title: Dictyostelium 17S, 25S, and 5S rDNAs lie within a 38,000 base pair repeated unit.
abstract: Mapping with the restriction enzymes Sal 1 and R1 has generated a picture of the organization of Dictyostelium ribosomal DNA. The DNA which codes for 17S and 25S ribosomal RNAs is located within a stretch of repetitive DNA at least 38,000 base pairs long. This repeated unit includes 5S DNA, linked to 25S DNA. Two techniques were especially useful in the mapping: "cloning" 14S + 25S DNA on the plasmid pMB9 to amplify individual R1 fragments, and digesting DNA with R1 in the presence of the antibiotic distamycin A to produce specific partial digestion products.
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000032:analysis* / Q000378:metabolism; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant; D004023:Dictyostelium / Q000032:analysis*; D004214:Distamycins; D009235:Myxomycetes / Q000032:analysis*; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D012335:RNA, Ribosomal / Q000096:biosynthesis*
chemical_list: D004274:DNA, Recombinant; D004214:Distamycins; D012335:RNA, Ribosomal; D004247:DNA; D004262:DNA Restriction Enzymes