A hemicentric inversion in the maize line knobless Tama flint created two sites of centromeric elements and moved the kinetochore-forming region |
| |
Authors: | Jonathan C Lamb Julie M Meyer James A Birchler |
| |
Institution: | (1) Division of Biological Sciences, University of Missouri-Columbia, 117 Tucker Hall, Columbia, MO 65211, USA;(2) Department of Agriculture, Truman State University, Kirksville, MO 63501, USA |
| |
Abstract: | A maize line, knobless Tama flint (KTF), was found to contain a version of chromosome 8 with two spatially distinct regions
of centromeric elements, one at the original genetic position and the other at a novel location on the long arm. The new site
of centromeric elements functions as the kinetochore-forming region resulting in a change of arm length ratio. Examination
of fluorescence in situ hybridization markers on chromosome 8 revealed an inversion between the two centromere sites relative
to standard maize lines, indicating that this chromosome 8 resulted from a hemicentric inversion with one breakpoint approximately
20 centi-McClintocks (cMc) on the long arm (20% of the total arm length from the centromere) and the other in the original
cluster of centromere repeats. This inversion moved the kinetochore-forming region but left the remainder of the centromere
repeats. In a hybrid between a standard line (Mo17) and KTF, both chromosome 8 homologues were completely synapsed at pachytene
despite the inversion. Although the homologous centromeres were not paired, they were always correctly oriented at anaphase
and migrated to opposite poles. Additionally, recombination on 8L was severely repressed in the hybrid. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|