The 5 '-flanking regions of CYP19A1 and CYP19A2 in zebrafish

This report describes the structure of the 5'-flanking regions of both the CYP19A1 and A2 genes that were isolated from the genome of the zebrafish (D anio rerio). Consensus sequences of three cAMP-responsive elements (CRE), a n aryl hydrocarbon-responsive element (AhR/Arnt), a steroidogenic factor I (SF-1) site, and a TATA box were observed in the 5'-flanking region of CYP1 9A1 In contrast, the 5'-flanking region of CYP19A2 was located upstream of an untranslated exon and possessed consensus sequences of a single CRE, an estrogen-responsive element (ERE), a peroxisome proliferator-activated rece ptor alpha /retinoid X receptor alpha heterodimer-responsive element (PPAR alpha /RXR alpha), and a TATA box. Primer extension analysis revealed that the predominant transcription initiation sites for CYP19A1 and A2 transcrip ts were 28 and 91 bp upstream from the putative translation initiation codo n, respectively. These analyses indicate that substantially different regul ators, including a variety of environmental xenobiotics, control the expres sion the two CYP19 genes. (C) 2001 Academic Press.