Life in high salinity environments poses challenges to cells in a variety of ways: maintenance of ion homeostasis and nutrient acquisition, often while concomitantly enduring saturating irradiances. Dunaliella salina has an exceptional ability to thrive even in saturated brine solutions. This ability has made it a model organism for studying responses to abiotic stress factors. Here we describe the occurrence of unique gene families, expansion of gene families, or gene losses that might be linked to osmoadaptive strategies. We discovered multiple unique genes coding for several of the homologous superfamily of the Ser-Thr-rich glycosyl-phosphatidyl-inositol-anchored membrane family and of the glycolipid 2-alpha-mannosyltransferase family, suggesting that such components on the cell surface are essential to life in high salt. Gene expansion was found in families that participate in sensing of abiotic stress and signal transduction in plants. One example is the patched family of the Sonic Hedgehog receptor proteins, supporting a previous hypothesis that plasma membrane sterols are important for sensing changes in salinities in D. salina. We also investigated genome-based capabilities regarding glycerol metabolism and present an extensive map for core carbon metabolism. We postulate that a second broader glycerol cycle exists that also connects to photorespiration, thus extending the previously described glycerol cycle. Further genome-based analysis of isoprenoid and carotenoid metabolism revealed duplications of genes for 1-deoxy-D-xylulose-5-phosphate synthase (DXS) and phytoene synthase (PSY), with the second gene copy of each enzyme being clustered together. Moreover, we identified two genes predicted to code for a prokaryotic-type phytoene desaturase (CRTI), indicating that D. salina may have eukaryotic and prokaryotic elements comprising its carotenoid biosynthesis pathways. In brief, our genomic data provide the basis for further gene discoveries regarding sensing abiotic stress, the metabolism of this halophilic alga, and its potential in biotechnological applications.

高盐度环境中的生命以多种方式对细胞构成挑战：维持离子稳态和养分吸收，同时又要经受饱和的辐照度。杜氏盐藻即使在饱和盐水溶液中也具有出色的to壮能力。这种能力使其成为研究非生物胁迫因素反应的模型生物。在这里，我们描述了可能与渗透适应策略有关的独特基因家族的发生，基因家族的扩展或基因损失。我们发现了多个独特的基因，它们编码富含Ser-Thr的糖基-磷脂酰-肌醇锚定的膜家族和糖脂2-α-甘露糖基转移酶家族的多个同源超家族，这表明细胞表面上的此类成分对于高盐生活。在参与感应非生物胁迫和植物信号传导的家族中发现了基因扩增。一个例子是Sonic Hedgehog受体蛋白的修补家族，d。盐沼。我们还研究了有关甘油代谢的基于基因组的功能，并提供了核心碳代谢的详尽图谱。我们假设存在第二个较宽的甘油循环，该循环也与光呼吸有关，因此扩展了先前描述的甘油循环。对异戊二烯和类胡萝卜素代谢的进一步基于基因组的分析显示，1-脱氧-D-木酮糖-5磷酸合酶（DXS）和八氢番茄红素合酶（PSY）的基因重复，每种酶的第二个基因拷贝聚集在一起。此外，我们确定了预测的用于原核型八氢番茄红素去饱和酶（CRTI）码的两个基因，这表明d。盐沼可能具有包含其类胡萝卜素生物合成途径的真核和原核元件。简而言之，我们的基因组数据为进一步的基因发现提供了基础，这些发现涉及感知非生物胁迫，该嗜盐藻类的代谢及其在生物技术应用中的潜力。