Housekeeping Genes

Housekeeping genes, also known as reference genes, are a set of genes that are constitutively expressed in cells and are essential for basic cellular functions. These genes encode for proteins that are involved in fundamental cellular processes, such as cell cycle regulation, DNA replication, and metabolism. In life science experiments, housekeeping genes are commonly used as internal controls or normalization factors to ensure accurate gene expression analysis. Their stable expression levels across different cell types and experimental conditions make them ideal references for comparing the expression levels of other genes of interest. Therefore, housekeeping genes play a crucial role in ensuring the reliability and reproducibility of experimental results in various applications, such as gene expression profiling, qPCR, and Western blotting. genomics-online offers a set of high quality siRNA Oligos for knockdown of housekeeping genes via RNA interference (RNAi).

What are Housekeeping Genes

Housekeeping genes are typically constitutive genes that are required for the maintenance of basal cellular functions that are essential for the existence of a cell, regardless of its specific role in the tissue or organism. Thus, they are expressed in all cells of an organism under normal and patho-physiological conditions, irrespective of tissue type, developmental stage, cell cycle state, or external signal.

What is the Purpose of Housekeeping Genes

They gain scientific value in two ways. On the one hand they represent the minimal set of genes required to sustain life. On the other hand Housekeeping genes are widely used as internal controls for experimental studies¹. The reliability of any relative RT-PCR experiment can be improved by including an invariant endogenous control (reference gene) in the assay to correct for sample to sample variations in RT-PCR efficiency and errors in sample quantification. A biologically meaningful reporting of target mRNA copy numbers requires accurate and relevant normalization to some standard and is strongly recommended in quantitative RT-PCR.

Limitations of Housekeeping Genes

The group of housekeeping genes unites unique genomic and evolutionary features. They have for example shorter introns and exons, more simple sequence repeats and lower potential for nucleosome formation in the 5′ region ². Nevertheless the gathering of new data about possible housekeeping genes struggles with the same reliability problems they are used to compensate. Several splice variants, duplicative regions, and the general lower expression of upstream exons caused by reverse transcriptase errors complicate interpretation of RT-PCR results (fig. 1).

Another issue is the definition of Housekeeping genes itself³. Is it enough to look for genes being expressed in all tissues, or should the genes also be expressed at a constant level across tissues? Early studies generally adopted the first definition and, in fact, GAPDH and other popular Housekeeping genes for experimental controls have been found to vary considerably across tissues. This is why before starting a new experiment it is advisable to review the literature and technical information in your field to determine which gene(s) other researchers commonly use. It is recommended that multiple Housekeeping genes be utilized for each gene expression experiment, to account for any impact that an experimental condition may have on the expression of an individual Housekeeping gene.

siRNA Oligos for Knockdown of Important Housekeeping Genes

Below you can find a list of important Housekeeping genes available at genomics-online, if u have further questions concerning your RT-PCR or are unsure which Housekeeping gene is the right choice our team of qualified scientist will gladly assist u, either per mail or phone.

References:

1. Moein, Javanmard, Abedi, Izadpanahi, Gheisari: "Identification of Appropriate Housekeeping Genes for Gene Expression Analysis in Long-term Hypoxia-treated Kidney Cells." in: Advanced biomedical research, Vol. 6, pp. 15, (2017) (PubMed).
2. Curina, Termanini, Barozzi, Prosperini, Simonatto, Polletti, Silvola, Soldi, Austenaa, Bonaldi, Ghisletti, Natoli: "High constitutive activity of a broad panel of housekeeping and tissue-specific cis-regulatory elements depends on a subset of ETS proteins." in: Genes & development, Vol. 31, Issue 4, pp. 399-412, (2017) (PubMed).
3. Eisenberg, Levanon: "Human housekeeping genes, revisited." in: Trends in genetics : TIG, Vol. 29, Issue 10, pp. 569-74, (2014) (PubMed).