Pattern formation in the Drosophila eye

Abstract

The insect compound eye is one of the most precise and highly ordered patterns in the living world. It develops from an unpatterned simple epithelium by a series of cell fate decisions and complex morphogenetic movements. In the first days of metamorphosis, this interplay is particularly noticeable. Recent insights have revealed how interactions between neighboring cells drive the process. Interaction between Delta on cone cells and Notch proteins on the surface of neighbors induces the first pigment cells to differentiate. The primary pigment cells then express a Nephrin protein, Hibris, that interacts with a different Nephrin, Roughest, on their neighbors. Heterophilic adhesion between Hibris and Roughest result in remodeling contacts between cells to favour their contact with the pigment cells. In conjunction, the primary pigment cells signal to neighbors through the EGF Receptor to survive rather than undergo apoptosis. This sorting and culling process results in a sculpted pattern with a precise number and position of cells that is repeated hundreds of times in each compound eye.

FuRMAS: triggering myoblast fusion in Drosophila

“…5). In addition, fusion-relevant proteins also participate in a number of other developmental processes such as muscle attachment (Schröter et al, 2004;Schä fer et al, 2007), sarcomere assembly (e.g., Kreisköther et al, 2006) and visceral fusion (Klapper et al, 2001(Klapper et al, , 2002San Martin and Bate, 2001), Malpighian tubule organization (Denholm et al, 2003;Pü tz et al, 2005), garland cell development (Weavers et al, 2009), as well as eye development (e.g., Carthew, 2007;Fischbach et al, 2009). Thus, because of the multifunctional roles of fusion-relevant proteins, care should be taken when interpreting biochemical protein interaction assays, and the findings need to be correlated to the particular biological function.…”

A Screen for Modifiers of Notch Signaling Uncovers Amun, a Protein With a Critical Role in Sensory Organ Development

“…In the developing eye, Notch signaling first promotes formation of a single R8 photoreceptor cell within a group of equivalent proneural cells and then prevents neighboring cells from adopting the R8 fate, thereby restricting the number of R8 photoreceptors to one per ommatidium (Baker and Yu 1997;Baker 2000;Lee et al 2000). Notch signaling is subsequently required for differential specification of the R3/R4 photoreceptor fates (Del Alamo and Mlodzik 2006) and for induction of the R7 photoreceptor, cone cell, and primary pigment cell fates (Cooper and Bray 2000;Tomlinson and Struhl 2001;Tsuda et al 2002;Carthew 2007;Nagaraj and Banerjee 2007).…”

Rheb in neuronal degeneration, regeneration, and connectivity

“…The Drosophila eye is composed of a pattern of eight photoreceptors (R1-R8) called ommatidia and has been used for detailed analysis of spatial aspects of differentiation (Carthew, 2007;Morante et al, 2007). Upon loss of TSC1, the photoreceptors 1, 6, and 7 and non-neuronal cone cells differentiate prematurely.…”