title: Organisation and sequence analysis of nuclear-encoded 5s ribosomal RNA genes in cryptomonad algae.
abstract: Southern hybridisation, polymerase chain reaction (PCR), and nucleotide sequence, data indicate that the 5s ribosomal RNA (rRNA) gene is linked to the main rRNA gene repeat in the nuclear genome of four cryptomonad algae (Rhinomonas pauca, Storeatula major, Komma caudata, and isolate Cs 134). The 5s gene is apparently transcribed in the same direction as the large and small subunit rRNA genes. The intergenic spacer between the 5s gene and the large subunit rRNA gene exhibits length and sequence polymorphism among the different species. Cryptomonads contain two different eukaryotic genomes: the host nucleus and the nucleus of a eukaryotic endosymbiont. Mapping experiments with isolated chromosomes of the host and endosymbiont genomes showed that the intergenic spacer between the large subunit and the 5s rRNA gene, which was amplified from total DNA by PCR, was derived from the host nuclear genome.
authors.affiliation: Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: P R
authors.initials: PR
authors.lastname: Gilson
authors.forename: G J
authors.initials: GJ
authors.lastname: Adcock
authors.forename: B J
authors.initials: BJ
authors.lastname: Howlett
authors.forename: G I
authors.initials: GI
authors.lastname: McFadden
mesh_terms: D001483:Base Sequence; D004275:DNA, Ribosomal / Q000235:genetics*; D056890:Eukaryota / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012341:RNA, Ribosomal, 5S / Q000737:chemistry / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
chemical_list: D004275:DNA, Ribosomal; D012341:RNA, Ribosomal, 5S