Further evidence that the majority of primary nuclear RNA transcripts in mammalian cells do not contribute to mRNA

Mol Cell Biol. 1982 Jun;2(6):701-7. doi: 10.1128/mcb.2.6.701.


Nuclear RNA from Chinese hamster ovary cells was effectively separated into polyadenylic acid [poly(A)]-containing [poly (A)+] and non-poly(A)-containing [poly(A)-] fractions so that -90% of the poly(A) was present in the (A)+ fraction. Only 25% of the 5'-terminal caps of the large nuclear molecules were present in the (A)+ class, but about 70% of the specific mRNA sequences (assayed with cDNA clones) were in the (A)+ class. It appears that many long capped heterogeneous nuclear RNA molecules are of a different sequence category from those molecules that are successfully processed into mRNA.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Composition
  • CHO Cells
  • Cricetinae
  • Poly A / metabolism
  • RNA Caps / genetics
  • RNA Caps / isolation & purification
  • RNA, Messenger / genetics*
  • RNA, Messenger / isolation & purification*
  • RNA, Messenger / metabolism
  • RNA, Nuclear / genetics*
  • RNA, Nuclear / isolation & purification*
  • Transcription, Genetic / genetics*


  • RNA Caps
  • RNA, Messenger
  • RNA, Nuclear
  • Poly A