Regulation of skeletal muscle stem cells for meat production

Regulation of skeletal muscle stem cells for meat production

Tomohide Takaya.

Institute for Biomedical Sciences, Faculty of Agriculture, Graduate School of Science and Technology, Shinshu University, Nagano, Japan.

2017 Japan-Thailand International Symposium on Animal Biotechnology (Ina, Japan), 2017/07/05 (Invited lecture).

Abstract

Skeletal muscle, which generates a great power for active behaviors, is the largest tissue in animals and also important for us as meat. Muscle tissue is composed of numerous myofibers that are multinuclear contractile cells. During development, myofibers are formed by fusion of myogenic progenitor cells called myoblasts. After birth, myofibers grow by fusion of satellite cells, which are muscle stem cells existing between basal lamina and cell membrane of myofibers. Understanding and regulating cell characteristics of satellite cells and myoblasts are crucial issues for meat production.

We have been screening natural molecules that act on myoblasts and are available as a feed for domestic animals. Now we are focusing on the short single-stranded DNA derived from genome sequence of lactic acid bacterium, Lactobacillus rhamnosus GG. This oligonucleotide named "myoDN" intensively promotes myogenic differentiation of mammalian and avian myoblasts. Around 40% of the myoblasts treated with myoDN terminally differentiate into myocytes within 48 hours in vitro. myoDN is expected to enhance skeletal muscle development and growth, and finally to improve meat yield.

The technology to regulate myoblasts is also essential to produce in vitro muscle or meat. We recently developed the hybrid muscle cells of mouse and chicken, which is the first evidence for the autonomous xenogenic fusion of mammalian and avian cells. Myoblast-based fusogenic technique will contribute to create novel and unique muscle products.