The mechanism of Drosophila leg development along the proximodistal axis

Abstract

During development of higher organisms, most patterning events occur in growing tissues. Thus, unraveling the mechanism of how growing tissues are patterned into final morphologies has been an essential subject of developmental biology. Limb or appendage development in both vertebrates and invertebrates has attracted great attention from many researchers for a long time, because they involve almost all developmental processes required for tissue patterning, such as generation of the positional information by morphogen, subdivision of the tissue into distinct parts according to the positional information, localized cell growth and proliferation, and control of adhesivity, movement and shape changes of cells. The Drosophila leg development is a good model system, upon which a substantial amount of knowledge has been accumulated. In this review, the current understanding of the mechanism of Drosophila leg development is described.

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

“…Analysis of imaginal disc patterning in Drosophila has led to the identification of three main regions of the limb disc, with corresponding suites of genes that regulate each region: proximal (closest to the body wall), medial (the middle of the appendage), and distal (the farthest from the body wall; Kojima 2004, Angelini & Kaufman 2005. The developmental patterning of this proximal-distal axis in insect appendages is highly conserved and regulated by many genes (Kojima 2004, Angelini & Kaufman 2005.…”

“…Analysis of imaginal disc patterning in Drosophila has led to the identification of three main regions of the limb disc, with corresponding suites of genes that regulate each region: proximal (closest to the body wall), medial (the middle of the appendage), and distal (the farthest from the body wall; Kojima 2004, Angelini & Kaufman 2005. The developmental patterning of this proximal-distal axis in insect appendages is highly conserved and regulated by many genes (Kojima 2004, Angelini & Kaufman 2005. Based on previous studies of appendage morphogenesis in Drosophila and Tribolium (Lecuit & Cohen 1997, Kojima 2004, Angelini et al 2009, Angelini et al 2012, we focused on seven of these appendage-patterning genes, Distal-less (Dll), aristaless (al), Epidermal growth factor receptor (Egfr), Keren (Krn), dachshund (dac), homothorax (hth) and escargot (esg), as likely candidates for the regulation of mandible growth.…”

“…The developmental patterning of this proximal-distal axis in insect appendages is highly conserved and regulated by many genes (Kojima 2004, Angelini & Kaufman 2005. Based on previous studies of appendage morphogenesis in Drosophila and Tribolium (Lecuit & Cohen 1997, Kojima 2004, Angelini et al 2009, Angelini et al 2012, we focused on seven of these appendage-patterning genes, Distal-less (Dll), aristaless (al), Epidermal growth factor receptor (Egfr), Keren (Krn), dachshund (dac), homothorax (hth) and escargot (esg), as likely candidates for the regulation of mandible growth.…”

“…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). …”

“…A transcriptional regulator dachshund (dac) is also an important appendage patterning gene which provides positional cues for cells in the developing appendage in a diversity of insect species including Drosophila, Tribolium, and Onthophagus (Mardon et al 1994, Abzhanov & Kaufman 2000, Prpic et al 2001, Kojima 2004, Moczek & Rose 2009, as well as crustacean species (Sewell et al 2008). Mutation or experimental silencing of dac leads to the loss or reduction of medial regions in the antenna and leg in Drosophila, Tribolium, and Onthophagus (Mardon et al 1994, Angelini et al 2009, Moczek & Rose 2009.…”