Mild heat stress enhances differentiation and proliferation of Japanese quail myoblasts and enhances slow muscle fiber characteristics

作者：Choi Y M; Chen P R; Shin S; Zhang J; Hwang S; Lee K^*

来源：POULTRY SCIENCE, 2016, 95(8): 1912-1917.

DOI：10.3382/ps/pew116

• mild heat stress
• quail primary myoblast
• myosin heavy chain isoforms
• Pax-7
• COX IV

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 degrees C, incubation at 39 degrees 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 degrees 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 degrees 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 degrees C. Our results suggest that mild heat stress plays a significant role in myogenic mechanisms related to muscle mass and development.

• 出版日期2016-8