Fig. 12

Diagrammatic model of the GnRHR gene promoters from the Meishan and Control/Index lines of swine. Within the upstream enhancer region, a bp substitution (T → C) next to the 22-bp deletion results in a functional GATA-4 site in the Meishan promoter, however, a neighboring NF-κB site in the control promoter binds the p52 and p65 subunits of NF-κB in the absence of GATA-4 binding. A single-bp substitution (C → G) at −1232 in the Meishan compared to Control/Index (−1235) GnRHR gene promoters allows for binding of a complex of transcription factors including the p52 and p65 subunits of NF-κB and a SP1-like protein capable of binding to a SP1 binding site. Interestingly, the NF-κB and SP1 elements within the Control/Index promoter overlap by a single bp, preventing binding of the protein complex, whereas the polymorphism (C → G) specific to the Meishan promoter shifts the SP1 site 3’ by 1 bp allowing it to abut the NF-κB element. An additional G → T bp alteration at −845 of the porcine GnRHR gene allows for Meishan-specific binding of GATA-4. An RXR binding site at −279/−274 and three SF1 binding sites (GSE) at −179/−171, −315/−310 and −1760/−1753 are members of the gonadotrope-specific promoter for the porcine GnRHR gene [30] and therefore, common to both lines