Meiotic recombination is evolutionarily ambiguous, as being associated with both benefits and costs to its bearers, with the resultant dependent on a variety of conditions. While existing theoretical models explain the emergence and maintenance of recombination, some of its essential features remain underexplored. Here we focus on one such feature, recombination plasticity, and test whether recombination response to stress is fitness-dependent. We compare desiccation stress effects on recombination rate and crossover interference in chromosome 3 between desiccation-sensitive and desiccation-tolerant Drosophila lines. We show that relative to desiccation-tolerant genotypes, desiccation-sensitive genotypes exhibit a significant segment-specific increase in single- and double-crossover frequencies across the pericentromeric region of chromosome 3. Significant changes (relaxation) in crossover interference were found for the interval pairs flanking the centromere and extending to the left arm of the chromosome. These results indicate that desiccation is a recombinogenic factor and that desiccation-induced changes in both recombination rate and crossover interference are fitness-dependent, with a tendency of less fitted individuals to produce more variable progeny. Such dependence may play an important role in the regulation of genetic variation in populations experiencing environmental challenges.

中文翻译：

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干燥诱导的黑腹果蝇重组率和交叉干扰的变化：适应度依赖性可塑性的证据

减数分裂重组在进化上是模棱两可的，因为与其承载者的利益和成本相关，其结果取决于各种条件。虽然现有的理论模型解释了重组的出现和维持，但其一些基本特征仍未得到充分探索。在这里，我们关注一个这样的特征，重组可塑性，并测试对压力的重组反应是否依赖于健康。我们比较了干燥应激对干燥敏感和干燥耐受果蝇品系之间 3 号染色体的重组率和交叉干扰的影响。我们表明，相对于耐干燥基因型，干燥敏感基因型在 3 号染色体的着丝粒周围区域的单交叉和双交叉频率上表现出显着的片段特异性增加。对于位于着丝粒两侧并延伸到染色体左臂的间隔对，发现了交叉干扰的显着变化（松弛）。这些结果表明干燥是一种重组因子，干燥引起的重组率和交叉干扰的变化都依赖于适应度，不太适合的个体倾向于产生更多可变的后代。这种依赖性可能在调节经历环境挑战的人群的遗传变异中发挥重要作用。这些结果表明干燥是一种重组因子，干燥引起的重组率和交叉干扰的变化都依赖于适应度，不太适合的个体倾向于产生更多可变的后代。这种依赖性可能在调节经历环境挑战的人群的遗传变异中发挥重要作用。这些结果表明干燥是一种重组因子，干燥引起的重组率和交叉干扰的变化都依赖于适应度，不太适合的个体倾向于产生更多可变的后代。这种依赖性可能在调节经历环境挑战的人群的遗传变异中发挥重要作用。