Dynamic actin-based epithelial adhesion and cell matching during Drosophila dorsal closure

Abstract

Dynamic, actin-based protrusions (filopodia and lamellae) are critical, both in the mechanics of epithelial adhesion during dorsal closure and in the correct 'matching' of opposing cells along the fusion seam.

Localization and requirement for Myosin II at the dorsal‐ventral compartment boundary of the Drosophila wing

“…These suggestions build on prior studies of Myosin II function in other developmental contexts. Morphologically, several features of the D-V compartment boundary are reminiscent of the leading edge in Drosophila embryos undergoing dorsal closure (Martin and Lewis, 1992;Bement et al, 1993;Young et al, 1993;Jacinto et al, 2000Jacinto et al, , 2002Kiehart et al, 2000;Franke et al, 2005). In both cases, the interface between cell populations is characterized by a prominent F-actin cable, and over-lapping, but discontinuous, localization of Myosin II.…”

“…While Myosin II and F-actin are generally present at the adherens junctions of epithelial cells, a number of developmental contexts in which their accumulation is polarized have been described. One of the best studied is that of dorsal closure, a morphogenetic process in the Drosophila embryo in which the dorsal-lateral epidermal cells move dorsally and fuse to seal the embryo at the dorsal midline (Martin and Lewis, 1992;Bement et al, 1993;Young et al, 1993;Jacinto et al, 2000Jacinto et al, , 2002Kiehart et al, 2000;Franke et al, 2005). Actin and myosin activity are required for dorsal closure, and mutations that disrupt their function can result in an irregular dorsal edge.…”

Amnioserosa is required for dorsal closure in Drosophila

“…Three signaling cascades have recognized leading edge epidermal roles in dorsal closure (for review see Jacinto et al, 2000). It is clear that the two we have studied here, the DJNK and Dpp signaling cascades, play central roles in closure as mutations in genes encoding components of either of these pathways severely disrupt the process.…”

“…Some additional insight into this important question might be drawn from phenotypic comparisons as shared loss-of-function phenotypes point to sequential function in single molecular pathways (Nusslein-Volhard and Wieschaus, 1980). In this regard, cuticles derived from animals harboring mutations in Dpp signaling components exhibit centrally positioned dorsal holes in contrast to those derived from animals harboring mutations in DJNK signaling components, which exhibit dorsal holes that span central and anterior domains (for review, see Jacinto et al, 2000). Our demonstration that cuticles generated by amnioserosal ablation and by mutations in Dpp pathway components (both tkv and punt) are strikingly similar, in combination with our molecular data showing DJNK signaling to be unaffected after amnioserosal ablation, points to an amnioserosal function in the process of dorsal closure that is downstream of Dpp.…”

Apical and lateral cell protrusions interconnect epithelial cells in live Drosophila wing imaginal discs

“…Important cellular processes involve cell protrusions, including nutrient resorption (Louvard et al, 1992), mechanosensing (Frolenkov et al, 2004), photosensing (Corbeil et al, 2001;Pellikka et al, 2002), establishment of cell adhesion (Vasioukhin et al, 2000), cell migration (Fulga and Rorth, 2002), fusion of epithelial sheets (Jacinto et al, 2000;MartinBlanco et al, 2000), wound healing (Wood et al, 2002), axon guidance (Ritzenthaler et al, 2000), and cell-tocell communication (reviewed in Rorth, 2003). Intercellular communication is important for the growth and patterning of tissues and organs and cell protrusions may mediate this communication by one of several mechanisms.…”