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Exon

1892

Refers to any part of a gene that will become a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing.

An exon is the portion of a gene that codes for amino acids.

Most gene sequences are broken up by one or more DNA sequences called introns.

The parts of the gene sequence that are expressed in the protein are called exons, because they are expressed, while the parts of the gene sequence that are not expressed in the protein are called introns, because they come in between–or interfere with–the exons.

Exons are that part of the RNA that code for proteins.

The important parts of that RNA are the exons.

Introns get excised out of the RNA to leave a string of exons together that will eventually code for the amino acids.

Refers to both the DNA sequence within a gene and to the corresponding sequence in RNA transcripts.

In RNA splicing, introns are removed and exons are covalently joined to one another as part of generating the mature messenger RNA.

In the human genome only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA.

Across all eukaryotic genes there are on average, 5.48 exons per gene.

The average exon encodes 30-36 amino acids.

The longest exon in the human genome is 11555 bp long, several exons have been found to be only 2 bp long.

In protein-coding genes, the open reading frame (ORF) that codes for a specific portion of the complete protein are located in the exons.

The term exon is often misused to refer only to coding sequences for the final protein, since many noncoding exons are known in human genes.

Exons can include sequences that code for amino acids and untranslated sequences.

Stretches of unused sequence, introns, are removed, and the exons are joined together to form the final functional mRNA.

The notation 5′ and 3′ refer to the direction of the DNA template in the chromosome and is used to distinguish between the two untranslated regions.

Some of the exons will be wholly or part of the 5′ untranslated region (5′ UTR) or the 3′ untranslated region (3′ UTR) of each transcript.

The untranslated regions are important for efficient translation of the transcript and for controlling the rate of translation and half-life of the transcript.

Transcripts made from the same gene may not have the same exon structure, since parts of the mRNA could be removed by the process of alternative splicing.

Some mRNA transcripts have exons with no open reading frames and, thus, are sometimes ref2242ed to as non-coding RNA.

Exonization is the creation of a new exon, as a result of mutations in intronic sequences.

Exon trapping or gene trapping is a molecular biology technique that exploits the existence of the intron-exon splicing to find new genes.

The first exon of a ‘trapped’ gene splices into the exon that is contained in the insertional DNA.

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