Aptamer-dependent full-length cDNA synthesis by overlap extension PCR

Area of Science:

• Molecular Biology
• Genomics
• Biotechnology

Background:

• Human genome sequencing has identified numerous predicted genes, but corresponding complementary DNAs (cDNAs) are often unavailable.
• Existing gene collections lack comprehensive coverage of diverse gene transcripts and alternative splice variants.
• Efficient in vitro synthesis of full-length cDNAs and novel splice variants is crucial for biological research.

Purpose of the Study:

• To establish optimal polymerase chain reaction (PCR) conditions for direct amplification of exons from genomic DNA.
• To develop a method for synthesizing full-length cDNAs and alternative splice variants.
• To demonstrate the effectiveness of the approach using the human mitochondrial aldehyde dehydrogenase 2 (ALDH2) gene.

Main Methods:

• Developed specific PCR conditions utilizing a Taq aptamer for direct amplification of exons from genomic DNA.
• Employed overlap extension to concatenate differentially tagged PCR-amplified exons into full-length cDNAs.
• Synthesized the 1900-bp open reading frame of the human ALDH2 gene in a two-step reaction.

Main Results:

• Successfully established optimal PCR conditions for direct exon amplification from genomic DNA.
• Demonstrated the concatenation of amplified exons into full-length cDNAs via overlap extension.
• Successfully synthesized the complete 13-exon ALDH2 gene cDNA, validating the method's efficacy.

Conclusions:

• The developed PCR conditions and cDNA synthesis strategy are effective for generating full-length cDNAs.
• This method facilitates the in vitro synthesis of novel splice variants and cDNAs for uncharacterized genes.
• The approach holds general value for molecular biology research, enabling efficient cDNA construction from genomic DNA.