SPECIES-DIFFERENCES IN CENTRAL OXYTOCIN RECEPTOR GENE-EXPRESSION - COMPARATIVE-ANALYSIS OF PROMOTER SEQUENCES

The distribution of oxytocin binding sites in the brain is highly vari able among mammals, Using two species of microtine rodents (voles) wit h strikingly different patterns of oxytocin binding sites in the brain , we demonstrate that these differences are due to differences in regi on specific gene expression and not post-translational processing, The distribution of oxytocin receptor mRNA closely resembles the distribu tion of oxytocin receptor binding sites in both species. Analysis of t he 5' flanking region of the oxytocin receptor gene from both species reveals few differences in potential regulatory elements which could e xplain the differences in gene expression, These data suggest that spe cies differences in oxytocin receptor binding are due to species diffe rences in: i) distant DNA sequences further upstream or downstream whi ch may influence expression; ii) the distribution of regulatory protei ns such as transcription factors in the brain or iii) epigenetic facto rs, such as prenatal and perinatal environment which may affect gene e xpression in the adult.