Relative levels of mRNA for selected genes upregulated by fasting as determined by microarray and qRT-PCR. Data were normalized to the housekeeping gene phosphoglycerate kinase 1 (PGK1), and are expressed relative to mRNA levels at hatch, which are set to the value of 1. Gene expression higher than 1 indicates upregulation compared to hatch, while gene expression levels less than 1 indicate downregulation compared to hatch. Chicks were either fully fed (FF), not fed (NF) or delayed fed (DF). Treatment groups are designated as follows: hatch (H), fed for 24 h (24FF), fasted for 24 h (24NF), fed for 48 h (48FF), fasted for 48 h (48NF), fasted for 48 h then fed for 4 h (4DF), fed for 72 h (72FF), fasted for 48 h then fed for 24 h (24DF), fed for 96 h (96FF), fasted for 48 h then fed for 48 h (48DF). Genes evaluated were: neuropeptide Y receptor 5 (NPY5R), aromatase (CYP19A), deiodinase II (DIO2), FK506 binding protein 51 (FKBP51), somatostatin receptor 5 (SSTR5), and coagulation factor C (COCH). Black bars are microarray results, and white bars are qRT-PCR results. Values within a single method with differing letters are significantly different (P < 0.05).