ABSTRACT
ObjectiveTo screen the appropriate reference genes for real-time fluorescence-based quantitative polymerase chain reaction（Real-time PCR）analysis of the Andrographis paniculata under methyl jasmonate（MeJA）and various abiotic stresses. MethodThe actin 1（ACT1），actin 2（ACT2），elongation factor（EF-1α），glyceraldehyde-3-phosphate dehydrogenase（GAPDH），tubulin（TUB），polyubiquitin（UBQ）， and 18S rRNA（18S）gene were selected as candidate reference genes based on the RNA-seq data of high temperature，drought， UV， and MeJA. The expression of seven candidate reference genes in the A. paniculata leaves was assessed by Real-time PCR，and the stability was analyzed by geNorm，NormFinder，BestKeeper， and Refinder. ResultThe results of stability evaluated by geNorm，NormFinder， and BestKeeper were not the same due to different indicators. As analyzed by Refinder， for the stability of the expression， the genes were ranked as UBQ>18S>EF-1α>ACT2>ACT1>GAPDH>TUB under high temperature stress， ACT1>UBQ>EF-1α>18S>ACT2>GAPDH>TUB under drought stress， EF-1α>TUB>ACT2>UBQ>18S>GAPDH>ACT1 under UV stress， and ACT1>EF-1α>UBQ>ACT2>18S>TUB>GAPDH under MeJA stress. Among them，18S gene was not suitable as an internal reference gene duo to its high expressive abundance. This study also verified the relative expression level of andrographolide synthesis-related gene hydroxy-methylglutaryl-CoA synthase （HMGS） in the four stresses on the basis of transcriptome data，and found that the Real-time PCR results of appropriate internal reference genes were accurate and reliable. ConclusionUBQ-ACT1-UBQ，EF-1α-TUB，and ACT1-EF-1α were the suitable combinations under stresses of high temperature，drought，UV， and MeJA. This study is expected to provide references for the research on function regulation and expression of genes in A. paniculata under high temperature，drought，UV， and MeJA stresses.
ABSTRACT
Objective: To clone and screen the stable internal reference genes from Dipsacus asper for qRT-PCR analysis correction, so as to provide a preliminary basis for future research on expression analysis and regulation mechanism of D. asper functional genes. Methods: The internal reference genes of Actin, Tubulin and GAPDH gene families were screened and cloned from D. asper transcriptome database. The D. asper plants from different origins, different tissues and different developmental stages were used to obtain expression information of each gene by qRT-PCR. The expression stability of each gene was analyzed by geNorm, NormFinder, BestKeeper, Delta CT and RefFinder, and the best genes were synthetically evaluated and screened. Results: Ten core fragments for candidate internal reference genes were cloned, belonging to three gene families: Actin, Tubulin and GAPDH, with high homology among them. The results of stability analysis showed that the expression of DaACT103 was stable and relatively high in different regions and tissues, while the expression of DaTUB5 was stable and relatively low in different developmental stages. Conclusion:s DaACT103 and DaTUB5 are suitable as the internal reference genes for D. asper. DaACT103 is used as the internal reference gene with high abundances and DaACT105 is used as the internal reference gene with low abundances.
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Objective·To compare the quality of RNA extracted from fresh and formalin-fixed paraffin-embedded (FFPE) brain tissues and to explore the long non-coding RNA (IncRNA) expression level.Methods·FFPE samples stored under various conditions and paired frozen brain tissues were collected and total RNA qualities were then detected.Amplification efficiency (AE) and expression stability of each RNA marker were calculated and analyzed based on real-time quantitative PCR.After selecting reference biomarkers,normalized △ Ct values of candidate makers within different amplicon size were measured to assess the possibility of lncRNA quantification in FFPE tissues.Results·The purity of RNA extracted from FFPE was relatively high,but the RNA integrity was lower than fresh samples.All biomarkers were successfully amplified and amplification efficiencies of long-chain RNA markers were correlated with amplicon sizes,sample treatment and preservation conditions,namely temperature and storage time.5S,miR-9 and miR 125b achieved optimal AE and showed quite stable expression in all specimens,therefore they were chosen as control markers.Compared with fresh samples,the △ Ct values of only 2 lncRNA (HAR1F and MALAT1-L,whose amplicon size were both higher than 200 bp,respectively) increased in the FFPE samples kept in 4 ℃,while in FFPE tissues kept in room temperature,increments of the △ Ct values were significant for most target genes except for short amplicon markers (＜60 bp),which showed consistently stable expression in all brain specimens.Conclusion·RNA integrity is affected by sample treatment and preservation conditions,but IncRNA expression levels in FFPE tissues can be accurately quantificated by using optimal amplicon sizes and considerable reference markers.
