Comparison of the predicted amino acid sequences
of CO proteins. PnCO, P. nil, (accession no. AF300700);
AtCO, Arabidopsis CO1 (accession no. A56133); and BnCO, oilseed rape
COa1, (accession no. AF016009). Regularly spaced Cys residues of a
putative Zn finger are indicated with asterisks. A putative bipartite
nuclear localization signal is indicated with plus signs. The site
where the intron is inserted in the corresponding nucleotide
sequence is marked with ▾. The annealing sites for primers TN178
(upstream) and TN179 (downstream) are indicated with solid lines above
the corresponding amino acid sequences. The alignment was performed
with the CLUSTAL W program (Thompson et al., 1994).