Suitable Reference Genes For Normalization Research Articles

Selection of suitable reference genes for normalization of RT-qPCR in three tissues of Northern bobwhite (Colinus virginianus) infected with eyeworm (Oxyspirura petrowi).

The Northern bobwhite (Colinus virginianus) is an economically important, and popular game bird in North America. Northern bobwhites have experiencing declines of > 3.5% annually in recent decades due to several factors. The eyeworm Oxyspirura petrowi is a nematode parasite frequently found in the eyes of bobwhites. Although reported frequently in wild bobwhites, there is no research to understand the host-parasite mechanism. Hence, it is important to investigate mechanisms of eyeworm invasion and immune modulation in bobwhite. Cytokine gene expression using RT-PCR is widely used to identify the innate immune response of a host to an infection. In this study, we evaluated ten reference genes (HMBS, RPL19, RPL32, RPS7, RPS8, TATA, SDHA, YWHAZ, GAPDH, and ACTB) for their stability across three tissues (liver, spleen, and caecal tonsils) of control and O. petrowi infected Northern bobwhites. Primer efficiency and reference genes stability were assessed using GeNorm, NormFinder, and BestKeeper. Expression of these reference genes with respect to O. petrowi infection in bobwhites showed RPL32 and HMBS were the most stable genes in the liver, HMBS and SDHA were the most stable genes in the spleen, and HMBS and YWHAZ were equally stable reference genes in the caecal tonsils. Based on the geometric mean of all three analyses, our results indicate that the combination of RPL32 and HMBS for the liver, HMBS and SDHA for the spleen, and YWHAZ and HMBS for caecal tonsils might be used as reference genes for normalization in gene expression investigations on Northern bobwhites.

Nanoparticle-Shielded dsRNA Delivery for Enhancing RNAi Efficiency in Cotton Spotted Bollworm Earias vittella (Lepidoptera: Nolidae).

The spotted bollworm Earias vittella (Lepidoptera: Nolidae) is a polyphagous pest with enormous economic significance, primarily affecting cotton and okra. However, the lack of gene sequence information on this pest has a significant constraint on molecular investigations and the formulation of superior pest management strategies. An RNA-seq-based transcriptome study was conducted to alleviate such limitations, and de novo assembly was performed to obtain transcript sequences of this pest. Reference gene identification across E. vittella developmental stages and RNAi treatments were conducted using its sequence information, which resulted in identifying transcription elongation factor (TEF), V-type proton ATPase (V-ATPase), and Glyceraldehyde -3-phosphate dehydrogenase (GAPDH) as the most suitable reference genes for normalization in RT-qPCR-based gene expression studies. The present study also identified important developmental, RNAi pathway, and RNAi target genes and performed life-stage developmental expression analysis using RT-qPCR to select the optimal targets for RNAi. We found that naked dsRNA degradation in the E. vittella hemolymph is the primary reason for poor RNAi. A total of six genes including Juvenile hormone methyl transferase (JHAMT), Chitin synthase (CHS), Aminopeptidase (AMN), Cadherin (CAD), Alpha-amylase (AMY), and V-type proton ATPase (V-ATPase) were selected and knocked down significantly with three different nanoparticles encapsulated dsRNA conjugates, i.e., Chitosan-dsRNA, carbon quantum dots-dsRNA (CQD-dsRNA), and Lipofectamine-dsRNA conjugate. These results demonstrate that feeding nanoparticle-shielded dsRNA silences target genes and suggests that nanoparticle-based RNAi can efficiently manage this pest.

Identification of suitable house-keeping genes during chikungunya virus infection.

Quantitative PCR (qPCR) is a reliable and robust technique for gene expression analysis, but its efficacy is dependent on the normalization of qPCR data with the stably expressed reference gene. Selection of a suitable reference gene is mandatory for accurate gene expression analysis, till data the most appropriate reference gene during chikungunya virus infection has not been elucidated. In this study the expression of reference genes(GAPDH, GUSB, HPRT, Beta-actin, 18S rRNA) was analysed during chikungunya virus infection by quantitative PCR. The stability of the house-keeping genes was evaluated with three bioinformatics softwares: BestKeeper, NormFinder and GeNorm. The significant variation in the expression of house-keeping genes (GusB, Beta-actin, HPRT) was observed during chikungunya virus infection; whereas GAPDH and 18S rRNA was most stable. The stability of reference genes analysed by the bioinformatics software further corroborate the results of qPCR. This is first study that identifies and validates the most suitable reference gene for normalization of qPCR data during chikungunya based gene expression analysis. This could serve as a reference study for the researchers working on different aspects of chikungunya virus infections.

