title: Differentiation of field bean heterochromatin by in situ hybridization with a repeated FokI sequence.
abstract: The chromosomes of a field bean line with a reconstructed karyotype (ACB) were hybridized in situ with biotinylated probes of a repetitive Fok I sequence, of DOP-PCR (degenerate oligonucleotide primed polymerase chain reaction) amplified DNA from a chromosome that does not contain this sequence, and with probes containing dispersed repetitive sequences. The results were compared with Giemsa banding, DNA late replication and Fok I in situ digestion patterns. This allowed further differentiation between the chromatin types of this species. Centromeric and NOR-associated heterochromatin as well as euchromatin were shown to be free of Fok I sequence repeats. Among the interstitial late replicating Giemsa bands, subdivided into 'marker' and 'additional' bands, most of the marker bands located at mid-arm positions were composed mainly or exclusively of tandemly arranged Fok I repeats. Some of the marker bands and nearly all of the additional bands located in the vicinity of centromeres were free of FokI sequence repeats, of Fok I recognition sites, and possibly also of dispersed repetitive sequences. They are probably composed of specific, not yet defined, repetitive sequences.
authors.affiliation: Institut für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Fuchs
authors.forename: U
authors.initials: U
authors.lastname: Pich
authors.forename: A
authors.initials: A
authors.lastname: Meister
authors.forename: I
authors.initials: I
authors.lastname: Schubert
mesh_terms: D001483:Base Sequence; D001710:Biotin; D002875:Chromosomes / Q000648:ultrastructure; D015252:Deoxyribonucleases, Type II Site-Specific; D007887:Fabaceae / Q000235:genetics* / Q000648:ultrastructure; D006570:Heterochromatin / Q000648:ultrastructure*; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008969:Molecular Sequence Data; D009697:Nucleolus Organizer Region / Q000648:ultrastructure; D010946:Plants, Medicinal; D016133:Polymerase Chain Reaction; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D006570:Heterochromatin; D001710:Biotin; C035042:endodeoxyribonuclease FokI; D015252:Deoxyribonucleases, Type II Site-Specific