Table 1.

Information on the twelve reference genes used in this study

Gene	Full description	Gene function	Product size (bp)
GAPDH	Glyceraldehyde-3-phosphate dehydrogenase	Glycolytic enzyme (Goossens et al. 2005)	220
TUBB	Tubulin, beta polypeptide	Member of the tubulin family of structural proteins (Zhang et al. 2005)	119
PPIA	Cyclophilin A	Protein folding and protein interaction (Thellin et al. 1999)	114
ACTB	β-actin	Cytoskeletal structural protein (Goossens et al. 2005)	188
YWHAZ	Tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, zeta polypeptide	Signal transduction by binding to phosphoserine-containing proteins (Goossens et al. 2005)	248
RRN18S	18S rRNA	Ribosome subunit (Goossens et al. 2005)	120
B2M	Beta-2-microglobulin	Cytoskeletal protein involved in cell locomotion (Zhang et al. 2005)	161
UBC	Ubiquitin C	Protein degradation (Perez et al. 2007)	239
TBP	TATA box binding protein	General RNA polymerase II transcription factor (Goossens et al. 2005)	174
RPLP	60S acidic ribosomal protein PO	Structural protein of ribosomes (Lyng et al. 2008)	150
GUSB	Beta-glucuronidase	Catalyses hydrolysis of β-d-glucuronic acid residues from the non-reducing end of mucopolysaccharides (Lyng et al. 2008)	165
HPRT1	Hypoxanthine phosphoribosyl-transferase I	Purine synthesis in salvage pathway (Goossens et al. 2005)	94

The sizes of the PCR products of the reference genes were obtained from the manufacturer