Do thermal acclimation and an acute heat challenge alter myonuclear domain of control- and fast-growing quail?

• Published in: Journal of thermal biology Vol. 100; p. 103050
• Main Authors: Jimenez, Ana Gabriela, De Jesus, Aliyah D.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2021; Elsevier BV
• Subjects: Acclimation; Animals; Avian Proteins - genetics; Avian Proteins - metabolism; Climate change; Cytoplasm; Growth rate; Heat; Heat-Shock Response; Life History Traits; Muscle; Muscle Fibers, Skeletal - metabolism; Myonuclear domain; Nuclei; Quail - growth & development; Quail - metabolism; Structure-function relationships; Temperature effects; Wildfowl; Growth rate; Muscle; Myonuclear domain
• ISSN: 0306-4565; 1879-0992
• DOI: 10.1016/j.jtherbio.2021.103050

Efforts to determine physiological traits that may render species resilient or susceptible to changing global temperatures have accelerated in recent years. Temperature is of critical importance to biological function; thus, climate change has the potential to severely affect all levels of biological organization in many species. For example, increases in environmental temperatures may alter muscle structure and function in birds. Myonuclear domain (MND), an under-studied aspect of avian muscle physiology that changes in response to thermal stress, is defined as the amount of cytoplasm within a muscle fiber that each nucleus is responsible for servicing. Here, we used two random bred lines of Japanese quail (Coturnix japonica) representing examples of control and fast growth rates. We used a factorial design to administer four treatment combinations to each line – an initial period of either heat-stress acclimation (Acclimation) or no acclimation (Not acclimated) followed by either a heat-stress challenge (HS) or no challenge (NC) after week 8 of age – to determine the effects of thermal acclimation and acute thermal stress on quail MND. We found a significant interaction between line * final treatment with fast-growing, HS birds demonstrating the lowest numbers of nuclei per mm of fiber, and Acclimated control-growing birds showing the highest numbers of nuclei per mm of fiber. There was a significant effect of line on MND with the fast-growing line having larger MNDs. Initial treatment with Not Acclimated birds showed larger MNDs. Additionally, control growing quail demonstrated positive correlations with fiber size, whereas fast growing quail did not. This may mean that nuclei in larger fibers of fast-growing quail may be functioning maximally, and that increases in temperature may also demonstrate similar effects. •Temperature may be a driving abiotic factor for evolution, and developing in warming conditions may select for adaptive traits.•Muscle structure and function has been demonstrated to show plasticity with acute increases and decreases in temperature.•Myonuclear domains (MND) in birds have scarcely been reported, though they are of importance to proper muscle function.•Growth rates are a key life history trait that may affect adaptive thermal traits.•Control growing quail demonstrated positive correlations with fiber size, whereas fast growing quail did not.