Hypoxia-inducible factor-1α (HIF-1α) is a key transcription factor for regulating oxygen-dependent homeostasis. Here, we characterized HIF-1α in Pacific abalone (Haliotis discus hannai), an aquaculture-relevant mollusk species, and its transcriptional regulation patterns in response to oxygen-dependent and oxygen-independent stimuli were investigated. The molecular cloning and sequence analysis revealed that the abalone HIF-1α shared conversed features in its domain organization such as basic helix–loop–helix (bHLH) domain, Per-Arnt-Sim (PAS) domain, oxygen-dependent degradation domains (ODDDs), and C-terminal transactivation domain (C-TAD) with metazoan orthologs. The abalone HIF-1α was proven to be transcriptionally active in multiple tissues according to dissolved oxygen contents, with the most sensitive responsiveness in the gill. Under non-hypoxic conditions, the tissue-dependent transcriptional regulation patterns of the abalone HIF-1α were closely correlated and intertwined with those of HSP90 and MT in response to thermal challenge and heavy metal exposure, respectively. The abalone HIF-1α expression was significantly modulated under normoxic conditions in response to immune challenges with lipopolysaccharide and Vibrio harveyi with the highest upregulation in the hemocytes. However, the combined treatment of hypoxia and immune stimulation exhibited no synergistic activation for the induction of HIF-1α mRNA. Collectively, dynamic transcriptional regulation of the abalone HIF-1α with the tissue specificity in response to oxygen-dependent and oxygen-independent stimulatory challenges suggests that HIF-1α plays crucial roles in interdependent crosstalk between hypoxia, innate immunity, and environmental stresses, which can be a useful basis to investigate cellular and physiological responses of farmed abalones to oxygen depletion and other-related stress factors.

缺氧诱导因子-1α（HIF-1α）是调节氧依赖性稳态的关键转录因子。在这里，我们表征了太平洋鲍鱼（Haliotis discus hannai）中的HIF-1α），与水产养殖有关的软体动物物种，及其对氧气依赖性和非氧气依赖性刺激的转录调控模式进行了研究。分子克隆和序列分析表明，鲍鱼HIF-1α在其域组织中具有相反的特征，例如基本螺旋-环-螺旋（bHLH）域，Per-Arnt-Sim（PAS）域，氧依赖性降解域（ODDDs） ），以及带有后生直系同源物的C末端反式激活域（C-TAD）。根据溶解氧含量，鲍鱼HIF-1α被证明在多个组织中具有转录活性，而ill中的反应最为灵敏。在无缺氧的情况下，鲍鱼HIF-1α的组织依赖性转录调控模式与HSP90和MT的转录调控模式密切相关，并相互交织，分别响应热挑战和重金属暴露。在常氧条件下，响应于脂多糖和脂蛋白的免疫攻击，鲍鱼HIF-1α的表达受到显着调节。哈维弧菌在血细胞中具有最高的上调。但是，缺氧和免疫刺激的联合治疗没有诱导HIF-1αmRNA的协同激活。总的来说，鲍鱼HIF-1α的动态转录调节具有组织特异性，以响应氧依赖性和非氧依赖性刺激性挑战，表明HIF-1α在缺氧，先天免疫和环境压力之间的相互依赖串扰中起关键作用。为研究养殖鲍鱼对耗氧和其他相关压力因素的细胞和生理反应提供有用的基础。