title: Mild heat stress enhances differentiation and proliferation of Japanese quail myoblasts and enhances slow muscle fiber characteristics.
abstract: The objective of this study was to investigate the effect of mild heat stress on muscle fiber hyperplastic and hypertrophic growth in quail primary myogenic cells to better understand the mechanisms leading to increased skeletal muscle development in avian embryos incubated at a higher temperature. Compared to control cultures maintained at 37°C, incubation at 39°C enhanced myotube length (P < 0.01) and diameter (P < 0.001) at 3 days after differentiation (D3). This enlargement of the myotubes incubated at 39°C can be explained by differences in the fusion index (56.7 vs. 46.2%, P < 0.05) and nuclei number per myotube (18.1 vs. 10.8, P < 0.001) compared to the control cells at D3. Additionally, a higher density of myotubes at D3 in cultures exposed to a higher temperature were related to higher levels of Pax-7 (P < 0.05) compared to the control cells incubated continuously at 37°C. These results indicated a higher proliferative capacity in cells exposed to mild heat stress compared to the control cells. On the other hand, mild heat stress enhanced protein levels of slow myosin heavy chain isoform (P < 0.01) and cytochrome c oxidase subunit IV (P < 0.01) compared to the control cells at D3. These discrepancies in protein expression indicated maintenance of slow muscle fiber type characteristics in myotubes incubated at 39°C. Our results suggest that mild heat stress plays a significant role in myogenic mechanisms related to muscle mass and development.
authors.affiliation: Department of Animal Sciences, Kyungpook National University, Sangju 37224, South Korea Department of Animal Sciences, The Ohio State University, Columbus, OH, 43210.
authors.forename: Y M
authors.initials: YM
authors.lastname: Choi
authors.affiliation: Department of Animal Sciences, The Ohio State University, Columbus, OH, 43210.
authors.forename: P R
authors.initials: PR
authors.lastname: Chen
authors.affiliation: Department of Animal Biotechnology, Kyungpook National University, Sangju 37224, South Korea Department of Animal Sciences, The Ohio State University, Columbus, OH, 43210.
authors.forename: S
authors.initials: S
authors.lastname: Shin
authors.affiliation: Department of Animal Sciences, The Ohio State University, Columbus, OH, 43210.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Animal Biotechnology Division, National Institute of Animal Science, RDA, Wanju-gun, Jeonbuk 565-851, Republic of Korea Department of Animal Sciences, The Ohio State University, Columbus, OH, 43210.
authors.forename: S
authors.initials: S
authors.lastname: Hwang
authors.affiliation: Department of Animal Sciences, The Ohio State University, Columbus, OH, 43210 lee.2626@osu.edu.
authors.forename: K
authors.initials: K
authors.lastname: Lee
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D002478:Cells, Cultured; D003370:Coturnix / Q000196:embryology / Q000254:growth & development*; D018869:Heat-Shock Response / Q000502:physiology*; D006358:Hot Temperature; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D018482:Muscle, Skeletal / Q000254:growth & development* / Q000502:physiology; D032446:Myoblasts / Q000502:physiology*
keywords: COX IV; Pax-7; mild heat stress; myosin heavy chain isoforms; quail primary myoblast