Unreplicated DNA (top) is distributed equally unless lpl1p is nonfunctional (bottom).
Tanaka/Elesevier
Chromosome biorientation—the attachment of a replicated chromosome to both poles of a spindle—is not a simple matter of pointing sister kinetochores in opposite directions and hoping for the best. Attachment errors need to be corrected. Tomoyuki Tanaka (University of Dundee, UK) and colleagues suggest that many sister kinetochores in budding yeast initially attach to a single pole, but then the Ipl1p kinase triggers detachment and reorientation of one sister kinetochore in each pair.
The majority of ipl1 kinetochores segregate into the yeast bud along with the older spindle pole body. The problem does not seem to be in the resolution of replicated centromere DNA into two separate kinetochores, at least not exclusively, as the same preferential association with the old spindle pole was seen when chromosome replication was prevented in ipl1 mutants.
This...
