title: Endogenous retinoids in the early avian embryo.
abstract: Vitamin A is required to rescue the vitamin A-deficient quail embryo from early death, but the endogenous presence of bioactive retinoids has not been documented in these embryos. The analysis of 2000 pooled stage 5-8 normal quail embryos described here provides for the first time direct evidence for the presence of endogenous all-trans-retinoic acid (5 nM) and 3,4-didehydroretinoic acid (4 nM), signaling molecules known to be potent ligands for nuclear retinoic acid receptors. The demonstration of all-trans-retinal (80 nM), all-trans-retinol (100 nM), 3,4-didehydroretinol (200 nM), and retinyl esters (100 nM) suggests the capability of the early avian embryo to generate in situ the vitamin A-bioactive molecules required for development. Analysis of 2100 pooled stage 5-8 quail embryos from vitamin A-deficient eggs revealed no vitamin A-like molecules, supporting the evidence that links vitamin A deficiency in these embryos to abnormalities and early death.
authors.affiliation: Dept. of Food Science & Human Nutrition, Michigan State University, East Lansing 48824, USA.
authors.forename: D
authors.initials: D
authors.lastname: Dong
authors.forename: M H
authors.initials: MH
authors.lastname: Zile
mesh_terms: D000818:Animals; D003370:Coturnix / Q000196:embryology*; D008024:Ligands; D018168:Receptors, Retinoic Acid / Q000502:physiology; D012176:Retinoids / Q000378:metabolism*; D014802:Vitamin A Deficiency / Q000196:embryology
chemical_list: D008024:Ligands; D018168:Receptors, Retinoic Acid; D012176:Retinoids