title: Uniparental chromosome elimination at mitosis and interphase in wheat and pearl millet crosses involves micronucleus formation, progressive heterochromatinization, and DNA fragmentation.
abstract: Complete uniparental chromosome elimination occurs in several interspecific hybrids of plants. We studied the mechanisms underlying selective elimination of the paternal chromosomes during the development of wheat (Triticum aestivum) x pearl millet (Pennisetum glaucum) hybrid embryos. All pearl millet chromosomes were eliminated in a random sequence between 6 and 23 d after pollination. Parental genomes were spatially separated within the hybrid nucleus, and pearl millet chromatin destined for elimination occupied peripheral interphase positions. Structural reorganization of the paternal chromosomes occurred, and mitotic behavior differed between the parental chromosomes. We provide evidence for a novel chromosome elimination pathway that involves the formation of nuclear extrusions during interphase in addition to postmitotically formed micronuclei. The chromatin structure of nuclei and micronuclei is different, and heterochromatinization and DNA fragmentation of micronucleated pearl millet chromatin is the final step during haploidization.
authors.affiliation: Institute of Plant Genetics and Crop Plant Research, D-06466 Gatersleben, Germany.
authors.forename: Dorota
authors.initials: D
authors.lastname: Gernand
authors.forename: Twan
authors.initials: T
authors.lastname: Rutten
authors.forename: Alok
authors.initials: A
authors.lastname: Varshney
authors.forename: Myroslava
authors.initials: M
authors.lastname: Rubtsova
authors.forename: Slaven
authors.initials: S
authors.lastname: Prodanovic
authors.forename: Cornelia
authors.initials: C
authors.lastname: Brüss
authors.forename: Jochen
authors.initials: J
authors.lastname: Kumlehn
authors.forename: Fritz
authors.initials: F
authors.lastname: Matzk
authors.forename: Andreas
authors.initials: A
authors.lastname: Houben
mesh_terms: D032461:Chromosomes, Plant / Q000378:metabolism*; D053938:DNA Fragmentation; D006570:Heterochromatin / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D020287:In Situ Nick-End Labeling; D007399:Interphase / Q000502:physiology*; D048629:Micronuclei, Chromosome-Defective; D008938:Mitosis / Q000502:physiology*; D009690:Nucleic Acid Conformation; D031782:Pennisetum / Q000196:embryology / Q000235:genetics* / Q000648:ultrastructure; D014908:Triticum / Q000196:embryology / Q000235:genetics* / Q000648:ultrastructure
chemical_list: D006570:Heterochromatin