Experimental evolution reveals that high relatedness protects multicellular cooperation from cheaters.
Experimental evolution reveals that high relatedness protects multicellular cooperation from cheaters.
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DOI：
10.1038/ncomms11435
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发表时间：
2016-05-03
影响因子：
16.6
通讯作者：
Aanen DK
中科院分区：
文献类型：
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作者：
Bastiaans E;Debets AJ;Aanen DK
在多细胞生物中，存在作弊突变体获得种系的潜在风险。单细胞受精卵的发育将细胞之间的相关性重置为每一代的最大值，这应该实现作弊突变体与非作弊突变体的分离，从而保护多细胞合作。在这里，我们提供高相关性条件和低相关性条件之间的关键直接比较来检验这一假设。我们允许真菌粗糙脉孢菌的两种变体进化，一种具有与其他个体形成嵌合体的能力，一种不具有与其他个体形成嵌合体的能力，从而产生两个相关性水平。虽然多细胞合作在高相关性品系中仍然很高，但在所有复制的低相关性品系中显着降低，导致孢子产量平均减少三倍。这种减少是由于作弊突变体对体细胞功能的投入减少，但与非作弊者融合时竞争成功率增加所致。我们的实验表明，高度的遗传相关性对于维持多细胞合作至关重要。 假设多细胞生物中合作的维持取决于细胞之间的高度相关性。在这里，巴斯蒂安斯等人。通过直接比较保持高相关性或低相关性的真菌实验系中多细胞合作的进化稳定性，为这一假设提供了经验支持。
In multicellular organisms, there is a potential risk that cheating mutants gain access to the germline. Development from a single-celled zygote resets relatedness among cells to its maximum value each generation, which should accomplish segregation of cheating mutants from non-cheaters and thereby protect multicellular cooperation. Here we provide the crucial direct comparison between high- and low-relatedness conditions to test this hypothesis. We allow two variants of the fungus Neurospora crassa to evolve, one with and one without the ability to form chimeras with other individuals, thus generating two relatedness levels. While multicellular cooperation remains high in the high-relatedness lines, it significantly decreases in all replicate low-relatedness lines, resulting in an average threefold decrease in spore yield. This reduction is caused by cheating mutants with reduced investment in somatic functions, but increased competitive success when fusing with non-cheaters. Our experiments demonstrate that high genetic relatedness is crucial to sustain multicellular cooperation. Maintenance of cooperation in multicellular organisms is hypothesized to depend on high relatedness among cells. Here, Bastiaans et al. provide empirical support for this hypothesis by directly comparing the evolutionary stability of multicellular cooperation in experimental lines of a fungus kept at either high or low relatedness.