Caprine sex affects skeletal muscle profile and MRFs expression during postnatal development

Area of Science:

• Animal Genetics and Molecular Biology
• Skeletal Muscle Physiology

Background:

• Myogenic regulatory factors (MRFs) are crucial for mammalian skeletal muscle development.
• Research on MRFs in small ruminants, particularly goats, is limited.
• The influence of gender on skeletal muscle development and MRF expression in goats is largely unknown.

Purpose of the Study:

• To identify and characterize caprine MRF genes (Myf5, Myf6, MyoD, myogenin).
• To quantify the expression levels of these MRFs at different postnatal ages.
• To determine the effects of gender on MRF expression and skeletal muscle development in goats.

Main Methods:

• Gene identification and sequencing of caprine Myf5, Myf6, MyoD, and myogenin.
• Real-time RT-PCR for quantifying gene expression across six postnatal time points.
• Histological analysis of muscle tissue to assess muscle fiber diameter and gender differences.

Main Results:

• Significant gender-based differences were observed in the expression of Myf5, MyoD, and myogenin across five skeletal muscles.
• Myf6 expression showed minor gender influence, except in Semitendinosus and Quadriceps femoris muscles (P < 0.001).
• Muscle fiber diameter increased with age, with no significant gender-related differences.

Conclusions:

• Caprine MRF expression is dependent on both age and gender.
• These findings highlight MRFs as potential candidate genes for goat trait-associated studies.
• Provides a foundation for understanding the molecular regulation of skeletal muscle growth in goats.