High-resolution genome-wide expression analysis of single myofibers using SMART-Seq

Area of Science:

• Molecular Biology
• Skeletal Muscle Physiology
• Genomics

Background:

• Skeletal muscle comprises diverse myofibers with varied metabolic and contractile functions.
• Existing biochemical and histological methods lack efficiency for whole transcriptome analysis of individual myofibers.
• A need exists for advanced techniques to study myofiber heterogeneity at the transcriptomic level.

Purpose of the Study:

• To introduce and validate a novel single-myofiber RNA-sequencing (smfRNA-Seq) method.
• To analyze the whole transcriptome of individual skeletal muscle fibers.
• To investigate age-related transcriptomic differences in mouse myofibers.

Main Methods:

• Development of a single-myofiber RNA-sequencing (smfRNA-Seq) approach.
• Integration of single-fiber isolation with Switching Mechanism at 5' end of RNA Template (SMART) technology.
• Transcriptomic analysis of myofibers from young and old mice.

Main Results:

• smfRNA-Seq successfully determined gene expression in whole muscle, including nonmyogenic cells.
• Significant age-related alterations in metabolic genes (e.g., Nos1) and structural genes (e.g., Myl1) were identified.
• The method demonstrated effectiveness in capturing transcriptomic variations between different age groups.

Conclusions:

• smfRNA-Seq is a powerful and efficient tool for analyzing the whole transcriptome of individual skeletal muscle fibers.
• This technique facilitates the study of developmental, disease-related, and age-related changes in skeletal muscle gene expression.
• The findings highlight the impact of aging on key genes within myofibers.