Introns: Movements


Introns can be lost, gained or displaced more or less frequently in evolution and in a lineage‐specific manner. These movements, leading to major mutations in eukaryotic genes and genomes, can happen at the deoxyribonucleic acid (DNA) level or involve ribonucleic acid (RNA) intermediates.

Keywords: sliding; slippage; insertion; deletion; intron mobility

Figure 1.

Intron sliding. White rectangles represents introns and shaded ones exons. The four triangles represent mutually compensating insertions and deletions (triangles that point towards and away from the gene respectively).

Figure 2.

The processes cDNA‐mediated intron loss (right) and intron slippage by reverse splicing (left).

Figure 3.

Intron sliding or slippage in the rat cholesterol esterase gene. The lower case letters stand for intron sequences; the upper case letters for exon sequences. Only partial sequences are shown. The single nucleotide insertion (T) and deletion (‐) preceding the rat intron are shown in bold. (Reproduced from Rogozin et al., .)

Figure 4.

Shuffling of symmetrical exons by illegitimate intronic recombination leading to modular multidomain proteins. Illegitimate intronic recombination between alleles may lead to tandem duplication of symmetrical exons.



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Further Reading

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How to Cite close
Long, Manyuan, and Cerff, Rüdiger(Jul 2006) Introns: Movements. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0005082]