title: Ribosomal RNA genes and the B chromosome of Brachycome dichromosomatica.
abstract: Fluorescence in situ hybridization (FISH) with biotinylated rDNA revealed the presence of an rRNA gene cluster on both the A and B chromosomes of Brachycome dichromosomatica, an Australian native ephemeral plant of the arid regions of south-eastern Australia. This species contains only two pairs of A chromosomes and up to three B chromosomes. The regular attachment of the B chromosome to a nucleolus suggests that these ribosomal RNA genes are transcribed. Southern hybridization of DNA from 0B and +B plants digested with a variety of restriction enzymes indicates that the rRNA genes on the A and B chromosomes are the same in sequence and methylation status.
authors.affiliation: Department of Genetics, University of Adelaide, South Australia.
authors.forename: T M
authors.initials: TM
authors.lastname: Donald
authors.forename: C R
authors.initials: CR
authors.lastname: Leach
authors.forename: A
authors.initials: A
authors.lastname: Clough
authors.forename: J N
authors.initials: JN
authors.lastname: Timmis
mesh_terms: D015139:Blotting, Southern; D002875:Chromosomes; D017404:In Situ Hybridization, Fluorescence; D008745:Methylation; D010944:Plants / Q000235:genetics*; D018749:RNA, Plant / Q000235:genetics*; D012335:RNA, Ribosomal / Q000235:genetics*
chemical_list: D018749:RNA, Plant; D012335:RNA, Ribosomal