Department of Microbiology, University of Georgia, Athens, Georgia, USA.
Department of Microbiology, University of Georgia, Athens, Georgia, USA
J Bacteriol. 2018 Apr 24;200(10). doi: 10.1128/JB.00572-17. Print 2018 May 15.
cells produce lipid bodies containing triacylglycerides during fruiting body development. Fatty acid β-oxidation is the most energy-efficient pathway for lipid body catabolism. In this study, we used mutants in (MXAN_5371 and MXAN_6987) and (MXAN_5372) homologs to examine whether β-oxidation serves an essential developmental function. These mutants contained more lipid bodies than the wild-type strain DK1622 and 2-fold more flavin adenine dinucleotide (FAD), consistent with the reduced consumption of fatty acids by β-oxidation. The β-oxidation pathway mutants exhibited differences in fruiting body morphogenesis and produced spores with thinner coats and a greater susceptibility to thermal stress and UV radiation. The MXAN_5372/5371 operon is upregulated in sporulating cells, and its expression could not be detected in , , or mutants. Lipid bodies were found to persist in mature spores of DK1622 and wild strain DK851, suggesting that the roles of lipid bodies and β-oxidation may extend to spore germination. Lipid bodies act as a reserve of triacylglycerides for use when other sources of carbon and energy become scarce. β-Oxidation is essential for the efficient metabolism of fatty acids associated with triacylglycerides. Indeed, the disruption of genes in this pathway has been associated with severe disorders in animals and plants. , a model organism for the study of development, is ideal for investigating the complex effects of altered lipid metabolism on cell physiology. Here, we show that β-oxidation is used to consume fatty acids associated with lipid bodies and that the disruption of the β-oxidation pathway is detrimental to multicellular morphogenesis and spore formation.
细胞在子实体发育过程中产生含有三酰基甘油的脂滴。脂肪酸β-氧化是脂滴分解代谢中最有效的能量途径。在这项研究中，我们使用了（MXAN_5371 和 MXAN_6987）和（MXAN_5372）同源物的突变体来检查β-氧化是否在发育过程中起着至关重要的作用。这些突变体比野生型菌株 DK1622 含有更多的脂滴，并且黄素腺嘌呤二核苷酸（FAD）增加了两倍，这与脂肪酸通过β-氧化的消耗减少相一致。β-氧化途径突变体在子实体形态发生方面表现出差异，并且产生的孢子具有更薄的涂层，对热应激和紫外线辐射的敏感性更高。MXAN_5372/5371 操纵子在孢子形成细胞中上调，并且在 、 或 突变体中无法检测到其表达。在 DK1622 和野生型 DK851 的成熟孢子中发现脂滴仍然存在，这表明脂滴和β-氧化的作用可能扩展到孢子萌发。脂滴作为三酰基甘油的储备，在其他碳源和能源变得稀缺时使用。β-氧化对于与三酰基甘油相关的脂肪酸的有效代谢是必不可少的。事实上，该途径中基因的破坏与动物和植物的严重疾病有关。作为发育研究的模式生物，是研究改变的脂质代谢对细胞生理学的复杂影响的理想选择。在这里，我们表明β-氧化用于消耗与脂滴相关的脂肪酸，并且β-氧化途径的破坏对子实体形态发生和孢子形成有害。
