Speaker: Professor Yusuke Ono, Department of Muscle Development and Regeneration, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Japan 

Host: Pete Zammit

Skeletal muscle is the contractile tissue that occupies approximately 40% of an individual’s body weight. Its size and shape are anatomically and physiologically diverse, presenting a variety of functions such as movement, respiration, articulation, facial expression and mastication. Muscle resident stem cells (satellite cells) have heterogeneous properties in different muscles, which may correspond to region-specific pathophysiology. However, region specific genes that have functions in satellite cells remain unknown. In my talk, I will describe how positional memory as regional identities influences muscle regeneration. We performed global DNA methylome and transcriptome analyses on different muscles and satellite cells to comprehensively uncover region-specific epigenetic and transcriptional properties in adult mice. We find that homeobox (Hox) genes mediate positional memory based on embryonic origin and anatomical location, which dictates satellite cell function in a regionally specific manner in adults. I will also discuss how the microenvironment controls skeletal muscle mass in disease conditions. Our results suggest that positional memory and microenvironment should be considered for the development of efficient regenerative therapies for muscle disorders such as muscular dystrophy and age-related sarcopenia.