Primary transcript
A primary transcript is an RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....

 molecule that has not yet undergone any modification
Post-transcriptional modification
Post-transcriptional modification is a process in cell biology by which, in eukaryotic cells, primary transcript RNA is converted into mature RNA. A notable example is the conversion of precursor messenger RNA into mature messenger RNA , which includes splicing and occurs prior to protein synthesis...

 after its synthesis
Transcription (genetics)
Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...

. For example, a precursor messenger RNA
Precursor mRNA
Precursor mRNA is an immature single strand of messenger ribonucleic acid . pre-mRNA is synthesized from a DNA template in the cell nucleus by transcription. Pre-mRNA comprises the bulk of heterogeneous nuclear RNA...

 (pre-mRNA) is a primary transcript that becomes a messenger RNA
Messenger RNA
Messenger RNA is a molecule of RNA encoding a chemical "blueprint" for a protein product. mRNA is transcribed from a DNA template, and carries coding information to the sites of protein synthesis: the ribosomes. Here, the nucleic acid polymer is translated into a polymer of amino acids: a protein...

 (mRNA) after processing, and a primary microRNA (pri-miRNA) precursor becomes a microRNA (miRNA) after processing.
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