BACKGROUND The leishmaniases are complex neglected diseases caused by protozoan parasites of the genus Leishmania. Leishmania braziliensis is the main etiological agent of cutaneous leishmaniasis in the New World. In recent studies, genomic changes such as chromosome and gene copy number variations (CNVs), as well as transcriptomic changes have been highlighted as mechanisms used by Leishmania species to adapt to stress situations. OBJECTIVES The aim of this study was to determine the effect of short-term minor temperature shifts in the genomic and transcriptomic responses of L. braziliensis promastigotes in vitro. METHODS Growth curves, genome and transcriptome sequencing of L. braziliensis promastigotes were conducted from cultures exposed to three different temperatures (24ºC, 28ºC and 30ºC) compared with the control temperature (26ºC). FINDINGS Our results showed a decrease in L. braziliensis proliferation at 30ºC, with around 3% of the genes showing CNVs at each temperature, and transcriptomic changes in genes encoding amastin surface-like proteins, heat shock proteins and transport proteins, which may indicate a direct response to temperature stress. MAIN CONCLUSIONS This study provides evidence that L. braziliensis promastigotes exhibit a decrease in cell density, and noticeable changes in the transcriptomic profiles. However, there were not perceptible changes at chromosome CNVs and only ~3% of the genes changed their copies in each treatment.

中文翻译：

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较小的温度变化不会影响染色体倍性，但会在体外导致巴西利什曼原虫前鞭毛体的转录组变化。

背景技术利什曼原虫病是由利什曼原虫属的原生动物寄生虫引起的被忽视的复杂疾病。巴西利什曼原虫是新世界中皮肤利什曼病的主要病原体。在最近的研究中，诸如利什曼原虫物种用来适应压力状况的机制已经强调了基因组变化，例如染色体和基因拷贝数变异（CNV）以及转录组学变化。目的本研究的目的是确定短期轻微温度变化对巴西乳杆菌前鞭毛体的基因组和转录组反应的影响。方法在暴露于三种不同温度（24ºC，28ºC和30ºC）的温度下，与对照温度（26ºC）相比，绘制了巴西乳杆菌前鞭毛体的生长曲线，基因组和转录组测序。结果我们的结果显示，巴西乳杆菌在30ºC时的增殖减少，每种温度下约有3％的基因显示CNV，编码amastin表面样蛋白，热休克蛋白和转运蛋白的基因在转录组中发生变化，这可能表明对温度应力的直接响应。主要结论这项研究提供的证据表明，巴西乳杆菌前鞭毛体细胞密度降低，转录组谱发生明显变化。但是，在染色体CNV处没有明显的变化，并且每次处理中只有约3％的基因改变了它们的拷贝。热激蛋白和转运蛋白，可能表明对温度胁迫有直接反应。主要结论这项研究提供的证据表明，巴西乳杆菌前鞭毛体细胞密度降低，转录组谱发生明显变化。但是，在染色体CNV处没有明显的变化，并且每次处理中只有约3％的基因改变了它们的拷贝。热激蛋白和转运蛋白，可能表明对温度胁迫有直接反应。主要结论这项研究提供的证据表明，巴西乳杆菌前鞭毛体细胞密度降低，转录组谱发生明显变化。但是，在染色体CNV处没有明显的变化，并且每次处理中只有约3％的基因改变了它们的拷贝。