title: Distinct single-copy sequence sets in sea urchin nuclear RNAs.
abstract: The purpose of this study was to determine whether nuclear RNAs (nRNA) of sea urchin embryos and adult tissues contain identical or partially distinct sets of single-copy sequence transcripts. A DNA tracer was prepared consisting mainly of sequences absent from gastrula nRNA; 3.6% of this tracer reacted with adult intestine nRNA but not with gastrula nRNA. The existence of a differentially transcribed DNA fraction was verified by its partial purification and rehybridization to intestine and gastrula nRNAs. About one-third of the genomic single-copy sequence is represented in both nRNAs, or about 2 x 10(8) nucleotides. The differentially transcribed portion of the single-copy genome identified in this work includes about 3.5 x 10(7) nucleotides.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000502:physiology; D004247:DNA / Q000235:genetics*; D004625:Embryo, Nonmammalian; D005260:Female; D007422:Intestines; D010053:Ovary; D012332:RNA, Heterogeneous Nuclear / Q000235:genetics*; D012617:Sea Urchins / Q000235:genetics*
chemical_list: D012332:RNA, Heterogeneous Nuclear; D004247:DNA