intronnucleotide sequences in nuclear
RNA that are eliminated during the formation of m
RNA; also called intervening
sequences
Source: Jenkins, John B. 1990.
Human Genetics, 2nd Edition. New York: Harper & Row ...
Full article >>>Intron RNA may have a large
variety of interlocking regulatory functions not yet explored, including a role in
gene silencing phenomena.
Full article >>>Introns are
transcribed as part of the normal
gene primary transcript, but
intron sequences are not found in the functional m
RNA.
Intron sequences are removed from the
primary transcript by a
splicing mechanism.
Full article >>>Intron evolutionThere are two competing theories as to the
evolutionary
origin of
introns, which is usually studied in a highly conserved
family of genes such as the
actins.
Full article >>>Dr. Jennifer Puck, of the National
Human Genome Research Institute's
Genetics and
Molecular Biology Branch, defines
intron.
illustrated:
View illustration ...
Full article >>>IntronThe
DNA base sequence interrupting the
protein-
coding sequences of a
gene;
intron sequences are
transcribed into
RNA but are cut out of the
message before it is
translated into
protein.
Full article >>>Intron DNA sequence that interrupts the
protein-
coding sequence of a
gene; an
intron is
transcribed into
RNA but is cut out of the
message before it is
translated into
protein.
See also:
exon ...
Full article >>>intron In
eukaryotes,
bases of a
gene transcribed but later excised from the m
RNA prior to exporting from the
nucleus and subsequent
translation of the
message into a
polypeptide. PICTURE ...
Full article >>>Intron A
sequence of a
gene which is
transcribed but which is excised by a
splicing re
action before the mature m
RNA is
translated. Found in Eukarya, Archae,
Bacteria, eukaryotic
viruses, and
phage.
Full article >>>intronA noncoding, intervening
sequence within a eukaryotic
gene.
invagination ...
Full article >>>intron An intervening or noncoding
segment of a
gene;
introns separate
exons.
introvert A tubular, eversible extension of the head, bearing the
mouth at its tip.
invagination An infolding of a layer of
tissue to form a sac-like structure.
Full article >>>intron - "intervening
sequence," a stretch of
nucleic acid sequence spliced out from the primary
RNA transcript before the
RNA is
transported to the
cytoplasm as a mature m
RNA; ...
Full article >>>INTRON - Intervening
sequences in eukaryotic genes which do not encode
protein but which are
transcribed into
RNA. Removed from
pre-mRNA during nuclear
splicing reactions.
Full article >>>Introns are
sequences of
DNA that interrupt a
gene, but do not
code for anything. The coding portions of a
gene are called
exons.
Full article >>>Intron:
Introns are portions of
genomic DNA which are
transcribed (and thus present in the
primary transcript) but which are later spliced out. They thus are not present in the mature m
RNA.
Full article >>>:
Introns end with the di
nucleotide ApG
[3' splice
site / acceptor] and start with the di
nucleotide GpT
[5' splice
site / donor].
Full article >>>The
introns in most
pre-mRNAs begin with a GU and end with an AG. Presumably these short
sequences assist in guiding the
spliceosome.
Visual Evidence ...
Full article >>>Making
Intron-Free
DNA:
The
DNA of
eukaryotes is extremely
long, containing many thousands of genes. It is often not possible to find specific genes in the
DNA. Artificial genes can be made, however, using m
RNA.
Full article >>>Spliceosomal
introns often reside in eukaryotic
protein-coding genes. Within the
intron, a 3' splice
site, 5' splice
site, and branch
site are required for
splicing.
Full article >>>Intron. A noncoding
DNA sequence within a
gene that is initially
transcribed into
messenger RNA but is later snipped out. See Coding,
DNA,
Messenger RNA,
Transcription. Invasiveness.
Full article >>>Most known
snRNAs have a role in the
splicing reactions that remove
introns from m
RNA, t
RNA, and r
RNA molecules. SNDA Supplemental New Drug Application.
somatic cells Body
cells. All the
cells except the germ-line
cells.
Full article >>>The situation is more complicated for eukaryotic genes, which often contain one or more noncoding regions (
introns). To find ORFs in these genes, the
introns are removed in a process called
splicing (Fig. 3).
Full article >>>Introns Sequences of non-coding
bases found in eukaryotic genes. They may make up a large proportion of the total
gene length.
Introns are spliced out of the
RNA transcript during its
processing to m
RNA.
kbp
kilobase pairs.
Full article >>>Moreover, the genes are often fragmented internally by non-
coding sequences called
introns, which can be many times longer than the genes themselves.
Introns are removed on the heels of
transcription by
splicing.
Full article >>>Mature transcript of
RNA splicing which removes
introns and joins
exons in the
primary transcript. m
RNA usually has a 5' UTR, 3' UTR and polyA.
Related
3' UTR 5' UTR
Mature transcript Primary transcript Splicing cis-
splicing polyA
trans-splicing ...
Full article >>>RNA splicing -
RNA-
processing step in which all of the
intron sequences are removed and
exon sequences are kept therebv producing a much shorter
RNA molecule.
second law of thermodynamics - the degree of dis
order in the universe can only increase ...
Full article >>>Introns -- a
segment of
DNA (between
exons) that is
transcribed into nuclear
RNA, but are removed in the subsequent
processing into m
RNA.
Full article >>>FRDA is caused by an expanded GAA repeat in
intron 1 of the X25
gene encoding a
protein called frataxin. Frataxin is widely
expressed and is a
mitochondrial
protein, although its function is unknown.
Full article >>>'"/>