ABSTRACT
The development and metabolism of medicinal plant is affected by many factors, among which the effect from endophytic fungi has been noticed recently and has become one of hot fields. In order to explore the effect of endophytic fungi on gene expression in R. crenulata, RNA-sequencing was used to find genes involved in metabolic pathways, and the differential genes were verified by real-time fluorescent quantitative PCR. The method of 2-△△Ct was used to analyze the relative expression levels of genes in related metabolic pathways, which was used to verify the result of transcriptomics sequencing. The results showed that the endophytic fungus, P. fortinii, could up-regulate the gene expression in lipid metabolic pathway of R. crenulata. In signal transduction pathway, the genes were influenced at different level but the gene expressions were significantly increased under control of Notch signaling pathway, which was 34 times of that in control. The gene expressions of environmental adaption pathway were up-regulated in R. crenulata after inoculation of P. fortinii. This study could provide help for further understanding on mechanism of plant-fungus interaction, root cause of geoherbalism of medicinal plant and exploring bio-function of endophytic fungi.
ABSTRACT
Objective: To compare the quality of RNA extracted from fresh and formalin-fixed paraffin-embedded (FFPE) brain tissues and to explore the long non-coding RNA (lncRNA) expression level. Methods: FFPE samples stored under various conditions and paired frozen brain tissues were collected and total RNA qualities were then detected. Amplification efficiency (AE) and expression stability of each RNA marker were calculated and analyzed based on real-time quantitative PCR. After selecting reference biomarkers, normalized △ Ct values of candidate makers within different amplicon size were measured to assess the possibility of lncRNA quantification in FFPE tissues. Results: The purity of RNA extracted from FFPE was relatively high, but the RNA integrity was lower than fresh samples. All biomarkers were successfully amplified and amplification efficiencies of long-chain RNA markers were correlated with amplicon sizes, sample treatment and preservation conditions, namely temperature and storage time. 5S, miR-9 and miR-125b achieved optimal AE and showed quite stable expression in all specimens, therefore they were chosen as control markers. Compared with fresh samples, the △ Ct values of only 2 lncRNA (HAR1F and MALAT1-L, whose amplicon size were both higher than 200 bp, respectively) increased in the FFPE samples kept in 4 ℃, while in FFPE tissues kept in room temperature, increments of the △ Ct values were significant for most target genes except for short amplicon markers (<60 bp), which showed consistently stable expression in all brain specimens. Conclusion: RNA integrity is affected by sample treatment and preservation conditions, but lncRNA expression levels in FFPE tissues can be accurately quantificated by using optimal amplicon sizes and considerable reference markers.
ABSTRACT
Objective To evaluate the stability of U6 and let-7a as internal reference genes of miRNAs in RTqPCR by using femoral head samples of cartilage tissue from inbred DA rats.Methods Total RNA was extracted from femoral head cartilage tissues of female DA rats at three different time points,i.e.at birth (D0),ablactation (D21) and maturation (D42).The expressions of different miRNAs (miR-1,-25,-26a,-140,-146a,-150,-181a,-195,-223 and-337) were detected by RT-qPCR using U6 or let-7a as the internal reference.The two sets of miR expression were compared with the results from Solexa sequencing in our pioneer work to evaluate the stability of the two internal references.Results The relative values of U6 (P =0.045) and let-7a (P =0.021 5) revealed significant difference in the D42 sample.Both in U6 and let-7a systems,miR-26a,-140,-223,and-337 showed a similar tendency in expression and quantification but miR-1 and-146a did not have significant differences.miR-25,-150,-181a and-195 differed significantly (P＜0.05).Comparison of absolute quantification results between the two generations' sequencing showed that let-7a is more stable than U6.Conclusion Let-7a is more suitable to be used as the internal reference gene in RT-qPCR for miRNAs in cartilage tissue.