exon

¹

[ ek-son ]

noun

1. (in Britain) one of four yeomen of the guard who act as commanding officers in the absence of higher authority.

exon

²

[ ek-son ]

noun

, Genetics.

1. any portion of an interrupted gene that is represented in the RNA product and is translated into protein.

exon

¹

/ ˈɛksɒn /

noun

1. one of the four officers who command the Yeomen of the Guard

exon

²

/ ˈɛksɒn /

noun

1. any segment of a discontinuous gene the segments of which are separated by introns Compare intron

exon

/ ĕk′sŏn /

1. A segment of a gene that contains information used in coding for protein synthesis. Genetic information within genes is discontinuous, split among the exons that encode for messenger RNA and absent from the DNA sequences in between, which are called introns . Genetic splicing, catalyzed by enzymes, results in the final version of messenger RNA, which contains only genetic information from the exons.
2. Compare intron

exon

1. Stretches of DNA in genes that code for proteins . In eukaryotes , exons in a given gene are generally separated from each other by stretches of DNA that do not contain instructions for constructing proteins. ( Compare intron .)

Derived Forms

• exˈonic, adjective

Word History and Origins

Origin of exon¹

1645–55; earlier exant, for French exempt (spelling altered to show French pronunciation)

Origin of exon²

1975–80; ex(pressed sequence) + -on ¹

Word History and Origins

Origin of exon¹

C17: a pronunciation spelling of French exempt exempt

Origin of exon²

C20: from ex- ¹+ -on

Example Sentences

The researchers found COL11A1 and the other targets by comprehensively analyzing the subparts of genes called exons.

From Science Daily

The active splicing factor splices out the inhibitory exon in the transcription factor, which turns on the genes that produce collagen.

From Science Daily

Further, the genomes of vertebrate animals evolved to feature alternative splicing, in which a single gene can code for more than one protein by leaving out or adding exon sequences.

From Science Daily

Those characteristics include the same number of exons, which encode the protein, and phases of introns, which act as interrupters to stop or start splicing of the RNA molecules transcribed from the gene.

From Science Daily

Before being turned into proteins, genes are transcribed into introns, or strands of RNA that do not code for proteins, and exons that code for proteins.

From Science Daily