Identification of suitable reference genes for normalization of reverse transcription quantitative real-time PCR (RT-qPCR) in the fibrotic phase of the bleomycin mouse model of pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a severe lung disease with a poor prognosis and few treatment options. In the most widely used experimental model for this disease, bleomycin is administered into the lungs of mice, causing a reaction of inflammation and consequent fibrosis that resembles the progression of human IPF. The inflammation and fibrosis together induce changes in gene expression that can be analyzed with reverse transcription quantitative real-time PCR (RT-qPCR), in which accurate normalization with a set of stably expressed reference genes is critical for obtaining reliable results. This work compares ten commonly used candidate reference genes in the late, fibrotic phase of bleomycin-induced pulmonary fibrosis and ranks them from the most to the least stable using NormFinder and geNorm. Sdha, Polr2a and Hprt were identified as the best performing and least variable reference genes when alternating between normal and fibrotic conditions. In order to validate the findings, we investigated the expression of Tnf and Col1a1, representing the hallmarks of inflammation and fibrotic changes, respectively. With the best three genes as references, both were found to be upregulated relative to untreated controls, unlike the situation when analyzed solely with Gapdh, a commonly used reference gene. We therefore recommend Sdha, Polr2a and Hprt as reference genes for RT-qPCR in the 4-week bleomycin challenge that represents the late fibrotic phase.

Identification of suitable reference genes for normalization of quantitative real-time PCR-based gene expression in chicken (Gallus gallus).

The recent availability of genome information greatly facilitates the fundamental research on chicken. In different organs, gene expression patterns can provide clues to understanding the biological functions. For rapid and accurate quantification of gene expression, quantitative real-time PCR (qPCR) has become one of the most widely used methods. However, the success of qPCR data normalization depends on the use of a suitable reference gene and a single reference gene is not universally suitable for all the experiments. Therefore, reference gene validation is a crucial step for different organ tissues of chicken where suitable reference genes for qPCR analysis in varieties of tissues have not been investigated exhaustively so far. In this study, we have selected 30 Gallus gallus candidate reference genes from NCBI, amplified and studied their expression profiles by qPCR in different organ tissues (breast muscle, thigh muscle, heart, liver, spleen, gizzard, and bursa) of chicken. The result showed that, for breast muscle HSP10 and RPL23, thigh muscle RPL14 and RPL13, liver ALB and HSP70, spleen ALB and GAPDH, heart CYCS and TUBA8B, gizzard RPL5 and 18S rRNA, and bursa EEF1A1 and PGK2 are most stable genes respectively. The results also showed that for different organ tissues, individual or a combination of reference genes should be selected for data normalization. In this study, we have identified and validated 30 reference genes in seven different organ tissues to provide accurate transcript normalization and quantification, which can be useful for gene expression studies in other avian species.

Reference gene identification for normalisation of RT-qPCR analysis in plasma samples of the rat middle cerebral artery occlusion model.

ObjectiveIn quantitative reverse transcription‐polymerase chain reaction (RT‐qPCR) studies, the selection and validation of reference genes are crucial for the accurate analysis of MicroRNAs (miRNAs) expression. In this work, the optimal reference genes for RT‐qPCR normalisation in plasma samples of rat middle cerebral artery occlusion (MCAO) models were identified.MethodsSix rat MCAO models were established. Blood samples were collected before modelling and approximately 16–24 h after modelling. Two commonly used reference genes (U6 and 5S) and three miRNAs (miR‐24, miR‐122 and miR‐9a) were selected as candidate reference genes, and the expression of these genes was detected with RT‐qPCR. The acquired data were analysed using geNorm, Normfinder, BestKeeper, RefFinder and comparative delta threshold cycle statistical models.ResultsThe analysed results consistently showed that miR‐24 was the most stably expressed reference gene. The ‘optimal combination’ calculated by geNorm was miR‐24, U6 and5S. The expression level of the target gene miR124 was similar when the most stable reference gene miR‐24 or the ‘optimal combination’ was used as a reference gene. However, compared with miR24 or the ‘optimal combination’, the less stable reference genes influenced the fold change and the data accuracy with a large standard deviation.ConclusionThese results confirmed the importance of selecting suitable reference genes for normalisation to obtain reliable results in RT‐qPCR studies and demonstrated that the identified reference gene miR‐24 or the ‘optimal combination’ could be used as an internal control for gene expression analysis in the rat MCAO model.

