Tang Qiguo, Ding Cui, Xu Qinqin, Bai Ying, Xu Qiao, Wang Kejun, Fang Meiying
Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China.
Front Cell Dev Biol. 2021 Feb 9;9:585166. doi: 10.3389/fcell.2021.585166. eCollection 2021.
The Tibetan chickens (; TBCs) are an indigenous breed found in the Qinghai-Tibet Plateau that are well-adapted to a hypoxic environment. As of now, energy metabolism of the TBCs embryonic brain has been little examined. This study investigated changes in energy metabolism in TBCs during hypoxia, and compared energy metabolism in TBCs and Dwarf Laying Chickens (DLCs), a lowland chicken breed, to explore underlying mechanisms of hypoxia adaptation. We found TBCs exhibited decreased oxygen consumption rates (OCR) and ATP levels as well as an increased extracellular acidification rate (ECAR) during hypoxia. Nevertheless, OCR/ECAR ratios indicated aerobic metabolism still dominated under hypoxia. Most important, our results revealed significant differences in TBCs brain cellular metabolism compared to DLCs under hypoxia. Compared to DLCs, TBCs had higher OCR and TCA cycle activities during hypoxia. Also, TBCs had more mitochondrial content, increased mitochondrial aspect ratio and MFN1, MFN2, and OPA1 proteins which have previously been reported to control mitochondrial fusion were expressed at higher levels in TBCs compared to DLCs, suggesting that TBCs may regulate energy metabolism by increasing the level of mitochondrial fusion. In summary, TBCs can reduce aerobic metabolism and increase glycolysis to enable adaptation to hypoxia. Regulation of mitochondrial fusion via MFN1, MFN2, and OPA1 potentially enhances the ability of TBCs to survive on the Qinghai-Tibet Plateau.
藏鸡（TBCs）是青藏高原的一个本土品种，对低氧环境具有良好的适应性。目前，对藏鸡胚胎大脑的能量代谢研究较少。本研究调查了藏鸡在低氧环境下能量代谢的变化，并比较了藏鸡与低地鸡品种矮小型蛋鸡（DLCs）的能量代谢，以探索低氧适应的潜在机制。我们发现，藏鸡在低氧环境下耗氧率（OCR）和ATP水平降低，细胞外酸化率（ECAR）升高。然而，OCR/ECAR比值表明，低氧环境下有氧代谢仍占主导。最重要的是，我们的结果显示，与低氧环境下的矮小型蛋鸡相比，藏鸡大脑细胞代谢存在显著差异。与矮小型蛋鸡相比，藏鸡在低氧环境下具有更高的OCR和三羧酸循环活性。此外，藏鸡的线粒体含量更多，线粒体长宽比增加，与线粒体融合调控相关的MFN1、MFN2和OPA1蛋白在藏鸡中的表达水平高于矮小型蛋鸡，这表明藏鸡可能通过增加线粒体融合水平来调节能量代谢。总之，藏鸡可以降低有氧代谢并增加糖酵解以适应低氧环境。通过MFN1、MFN2和OPA1对线粒体融合的调控可能增强了藏鸡在青藏高原生存的能力。
