Adipogenic - myogenic regulation leads effective meat production

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K08065
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Animal production science
• Research Institution: Kyushu University
• Principal Investigator: Nakamura Mako 九州大学, 農学研究院, 准教授 (80452746)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: Pax7 / Adipogenesis / Cell specific expression / Lipid droplet / Inhibition / PPARgamma

Outline of Final Research Achievements

Myogenesis is precisely proceeded by myogenic regulatory factors. Myogenic stem cells are activated, proliferated and fused into a multinuclear myofiber. Pax7, paired box 7, one of the earliest markers during myogenesis. It has been reported that Pax7 regulates the muscle marker genes, Myf5 and MyoD toward differentiation. The possible roles of Pax7 in myogenic cells have been well researched. However, it has not yet been clarified if Pax7 itself is able to induce myogenic fate in non-myogenic lineage cells. In this study, we performed experiments using stably expressed Pax7 in 3T3-L1 preadipocytes to elucidate if Pax7 inhibits adipogenesis. We found that Pax7 represses adipogenic markers and prevents differentiation. These cells showed decreased expression of PDGFRalpha, PPARganma and Fabp4 and inhibited forming lipid droplets.

Free Research Field

筋細胞生物学

Academic Significance and Societal Importance of the Research Achievements

現在の食肉生産は、長期間の肥育の結果、屠殺後に高品質であれば付加価値が望めるが低品質の場合は原価の回収が不能となる。そのための安全策として環境負荷の高い穀物飼料に依存することで脂肪交雑率を維持するため、飼料経費や施設・設備の維持の点からも問題となっている。食肉はきめ細かさ、硬さ、脂肪交雑率といった基準で評価されるが、その肉質は形成される筋肉線維の太さ、脂肪細胞の割合、結合組織（線維芽細胞）の割合等に影響される。そこで、筋肉と脂肪の割合を調節できることを目指し、両者が組織形成に与える影響を細胞レベルで検証した。