Mouse Dach, a homologue of Drosophila dachshund, is expressed in the developing retina, brain and limbs

The Drosophila genes eyeless, eyes absent sine oculis, and dachshund cooper ate as key regulators of retinal cell-fate determination. Homologues of eye less (Pax6), eyes absent (Eyal-2), and sine oculis (Six3) have been identif ied and are expressed in the developing vertebrate eye. We have cloned and characterized the structure and expression of mouse Dach, a homologue of Dr osophila dachshund. Sequence analysis reveals the presence of two motifs, D D1 and DD2, which may be involved in the function of Dach/Dacbshund as gene regulatory factors. In addition, DD1 shares sequence similarity to N-termi nal sequences of Ski and SnoN, which are involved in cellular transformatio n and differentiation. Mouse and human Dach/DACH were localized to chromoso me 14E1 and 13q21.3-22, respectively, by fluorescence in situ hybridization . Finally, in situ hybridization analysis demonstrated that Dach is express ed in similar tissues to those observed in Drosophila, including the embryo nic nervous system, sensory organs, and limbs. The finding of Dach expressi on in the eye completes the list of vertebrate homologues of eyeless, eyes absent, sine oculis, and dachshund which as a group may function to control cell-fate determination in the vertebrate eye.