intron Genetics.
(ˈɪntrɒn)
[f. intr(agenic adj. s.v. intra- + -on1: see quot. 1978.]
A segment of an RNA molecule which is excised during or soon after its transcription from DNA and takes no part in forming the eventual gene; a segment of a DNA molecule which codes for this. Cf. exon2.
| 1978, etc. [see exon2]. 1980 Sci. Amer. Sept. 87/3 A similar explanation could account for introns, the noncoding sequences that interrupt coding sequences in many eukaryotic genes. 1980 Amer. Jrnl. Trop. Med. & Hygiene XXIX. 1034/1 These results show that VSG genes are not riddled with introns. 1981 [see exonic a.]. 1982 P. N. Gray in T. M. Devlin Textbk. Biochem. xviii. 910 The nucleotide sequences of the intron–exon borders have some similarities that appear to be common for several species. Introns in RNA generally begin with..pGpU..and end with..pApG. 1985 B. Lewin Genes (ed. 2) xx. 362 Many of the long introns in these genes have open reading frames in register with the preceding exon; at least in some cases, there is evidence for translation of the intron. |
Hence inˈtronic a.
| 1978 Nature 9 Feb. 501/1 The gene is a mosaic: expressed sequences held in a matrix of silent DNA, an intronic matrix. 1980 Ann. N.Y. Acad. Sci. CCCXLIII. 430 The middle of the hybridized strand..was looped out, presumably because the intronic sequence was spliced out from the mRNA. 1985 Science 20 Sept. 1264/3 The abundance of this repeat in nuclear RNA of the rat and mouse is roughly proportional to the copy number of the sequence in the respective genomes. This is consistent with the notion of random intronic distribution and transcription of this repeat. |