Cloning and developmental expression patterns of Dlx2, Lhx7 and Lhx9 in the medaka fish (Oryzias latipes)

We have isolated three homeodomain and LIM-homeodomain developmental transcription factors from the medaka fish (Oryzias latipes): OlDlx2, OlLhx7, and OlLhx9, and we have studied their expression patterns in the developing and adult brain. This analysis showed that OlDlx2 and OlLhx7 (together with OlNkx2.1b) delineate the subpallial divisions of the medaka telencephalon, and that OlLhx9 exhibits a typical and specific topology of expression in the pallium and diencephalic neuromeres. The expression patterns of these three genes, when compared in details with those of their tetrapod homologs, reveal both commonalities and differences in the basic organization of the developing teleost and vertebrate forebrain.