Cover image

Cover The Drosophila developmental patterning gene, homothorax (hth), encodes two alternatively spliced types of protein isoforms: one that contains a DNA-binding homeodomain, and one that does not. Shown here is an immunofluorescence analysis of a leg imaginal disc with mitotic clones expressing a strongly hypomorphic allele ofhth, as marked by the absence of GFP (green). Loss of all Hth isoforms results in the derepression of dachsund (dac, red), a medial cell fate marker, and the loss of teashirt (tsh, blue), which defines the proximal domain. In contrast, mitotic clones expressing only homeodomain-less isoforms of Hth have a normal pattern of tsh and dac expression, suggesting that the homeodomain is not required for these Hth functions. (For details, see Noro et al., p. 1636.)