The use of reference gene selection programs to study the silvering transformation in a freshwater eel Anguilla australis: a cautionary tale

Table 2 Ranking of reference gene candidates based on overall transcription stability.

	Liver	Ovary
GeNorm[M value] (without 18s*)	eef1-18 s [0.316] < l36 < nop14 < actb < odc1 (eef1-l36 [0.330] < nop14 < actb < odc1)	eef1-actb [0.188] <l36 < nop14 < odc1 < 18s
BestKeeper [SD x-fold]	18 s [1.13] <eef1 [1.19] < l36< nop14< actb < odc1	l36 [1.28] <nop14 < actb < eef1 < 18s < odc1
Normfinder [Stability value] (best pair)	18 s [0.183] < nop14 [0.189] actb < l36 < eef1 < odc1 (actb-l36 [0.100])	nop14 [0.125] < actb < l36< eef1 < 18s < odc1 (nop14-actb [0.098])

*GeNorm does not select the single best gene but the best pair of genes.
Rankings were based on overall transcription stability parameters as calculated by GeNorm (M-value), BestKeeper, (SD x-fold) or that calculated by a model based approach by Normfinder (Stability value). High transcript abundance of 18 s may make it unsuitable as a reference gene, therefore where 18 s had been selected by GeNorm as part of the best pair of genes, an additional analysis was conducted without 18 s (results in parantheses). Values in boxed parentheses [ ] indicate indices of stability of the top ranked gene or pair of genes, or the second highest if the top ranked gene was 18s. Lower scores denote greater transcription stability and suitability as a reference gene. Both GeNorm and Normfinder select the best pair combination of reference genes.

ISSN: 1471-2199