Carotenoid composition and conformation in retinal oil droplets of the domestic chicken

Ana-Andreea Arteni (1) , Amy M. Lafountain (2) , Maxime T. A. Alexandre (1) , Mathias Fradot (3) , Maria M. Mendes-Pinto (1) , José-Alain Sahel (3) , Serge Picaud (3) , Harry A. Frank (2) , Bruno Robert (1, 4) , Andrew A. Pascal (1)

1 I2BC - Institut de Biologie Intégrative de la Cellule
2 UCONN - University of Connecticut
3 Institut de la Vision
4 B3S - Département Biochimie, Biophysique et Biologie Structurale

Carotenoid-containing oil droplets in the avian retina act as cut-off filters to enhance colour discrimination. We report a confocal resonance Raman investigation of the oil droplets of the domestic chicken, Gallus gallus domesticus. We show that all carotenoids present are in a constrained conformation, implying a locus in specific lipid binding sites. In addition, we provide proof of a recent conclusion that all carotenoid-containing droplets contain a mixture of all carotenoids present, rather than only a subset of them-a conclusion that diverges from the previously-held view. Our results have implications for the mechanism(s) giving rise to these carotenoid mixtures in the differently-coloured droplets.

Domaines: Sciences du Vivant [q-bio]

Ana-Andreea Arteni, Amy M. Lafountain, Maxime T. A. Alexandre, Mathias Fradot, Maria M. Mendes-Pinto, et al.. Carotenoid composition and conformation in retinal oil droplets of the domestic chicken. PLoS ONE, 2019, 14 (5), pp.e0217418. ⟨10.1371/journal.pone.0217418⟩. ⟨hal-02169471⟩