Como selecionar o gene de referência interno do arroz transgênico para identificação por PCR?

1. Selection Strategy for Reference Genes

The identification and screening of reference genes are fundamental to ensuring the reliability of experimental results in transgenic rice research.

2.1Basic Principles for Selection

Ideal reference genes should exhibit stable expression across different tissues, organs, developmental stages, and experimental conditions. A widely accepted criterion is a Cq value (Quantification Cycle) variation range of less than 2.5.

2.2Preliminary Screening Using Public Databases

Utilize public databases such as IC4R (Information Commons for Rice) and RiceXRro (Rice Expression Profile Database) for initial screening. Bioinformatics analysis can help identify candidate genes with stable expression under various conditions.

2.3Evaluation of Traditional and Novel Genes

(1) Traditional Genes: Commonly used reference genes include OsSBE4, RbcS, Act1, and SPS (Sucrose Phosphate Synthase Gene).

(2) Novel Stable Genes: Some studies recommend newer reference genes with demonstrated stability, such as UFC1 (Homolog of UFM1-Conjugating Enzyme 1) and FhaB (Homolog of Adhesin FhaB), which may outperform traditional ones in specific contexts.

2. Experimental Validation Steps

After selecting candidate reference genes, experimental validation is required, which primarily includes the following steps:

2.1Preparation of Experimental Materials

Collect a diverse set of rice samples, representing different varieties (por exemplo, japonica and indica), tissues/organs (por exemplo, roots, caules, folhas, anthers, seeds), developmental stages, and treatment conditions (por exemplo, biotic/abiotic stress). Include specific transgenic materials if applicable.

2.2RNA Extraction and cDNA Synthesis

Extract high-quality total RNA using reliable kits and reverse transcribe into cDNA. It is imperative to check RNA purity and integrity.

Using Shanghai LNJNBio Plant Total RNA Extraction Kit(Método de Conta Magnética) extract 20mg different kinds of plant leaves RNA，result as show below：

O eletroferograma é mostrado abaixo：

2.3 Primer and Probe Design

Design primers and probes for quantitative real-time PCR (qPCR) targeting the candidate reference genes. Key considerations include:

• Primers should span exon-exon junctions to prevent genomic DNA amplification.
• Amplicon length should ideally be between 80-200 bp.
• Employ the TaqMan probe method when higher specificity is required.

2.4qPCR Execution and Stability Assessment

• Perform qPCR amplification using SYBR Green or TaqMan chemistry.
• Record and analyze the Cq values for each candidate gene across all samples.
• Utilize specialized algorithms (por exemplo, geNorm, NormFinder, BestKeeper) to evaluate expression stability and select the most stable reference gene(é).

3. Applications in Transgenic Research

Validated reference genes are crucial for various applications in transgenic rice studies:

3.1Determination of Transgene Copy Number

Use qPCR or digital PCR (dPCR) with a single-copy reference gene as a calibrator to quantitatively determine the copy number of integrated T-DNA in the rice genome.

3.2Rapid Screening of Homozygous Transgenic Lines

Employ qPCR analysis comparing reference and transgene signals (por exemplo, via ΔΔCt method) to accurately identify homozygous single-insertion lines in the T1 generation, significantly accelerating the breeding process.

3.3Analysis of Transgene Expression Levels

In functional studies, use stable reference genes for normalization to precisely quantify transgene transcript levels across different transgenic lines.

3.4Detection of Transgenic Components

In diagnostic settings, reference genes serve as internal positive controls to monitor DNA extraction quality and PCR efficiency. Multiplex real-time PCR methods can be developed to simultaneously detect target transgenes (por exemplo, promoter, terminator, marker genes) and the reference gene, enabling high-throughput analysis.

4. Project Considerations

To ensure project success and result reliability, adhere to the following:

4.1 Include Appropriate Controls

Always include positive controls (por exemplo, plasmids with target sequences) and negative controls (no-template controls) in PCR assays to rule out false positives/negatives.

4.2 Continuous Optimization of Reference Genes

No reference gene is universally perfect. Re-validate or screen for the most suitable reference gene(é) under specific experimental conditions.

4.3 Adherence to Relevant Standards

If the research involves detection of genetically modified components, follow applicable national (por exemplo, GB/T series) or international (por exemplo, ISO standards) guidelines to ensure procedural compliance.

5. Project Workflow Summary

A systematic approach for a reference gene identification project is as follows:

• Define Research Scope: Clarify whether a universal reference gene is needed or one for specific conditions (por exemplo, specific tissue, stress).
• Select Candidate Genes: Choose a set of candidate genes based on literature and database mining.
• Validate Stability: Experimentally assess and identify the most stably expressed gene(é) using qPCR and bioinformatics tools across a representative sample set.
• Apply in Research: Implement the validated reference gene(é) in practical transgenic rice research applications.

Fornecedor

Xangai Lingjun Biotecnologia Co., Ltda.foi estabelecido em 2016 que é um fabricante profissional de materiais biomagnéticos e reagentes de extração de ácido nucleico.

Temos vasta experiência em extração e purificação de ácidos nucleicos, purificação de proteínas, separação celular, quimioluminescência, e outras áreas técnicas.

Nossos produtos são amplamente utilizados em muitos campos, como exames médicos, testes genéticos, pesquisa universitária, melhoramento genético, e assim por diante. Nós não apenas fornecemos produtos, mas também podemos realizar OEM, ODM, e outras necessidades. Se você tiver uma necessidade relacionada, não hesite em contactar-nos .