Cloning and analysis of the untranslated regions of the Xenopus laevis Connexin30 mRNA

The full-length 5' and 3' untranslated regions (UTRs) of Xenopus laevis Con nexin30 (Cx30) mRNA were cloned and sequenced. The Cx30 messenger contains a 148 nt 5' UTR and a 480 nt 3' UTR. Four different constructs were made to enable the analysis of the role of the Cx30 UTRs in translation efficiency and in protein localization in the early Xenopus embryo. Transcripts encod ed the Green Fluorescent Protein (GFP) reporter and contained the 5' and 3' UTR of either Cx30 or globin. In vivo analyses after injection of the tran scripts into one cell-stage Xenopus embryos showed that the Cx30 3' UTR ena bles very efficient translation. The 5' UTR was slightly inhibitory compare d with the globin 5' UTR. The localization of the produced GFP was analyzed . GFP was ubiquitously expressed in all parts of the embryo. Based on this observation we conclude that neither the 5' UTR nor the 3' UTR confers spec ific localization of the translation of the Cx30 mRNA in the embryo. (C) 20 00 Elsevier Science B.V. All rights reserved.