A potential role for beta-carotene in avian embryonic development.
Vitamin A is essential for vertebrate embryonic development; dietary carotenoids are the primary source of vitamin A since animals cannot synthesize it de novo. To study the role of beta-carotene during embryonic development, we analyzed in chick embryos the expression of beta,beta-carotene 15,15'-oxygenase (beta-oxy) which cleaves beta-carotene to produce two molecules of retinal. Beta-oxy transcripts were detected in one-and-a-half- to five-day-old embryo homogenates and in situ hybridization in five-day-old embryos, revealing their presence in tissues including the central nervous system, lungs, limbs, and cardiovascular system. Moreover, we detected beta-oxy enzymatic activity in extracts from five-day-old embryos as well as small amounts of beta-carotene in the egg yolk. These results indicate that beta-oxy is present during early developmental stages, raising the possibility that yolk-stored beta-carotene is utilized as a source of vitamin A. Thus, our results suggest that beta-carotene could play an important role in early avian embryonic development as a local source of vitamin A in specific tissues.
Mora
Ofelia
O
Coordinación General de Estudios de Posgrado e Investigación, Facultad de Estudios Superiores-Cuautitlán, Universidad Nacional Autónoma de Mexico, Arboledas, Querétaro, Qro. México, CP 76140. mora@mail.cnb.unam.mx
Kuri-Melo
Lourdes
L
González-Gallardo
Adriana
A
Meléndez
Esperanza
E
Morales
Adriana
A
Shimada
Armando
A
Varela-Echavarría
Alfredo
A
D000818:Animals; D002642:Chick Embryo / Q000201:enzymology / Q000254:growth & development*; D004530:Egg Yolk / Q000737:chemistry; D015870:Gene Expression; D017403:In Situ Hybridization; D010105:Oxygenases / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014801:Vitamin A / Q000502:physiology; D019207:beta Carotene / Q000032:analysis / Q000502:physiology*; D050559:beta-Carotene 15,15'-Monooxygenase
D012333:RNA, Messenger; D019207:beta Carotene; D014801:Vitamin A; D010105:Oxygenases; D050559:beta-Carotene 15,15'-Monooxygenase