SEQUENCE-ANALYSIS REVEALS THAT THE BTG1 ANTIPROLIFERATIVE GENE IS CONSERVED THROUGHOUT EVOLUTION IN ITS CODING AND 3' NONCODING REGIONS

The human BTG1 gene (expressing an anti-proliferative function) is an evolutionarily conserved gene homologous to the murine PC3/TIS21 genes . Here, we report the cloning and sequencing of the murine BTG1 coding region and chicken BTG1 cDNA. The putative human and mouse BTG1 prote ins are 100% identical; the chicken BTG1 cDNA contains an open reading frame of 170 amino acids with a 91% identity to its human and murine counterparts. The 3'-untranslated region of BTG1 is also highly conser ved (82% homology between human and chicken), suggesting that it plays a key role in the regulation of BTG1 expression. These data confirm t hat BTG1 is phylogenetically highly conserved and that BTG1 and PC3/TI S21 may constitute the first members of a new family of functionally r elated genes.