title: Unusual ribosomal RNA gene organization in copepods of the genus Calanus.
abstract: Ribosomal RNA genes in the nuclear genomes of eukaryotes are generally found in tandemly repeated units encoding 18 S, 5.8 S and 28 S rRNA (in that order). 5 S rRNA genes typically lie outside these units, most often in tandem clusters coding exclusively for 5 S rRNA. Inclusion of 5 S genes within the 18 S-5.8 S-28 S repeat unit is known only for certain protozoa and fungi. Here we report that, in the copepod Calanus finmarchicus, single 5 S genes are included within many or all of the 18 S-5.8 S-28 S repeat units. Sequence analyses of regions cloned from two of these repeat units show that they indeed include 5 S genes (which are distal to 28 S genes) and that these are transcribed from opposite strands.
authors: Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
authors: G
authors: G
authors: Drouin
authors: J D
authors: JD
authors: Hofman
authors: W F
authors: WF
authors: Doolittle
mesh_terms: D000818:Animals; D003445:Crustacea / Q000235:genetics*; D004247:DNA; D005796:Genes; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D012335:RNA, Ribosomal / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D012335:RNA, Ribosomal; D004247:DNA