Hierarchical cluster tree of hepatic gene expression. The genes panel included antioxidant genes (CAT, SOD, GPx1, NOX1, NOX4, and NRF2) and lipid metabolism genes (ACC, FAS, EXFABP, and PPAR-γ). Each row represents a gene and each column represents an experimental unit belonging to a specific treatment. The treatments are described as follows: CON, control eggs without in ovo injection and incubated at standard temperature; G10, eggs injected at 17.5 days of incubation with 0.6 mL of 10% γ-aminobutyric acid dissolved in distilled water; TM, thermally manipulated eggs exposed to 39.6°C for 6 h daily from embryonic day 10 to 18; G10+TM, eggs that received both previous treatments during incubation. Gene expression analysis was performed using real-time quantitative polymerase chain reaction (RT-qPCR) with GAPDH and β-actin as reference genes. The tree was constructed using the package “ComplexHeatmap” of the R software version 4.0.3 (R Core Team, 2020). CAT, catalase; ACC, acetyl-CoA carboxylase; PPAR-γ, peroxisome proliferator-activated receptor-gamma; EXFABP, extracellular fatty acid-binding protein; NOX4, nicotinamide adenine dinucleotide phosphate oxidase 4; NOX1, nicotinamide adenine dinucleotide phosphate oxidase 1; SOD, superoxide dismutase; GPx1, glutathione peroxidase 1; NRF2, nuclear factor erythroid 2-related factor 2; FAS, fatty acid synthase.