Temporal distribution, localization and metabolism of all-trans-retinol, didehydroretinol and all-trans-retinal during Xenopus development

Abstract

Recently, the temporal and spatial distribution patterns of the patterns of all-trans-retinol, didehydroretinol and all-transretinoid receptor ligands 9-cis-retinoic acid and all-trans-retinoic retinal did not coincide with that observed for 9-cis-retinoic acid were described in Xenopus embryos during early develacid but, in certain regards, were similar to the patterns delineated opment [Creech Kraft, Schuh, Juchau and Kimelman (1994) for all-trans-retinoic acid and all-trans-retinoyl fl-glucuronide.Proc. Natl. Acad. Sci. U.S.A., in the press]. The present study Evidence is presented that 9-cis-retinoic acid can be synthesized demonstrates the presence and distribution of their likely prefrom both all-trans-retinoic acid and all-trans-retinol in Xenopus cursors, all-trans-retinol, didehydroretinol, didehydroretinal and embryos, suggesting that the difference between the distributions all-trans-retinal, as well as the occurrence of 4-oxo metabolites, of 9-cis-retinoic acid and the other retinoids may be caused by in Xenopus embryos. The temporal and spatial distribution selective synthesis and/or protein binding of the 9-cis isomer.

Stimulation of premature retinoic acid synthesis in Xenopus embryos following premature expression of aldehyde dehydrogenase ALDH1

“…The discovery of this assay for aldehyde dehydrogenase is more understandable when one considers that Xenopus eggs and embryos contain large amounts of the vitamin A substrate retinal, the immediate precursor of RA. In Xenopus eggs and embryos retinal is present at much higher levels than retinol [31, 32, 52], whereas in mammalian embryos retinol is the abundant form of vitamin A and retinal is undetectable [53]. Retinal in Xenopus eggs is primarily bound to the yolk storage protein lipovitellin 1 by a Schiff base linkage, which protects its reactive aldehyde group [33].…”

“…RA and retinoid receptors are found in Xenopus embryos [28–30]. The vitamin A precursors retinol and retinal are both present in Xenopus eggs and embryos, with the more abundant retinal existing as a Schiff base linkage with lipovitellin 1 [31–33]. Metabolism of retinol and retinal to RA has been demonstrated in Xenopus embryos [34], and has been shown to be sensitive to the aldehyde dehydrogenase inhibitor citral [35].…”

The role of retinoic acid in embryonic and post-embryonic development

“…Xenopus and zebrafish (Danio rario) embryos also contain a variety of retinoids (Durston et al 1989;Pijnappel et al 1993;Creech-Kraft et al 1994;Costaridis et al 1996). Chick and mouse embryos have been divided into eight regions, and all parts of the embryo were found to contain RA, but at varying levels Maden et al 1998b).…”

Insights into retinoic acid deficiency and the induction of craniofacial malformations and microcephaly in fetal alcohol spectrum disorder

“…These observations place multiple retinoic acid biosynthetic and signaling components in the embryonic organizer or its derivatives active in head induction. Not only are components of the retinoic acid biosynthetic network expressed within the embryonic organizer, but several reports have detected retinoids within this structure in a number of vertebrate experimental models showing that retinoic acid is actually produced de novo in this structure (Creech Kraft, Schuh, Juchau, & Kimelman, ; Hogan, Thaller, & Eichele, ; Kraft, Schuh, Juchau, & Kimelman, ; Ulven et al, ). Furthermore, using reporter systems that depend on active retinoic acid signaling for their activation, retinoic acid signaling has been detected in the embryonic organizer (Deltour et al, ; Rossant, Zirngibl, Cado, Shago, & Giguère, ; Samarut, Fraher, Laudet, & Gibert, ; Yelin et al, ).…”