title: Holocentric chromosomes of Luzula elegans are characterized by a longitudinal centromere groove, chromosome bending, and a terminal nucleolus organizer region.
abstract: The structure of holocentric chromosomes was analyzed in mitotic cells of Luzula elegans. Light and scanning electron microscopy observations provided evidence for the existence of a longitudinal groove along each sister chromatid. The centromere-specific histone H3 variant, CENH3, colocalized with this groove and with microtubule attachment sites. The terminal chromosomal regions were CENH3-negative. During metaphase to anaphase transition, L. elegans chromosomes typically curved to a sickle-like shape, a process that is likely to be influenced by the pulling forces of microtubules along the holocentric axis towards the corresponding microtubule organizing regions. A single pair of 45S rDNA sites, situated distal to Arabidopsis-telomere repeats, was observed at the terminal region of one chromosome pair. We suggest that the 45S rDNA position in distal centromere-free regions could be required to ensure chromosome stability.
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Heckmann
authors.forename: E
authors.initials: E
authors.lastname: Schroeder-Reiter
authors.forename: K
authors.initials: K
authors.lastname: Kumke
authors.forename: L
authors.initials: L
authors.lastname: Ma
authors.forename: K
authors.initials: K
authors.lastname: Nagaki
authors.forename: M
authors.initials: M
authors.lastname: Murata
authors.forename: G
authors.initials: G
authors.lastname: Wanner
authors.forename: A
authors.initials: A
authors.lastname: Houben
mesh_terms: D000705:Anaphase; D032461:Chromosomes, Plant; D017404:In Situ Hybridization, Fluorescence; D019684:Magnoliopsida / Q000235:genetics*; D008677:Metaphase; D008855:Microscopy, Electron, Scanning; D009697:Nucleolus Organizer Region