A possible approach to enrich cDNA yields with full-length molecules

Area of Science:

• Molecular Biology
• Virology

Background:

• Eukaryotic messenger RNAs (mRNAs) exist as ribonucleoproteins (mRNPs) in cell cytoplasm.
• Free RNases in cell sap can degrade mRNA during extraction, impacting downstream applications.

Purpose of the Study:

• To develop an improved method for synthesizing complementary DNA (cDNA) from Newcastle disease virus (NDV)-specific hemagglutinin-neuraminidase (HN) mRNA.
• To enhance the suitability of mRNA templates for cDNA synthesis by minimizing enzymatic degradation.

Main Methods:

• Isolation of polyadenylated RNAs from the particulate fraction of cytoplasmic extracts of NDV-infected cells to obtain mRNPs.
• Separation of mRNPs from cell sap RNases prior to RNA extraction.
• Synthesis and cloning of cDNAs into lambda gt10 phage.
• Identification and analysis of phages containing HN-specific inserts, verifying the presence of the 5' terminus.

Main Results:

• Approximately 300 Newcastle disease virus (NDV)-specific hemagglutinin-neuraminidase (HN) phages were identified from 50,000 recombinants.
• Analysis of nine clones confirmed the presence of the 5' terminus in all HN cDNA inserts.
• The results indicate successful cDNA synthesis from intact mRNA templates.

Conclusions:

• Separating ribonucleoproteins (mRNPs) from cell sap RNases before RNA extraction significantly improves mRNA template suitability for cDNA synthesis.
• This method enhances the efficiency and integrity of cDNA synthesis for viral gene studies.