Genome size variation affects song attractiveness in grasshoppers: Evidence for sexual selection against large genomes
Genome size variation affects song attractiveness in grasshoppers: Evidence for sexual selection against large genomes
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DOI：
10.1111/evo.12522
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发表时间：
2014-12
期刊：
影响因子：
3.3
通讯作者：
H. Schielzeth;C. Streitner;Ulrike Lampe;A. Franzke;K. Reinhold
中科院分区：
文献类型：
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作者：
H. Schielzeth;C. Streitner;Ulrike Lampe;A. Franzke;K. Reinhold
基因组大小与生物体的复杂性和适应性情景基本上不相关。遗传漂变和基因组内冲突被提出来解释这一现象。我们在这里研究基因组大小对弓翅蚱蜢Chorthippus biguttulus性吸引力的影响。蚱蜢在基因组大小上表现出特别大的变化，这是由于被认为是（轻度）自私的额外染色体的高流行率，如非孟德尔遗传和适应性成本所证明的，如果大量存在。我们根据已知会影响该物种雌性偏好的歌曲特征对雄性蚱蜢进行了排名，并从这种分布的极端对有吸引力和无吸引力的个体的基因组大小进行了评分。我们发现，有吸引力的歌手有显着较小的基因组，这表明基因组的大小反映在男性求偶歌曲和女性更喜欢歌曲的男性与小基因组。这种依赖于基因组大小的择偶偏好有效地选择了倾向于增加基因组大小的自私遗传因子。因此，这些数据提供了一个新的例子，说明性选择如何加强自然选择，并在基因组内的军备竞赛中发挥作用。此外，我们的研究结果表明，挑剔的女性如何获得间接利益的路线被低估。
Genome size is largely uncorrelated to organismal complexity and adaptive scenarios. Genetic drift as well as intragenomic conflict have been put forward to explain this observation. We here study the impact of genome size on sexual attractiveness in the bow‐winged grasshopper Chorthippus biguttulus. Grasshoppers show particularly large variation in genome size due to the high prevalence of supernumerary chromosomes that are considered (mildly) selfish, as evidenced by non‐Mendelian inheritance and fitness costs if present in high numbers. We ranked male grasshoppers by song characteristics that are known to affect female preferences in this species and scored genome sizes of attractive and unattractive individuals from the extremes of this distribution. We find that attractive singers have significantly smaller genomes, demonstrating that genome size is reflected in male courtship songs and that females prefer songs of males with small genomes. Such a genome size dependent mate preference effectively selects against selfish genetic elements that tend to increase genome size. The data therefore provide a novel example of how sexual selection can reinforce natural selection and can act as an agent in an intragenomic arms race. Furthermore, our findings indicate an underappreciated route of how choosy females could gain indirect benefits.