Ancestral nuclear genes were probably multi-intronic genes

The exon/intron organisation of homologous nuclear genes like YFL037w/TUB2 was compared in several yeast species.

CLUSTALX multiple alignments were performed to help these comparisons and the reconstruction of a virtual (scaffold) YFL037w gene, exhibiting the probable ancestral intron arrangement. Intron position was defined at the nucleotide level making it possible to determine whether the intron is at an identical position (same codon and same phase) or not in homologous YFL037w genes.

The genomic DNA sequence analysis and the CLUSTAL multiple alignments brought evidences that, like the ancestral YFL037w gene, most ancestral yeast nuclear genes probably contained numerous introns scattered all along the length of ORFs [Bon et al., 2003].

CLUSTALX multiple alignment of TUB2 homologues

Orthologous intron positions

Last modified: Tue Feb 10 11:11:14 CET 2004