In vivo expression profile and stability of Bd candidate reference genes. Shown is (a) the variation in the mRNA expression (Cq) of GAPDH, TUB, R6046 and APRT in skin tissue (thigh) of experimentally Bd-infected midwife toads (n = 6). The whiskers represent the median, the minimum and maximum values, and the first and third quartiles. A plus (+) indicates the mean Cq value. (b) At euthanasia, different fungal loads were detected in the skin tissues. (c) GeNorm stability analysis providing a GeNorm M and coefficient of variation (CV) value. (d) CRN_23176 mean fold change in mRNA expression profiles. The data shows the normalized target gene quantity in skin tissue from Bd-infected midwife toads, relative to freshly collected spores which is considered 1. The results are presented as means + standard error of the mean (SEM) with significant differences shown by the P value.