GPx gene structures of Arabidopsis thaliana (At), Selaginella moellendorffii (Sm), Physcomitrella patens (Pp) and Chlamydomonas reinhardtii (Cr). Expressed GPx genes are shown in green, putatively non-expressed in blue. The vertical lines connect corresponding splice sites. The numbers represent position of corresponding amino acids in the alignment shown in Fig. 14A and the relative splice sites within the corresponding codon.