Mammalian mRNA splice-isoform selection is tightly controlled

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• Post-transcriptional RNA processing, particularly alternative splicing, is crucial for eukaryotic cell phenotype determination.
• Alternative splice isoforms enable diverse cellular functions, with cells actively controlling their relative quantities.

Purpose of the Study:

• To investigate the extent of interindividual variation in alternative splice isoform selection.
• To determine if splice-isoform ratios are conserved across different populations and tissues.

Main Methods:

• Quantitative reverse transcription-PCR (qRT-PCR) was used to examine alternatively spliced isoforms of five mRNA transcription units.
• Analysis was performed on a large population of genetically diverse mice (N=150) and a second, distinct population.

Main Results:

• Splice-isoform selection exhibited highly constrained interindividual variation, representing one of the most invariant phenotypes observed.
• These findings were confirmed in a second, genetically distinct mouse population.
• Tissue-specific and age-related changes in splice-isoform selection patterns were identified.

Conclusions:

• Splice-isoform selection is exceptionally robust to genetic and environmental variability, suggesting a role in maintaining cellular homeostasis.
• Stable splice-isoform ratios may serve as a practical quantitative biomarker for assessing the physiological status of cells and tissues.