Sprouty genes are essential for the normal development of epibranchial ganglia in the mouse embryo.
Bottom Line: Fibroblast growth factor (FGF) signalling has important roles in the development of the embryonic pharyngeal (branchial) arches, but its effects on innervation of the arches and associated structures have not been studied extensively.However, epithelial-specific gene deletion only results in defects in the facial nerve and not the glossopharyngeal and vagus nerves, suggesting that the facial nerve is most sensitive to perturbations in RTK signalling.Reducing the Fgf8 gene dosage only partially rescued defects in the glossopharyngeal nerve and was not sufficient to rescue facial nerve defects, suggesting that FGF8 is functionally redundant with other RTK ligands during facial nerve development.
Affiliation: Department of Craniofacial Development, King's College London, Floor 27, Guy's Tower, London, SE1 9RT, UK.Show MeSH
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Mentions: The mouse lines used in this study were maintained on a mixed genetic background and have been described previously: β-actin-cre (Lewandoski et al., 1997), Ap2αcre (Macatee et al., 2003), Sox17i-2A-iCre (Sox17icre) (Engert et al., 2009), Wnt1cre (Danielian et al., 1998), R26R (Soriano, 1999), Spry1tm1.1Jdli (Basson et al., 2005) and Spry2tm1.1Mrt (Shim et al., 2005). Mice carrying β-actin-cre were crossed with those carrying conditional Spry1flox and Spry2flox alleles to generate Spry1−and Spry2− alleles. Embryos lacking both genes (Spry1−/−;Spry2−/−) were produced by crossing βactinCre/βactinCre;Spry1+/−;Spry2+/− males with Spry1flox/flox;Spry2flox/flox females. For rescue experiments, βactinCre2;Spry1+/−;Spry2+/−;Fgf8+/− males were crossed with Spry1flox/flox;Spry2flox/flox females using the Fgf8tm1.2Mrt allele (Meyers et al., 1998). Tissue-specific mutants were produced by crossing Cre;Spry1flox/+;Spry2flox/+ males to Spry1flox/flox;Spry2flox/flox females. Tissue specific cre recombinase activity was confirmed using the R26R (Soriano, 1999) or RosaYFP (Srinivas et al., 2001) reporter mouse lines and in situ hybridisation for Spry1 or Spry2 (Suppl. Fig. 1).
Affiliation: Department of Craniofacial Development, King's College London, Floor 27, Guy's Tower, London, SE1 9RT, UK.