Résumé
The expression pattern of the fibroblast growth factor receptor
Fgf-R1,
R2 and
R3 genes was studied in the chicken spinal cord using in situ hybridization (ISH). Unlike
Fgf-R1 which is widely expressed in motoneurons,
Fgf-R3 is expressed in a subset of motoneurons in the medial subdivision of the median motor column (MMCm) that also express
Islet-1 and
Lim-3. The motoneuron identity of the labelled cells was confirmed by double ISH and by single cell RT-PCR. Interestingly, E3.5 spinal cord motoneurons do not express
Fgf-R3, suggesting the expression of
Fgf-R3 in motoneurons begins with axonal growth.