title: Chromosomal localization and molecular characterization of three different 5S ribosomal DNA clusters in the sea urchin Paracentrotus lividus.
abstract: In this paper the chromosomal localization and molecular cloning and characterization of three 5S rDNA clusters of 700 bp (base pairs), 900 bp, and 950 bp in the sea urchin Paracentrotus lividus are reported. Southern blot hybridization demonstrated the existence of three 5S rDNA repeats of differing length in the P. lividus genome. Fluorescence in situ hybridization analysis, performed in parallel on both haploid and diploid metaphases and interphase nuclei using different 5S rDNA units as probes, localized these 5S rDNA clusters in 3 different pairs of P. lividus chromosomes. This is the first complete gene mapping not only in a sea urchin but also in the phylum of echinoderms as a whole.
authors: Dipartimento di Biologia Cellulare e dello Sviluppo, Università di Palermo, Viale delle Scienze, 90128, Palermo, Italy.
authors: Fabio
authors: F
authors: Caradonna
authors: Daniele
authors: D
authors: Bellavia
authors: Ann Maria
authors: AM
authors: Clemente
authors: Giorgia
authors: G
authors: Sisino
authors: Rainer
authors: R
authors: Barbieri
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D002875:Chromosomes; D003001:Cloning, Molecular; D004275:DNA, Ribosomal / Q000032:analysis / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D047328:Paracentrotus / Q000235:genetics*; D012341:RNA, Ribosomal, 5S / Q000235:genetics*
chemical_list: D004275:DNA, Ribosomal; D012341:RNA, Ribosomal, 5S