EARLY EXPRESSION OF A BETA(1)-ADRENERGIC RECEPTOR AND CATECHOLAMINES IN XENOPUS OOCYTES AND EMBRYOS

From a Xenopus stage 11 cDNA library, we have cloned a gene, termed X- beta 1AR, whose sequence is highly homologous to that of the human bet a(1)-adrenergic receptor, As shown by RT-PCR assay, X-beta 1AR RNA is present in the mature oocyte, decreases after fertilization up to stag e 6 and then gradually increases during gastrulation, Binding studies performed with radiolabeled ligands reveal that X-beta 1AR RNA is tran slated into the receptor protein, Furthermore, noradrenaline and adren aline are also detected in oocytes and early embryos, The concomitant presence of beta(1)-adrenergic receptors and catecholamines suggest th at this ligand-receptor couple could play a role in the very early sta ges of embryonic development. (C) 1997 Federation of European Biochemi cal Societies.