splice sites
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
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#