from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun A segment of a gene situated between exons that is removed before translation of messenger RNA and does not function in coding for protein synthesis.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun genetics A portion of a split gene that is included in pre-
RNA transcriptsbut is removed during RNA processing and rapidly degraded.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun sequence of a eukaryotic gene's DNA that is not translated into a protein
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
We start from an organism that stores its genetic information in intron-less DNA and copies this to RNA as an intermediate to generate proteins.
The functional SNP that the scientists found was located on what is known as intron 6, a reference to a specific location within the gene that is typically overlooked when searching for a functionally relevant mutation.
But that could well be a real problem to solve – design me an intron depot so I can manage the traffic flow of nanoscopic drug delivery cars.
Sequence data from the mitochondrial cytochrome-b gene and the hypervariable control region as well as 7th intron of the nuclear fibrinogen gene show these 2 taxa to be reciprocally monophyletic.
Two nuclear intron regions (7th intron of the beta fibrinogen gene and thyrotropin) also were included, but showed limited genetic variation and no fixed differences between the 2 taxa.
They are separated by 13.8% sequence divergence (uncorrected) based on the 2 mitochondrial segments, and 4.2% based on the nuclear intron sequences.
I seem to recall reading a paper by King where she considers this possibility and did a good job of knocking it down (although the intron stuff mentioned in the ScienceDaily argument might resurrect this objection).
Gene mutation can occur at many levels - from single nucleotide polymorphisms, to the introduction of stop codons and longer stretches of DNA (whole genes, even) via intron/exon shuffling.
Examination of DNA has shown genetic variation in both coding regions and in the non-coding intron region of genes.
Third, the dsRNA had to correspond to the mature mRNA sequence; neither intron nor promoter sequences triggered a response.