Crosstalk between nitric oxide and retinoic acid pathways is essential for amphioxus pharynx development

During animal ontogenesis, body axis patterning is finely regulated by complex interactions among several signaling pathways. Nitric oxide (NO) and retinoic acid (RA) are potent morphogens that play a pivotal role in vertebrate development. Their involvement axial of the head pharynx shows conserved features chordate phylum. Indeed, cephalochordate amphioxus, NO RA crucial for correct development pharyngeal structures. Here, we demonstrate functional cooperation between occurs during amphioxus embryogenesis. neurulation, modulates production through transcriptional regulation Aldh1a.2 irreversibly converts retinaldehyde into RA. On other hand, directly or indirectly regulates transcription Nos genes. This reciprocal pathways essential normal it could be vertebrates.