REGULATION OF VASOPRESSIN AND OXYTOCIN GENE-EXPRESSION BY ESTROGEN AND THYROID-HORMONE

This chapter delineates the potential of the oxytocin (OT) and vasopressin (VP) genes to be regulated by ligand-activated transacting factors of the steroid/thyroid hormone superfamily, reveals the sensitivity of the OT gene to estrogens and thyroid hormone, and outlines the mapping of elements involved in the response. The VP gene does not contain response elements in the investigated fragment (2 kb) of the 5' flanking region, which indicates that the regulatory control elements of OT and VP genes are distinctly different. Although, there are similarities in the responses, this indicates that VP and OT expressing neurons in vivo have the intrinsic capacity to respond specifically with OT or VP gene expression. Because sequences necessary for proper OT expression are known, transgenic animals could be made with mutated regulatory elements to study the significance of this particular element for proper expression and regulation of the OT gene. The cell lines may then provide model systems to study the regulation of VP and OT gene expression in a cellular environment, which closely resembles the normal VP- and OT-neurons. © 1992 Academic Press Inc.