|RNAinfo:||Splicing signals||Genefinding||Splice site consensus|
|ESEs||Genome Annotation||Alternative Splicing||RNA links|
A list of selected documented microexons
is available. Very small exons, or microexons, pose special problems for
gene annotation. They are difficult to recognize using computational
genefinding methods, and can even confound the alignment of cDNA and
genomic sequences. Furthermore, because microexons are very often the
of alternative splicing, an understanding of how they are recognized
regulated) is key to understanding gene expression.
A conserved 9 nt. exon in invertase described by Simpson et al. 2000. Requirements for mini-exon inclusion in potato invertase mRNAs provides evidence for exon-scanning interactions in plants. RNA 6:422-433.
A 6 nt. exon in troponin T. Carlo et al. 2000 5' splice site-proximal enhancer binds SF1 and activates exon bridging of a microexon. Mol Cell Biol 20:3988-3995
The Drosophila melanogaster couch potato gene may have an exon of 1 nt.
The Drosophila melanogaster invected gene has an exon of 6 nt.
The Drosophila melanogaster fasciclin 1 gene has an exon of 9 nt. This microexon is flanked by an extended 3' splice site-like region devoid of AG dinucleotides (accession numbers AE003714, nt. 66,492-66,500; and M20545 nt. 1,141-1,149. This microexon also incorrectly annotated).
There is an alternatively spliced microexon of 3 nt. in the NCAM gene.
There is a conserved microexon in the troponin 1 gene that is 4 nt. in mammals and 7 nt. in birds.