FGF control of E-cadherin targeting in the Drosophila midgut impacts on primordial germ cell motility

Abstract

Embryo formation requires tight regulation and coordination of adhesion in multiple cell types. By undertaking imaging, threedimensional (3D) reconstructions and genetic analysis during posterior midgut morphogenesis in Drosophila, we find a new requirement for the conserved fibroblast growth factor (FGF) signaling pathway in the maintenance of epithelial cell adhesion through FGF modulation of zygotic E-cadherin. During Drosophila gastrulation, primordial germ cells (PGCs) are transported with the posterior midgut while it undergoes dynamic cell shape changes. In embryos mutant for the FGF signaling pathway components Branchless and Breathless, zygotic E-cadherin is not targeted to adherens junctions, causing midgut pocket collapse, which impacts on PGC movement. We find that the ventral midline also requires FGF signaling to maintain cell-cell adhesion. We show that FGF signaling regulates the distribution of zygotic E-cadherin during early embryonic development to maintain cell-cell adhesion in the posterior midgut and the ventral midline, a role that is likely crucial in other tissues undergoing active cell shape changes with higher adhesive needs.

The vascular niche controlsDrosophilahematopoiesis via Fibroblast Growth Factor signaling

“…3h-m). We then performed rescue experiments with a constitutively active form of Btl ( btl CA , (Pares and Ricardo, 2016)). The expression of btl CA in progenitors ( dome>btl CA ) led to reduced crystal cell numbers, i.e., a phenotype opposite to that of btl loss-of-function (Fig.…”

“…The handΔ-gal4 is expressed in all cardiac cells, whereas the NP1029- gal4 is expressed in all cardiac cells except those that are expressing seven-up (Monier et al, 2005). Strains used are BcGFP (Tokusumi et al, 2009), bnl P2 (Sutherland et al, 1996), hhF4-GFP (Tokusumi et al, 2010), domeMESO-LacZ (Krzemien et al, 2007), domeMESO-Gal4 (Louradour et al, 2017), UAS-Bnl::GFP (Lin and Affolter, 2009), UAS-btl CA on II or III (Pares and Ricardo, 2016), UAS-Bnl (Jarecki et al, 1999). Ubiquitin-rab11cherryFP (Y. Bellaiche), bnl:GFP endo and btl:cherry endo knock-in alleles (Du et al, 2018).…”

Domain-specific control of germ cell polarity and migration by multifunction Tre1 GPCR

“…Their subsequent delamination creates openings through which germ cells cross the primordium ( Fig. 2, A and A′; Campos-Ortega and Hartenstein, 1985 ; Seifert and Lehmann, 2012 ; Parés and Ricardo, 2016 ). In both mutants, germ cells exit the midgut primordium later than their wild-type counterpart and follow abnormal migration patterns ( Fig.…”

“…We do not know how the NPIIY domain is regulated. One intriguing possibility is that reorganization of E-cadherin in the underlying midgut epithelium may provide a cue for germ cell polarization ( Parés and Ricardo, 2016 ).…”

Gonad Ontogeny and Sex Differentiation in a Poeciliid, Gambusia holbrooki: Transition from a Bi- to a Mono-Lobed Organ

“…In vertebrates, gonadogenesis typically commences at late segmentation/early pharyngula stage, marked by homing of PGCs at the gonadal ridge [1][2][3][4]. Mechanistically, this is orchestrated by a combination of chemotaxis cues [5][6][7], topology of the somatic environment [8,9] and tuning of cell-cell adhesion [10,11], resulting in PGC colonisation and their compaction at the gonad primordia. Following this, gonadosoma cells emerge at the presumptive gonad, skirt the colonised PGCs and promote sexual differentiation in sync with the genotype of the germline.…”