Reference genes for gene expression analysis in the fungal pathogen Neonectria ditissima and their use demonstrating expression up-regulation of candidate virulence genes.

European canker, caused by the necrotrophic fungal phytopathogen Neonectria ditissima, is one of the most damaging apple diseases worldwide. An understanding of the molecular basis of N. ditissima virulence is currently lacking. Identification of genes with an up-regulation of expression during infection, which are therefore probably involved in virulence, is a first step towards this understanding. Reverse transcription quantitative real-time PCR (RT-qPCR) can be used to identify these candidate virulence genes, but relies on the use of reference genes for relative gene expression data normalisation. However, no report that addresses selecting appropriate fungal reference genes for use in the N. ditissima-apple pathosystem has been published to date. In this study, eight N. ditissima genes were selected as candidate RT-qPCR reference genes for gene expression analysis. A subset of the primers (six) designed to amplify regions from these genes were specific for N. ditissima, failing to amplify PCR products with template from other fungal pathogens present in the apple orchard. The efficiency of amplification of these six primer sets was satisfactory, ranging from 81.8 to 107.53%. Analysis of expression stability when a highly pathogenic N. ditissima isolate was cultured under 10 regimes, using the statistical algorithms geNorm, NormFinder and BestKeeper, indicated that actin and myo-inositol-1-phosphate synthase (mips), or their combination, could be utilised as the most suitable reference genes for normalisation of N. ditissima gene expression. As a test case, these reference genes were used to study expression of three candidate virulence genes during a time course of infection. All three, which shared traits with fungal effector genes, had up-regulated expression in planta compared to in vitro with expression peaking between five and six weeks post inoculation (wpi). Thus, these three genes may well be involved in N. ditissima pathogenicity and are priority candidates for further functional characterization.

Evaluation of suitable reference genes for normalization of quantitative real-time PCR analysis in rice plants under Xanthomonas\xa0oryzae\xa0pv. oryzae--infection and melatonin supplementation

Exogenous melatonin (MT) was found to be an interesting tool for enhancing the resistance of rice to Xanthomonasoryzaepv. oryzae (Xoo)-caused bacterial blight (BB). However, the accurate comparison of the expression levels across samples was a challenging task. In this work, the stability of 10 common used housekeeping genes under Xoo-infection and MT supplementation in rice was analyzed using quantitative real-time PCR (qRT-PCR), and algorithms geNorm, NormFinder and BestKeeper. Our results indicated that most reference genes remained stable in Xoo-infected rice plants, while a number of reference genes were affected by MT supplementation. Among all studied genes, the transcript levels of 18S(18S ribosomal RNA) and UBC (Ubiquitin-conjugating enzyme E2) remained unaltered by Xoo infection, while UBC and UBQ5(Ubiquitin 5) were the most stable genes when examining simultaneous Xoo-infection and MT supplementation, demonstrating that UBC is a suitable reference gene for qRT-PCR data normalization in rice under Xoo-infection and MT supplementation.

TATA box binding protein and ribosomal protein 4 are suitable reference genes for normalization during quantitative polymerase chain reaction study in bovine mesenchymal stem cells.

