Specific cleavage of 28S ribosomal RNA in murine coronavirus-infected cells

Identification and Validation of Reference Genes for RT-qPCR Normalization in Mythimna separata (Lepidoptera: Noctuidae)

Mythimna separata is a major agricultural pest with seasonal migrating trait in China. Formation and regulation mechanism of migration behavior has resulted in a large number of fundamental researches involving quantitative studies of gene expression in this species. Using appropriate reference gene is critical in RT-qPCR data normalization. A comprehensive study on the reference genes in M. separata is lacking. In this paper, expression stabilities of ten candidate reference genes were evaluated in M. separata under various biotic and abiotic conditions by employing four different software geNorm, NormFinder, BestKeeper, and the comparative ΔCT method. The comprehensive stabilities ranking of these genes were suggested by RefFinder. PKG as a target gene was employed to justify the number of reference genes in four larval tissues and two photoperiod treatments. Results demonstrate that the first three most stable genes were as follows: EF, CypA, and β-TUB for developmental stages; EF, CypA, and RPL12 for larval tissues; EF, TBP, and β-TUB for adult tissues. RPL12, β-TUB, and EF for densities; EF, RPL12, and GAPDH for photoperiod treatments; β-TUB, EF, and ATPase for temperature treatments. Stable reference gene combinations may reduce bias in normalization. This work provides for the first time a comprehensive list of appropriate reference genes and facilitates future studies on gene function of M. separata.

Quantitative reverse transcriptase real-time polymerase chain reaction (qRT-PCR) in translational oncology: lung cancer perspective

Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) is rapidly becoming a basic method in lung cancer research. Analysis of transcriptional activity of tumor cells or detection of tumor markers by this technique has the potential to change lung cancer diagnosis and treatment. Quantitative RT-PCR is characterized by unparalleled sensitivity and specificity, with very reliable reproducibility. Its prime advantage for gene expression analysis is its broad dynamic range of 10(7)-fold. Moreover, it is cost-effective, feasible in every day laboratory routine and efficient in terms of biological material consumption. Still, there are a number of methodological aspects that need to be carefully considered before it can sensibly be implemented into clinical practice. Three major technical issues: the choice of chemistries, gene expression data normalization and statistical processing of the results will be specifically highlighted in this review. Further, clinical applications of qRT-PCR will be thoroughly discussed: detection and staging of lung cancer and construction and validation of prognostic and predictive gene expression signatures.

Real-time PCR for mRNA quantitation

Real-time PCR has become one of the most widely used methods of gene quantitation because it has a large dynamic range, boasts tremendous sensitivity, can be highly sequence-specific, has little to no post-amplification processing, and is amenable to increasing sample throughput. However, optimal benefit from these advantages requires a clear understanding of the many options available for running a real-time PCR experiment. Starting with the theory behind real-time PCR, this review discusses the key components of a real-time PCR experiment, including one-step or two-step PCR, absolute versus relative quantitation, mathematical models available for relative quantitation and amplification efficiency calculations, types of normalization or data correction, and detection chemistries. In addition, the many causes of variation as well as methods to calculate intra- and inter-assay variation are addressed.