Combining RT-PCR-seq and RNA-seq to catalog all genic elements encoded in the human genome.

Area of Science:

• Genomics
• Transcriptomics
• Bioinformatics

Background:

• The GENCODE project aimed to comprehensively annotate the human genome.
• Accurate gene annotation is crucial for understanding human biology and disease.
• Existing methods like RNA sequencing have limitations in detecting low-expressed transcripts.

Purpose of the Study:

• To experimentally validate GENCODE's human genome annotation.
• To assess the efficiency of RT-PCR-seq for transcript validation.
• To discover novel genes and exons in the human genome.

Main Methods:

• Manual curation and computational methods for gene annotation.
• Reverse transcription PCR amplification followed by sequencing (RT-PCR-seq) for junction validation.
• Utilized Human Body Map (HBM) RNA-seq data for gene model prediction.

Main Results:

• RT-PCR-seq confirmed 79% of assessed exon-exon junctions in the GENCODE gene set.
• Validated 73% of predicted gene models from HBM RNA-seq data.
• Discovered 1168 novel genes, predominantly noncoding, and identified unannotated exons in ~11% of introns.

Conclusions:

• RT-PCR-seq is a highly sensitive and efficient method for experimental validation of transcript structures.
• A combination of unbiased (RNA-seq) and targeted (RT-PCR-seq) approaches is necessary for comprehensive human genome cataloging.
• The study highlights the ongoing need for refining and expanding the human gene catalog.