ObjectiveQuantitative polymerase chain reaction (qPCR) has been extensively used in the field of mesenchymal stem cell (MSC) research to elucidate their characteristics and clinical potential by normalization of target genes against reference genes (RGs), which are believed to be stably expressed irrespective of various experimental conditions. However, the expression of RGs is also variable depending on the experimental conditions, which may lead to false or contradictory conclusions upon normalization. Due to the current lack of information for a clear list of stable RGs in bovine MSCs, we conducted this study to identify suitable RGs in bovine MSCs.MethodsThe cycle threshold values of ten traditionally used RGs (18S ribosomal RNA [18S], beta-2-microglobulin [B2M], H2A histone family, member Z [H2A], peptidylprolyl isomerase A [PPIA], ribosomal protein 4 [RPL4], succinate dehydrogenase complex, subunit A [SDHA], beta actin [ACTB], glyceraldehyde-3-phosphate dehydrogenase [GAPDH], TATA box binding protein [TBP], and hypoxanthine phosphoribosyltrasnfrase1 [HPRT1]) in bovine bone marrow-derived MSCs (bBMMSCs) were validated for their stabilities using three types of RG evaluation algorithms (geNorm, Normfinder, and Bestkeeper). The effect of validated RGs was then verified by normalization of lineage-specific genes (fatty acid binding protein 4 [FABP4] and osteonectin [ON]) expressions during differentiations of bBMMSCs or POU class 5 homeobox 1 (OCT4) expression between bBMMSCs and dermal skins.ResultsBased on the results obtained for the three most stable RGs from geNorm (TBP, RPL4, and H2A), Normfinder (TBP, RPL4, and SDHA), and Bestkeeper (TBP, RPL4, and SDHA), it was comprehensively determined that TBP and RPL4 were the most stable RGs in bBMMSCs. However, traditional RGs were suggested to be the least stable (18S) or moderately stable (GAPDH and ACTB) in bBMMSCs. Normalization of FABP4 or ON against TBP, RPL4, and 18S presented significant differences during differentiation of bBMMSCs. However, although significantly low expression of OCT4 was detected in dermal skins compared to that in bBMMSCs when TBP and RPL4 were used in normalization, normalization against 18S exhibited no significance.ConclusionThis study proposes that TBP and RPL4 were suitable as stable RGs for qPCR study in bovine MSCs.

Selection and Validation of Reference Genes for the qRT-PCR Assays of Populus ussuriensis Gene Expression under Abiotic Stresses and Related ABA Treatment

Populus ussuriensis Kom. is one of the most important tree species for forest renewal in the eastern mountainous areas of Northeast China due to its fast growth, high yield, and significant commercial and ecological value. The selection of optimal reference genes for the normalization of qRT-PCR data is essential for the analysis of relative gene expression. In this study, fourteen genes were selected and assessed for their expression stability during abiotic stress (drought, high salinity, and cold stress) and after the treatment with the drought-related hormone ABA. Three algorithms were used, geNorm, NormFinder, and BestKeeper, and a comprehensive ranking of candidate reference genes was produced based on their output. The most appropriate reference genes were UBQ10 and RPL24 for drought and ABA treatment, UBQ10 and TUB3 for cold stress, and UBQ10 and 60S rRNA for high salinity. Overall, UBQ10 was the most stable reference gene for use as an internal control, whereas PP2A was the least stable. The expression of two target genes (P5CS2 and GI) was used to further verify that the selected reference genes were suitable for gene expression normalization. This work comprehensively assesses the stability of reference genes in Populus ussuriensis and identifies suitable reference genes for normalization during qRT-PCR analysis.

Identification and evaluation of reference genes for quantitative real-time PCR analysis in Passiflora edulis under stem rot condition.

Passion fruit (Passiflora edulis), an important tropical and subtropical fruit, has a high edible and medicinal value. Stem rot disease is one of the most important diseases of passion fruit. An effective way for control and prevention of this disease is to identify the genes associated with resistance to this disease. Quantitative real-time PCR (RT-qPCR) has mainly been widely applied to detect gene expression because of its simplicity, fastness, low cost and high sensitivity. One of the requirements for RT-qPCR is the availability of suitable reference genes for normalization of gene expression. However, currently, no Passiflora edulis reference genes have been identified andthus it has hindered the gene expression studies in this plant. The present study aimed to address this issue. We analyzed sixteen candidate reference genes, including nine common (GAPDH, UBQ, ACT1, ACT2, EF-1α-1, EF-1α-2, TUA, NADP, and GBP) and seven novel genes (C13615, C24590, C27182, C10445, C21209, C22199, and C22526), in different tissues (stem, leaf, flower and fruit) of two accessions under stem rot condition. We calculated the expression stability in twenty-four samples using the ΔCt, GeNorm, NormFinder, BestKeeper and RefFinder. The results showed that both C21209 and EF-1α-2 were sufficient to normalize gene expression under stem rot, whereas the commonly used reference genes, GAPDH and UBQ, were the least stable ones. The expression patterns of PeUFC under stem rot condition normalized by stable and unstable reference genes indicated the suitability of using the optimal reference genes. To our knowledge, this is the first systematic study of reference genes in Passiflora edulis, which identified a number of reliable reference genes suitable for gene expression studies in Passiflora edulis by RT-qPCR.

