A primary transcript is the single-stranded ribonucleic acid (RNA) product synthesized by transcription of DNA, and processed to yield various mature RNA products such as mRNAs, tRNAs, and rRNAs. The primary transcripts designated to be mRNAs are modified in preparation for translation. For example, a precursor mRNA (pre-mRNA) is a type of primary transcript that becomes a messenger RNA (mRNA) after processing.
Micrograph of gene transcription of ribosomal RNA illustrating the growing primary transcripts
Transcription of DNA by RNA polymerase to produce primary transcript
Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself or by forming a template for the production of proteins. RNA and deoxyribonucleic acid (DNA) are nucleic acids. The nucleic acids constitute one of the four major macromolecules essential for all known forms of life. RNA is assembled as a chain of nucleotides. Cellular organisms use messenger RNA (mRNA) to convey genetic information that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome.
Secondary structure of a telomerase RNA
Robert W. Holley, left, poses with his research team.