Integrated genomic analysis reveals key features of long undecoded transcript isoform-based gene repression

Area of Science:

• Molecular Biology
• Genetics
• Gene Regulation

Background:

• Long undecoded transcript isoforms (LUTIs) are non-canonical mRNAs known to repress gene expression.
• Previous studies focused on individual genes, leaving the global impact of LUTIs on gene regulation unclear.

Purpose of the Study:

• To investigate the global effects of LUTIs on gene expression during meiotic prophase.
• To identify factors predicting LUTI-mediated transcriptional repression.

Main Methods:

• Transcript leader sequencing and direct RNA sequencing were employed.
• Analysis included identifying LUTI candidates and assessing translational and transcriptional repression mechanisms.

Main Results:

• Identified 74 LUTI candidates induced in meiotic prophase.
• Found ubiquitous translational repression dependent on upstream open reading frames.
• Demonstrated variable LUTI-based transcriptional repression (50% of cases).
• Higher LUTI expression, H3K36 trimethylation, and nucleosome positioning predicted transcriptional repression.

Conclusions:

• LUTIs globally downregulate gene expression through a combination of translational repression and chromatin state changes.
• The magnitude of LUTI expression is a key determinant of transcriptional repression effectiveness.