Pre-mrna The unspliced, immediate product of RNA polymerase II in eukaryotes.
When the pre-mRNA has been transcribed from the DNA, it includes several introns and exons. In nematodes, the mean is 4-5 exons and introns; in the fruit fly Drosophila there are more than 100 introns and exons in one transcribed pre-mRNA.
Not only pre-mRNA but also proteins can undergo splicing. Although the biomolecular mechanisms are different, the principle is the same, that parts of the protein, called inteins instead of introns, are removed.
RNA Processing: pre-mRNA → mRNA
All the primary transcripts produced in the nucleus must undergo processing steps to produce functional RNA molecules for export to the cytosol.
The name originally given to large RNA molecules found in the nucleus, which are now known to be unedited mRNA transcripts, or pre-mRNAs. (See RNA.) HGH. See Human growth hormone. hnRNA. See Heterogeneous nuclear RNA. Homologous chromosomes.
Why do pre-mRNAs get smaller during RNA processing?
Self-catalytic RNAs
DNA-DNA renaturation and DNA-RNA hybridization
Interpreting a pre-mRNA splicing diagram
Promoters
Protein coding sequences
Hybridization of mRNA with the DNA coding strand ...
RNA splicing is the normal process in which intron sequences are removed from the pre-mRNA, producing the mRNA, which corresponds to the exons.
In alternative splicing, the same pre-mRNA molecule, which consists of introns and exons, is spliced in different ways to produce mature mRNAs of different lengths and different functionality.
altruistic behavior ...
Various ways of splicing out introns in eukaryotic pre-mRNAs resulting in one gene producing several different mRNAs and protein products.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ...
the nuclear RNA that still contains the introns (also referred to as pre-mRNA)
Source: Jenkins, John B. 1990. Human Genetics, 2nd Edition. New York: Harper & Row
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Poly(A) polymerase. Catalyzes the addition of adenine residues to the 3' end of pre-mRNAs to form the poly(A) tail. (See Polymerase.) ...
 See also: Protein, Trans, Gene, Splicing, Human
  
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