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Sprouty genes are essential for the normal development of epibranchial ganglia in the mouse embryo.

Simrick S, Lickert H, Basson MA - Dev. Biol. (2011)

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.

View Article: PubMed Central - PubMed

Affiliation: Department of Craniofacial Development, King's College London, Floor 27, Guy's Tower, London, SE1 9RT, UK.

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Analysis of Spry1−/−;Spry2−/− facial and vagus nerve projections. The VIIth nerve penetrates the proximal second arch and turns anteriorly once it reaches the distal arch (red arrow) in control embryos (A). This nerve fails to turn in an anterior direction in Spry1−/−;Spry2−/− embryos with variable branching patterns (red arrows in B). High magnification views of the ventral-posterior projections of the distal vagus nerve are shown in control (C) and mutant (D) embryos at E10.5. A ventral projection towards the heart (blue arrows) appears diminished in mutant embryos and a posterior projection towards the gut (red arrow) appears to be absent (red asterisks) in mutant embryos at E10.5. The vagus nerve projection to the heart can be visualised in sections through an E11.5 control embryo by neurofilament stain (green stain in E), which appears to be absent in sections through a mutant embryo (red asterisk). VII = facial nerve; VIIg = facial ganglion; IX = glossopharyngeal nerve and X = vagus nerve.
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f0045: Analysis of Spry1−/−;Spry2−/− facial and vagus nerve projections. The VIIth nerve penetrates the proximal second arch and turns anteriorly once it reaches the distal arch (red arrow) in control embryos (A). This nerve fails to turn in an anterior direction in Spry1−/−;Spry2−/− embryos with variable branching patterns (red arrows in B). High magnification views of the ventral-posterior projections of the distal vagus nerve are shown in control (C) and mutant (D) embryos at E10.5. A ventral projection towards the heart (blue arrows) appears diminished in mutant embryos and a posterior projection towards the gut (red arrow) appears to be absent (red asterisks) in mutant embryos at E10.5. The vagus nerve projection to the heart can be visualised in sections through an E11.5 control embryo by neurofilament stain (green stain in E), which appears to be absent in sections through a mutant embryo (red asterisk). VII = facial nerve; VIIg = facial ganglion; IX = glossopharyngeal nerve and X = vagus nerve.

Mentions: In agreement with this hypothesis, Spry1−/−;Spry2−/− embryos (n = 36) displayed severe abnormalities in all the branchial nerves at E10.5 (Fig. 2E,E′, Table 1). An abnormally developing facial nerve (VII) was the most prevalent defect observed in Spry1−/−;Spry2−/− embryos (n = 35/36). In control embryos, the VIIth nerve penetrated the proximal second arch and turned anteriorly once it reached the distal arch (Fig. 2A and Suppl. Fig. 3). Nerve projections from the facial ganglion into the second arch appeared stunted and failed to turn in an anterior direction (red arrow in Fig. 2E,E′, n = 34/36, two-tailed Fisher's exact text, p < 0.0001). In some cases, the VIIth nerve also exhibited severe defasciculation (Fig. 2E′, Suppl. Fig. 3).


Sprouty genes are essential for the normal development of epibranchial ganglia in the mouse embryo.

Simrick S, Lickert H, Basson MA - Dev. Biol. (2011)

Analysis of Spry1−/−;Spry2−/− facial and vagus nerve projections. The VIIth nerve penetrates the proximal second arch and turns anteriorly once it reaches the distal arch (red arrow) in control embryos (A). This nerve fails to turn in an anterior direction in Spry1−/−;Spry2−/− embryos with variable branching patterns (red arrows in B). High magnification views of the ventral-posterior projections of the distal vagus nerve are shown in control (C) and mutant (D) embryos at E10.5. A ventral projection towards the heart (blue arrows) appears diminished in mutant embryos and a posterior projection towards the gut (red arrow) appears to be absent (red asterisks) in mutant embryos at E10.5. The vagus nerve projection to the heart can be visualised in sections through an E11.5 control embryo by neurofilament stain (green stain in E), which appears to be absent in sections through a mutant embryo (red asterisk). VII = facial nerve; VIIg = facial ganglion; IX = glossopharyngeal nerve and X = vagus nerve.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3368431&req=5

f0045: Analysis of Spry1−/−;Spry2−/− facial and vagus nerve projections. The VIIth nerve penetrates the proximal second arch and turns anteriorly once it reaches the distal arch (red arrow) in control embryos (A). This nerve fails to turn in an anterior direction in Spry1−/−;Spry2−/− embryos with variable branching patterns (red arrows in B). High magnification views of the ventral-posterior projections of the distal vagus nerve are shown in control (C) and mutant (D) embryos at E10.5. A ventral projection towards the heart (blue arrows) appears diminished in mutant embryos and a posterior projection towards the gut (red arrow) appears to be absent (red asterisks) in mutant embryos at E10.5. The vagus nerve projection to the heart can be visualised in sections through an E11.5 control embryo by neurofilament stain (green stain in E), which appears to be absent in sections through a mutant embryo (red asterisk). VII = facial nerve; VIIg = facial ganglion; IX = glossopharyngeal nerve and X = vagus nerve.
Mentions: In agreement with this hypothesis, Spry1−/−;Spry2−/− embryos (n = 36) displayed severe abnormalities in all the branchial nerves at E10.5 (Fig. 2E,E′, Table 1). An abnormally developing facial nerve (VII) was the most prevalent defect observed in Spry1−/−;Spry2−/− embryos (n = 35/36). In control embryos, the VIIth nerve penetrated the proximal second arch and turned anteriorly once it reached the distal arch (Fig. 2A and Suppl. Fig. 3). Nerve projections from the facial ganglion into the second arch appeared stunted and failed to turn in an anterior direction (red arrow in Fig. 2E,E′, n = 34/36, two-tailed Fisher's exact text, p < 0.0001). In some cases, the VIIth nerve also exhibited severe defasciculation (Fig. 2E′, Suppl. Fig. 3).

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.

View Article: PubMed Central - PubMed

Affiliation: Department of Craniofacial Development, King's College London, Floor 27, Guy's Tower, London, SE1 9RT, UK.

Show MeSH
Related in: MedlinePlus