INACTIVATION OF THE ZEBRAFISH HOMOLOG OF CHX10 BY ANTISENSE OLIGONUCLEOTIDES CAUSES EYE MALFORMATIONS SIMILAR TO THE OCULAR RETARDATION PHENOTYPE

We report the cloning of a zebrafish paired-type homeobox gene, Air, c losely related to the murine Chx10 and the gold fish Vsx-1 homeodomain proteins. Air is first expressed at about 12 h post-fertilization (hp f) when optic vesicles appear. Its expression is restricted to the ear ly retinal neuroepithelium, whereas no signal can be detected in the o ptic placode. Later, Alx expression follows the differentiation of the neural retina. Inhibition experiments with antisense oligonucleotides resulted in specific eye malformations which are reminiscent of the p henotype of ocular retardation (or) mice, caused by a spontaneous Chx1 0 mutation. The expression of other developmentally relevant genes suc h as pax(zf-a), pax(zf-b) and krx-20 was not affected in the antisense treated embryos. (C) 1997 Elsevier Science Ireland Ltd.