Validation of suitable reference genes for normalization of quantitative reverse transcriptase- polymerase chain reaction in rice infected by Xanthomonas oryzae pv. oryzae

Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a costly disease in rice that threatens global rice production. Gene expression analysis by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) allows the study of the underlying mechanisms of both BB pathogenesis and resistance. In relative quantification, reference genes are often used to normalize the results to remove technical variations allowing the determination of true biological changes in a pilot experiment. However, variations in the expression of these reference genes can lead to erroneous and unreliable results. Thus, choosing the most stable reference genes for any specific experimental condition is of utmost importance in qRT-PCR experiments. Here, we used geNorm, NormFinder, Bestkeeper, Delta-Ct and RefFinder programs and/or methods to analyze the stability of the expression of eleven candidate reference genes namely: 18S ribosomal RNA (18S rRNA), Actin-1 (ACT1), ADP-Ribosylation Factor (ARF), Endothelial differentiation factor (Edf), eukaryotic Elongation Factor-1α (eEF-1α), eukaryotic Initiation Factor-4a (eIF-4a), Profilin 2 (Prof2), Nucleic Acid Binding Protein (NABP), Triosephosphate Isomerase (TI), Ubiquitin 5 (UBQ5) and Ubiquitin 10 (UBQ10) in cDNA samples from BB-susceptible and Xa21-mediated resistant rice cultivars collected at various times after Xoo inoculation. Under our experimental conditions, Edf and TI were the most stable reference genes while the common housekeeping genes 18S rRNA, and UBQ5 were among the least stable genes. Though using either Edf or TI as internal control is adequate for gene expression analysis, we suggest using both genes to normalize the data of qRT-PCR assays for rice subjected to Xoo inoculation.

Evaluation of Suitable Reference Genes for Normalization of RT-qPCR in Echiura (Urechis unicinctus) during Developmental Process

Reverse transcription quantitative PCR (RT-qPCR) is commonly used for gene expression analysis. Appropriate reference genes enable the accurate quantification of gene expression. In this study, expressional stability of seven candidate reference genes in embryos and larvae of the Echiura Urechis unicinctus were evaluated using four programs, geNorm, NormFinder, BestKeeper, and ∆Ct method. The expressional stability was ATPase > eIF3 > EF-1-α > TUB > IDH > VDAC > ABL based on the comprehensive analysis, and the combination of ATPase, eIF3, and EF-1-α was predicted to be the most optimum choice for accurate gene quantification during the developmental process. Furthermore, we verified the competence of the candidate reference genes/combinations through evaluating the expression levels of TGF-β receptor 1 (TGFβR1) and SMAD4, and inspiringly found using either ATPase or eIF3 alone generated exactly similar results with that of using reference gene combinations. Therefore, we suggested that under certain circumstances, ATPase or eIF3 could be independently used as an alternative to quantify target gene expression in U. unicinctus during developmental process. This study provides important information for gene expression and function researches in Echiura or Annelida species.

Suitable reference genes determination for real-time PCR using induced sputum samples.

Induced sputum is a non-invasive method of collecting cells from airways. Gene expression analysis from sputum cells has been used to understand the underlying mechanisms of airway diseases such as asthma or chronic obstructive pulmonary disease (COPD). Suitable reference genes for normalisation of target mRNA levels between sputum samples have not been defined so far.The current study assessed the expression stability of nine common reference genes in sputum samples from 14 healthy volunteers, 12 asthmatics and 12 COPD patients.Using three different algorithms (geNorm, NormFinder and BestKeeper), we identified HPRT1 and GNB2L1 as the most optimal reference genes to use for normalisation of quantitative reverse transcriptase (RT) PCR data from sputum cells. The higher expression stability of HPRT1 and GNB2L1 were confirmed in a validation set of patients including nine healthy controls, five COPD patients and five asthmatic patients. In this group, the RNA extraction and RT-PCR methods differed, which attested that these genes remained the most reliable whatever the method used to extract the RNA, generate complementary DNA or amplify it.Finally, an example of relative quantification of gene expression linked to eosinophils or neutrophils provided more accurate results after normalisation with the reference genes identified as the most stable compared to the least stable and confirmed our findings.

