Co-orthology of Pax4 and Pax6 to the fly eyeless gene: molecular phylogenetic, comparative genomic, and embryological analyses
one with the Pax4–Pax6 duplication early in vertebrate evolution and the other with this duplication before the bilaterian radiation. We then investigated gene compositions in the genomic regions containing Pax4 and Pax6, and identified
(1) conserved synteny between these two regions, suggesting that the Pax4–Pax6 split was caused by a large-scale duplication and (2) its timing within early vertebrate evolution based on the duplication timing of the members of neighboring gene families. Our results are consistent with the so-called
two-round genome duplications in early vertebrates. Overall, the Pax6/eyeless ortholog is merely part of a 2:2 orthology relationship between vertebrates (with Pax4 and Pax6) and the fly (with eyeless and toy). In this context, evolution of transcriptional regulation associated with the Pax4–Pax6 split is also discussed in light of the zebrafish pax4 expression pattern that is analyzed here for the first time.
- Evolutionary Biology
- ISSN: 1525-142X