Mesquita Paulo H C, Rhodes Emma M, Yap Kang Nian, Mueller Breanna J, Hill Geoffrey E, Hood Wendy R, Kavazis Andreas N
School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.
Proc Biol Sci. 2024 Dec;291(2036):20242409. doi: 10.1098/rspb.2024.2409. Epub 2024 Dec 11.
The migratory movements undertaken by birds are among the most energetically demanding behaviours observed in nature. Mitochondria are the source of aerobic energy production on which migration depends, but a key component of mitochondrial function, mitochondrial remodelling, has not been investigated in the context of bird migration. We measured markers of mitochondrial remodelling in the skeletal muscles of the Gambel's (migratory) and Nuttall's (non-migratory) white-crowned sparrows within and outside migratory periods. Gambel's were collected in (i) a non-migration period (baseline), (ii) preparation to depart for spring migration (pre-migration) and (iii) active autumn migration (mid-migration). Nuttall's were collected at timepoints corresponding to baseline and mid-migration in Gambel's. Across all sampling periods, we found that migratory birds had greater mitochondrial remodelling compared with non-migratory birds. Furthermore, birds from the migratory population also displayed flexibility, increasing several markers of mitochondrial remodelling (e.g. NRF1, OPA1 and Drp1) pre- and during migration. Further, the greater levels of mitochondrial remodelling and its upregulation during migration were specific to the pectoralis muscle used in flapping flight. Our study is the first to show that mitochondrial remodelling supports migration in Gambel's white-crowned sparrows, indicating a highly specific and efficient phenotype supporting the increased energetic demands of migration.
鸟类进行的迁徙活动是自然界中观察到的能量需求最高的行为之一。线粒体是有氧能量产生的来源，而迁徙依赖于有氧能量产生，但线粒体功能的一个关键组成部分——线粒体重塑，尚未在鸟类迁徙的背景下进行研究。我们在迁徙期内外测量了甘贝尔氏（迁徙型）和纳塔尔氏（非迁徙型）白冠雀骨骼肌中线粒体重塑的标志物。甘贝尔氏白冠雀在以下三个阶段被采集：（i）非迁徙期（基线），（ii）准备春季迁徙（迁徙前），（iii）秋季活跃迁徙期（迁徙中期）。纳塔尔氏白冠雀在与甘贝尔氏白冠雀基线和迁徙中期相对应的时间点被采集。在所有采样阶段，我们发现与非迁徙鸟类相比，迁徙鸟类具有更大程度的线粒体重塑。此外，来自迁徙种群的鸟类也表现出灵活性，在迁徙前和迁徙期间增加了线粒体重塑的几个标志物（如NRF1、OPA1和Drp1）。此外，线粒体重塑水平的提高及其在迁徙过程中的上调特定于用于扑翼飞行的胸肌。我们的研究首次表明线粒体重塑支持甘贝尔氏白冠雀的迁徙，这表明存在一种高度特异性和高效的表型来支持迁徙增加的能量需求。
