Transcriptome analysis of human tissues and cell lines reveals one dominant transcript per gene

Area of Science:

• Molecular Biology
• Genomics
• Transcriptomics

Background:

• RNA sequencing (RNA-seq) reveals extensive human transcriptome complexity with over 100,000 distinct transcripts.
• The relative abundance and functional significance of different transcripts from the same gene remain incompletely understood.

Purpose of the Study:

• To investigate the prevalence and dominance of specific transcripts within the human transcriptome.
• To determine the contribution of major transcripts to overall gene expression and proteome diversity.

Main Methods:

• Analysis of RNA sequencing data to quantify transcript abundances across various human tissues.
• Comparison of identified major transcripts with databases of alternatively spliced and translated transcripts.

Main Results:

• In specific conditions, most protein-coding genes exhibit one dominant transcript, accounting for approximately 85% of total mRNA from protein-coding loci.
• A high degree of overlap exists between major transcripts and predicted translated, alternatively spliced transcripts.
• A notable fraction of genes show a major transcript that does not encode a protein.

Conclusions:

• The human transcriptome from protein-coding loci is largely dominated by a single major transcript per gene.
• Transcriptome diversity does not directly equate to protein diversity, as major transcripts are the primary contributors to the proteome.
• Findings can guide target prioritization in proteomics and enhance the interpretation of variation studies.