Quantitative real-time RT-PCR (qRT-PCR) is the most sensitive and advanced method to quantify the expression of target genes of animals including fish. However, the broad variation in the expression patterns of housekeeping genes (HKGs) among tissues and different developmental stages makes it necessary to conduct studies for the selection of the suitable internal control. There is no report available on the reference genes for normalization of gene expression studies in Pterophyllum scalare. In the present study, four reference genes, viz. alpha-actin (α-actin), beta-actin (β-actin), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and elongation factor-alpha 1 (EF1α), were first characterized and then screened for their efficacy as a suitable HKG at different developmental stages and tissue types of P. scalare. The different statistical algorithms such as Delta-cT, NormFinder, and geNorm portray β-actin to be the most suitable gene among the four genes, whereas BestKeeper revealed EF1α as the most stable reference gene during different developmental stages and tissue types. However, comprehensive gene stability method demonstrated β-actin to be the most stable gene for conducting any gene expression studies. In conclusion, β-actin is recommended as the most suitable reference gene among the four selected genes for qPCR data normalization during different developmental stages and tissue types of P. scalare.

定量实时 RT-PCR (qRT-PCR) 是量化包括鱼类在内的动物靶基因表达的最灵敏和最先进的方法。然而，管家基因（HKGs）在组织和不同发育阶段的表达模式存在广泛差异，因此有必要进行研究以选择合适的内部对照。没有关于Pterophyllum scalare基因表达研究标准化的参考基因的报告。在本研究中，四个参考基因，即。α-肌动蛋白（α-肌动蛋白）、β-肌动蛋白（β-肌动蛋白）、3-磷酸甘油醛脱氢酶（GAPDH）和延伸因子-α1（EF1α），首先被表征，然后筛选它们作为合适的HKG的功效在不同的发育阶段和组织类型P. 标量。Delta-cT、NormFinder 和 geNorm 等不同的统计算法将 β-actin 描述为四个基因中最合适的基因，而 BestKeeper 显示 EF1α 是不同发育阶段和组织类型中最稳定的参考基因。然而，综合基因稳定性方法证明 β-肌动蛋白是进行任何基因表达研究的最稳定的基因。总之，β-actin 被推荐为四个选定基因中最合适的参考基因，用于P. scalare不同发育阶段和组织类型的 qPCR 数据标准化。