Identification of suitable reference genes for normalization of RT-qPCR data in eggplant fruit and shoot borer (Leucinodes orbonalis Guenée)

The eggplant shoot and fruit borer, Leucinodes orbonalis Guenee (Lepidoptera: Crambidae) is a monophagous and destructive insect pest of eggplant. L. orbonalis developed multiple insecticide resistance that led to frequent field control failures in many countries. The possible reversal of resistance in L. orbonalis requires an understanding of the expression dynamics of individual genes conferring resistance to insecticides through gene expression analysis. The availability of reference genes (RG) to normalize transcript data of target genes, achieved by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), is mandatory. Hence, the present study investigated the stable expression pattern of nine putative reference genes viz., actin, 28S ribosomal protein S18c, mitochondrial isoform X2 (28SM), calnexin, β-tubulin, 28S ribosomal protein S3 mitochondrial (28SR3), TATA box binding protein (TATA), elongation factor-1α (EF-1α), glyceraldehyde-3-phosphate-dehydrogenase (GAPDH), and ubiquitin 60S ribosomal protein (Ubiquitin) to select the most stable genes that could be used as reference genes for target transcript gene normalization. Different algorithms such as ΔCt, geNorm, NormFinder and BestKeeper were used to assess gene expression stability. By integrating these data into online RefFinder tool, 28SR3 and GAPDH, were chosen as highly suitable RGs based on their stable expression pattern.

Comparative transcriptomics-based selection of suitable reference genes for normalization of RT-qPCR experiments in drought-stressed leaves of three European Quercus species

Reference genes for normalization of reverse transcription quantitative real-time PCR (RT-qPCR) experiments were selected and evaluated for drought-stressed leaves of three European Quercus species (Q. ilex, Q. pubescens, and Q. robur). A drought experiment was conducted over the course of 2 years. In the first year, a comparative transcriptome analysis was conducted between control and drought-stressed plants in all three species. Based on this analysis, six genes which showed a low fold change and low individual variation of normalized expression values were selected as novel candidate reference genes. The six novel candidate genes were homologs of the serine/threonineprotein kinase At1g54610 (At1g54610), ATP synthase gamma chain (ATPC1), far-red elongated hypocotyl 3-like (FHY3), 50S ribosomal protein L13 (RPL13), serine/threonine-protein phosphatise PP1 (TOPP2), and splicing factor U2af small subunit B-like (U2AF35B). As a control, the two classical candidate reference genes glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and elongation factor 1 alpha (EF1a) were included. Cross-species primers were designed for all candidate reference genes. The reference genes were evaluated in samples from three dates in the second year of the drought experiment. Four different algorithms (Bestkeeper, the comparative Ct method, geNorm, and Normfinder) were utilized to analyze expression stability. The results of the algorithms were summarized, and the most stable genes and optimal number of reference genes were identified for every species. These results demonstrated that, in each species, at least four of the novel reference genes are more stably expressed than the classical reference genes and that two reference genes are the optimal number for each species. One novel reference gene, At1g54610, was found to be among the two most stable reference genes across all three species; the second most stable gene was found to be TOPP2 in Q. ilex, U2AF35B in Q. pubescens, and FHY3 in Q. robur. Reference genes are crucial to normalize qPCR data and to identify stress-responsive genes, e.g., in the context of a search for drought-tolerant Quercus genotypes able to withstand the predicted increase of drought events in large parts of Europe during climate change.

Identification of suitable reference genes for gene expression studies in rat skeletal muscle following sciatic nerve crush injury.

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is a molecular biological method used to assess gene expression characterized by high simplicity, effectiveness, specificity and sensitivity. The selection of a suitable reference gene for normalization is critical for the accuracy of quantitative results. Peripheral nerve injury is a common clinical disorder that affects multiple tissues and organs, including peripheral nerves, neurons and the innervated muscles. Numerous genes are differentially expressed in skeletal muscles during muscle denervation and reinnervation following peripheral nerve injury. The identification of a suitable reference gene in innervated muscles following nerve injury may improve the understanding of the alterations in gene expression in the processes of peripheral nerve repair and regeneration. Therefore, in the present study, by using a rat sciatic nerve crush model, the expression levels of various housekeeping genes were examined. In particular, the expression levels of 13 housekeeping genes, including 18S ribosomal RNA, actin β, ankyrin repeat domain 27, cyclophilin A, GAPDH, hypoxanthine phosphoribosyltransferase 1 (HPRT1), mitochondrial ribosomal protein L10, phosphoglycerate kinase 1, RPTOR independent companion of mammalian target of rapamycin complex 2, TATA-box binding protein, ubiquitin C, UBX domain protein 11 and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein ζ, were investigated in gastrocnemius muscles. The geNorm and NormFinder analyses suggested that the expression level of HPRT1 was particularly stable in gastrocnemius muscles following rat sciatic nerve crush injury. Therefore, HPRT1 may be used as a reference gene for the normalization of gene expression data generated by RT-qPCR.

