title: Ectopic pairing and evolution of 5S ribosomal RNA genes in the chromosomes of Drosophila funebris.
abstract: 5S ribosomal RNA from Drosophila melanogaster labeled with 125I was used to locate the 5S rRNA genes in chromosomes of D. funebris by means of in situ hybridization. Silver grains were observed at three distinct sites, one of which was a recognized reverse repeat. Only one half of the reverse repeat, however, hybridizes with 5S rRNA and the significance of this phenomenon is discussed. A case of ectopic pairing between two different 5S sites in the genome is reported, and the significance of ectopic pairing is considered.
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002874:Chromosome Mapping; D004330:Drosophila / Q000378:metabolism*; D004331:Drosophila melanogaster; D005796:Genes; D009693:Nucleic Acid Hybridization; D012335:RNA, Ribosomal / Q000096:biosynthesis*
chemical_list: D012335:RNA, Ribosomal