Expression of ghrelin variants in white blood cells of sheep and overview of the proximal promoter region of the ovine ghrelin gene. Expression of ghrelin variant transcripts, Δex2 preproghrelin (A) and Δex2,3 preproghrelin (B) in white blood cells from genetically resistant (dark grey diamond symbol) or susceptible (light grey square symbol) sheep, following infection with Haemonchus contortus, demonstrated using real time RT-PCR. Results at each time point indicate mean and standard error from a group of 8 sheep. (C) Promoter region of the ovine ghrelin gene (GHRL). Predicted transcription factor binding sites are boxed and the transcription factor families that target this sequence are shown below the sequence. The transcription factor sites identified are also conserved in the promoter region of bovine ghrelin. The TATA box, a consensus sequence upstream of the transcription start site that plays a role in transcription initiation, and the first exon of the ghrelin gene (exon 0) are also shown.