Intron size in mammals: complexity comes to terms with economy.
Different and contrasting models have been proposed to explain intron size evolution in mammals. Here, we demonstrate that intron and intergenic size per se has no adaptive role in gene expression regulation but reflects the need to preserve conserved intronic elements. Although the amount of non-coding functional elements explains the within-genome size variation of intergenic spacers, we show that an additional, additive pressure has been acting on highly expressed introns to reduce the cost of their transcription.
Pozzoli
Uberto
U
Bioinformatic Laboratory, Scientific Institute IRCCS E. Medea, Via don L. Monza 20, 23842 Bosisio Parini (LC), Italy.
Menozzi
Giorgia
G
Comi
Giacomo P
GP
Cagliani
Rachele
R
Bresolin
Nereo
N
Sironi
Manuela
M
D000818:Animals; D017124:Conserved Sequence / Q000235:genetics; D019143:Evolution, Molecular; D005786:Gene Expression Regulation / Q000235:genetics; D006801:Humans; D007438:Introns / Q000235:genetics*; D008322:Mammals / Q000235:genetics*; D008957:Models, Genetic; D012641:Selection, Genetic; D013045:Species Specificity