Distal-less encodes a homoeodomain protein required for limb development in Drosophila

Abstract

The spatial organization of the Drosophila embryo depends on the activity of three axial pattern-forming systems. In addition to the anterior-posterior and dorsal-ventral systems that organize the segmented body plan, a proximal-distal pattern-forming system is required to provide positional information for the developing limbs. The development of both the larval and adult limbs depends directly on the activity of the Distal-less gene. Genetic analysis has shown that Distal-less functions as a developmental switch that is required to promote the development of limb structures above the evolutionary ground-state of body wall. Here we provide genetic evidence that indicates a graded requirement for Distal-less activity during limb development. Reduction of this activity has a global effect on pattern formation in the limb. The molecular structure of the Distal-less locus indicates that the gene encodes a homoeodomain-containing protein which is therefore likely to specify limb development through differential regulation of subordinate genes.

The function of appendage patterning genes in mandible development of the sexually dimorphic stag beetle

“…A homeodomain transcription factor Dll plays significant roles in establishing the identity of distal regions in appendages during embryonic and post-embryonic development across the insects (Cohen et al 1989, Panganiban et al 1994, Cohen et al 1989, Popadic et al 1998, Scholtz et al 1998, Kojima 2004). …”

Jaw transformation with gain of symmetry after Dlx5/Dlx6 inactivation: Mirror of the past?

“…In insects, Distal-less (Dll) is required for correct morphogenesis of the distal portion of the legs, antennae, and mouth parts (Cohen et al, 1989;O'Hara et al, 1993). Based on sequencing comparison, it is thought that during the evolution of chordates an initial gene duplication occurred, followed by several cluster duplications and selective gene losses (Stock et al, 1996;Ruddle, 1997;Zerucha and Ekker, 2000).…”

Genetic interactions underlying otic placode induction and formation

“…Mutational analyses in mice have demonstrated functional redundancy among Pax genes (Borycki et al, 1999), so it is possible that genetic redundancy conceals earlier roles for Pax8 and Pax2 in single mutants. Zebrafish dlx3b and dlx4b (dlx3b/ 4b), transcription factors with homeobox domains similar to Drosophila distal-less (Cohen et al, 1989), are expressed around the border of the neural plate during mid-to-late gastrulation, corresponding with the presumptive domain of preplacodal competence Akimenko et al, 1994;Ellies et al, 1997). Expression becomes progressively restricted and up-regulated in the otic and olfactory primordia during early somitogenesis.…”