TEMPORAL DISTRIBUTION, LOCALIZATION AND METABOLISM OF ALL-TRANS-RETINOL, DIDEHYDRORETINOL AND ALL-TRANS-RETINAL DURING XENOPUS DEVELOPMENT

Recently, the temporal and spatial distribution patterns of the retino id receptor ligands 9-cis-retinoic acid and all-trans-retinoic acid we re described in Xenopus embryos during early development [Creech Kraft , Schuh, Juchau and Kimelman (1994) Proc. Natl. Acad. Sci. U.S.A., in the press]. The present study demonstrates the presence and distributi on of their likely precursors, all-trans-retinol, didehydroretinol, di dehydroretinal and all-transretinal, as well as the occurrence of 4-ox o metabolites, in Xenopus embryos. The temporal and spatial distributi on patterns of all-trans-retinol, didehydroretinol and all-trans-retin al did not coincide with that observed for 9-cis-retinoic acid but, in certain regards, were similar to the patterns delineated for all-tran s-retinoic acid and all-trans-retinoyl beta-glucuronide. Evidence is p resented that 9-cis-retinoic acid can be synthesized from both all-tra ns-retinoic acid and all-trans-retinol in Xenopus embryos, suggesting that the difference between the distributions of 9-cis-retinoic acid a nd the other retinoids may be caused by selective synthesis and/or pro tein binding of the 9-cis isomer.