Background and objectives. Though glyceraldehyde-3-phosphate dehydrogenase (Gapdh) is one of the most commonly used housekeeping genes for comparison of gene expression data, studies have revealed that Gapdh expression is not constant at different developmental stages, and is modulated by many factors including ethanol. In view of this, in the present study, we investigated the effect of ethanol on Gapdh stability and expression levels in different model systems.
Methods. Evaluation of Gapdh stability was determined by comparison with three commonly used housekeeping genes in alcohol-exposed and control mouse blastocysts, embryos, and placentas (ActB, Hsp90ab1, and Atp5b), and in alcohol-dependent and healthy humans (ACTB, ATP5B, and HSPCB), and was ranked by the software program RefFinder. To detect the Gapdh expression patterns as a target gene, qRT-PCR analysis was applied.
Results. The order of expression stabilities obtained by the RefFinder ranked Gapdh as the most unstable reference gene in studied groups. The study of the expression dynamics of Gapdh showed significant upregulation in ethanol-exposed mouse blastocysts and embryos (FC = 1.56, p = 0.05 and FC = 6.0, p = 0.01) and downregulation in placentas (FC = 0.60, p = 0.01).
Conclusions. Our results revealed that the expression of Gapdh can vary in different model systems under ethanol exposure and imply the need for caution when using it as an internal control. This is the first report for statistically significant change in Gapdh expression after ethanol exposure during preimplantation mouse development.
