Assessment of internal controls for data normalization of gene expression after different bacterial stimulation by quantitative real-time PCR in golden pompano Trachinotus blochii

Trachinotus blochii is one of the important commercial fish species.In this study,we aim to confirm the reliability reference genes in T.blochii during different bacterial challenge through quantitative real-time PCR(qRT-PCR).The expression of the seven selected genes in four immune organs(i.e.,spleen,kidney,intestine,and gill)stimulated with Vibrio harveyi,Edwardsiella tarda,and Streptococcus agalactiae were determined by qRT-PCR.The PCR data was analyzed using the geNorm and NormFinder algorithms.The results showed the selection of the internal controls should be tissue specific when studying gene expression in response to bacterial stimulation.After 48 h of stimulation with V.harveyi,geNorm ranked EF1 A/Actin,18 S rRNA/B2M,UBCE/B2M,and 18 S rRNA/B2M,as the most stably expressed genes in spleen,kidney,intestine,and gill,respectively.After 48 h of stimulation with E.tarda,geNorm ranked 18 S rRNA/EF1 A,18 S rRNA/B2M,B2M/RPL13,and 18 S rRNA/EF1 A,as the most stably expressed genes in spleen,kidney,intestine,and gill,respectively.After 48 h of stimulation with S.agalactiae,18 S rRNA/EF1 A,18 S rRNA/B2 M,B2 M/Actin,and 18 S rRNA/B2M were ranked as the most stably expressed genes in spleen,kidney,intestine,and gill,respectively.Compared to the results analyzed by geNorm,reference genes received similar rankings when using NormFinder software.The results showed that the reference genes appeared to be not only tissue specific,but also specific to the infecting species of bacteria.If one gene is preferred when T.blochii were infected by bacteria,18 S rRNA,B2M,B2M,18 S rRNA may be used in spleen,kidney,intestine,and gill,respectively.

Transcriptional search to identify and assess reference genes for expression analysis in Solanum lycopersicum under stress and hormone treatment conditions

Tomato(Solanum lycopersicum)is a model plant for research on fruit development and stress response,in which gene expression analysis is frequently conducted.Quantitative PCR(qPCR)is a widely used technique for gene expression analysis,and the selection of reference genes may affect the accuracy of results and even conclusions.Although there have been some frequently used reference genes in tomato,it has been shown that the expressions of some of these genes are not constant in different tissues and environmental conditions.Moreover,little information on genomic identification of reference genes is available in tomato.Here,we mined the publicly available transcriptional sequencing data and screened out fifteen candidate reference genes,and the expression stability of these candidate genes and seven traditionally used ones were evaluated under stress and hormone treatment.The results showed that over half of the selected candidate references were housekeeping genes in tomato cells.Among the candidate reference genes and the traditionally used ones,the most stably expressed genes varied under different treatments,and most of these genes were recommended as preferred reference genes at least once except Solyc04g009030 and Solyc07g066610,two traditionally used reference genes.This study provides some novel reference genes in tomato,and the preferred reference genes under different environmental stimuli,which may be useful for future research.Our study suggests that excavating stably expressed genes from transcriptome sequencing data is a reliable approach to screening reference genes for qPCR analysis.

Selection of suitable internal controls for gene expression normalization in rats with spinal cord injury

There is a lack of systematic research on the expression of internal control genes used for gene expression normalization in real-time reverse transcription polymerase chain reaction in spinal cord injury research.In this study,we used rat models of spinal cord hemisection to analyze the expression stability of 13 commonly applied reference genes:Actb,Ankrd27,CypA,Gapdh,Hprt1,Mrpl10,Pgk1,Rictor,Rn18s,Tbp,Ubc,Ubxn11,and Ywhaz.Our results show that the expression of Ankrd27,Ubc,and Tbp were stable after spinal cord injury,while Actb was the most unstable internal control gene.Ankrd27,Ubc,Tbp,and Actb were consequently used to investigate the effects of internal control genes with differing stabilities on the normalization of target gene expression.Target gene expression levels and changes over time were similar when Ankrd27,Ubc,and Tbp were used as internal controls but different when Actb was used as an internal control.We recommend that Ankrd27,Ubc,and Tbp are used as internal control genes for real-time reverse transcription polymerase chain reaction in spinal cord injury research.This study was approved by the Administration Committee of Experimental Animals,Jiangsu Province,China(approval No.20180304-008)on March 4,2018.

Screening of stable internal reference genes by quantitative real-time PCR in humpback grouper Cromileptes altivelis

Humpback grouper Cromileptes altivelis is one commercial fish with considerable economic value.To determine the expression stabilities of six commonly used internal reference genes in C.altivelis challenged by Vibrio harveyi and viral nervous necrosis virus(VNNV)through quantitative real-time PCR(qRT-PCR),the expression levels of selected genes in five immune organs stimulated with pathogenic infection were carefully evaluated using algorithms of geNorm,NormFinder,and BestKeeper.The results show that the expre ssion stabilities of the six candidate inte rnal reference genes were diffe re nt.Under no rmal physiological conditions,RPL13 were identified as the most stably expressed genes among five different immune organs(liver,spleen,kidney,intestine,and gill).After V.harveyi stimulation,RPL13,RPL13,EF1 A,RPL13,and EF1 A were identified by geNorm,NormFinder,and BestKeeper as the most stable genes in liver,spleen,kidney,intestine,and gill,respectively.Combining these three algorithms suggested that under stimulation of VNNV,RPL13,EF1 A,Actin,RPL13,and Actin were as the most stable genes in liver,spleen,kidney,intestine,and gill,respectively.These results suggest that specific experiment conditions and tissue types shall be considered when selecting the reference genes in qRT-PCR analysis.This study provided a solid foundation for future studies on gene expression of C.altivelis under different conditions.

Assessment of suitable reference genes for qRT-PCR analysis in Adelphocoris suturalis

Quantitative reverse transcription polymerase chain reaction(qRT-PCR) is the most commonly-used tool for measurement of gene expression, but its accuracy and reliability depend on appropriate data normalization with the use of one or more stable reference genes. Adelphocoris suturalis is one of the most destructive pests of cotton, but until recently knowledge of its underlying molecular physiology had been hindered by a lack of molecular resources. To facilitate research on this pest, we evaluated 12 common housekeeping genes studied in insects(GAPDH, ACT, βACT, TBP, SDH, βTUB, EF1γ, EF1α, EF1δ, RPL32, RPS15, and RPL27) for their expression stability in A. suturalis when subjected to various experimental treatments, including three biotic(developmental stage and sex, tissue type, and metathoracic scent gland for varying developmental stages and sexes) and one abiotic(RNA interference injection) conditions. Four dedicated algorithms(ΔCt method, geNorm, BestKeeper and NormFinder) were used to analyze gene expression stability. In addition, RefFinder provided an overall ranking of the stability/suitability of these candidates. This study is the first to provide a comprehensive list of suitable reference genes for gene expression analyses in A. suturalis, which can serve to facilitate transcript expression study of related biological processes in this and related species.