Muscle fiber size, myonuclear domain, and fat mass phenotypes in pre-migratory snow buntings ...

• Main Authors: Vézina, François, O'Connor, Ryan, Le Pogam, Audrey, De Jesus, Aliyah, Love, Oliver, Jimenez, Ana
• Format: Dataset
• Language: English
• Published: Dryad 2021
• Subjects: Plectrophenax nivalis
• Online Access: https://dx.doi.org/10.5061/dryad.gxd2547kx; https://datadryad.org/stash/dataset/doi:10.5061/dryad.gxd2547kx

In long-distance migrants, preparation for migration is typically associated with increases in fat and body mass, and with an enlargement of pectoralis muscle mass that likely improves flight performance. Although changes in muscle mass or size have been well described in migratory birds, potential changes in muscle ultrastructure during this transition still deserves scrutiny. Using outdoor captive snow buntings (Plectrophenax nivalis n = 15) measured during their transition into a spring migratory phenotype as a model system, we studied changes in pectoralis muscle ultrastructure and predicted that muscle fiber diameter could increase in parallel with the gain in body mass. We also expected that larger fibers could either recruit satellite cells to support cellular maintenance and protein turnover, increase myonuclear domain (cytoplasm per nuclei) with the potential increase for protein turnover load per myonucleus, or existing myonuclei could undergo endoreduplication. Buntings increased body mass by 46% ...