Selection of suitable reference genes for reverse transcription-quantitative polymerase chain reaction normalization in Artemisia annua L. plants at different stages of growth and development

Background: Artemisinin, an antimalarial compound suggested by the WHO to treat drug-resistant malaria, was obtained from Artemisia annua L. plants. However, due to the low level of artemisinin in the plant causes limitation to its commercialization, so to increase the concentration of artemisinin, two transgenic lines were developed by us, overexpressing the key genes of artemisinin biosynthetic pathway, namely, 3 S-hydroxy-3-methyl glutaryl-CoA reductase (HMGR), amorpha-4,11-diene synthase (ADS) (Trans. 1) and HMGR, ADS, and CYP71AV1 (cytochrome P450 monooxygenase) (Trans. 2). Objectives: Our main aim for this study was to select the suitable reference gene for the normalization of reverse transcription-quantitative polymerase chain reaction ( Reverse transcription RT-qPCR) data in different tissues at various developmental stages in A. annua L. plants. Materials and Methods: Six candidate reference genes, namely; β-actin (ACT), elongation factor 1-alpha (EF1α), TAP-42 interacting protein (TAP42), SAND family protein, β-tubulin, and protein phosphatase 2A (PP2A) for their expression stability in the root, stem, leaf, and flower of A. annua L. plants at vegetative, preflowering, and flowering stages were analyzed using geNorm, NormFinder and BestKeeper, the Excel-based research tools. Results: The genes ACT/PP2A, PP2A/TAP42, and EF1&#945/PP2A were appropriate as reference genes in the leaf tissues at vegetative, preflowering, and flowering stages, respectively. In addition, EF1&#945/PP2A genes at vegetative and flowering stage, while EF1&#945/TAP42 gene at preflowering stage was found suitable reference genes for normalization of expression data in the stem. In the root samples, ACT/EF1&#945, EF1&#945/PP2A, and ACT/TAP42 sets were found to be reliable reference genes at vegetative, preflowering, and flowering stages, respectively, whereas, PP2A/TAP42 gene set was found suitable for flower tissues at flowering stage. Conclusion: These results will be helpful in the normalization of expression data in RT-qPCR to find the reliable outcome.

Mir-16-5p as a Suitable Reference Gene for Normalization of Quantitative Real Time PCR in Acute Lymphoblastic Leukemia

mir-16-5p as a Suitable Reference Gene for Normalization of Quantitative Real Time PCR in Acute Lymphoblastic Leukemia

Selection of endogenous reference genes for qRT-PCR analysis in Camelina sativa and identification of FLOWERING LOCUS C allele-specific markers to differentiate summer- and winter-biotypes

Quantitative real-time polymerase chain reaction (qRT-PCR) analysis greatly relies on transcript normalization using stably expressed reference genes. This study identifies reference genes for qRT-PCR analysis in different organs and vernalized tissues of camelina (Camelina sativa). Nineteen stably expressed candidate reference genes from 22,157 genes were identified by RNAseq analysis of pre- and post-vernalized tissues of a summer- (CO46) and winter- (Joelle) biotype. Two additional candidate reference genes were also selected from orthologs of arabidopsis encoding ACTIN2 (ACT2) and NOT INDUCED BY SCLEROTINIA INFECTION (NIS). We also evaluated the transcript levels of three camelina plant genes, SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1), FLOWERING LOCUS C (FLC), and MADS AFFECTING FLOWERING 2 (MAF2), which are known to be differentially-regulated in response to cold temperatures. The stability of transcript abundance was ranked using NormFinder, geNorm, BestKeeper, and Comparative ΔCT software. EXOCYST COMPLEX COMPONENT SEC3A (SEC3A), UBIQUINONE OXIDOREDUCTASE (UbOxRed), and RING-U-BOX domains-containing protein (RUB) were the most suitable reference genes for normalization of gene expression in camelina. In this study, SEC3A was used to normalize qRT-PCR expression data obtained using two sets of allele-specific FLC markers to differentiate summer- and winter-biotypes across 30 accessions of camelina.