Expression analysis of the peroxiredoxin gene family during early development in Xenopus laevis

Development in the frog, Xenopus laevis, requires the utilization of yolk glyco-lipo-proteins in a temporally- and spatially-dependent manner. The metabolism of the yolk produces hydrogen peroxide (H(2)O(2)), a potent reactive oxygen species (ROS). Peroxiredoxins (prdxs) are a family of six anti-oxidant enzymes that, amongst other roles, reduce H(2)O(2). Prdxs reduce H(2)O(2) through a thiol-redox reaction at conserved cysteine residues which results in the creation of disulfide bonds. Recently the thiol-redox reaction of Prdxs has also been implicated in several cell signaling systems. Here we report the cloning and expression patterns during development of six peroxiredoxin homologs from the frog X. laevis. Sequence analysis confirmed their identity as well as their evolutionary relationship with peroxiredoxins from several other species. Using RT-PCR and in situ hybridization analysis we have shown that there is early and robust expression of all six homologs during development. All six X. laevis peroxiredoxins are expressed in neural regions including the brain, eyes, as well as the somites. Different expression patterns for each peroxiredoxin are also observed in the pronephric region, including the proximal and distal tubules. Expression of several peroxiredoxins was also observed in the blood precursors and the olfactory placode. These results suggest important roles for all six peroxiredoxins during early development. These roles may be restricted to their functions as anti-oxidant enzymes, but may also be related to their emerging roles in redox signaling.