Abstract
BACKGROUND/OBJECTIVES: Muscle aging is a complex, dynamic process that impairs overall metabolism and physiological function. The molecular mechanisms underlying declines in muscle performance and metabolic efficiency remain poorly understood, largely due to the time and resource demands of traditional model organisms. The hawk moth Manduca sexta offers a promising alternative, with a short adult lifespan (~10 days) and notable similarities to vertebrate muscle systems, making it well-suited for time-course molecular dissection of muscle aging. METHODS: In this study, we performed high-resolution temporal analysis of muscle tissues from aging M. sexta, spanning the physiomuscular aging process from middle age to advanced age. RESULTS: We observed decreased expression of genes involved in fatty acid β-oxidation, ATP synthase subunits, superoxide dismutase, glutathione S-transferases, and heat shock proteins. In contrast, genes associated with proteolysis, catabolic processes, insulin signaling, akirin, titin, high-affinity choline transporters, and vesicular acetylcholine transporters were increased in expression. CONCLUSIONS: These changes suggest a shift toward increased proteolysis and protein catabolism with age. Our findings support the use of M. sexta as a complementary model for muscle aging research. However, it remains unclear whether the observed gene expression changes are driven by intrinsic, sex-specific age-related muscle aging or confounded by potential starvation effects in older males.