Genomic Structure and Chromosomal Mapping of the Nuclear Orphan Receptor RORγ (RORC) Gene

The nuclear orphan receptor subfamily ROR/RZR is part of the steroid and thyroid hormone/retinoid receptor superfamily and consists of three different genes, α, β, and γ. In this study, we determined the genomic structure of mouse RORγ and the chromosomal localization of both mouse RORγ and human RORγ (HGMW-approved symbol RORC). The genomic structure of the mouse RORγ gene was derived from the analysis of P1 vector clones containing large genomic fragments encoding RORγ. These results revealed that the mRORγ gene has a complex structure consisting of 11 exons separated by 10 introns spanning more than 21 kb of genomic DNA. The DNA-binding domain is contained in two exons, 3 and 4, each encoding one zinc-finger. The splice site between exon 3 and exon 4 is identical to that found in RAR and TR3 receptors. RORγ is expressed as two mRNAs, 2.3 and 3.0 kb in size, that are derived by the use of alternative polyadenylation signals. We show by fluorescencein situhybridization that the mouse RORγ gene is located on chromosome 3, in a region that corresponds to band 3F2.1–2.2. The human RORγ was mapped to chromosome region 1q21. The results demonstrate that the RORγ genes are located in chromosomal regions that are syntenic between mouse and human