Abreu Vinicius A C, Popin Rafael V, Alvarenga Danillo O, Schaker Patricia D C, Hoff-Risseti Caroline, Varani Alessandro M, Fiore Marli F
Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, Brazil.
School of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, Brazil.
Front Microbiol. 2018 Feb 26;9:306. doi: 10.3389/fmicb.2018.00306. eCollection 2018.
is a freshwater cyanobacterial species with increasing bloom reports worldwide that are likely due to factors related to climate change. In addition to the deleterious effects of blooms on aquatic ecosystems, the majority of ecotypes can synthesize toxic secondary metabolites causing public health issues. To overcome the harmful effects of blooms, it is important to advance knowledge of diversity, genetic variation, and evolutionary processes within populations. An efficient approach to exploring this diversity and understanding the evolution of is to use comparative genomics. Here, we report two new draft genomes of (strains CENA302 and CENA303) from Brazilian isolates of different origins and explore their molecular diversity, phylogeny, and evolutionary diversification by comparing their genomes with sequences from other strains available in public databases. The results obtained by comparing seven and the D9 genomes revealed a set of conserved core genes and a variable set of accessory genes, such as those involved in the biosynthesis of natural products, heterocyte glycolipid formation, and nitrogen fixation. Gene cluster arrangements related to the biosynthesis of the antifungal cyclic glycosylated lipopeptide hassallidin were identified in four genomes, including the non-nitrogen fixing strain CENA303. Shifts in gene clusters involved in toxin production according to geographic origins were observed, as well as a lack of nitrogen fixation () and heterocyte glycolipid ) gene clusters in some strains. Single gene phylogeny (16S rRNA sequences) was congruent with phylogeny based on 31 concatenated housekeeping protein sequences, and both analyses have shown, with high support values, that the species is monophyletic. This comparative genomics study allowed a species-wide view of the biological diversity of and in some cases linked genome differences to phenotype.
是一种淡水蓝藻物种，全球范围内有关其水华爆发的报道日益增多，这可能与气候变化相关因素有关。除了水华对水生生态系统的有害影响外，大多数生态型能够合成有毒的次生代谢产物，从而引发公共卫生问题。为了克服水华的有害影响，深入了解种群内的多样性、遗传变异和进化过程非常重要。探索这种多样性并理解其进化的一种有效方法是使用比较基因组学。在此，我们报告了来自巴西不同来源分离株的两个新的 （菌株CENA302和CENA303）基因组草图，并通过将它们的基因组与公共数据库中其他菌株的序列进行比较，探索其分子多样性、系统发育和进化分化。通过比较七个 和D9基因组获得的结果揭示了一组保守的核心基因和一组可变的辅助基因，例如参与天然产物生物合成、异形胞糖脂形成和固氮的基因。在四个 基因组中，包括非固氮菌株CENA303，鉴定出了与抗真菌环状糖基化脂肽哈萨利定生物合成相关的基因簇排列。观察到根据地理来源毒素产生相关基因簇的变化，以及一些菌株中缺乏固氮（ ）和异形胞糖脂（ ）基因簇。单基因系统发育（16S rRNA序列）与基于31个串联管家蛋白序列的系统发育一致，并且两种分析都以高支持值表明该物种 是单系的。这项比较基因组学研究使我们能够从全物种角度了解 的生物多样性，并且在某些情况下将基因组差异与表型联系起来。
