TY  - JOUR
A1  - Fedorov, Alexei
A1  - Roy, Scott
A1  - Cao, Xiaohong
A1  - Gilbert, Walter
T1  - Phylogenetically Older Introns Strongly Correlate With Module Boundaries in Ancient Proteins
Y1  - 2003/06/01 
JF  - Genome Research 
JO  - Genome Research 
SP  - 1155 
EP  - 1157 
DO  - 10.1101/gr.1008203 
VL  - 13 
IS  - 6a 
UR  - http://genome.cshlp.org/content/13/6a/1155.abstract 
N2  - The hypothesis that some (but not all) introns were used to construct  ancient genes by exon shuffling of modules at the earliest stages of evolution  is supported by the finding of an excess of phase-zero intron positions in the  boundary regions of such modules in 276 ancient proteins (defined as common to  eukaryotes and prokaryotes). Here we show further that as phase-zero intron  positions are shared by distant taxa, and thus are truly phylogenetically  ancient, their excess in the boundaries becomes greater, rising to an 80%  excess if shared by four out of the five taxa: vertebrates, invertebrates,  fungi, plants, and protists. 
ER  -