DNA-methylation dependent regulation of embryo-specific 5S ribosomal DNA cluster transcription in adult tissues of sea urchin Paracentrotus lividus.
We have previously reported a molecular and cytogenetic characterization of three different 5S rDNA clusters in the sea urchin Paracentrotus lividus and recently, demonstrated the presence of high heterogeneity in functional 5S rRNA. In this paper, we show some important distinctive data on 5S rRNA transcription for this organism. Using single strand conformation polymorphism (SSCP) analysis, we demonstrate the existence of two classes of 5S rRNA, one which is embryo-specific and encoded by the smallest (700 bp) cluster and the other which is expressed at every stage and encoded by longer clusters (900 and 950 bp). We also demonstrate that the embryo-specific class of 5S rRNA is expressed in oocytes and embryonic stages and is silenced in adult tissue and that this phenomenon appears to be due exclusively to DNA methylation, as indicated by sensitivity to 5-azacytidine, unlike Xenopus where this mechanism is necessary but not sufficient to maintain the silenced status.
Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Sezione di Biologia Cellulare, Ed. 16, Università degli Studi di Palermo, V.le delle Scienze, 90128 Palermo, Italy; Istituto Ortopedico Rizzoli, c/o Dipartimento di Biopatologia e Biotecnologie Mediche e Forensi (DIBIMEF), Università degli Studi di Palermo, Via Divisi 81, 90133 Palermo, Italy. Electronic address: daniele.bellavia@unipa.it.
Daniele
D
Bellavia
Eufrosina
E
Dimarco
Flores
F
Naselli
Fabio
F
Caradonna
D000818:Animals; D001374:Azacitidine / Q000494:pharmacology; D019175:DNA Methylation; D004275:DNA, Ribosomal / Q000235:genetics* / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism; D044127:Epigenesis, Genetic; D005260:Female; D020868:Gene Silencing; D009865:Oocytes / Q000378:metabolism; D009928:Organ Specificity; D047328:Paracentrotus / Q000196:embryology / Q000235:genetics*; D018807:Polymorphism, Single-Stranded Conformational; D012341:RNA, Ribosomal, 5S / Q000235:genetics*; D014158:Transcription, Genetic
D004275:DNA, Ribosomal; D012341:RNA, Ribosomal, 5S; D001374:Azacitidine
5-AZA; 5-azacytidine; 5S ribosomal RNA; 5S ribosomal genes; CCM; Epigenetic; MCF; NTS; SSCP; Sea urchin; Silencing; VGGE; base pair; bp; cell culture medium; millipore-filtered coelomic fluid; non-transcribed spacer; rDNA; rRNA; ribosomal DNA; ribosomal RNA; single-strand conformation polymorphism; voltage gradient gel electrophoresis