements are limited to centromeric regions of every maize chromosome. Southern blot hybridization of DNA from oat-maize addition lines revealed polymorphism of restriction fragments of these elements in individual maize chromosomes. Significant variation among different chromosomes in the size of the blocks of CentC and copy number of CentA elements and other retrotransposon-like elements provide each maize centromere a unique overall structure.