The regulation mechanism of the hybrid yellow catfish “Huangyou-1” was assessed under conditions of hypoxia and reoxygenation by examination of oxygen sensors and by monitoring respiratory metabolism, oxidative stress, and apoptosis. The expressions of genes related to oxygen sensors (HIF-1α, HIF-2α, VHL, HIF-1β, PHD2, and FIH-1) were upregulated in the brain and liver during hypoxia, and recovered compared with control upon reoxygenation. The expressions of genes related to glycolysis (HK1, PGK1, PGAM2, PFK, and LDH) were increased during hypoxia and then recovered compared with control upon reoxygenation. The mRNA levels of CS did not change during hypoxia in the brain and liver, but increased during reoxygenation. The mRNA levels of SDH decreased significantly only in the liver during hypoxia, but later increased compared with control upon reoxygenation in both tissues. Under hypoxic conditions, the expressions of genes related to oxidative stress (SOD1, SOD2, GSH-Px, and CAT) and the activity of antioxidant enzymes (SOD, CAT, and GSH-Px) and MDA were upregulated compared with control. The expressions of genes related to apoptosis (Apaf-1, Bax, Caspase 3, Caspase 9, and p53) were higher than those in control during hypoxic exposure, while the expressions of Bcl-2 and Cyt C were decreased. The findings of the transcriptional analyses will provide insights into the molecular mechanisms of hybrid yellow catfish “Huangyou-1” under conditions of hypoxia and reoxygenation. Overall, these findings showed that oxygen sensors of “Huangyou-1” are potentially useful biomarkers of environmental hypoxic exposure. Together with genes related to respiratory metabolism, oxidative stress and apoptosis occupy a quite high position in enhancing hypoxia tolerance. Our findings provided new insights into the molecular regulatory mechanism of hypoxia in “Huangyou-1.”

通过氧传感器的检测和呼吸代谢、氧化应激和细胞凋亡的监测，评估了杂交黄鲇“黄优一号”在缺氧和复氧条件下的调控机制。与氧传感器相关的基因（HIF-1α、HIF-2α、VHL、HIF-1β、PHD2和FIH-1）在缺氧期间在大脑和肝脏中的表达上调，并且在复氧时与对照相比恢复。糖酵解相关基因（HK1、PGK1、PGAM2、PFK、LDH ）的表达) 在缺氧期间增加，然后与复氧时的对照相比恢复。CS的mRNA水平在大脑和肝脏缺氧期间没有变化，但在复氧期间增加。SDH 的 mRNA 水平仅在缺氧期间在肝脏中显着降低，但随后在两种组织中的复氧后与对照相比增加。在低氧条件下，与对照相比，氧化应激相关基因（SOD1、SOD2、GSH-Px和CAT）的表达以及抗氧化酶（SOD、CAT和GSH-Px）和MDA的活性均上调。凋亡相关基因（Apaf-1、Bax、Caspase 3、Caspase 9和p53）在缺氧暴露期间高于对照组，而Bcl-2和Cyt C的表达降低。转录分析的结果将有助于深入了解杂交黄鲇“黄优一号”在缺氧和复氧条件下的分子机制。总体而言，这些研究结果表明，“黄优一号”的氧传感器是环境缺氧暴露的潜在有用的生物标志物。与呼吸代谢相关的基因一起，氧化应激和细胞凋亡在增强缺氧耐受性方面占有相当高的地位。我们的研究结果为“黄优一号”缺氧的分子调控机制提供了新的见解。