title: Transcription of similar sets of rare maternal RNAs and rare nuclear RNAs in sea urchin blastulae and adult coelomocytes.
abstract: We studied the sequences transcribed in the rare class of hnRNA and the rare maternal RNA set in blastula embryos and a tissue of adult sea urchins, coelomocytes. About 26% of labelled single-copy DNA formed hybrids which bound to hydroxyapatite after three cycles of hybridization with nuclear RNA from blastulae and coelomocytes. This corresponds to transcription of about 50% of the single-copy genome by both cell populations. To compare the rare hnRNA sequences synthesized by blastulae and coelomocytes directly, labelled single-copy DNA was hybridized with blastula nuclear RNA to high RNA C0t, fractionated into sequences complementary and non-complementary to blastula nuclear RNA by chromotography on hydroxyapatite, and then each fraction was rehybridized with nuclear RNA from blastulae and coelomocytes. About 62% of the labelled DNA complementary to blastula nuclear RNA and about 1.5% of the labelled DNA non-complementary to blastula nuclear RNA hybridized with nuclear RNA from both cell populations. Thus, coelomocytes and blastula embryos transcribe essentially the same single-copy sequences in the rare hnRNA class. A probe for the rare maternal RNA set was isolated by hybridizing single-copy DNA with total egg RNA to high RNA C0t. 65-67% of this probe hybridized with whole-cell RNA from eggs, blastulae, plutei and coelomocytes demonstrating that essentially all rare maternal RNAs are present, and presumably transcribed, in blastulae, plutei and coelomocytes.
authors.forename: K C
authors.initials: KC
authors.lastname: Kleene
authors.forename: T
authors.initials: T
authors.lastname: Humphreys
mesh_terms: D000818:Animals; D001755:Blastocyst; D004247:DNA; D009693:Nucleic Acid Hybridization; D012313:RNA / Q000235:genetics*; D012332:RNA, Heterogeneous Nuclear / Q000235:genetics*; D012617:Sea Urchins / Q000196:embryology / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D012332:RNA, Heterogeneous Nuclear; D012313:RNA; D004247:DNA