Abstract：
The Amazon basin includes 1000s of bodies of water, that are sorted according to their color in three types: blackwater, clearwater, and whitewater, which significantly differ in terms of their physicochemical parameters. More than 3,000 species of fish live in the rivers of the Amazon, among them, the sardine, Triportheus albus, which is one of the few species that inhabit all three types of water. The purpose of our study was to analyze if the gene expression of T. albus is determined by the different types of water, that is, if the species presents phenotypic plasticity to live in blackwater, clearwater, and whitewater. Gills of T. albus were collected at well-characterized sites for each type of water. Nine cDNA libraries were constructed, three biological replicates of each condition and the RNA was sequenced (RNA-Seq) on the MiSeq® Platform (Illumina®). A total of 51.6 million of paired-end reads, and 285,456 transcripts were assembled. Considering the FDR ≤ 0.05 and fold change ≥ 2, 13,754 differentially expressed genes were detected in the three water types. Two mechanisms related to homeostasis were detected in T. albus that live in blackwater, when compared to the ones in clearwater and whitewater. The acidic blackwater is a challenging environment for many types of aquatic organisms. The first mechanism is related to the decrease in cellular permeability, highlighting the genes coding for claudin proteins, actn4, itgb3b, DSP, Gap junction protein, and Ca2+-ATPase. The second with ionic and acid-base regulation [rhcg1, slc9a6a (NHE), ATP6V0A2, Na+/K+-ATPase, slc26a4 (pedrin) and slc4a4b]. We suggest T. albus is a good species of fish for future studies involving the ionic and acid-base regulation of Amazonian species. We also concluded that, T. albus, shows well defined phenotypic plasticity for each water type in the Amazon basin.
摘要：
亚马逊流域包括1000个水体，根据颜色分为三种类型：黑水，清水,和白水，它们的物理化学参数有很大不同。超过3000种鱼类生活在亚马逊河中，其中,沙丁鱼,TriportheusAlbus,这是少数居住在所有三种水中的物种之一。我们的研究的目的是分析T.albus的基因表达是否由不同类型的水决定，也就是说,如果该物种表现出生活在黑水中的表型可塑性，清水,和白水。对于每种类型的水，在特征明确的地点收集T.albus。构建了9个cDNA文库，每种条件的三个生物学重复,并且在MiSeq®平台(Illumina®)上对RNA进行测序(RNA-Seq)。共有5160万成对的末端读数,并组装了285,456个转录本。考虑到FDR≤0.05和倍数变化≥2，在三种水类型中检测到13,754个差异表达基因。在生活在黑水中的T.albus中检测到两种与体内平衡有关的机制，与清水和白水相比。酸性黑水是许多类型的水生生物具有挑战性的环境。第一个机制与细胞通透性降低有关，突出编码claudin蛋白的基因，actn4,itgb3b,DSP,间隙连接蛋白,和Ca2+-ATP酶。第二个具有离子和酸碱调节[rhcg1，slc9a6a（NHE），ATP6V0A2,Na+/K+-ATP酶,slc26a4(pedrin)和slc4a4b]。我们建议T.albus是未来研究中涉及亚马逊物种离子和酸碱调节的良好鱼类。我们还得出结论，T.albus,显示了亚马逊盆地中每种水类型的明确的表型可塑性。
