Total RNA (500 ng) was reverse transcribed using a High Capacity cDNA Reverse Transcription Kit (Applied Biosystems) according to the manufacturer's protocol in a final volume of 20 µL. The cDNA was subsequently stored at −20 °C. Pooled cDNAs were then used in preliminary experiments to evaluate primer performance and specificity and for PCR protocol optimization. Subsequently, the expression profile of the selected genes was analysed in each cDNA sample separately.