Characterization of hypoxia-inducible factor α and its response to hypoxia in Callosobruchus chinensis (Coleoptera, Bruchidae)

<p class="MsoNormal"><span>Hypoxia-inducible factor (HIF) plays an essential role in hypoxic adaptation in various organisms. <em>Callosobruchus chinensis,</em> a common food storage pest, is highly adapted to hypoxic conditions,</span><span> while</span><span> the underlying mechanism of which is currently unclear. Here, we isolated, sequenced, and bioinformatically analyzed <em>HIF1α</em> from <em>C. chinensis</em>, then examined its mRNA and protein expression profiles under hypoxic conditions for various developmental stages and tissue types. The effects of environmental hypoxia on other genes in the HIF pathway response, aspartyl-hydroxylase (FIH) and prolyl hydroxylase (PHD), were also examined. We found that FIH and PHD were also highly conserved and that their expression varied with developmental stage, tissue type, and environmental hypoxia. Overall, hypoxia caused an increase in <em>HIF1α </em>and <em>FIH</em> mRNA expression, and a decrease in <em>PHD </em>mRNA expression, while expression of their proteins showed different</span><span> in response to hypoxia</span><span>. HIF1α protein levels increased, PHD and FIH protein levels decreased</span><span> under hypoxic conditions, compared to normoxic conditions</span><span>. This study has preliminarily investigated the bioinformation of <em>C. chinensis</em> HIF1α response relationship between HIF1α and its hydroxylases under normoxic and hypoxic conditions, which might provide important clues for future work on clarifying the mechanism of stored-product insect unique hypoxia adaption.</span></p>