spliceosome

Spliceosomal intron numbers and boundary sequences vary dramatically in eukaryotes.

There is a striking correspondence between low intron number and strong sequence conservation of 5’ splice sites (5’ss) across eukaryotic genomes. (17442445)

The phylogenetic pattern suggests that ancestral 5’ss were relatively weakly conserved, but that some lineages independently underwent both major intron loss and 5’ss strengthening. (17442445)

Eukaryotic ancestors had relatively large intron numbers and ’weak’ 5’ss, a pattern associated with frequent alternative splicing in modern organisms. (17442445)

References

 Spliceosome mutations in hematopoietic malignancies. Hahn CN, Scott HS. Nat Genet. 2011 Dec 27;44(1):9-10. PMID: 22200771

 Irimia M, Penny D, Roy SW. Coevolution of genomic intron number and splice sites. Trends Genet. 2007 Apr 17; PMID: 17442445

 Roy SW, Gilbert W. The evolution of spliceosomal introns: patterns, puzzles and progress. Nat Rev Genet. 2006 Mar;7(3):211-21. PMID: 16485020

 Mansfield SG, Chao H, Walsh CE. RNA repair using spliceosome-mediated RNA trans-splicing. Trends Mol Med. 2004 Jun;10(6):263-8. PMID: 15177190

 Meister G, Eggert C, Fischer U. SMN-mediated assembly of RNPs : a complex story. Trends Cell Biol. 2002 Oct ;12(10):472-8. PMID : 12441251