5S RIBOSOMAL-RNA GENE HYBRIDIZES TO HUMAN-CHROMOSOME-1 AT 2 SITES (1Q42.11-]Q42.13 AND 1Q43)

Hybridization of a loach (Misgurnus fossilis) oocyte 5S rRNA gene repe at with human chromosomes was carried out to refine the localization o f the 5S RNA gene in the human genome. Preliminary in situ hybridizati on analysis showed that this repeat hybridized with human chromosome r egion 1q42-->q43, the same location previously reported for the human 5S rRNA gene. High-resolution banding revealed the presence of two sit es of hybridization, with a main peak in chromosome region 1q42.1 and a second peak in 1q43. These results are consistent with our data on t he existence in the human genome of different 5S rRNA gene clusters sp ecified by BamHI and HindIII restriction sites in spacer DNA (Timofeev a et al., 1993) and suggest a multicluster organization of the human 5 S rRNA genes.