Transposable elements have driven genome evolution and plasticity in many ways across a range of organisms. Different types of biotic and abiotic stresses can stimulate the expression or transposition of these mobile elements. Here, we cytogenetically analyzed natural fish populations of the same species living under different environmental conditions to test the influence and organization of transposable elements in their genome. Differential behavior was observed for the markers Rex 1, Rex 3, and Rex 6 in the chromosomes of individuals of the same species but coming from different environments (polluted and unpolluted). An increase in the number of Rex transposable elements in the chromosomes and their influence on the genome of populations living in a polluted environment indicates that they must be under constant adaptive evolution.

中文翻译：

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亚马逊鱼类中的转座 DNA 元件：从基因组扩大到遗传适应压力环境

转座因子以多种方式推动了一系列生物体的基因组进化和可塑性。不同类型的生物和非生物胁迫可以刺激这些移动元件的表达或转座。在这里，我们对生活在不同环境条件下的同一物种的天然鱼类种群进行细胞遗传学分析，以测试其基因组中转座因子的影响和组织。在来自不同环境（污染和未污染）的同一物种个体的染色体中观察到标记 Rex 1、Rex 3 和 Rex 6 的差异行为。染色体中 Rex 转座因子数量的增加及其对生活在污染环境中的种群基因组的影响表明它们必须处于不断的适应性进化中。