Department of Biology, Indiana University, Bloomington, IN 47405, USA.
Science. 2010 Sep 17;329(5998):1521-3. doi: 10.1126/science.1193063.
Among the reproductive barriers that can isolate species, hybrid sterility is frequently due to dysfunctional interactions between loci that accumulate between differentiating lineages. Theory describing the evolution of these incompatibilities has generated the prediction, still empirically untested, that loci underlying hybrid incompatibility should accumulate faster than linearly with time--the "snowball effect." We evaluated the accumulation of quantitative trait loci (QTL) between species in the plant group Solanum and found evidence for a faster-than-linear accumulation of hybrid seed sterility QTL, thus empirically evaluating and confirming this theoretical prediction. In comparison, loci underlying traits unrelated to hybrid sterility show no evidence for an accelerating rate of accumulation between species.
在可能导致物种隔离的生殖障碍中，杂种不育通常是由于分化谱系之间积累的功能失调的基因座之间的相互作用所致。描述这些不兼容性进化的理论预测，尚未经过经验验证，即杂种不兼容性的潜在基因座的积累速度应该比线性随时间更快——即“滚雪球效应”。我们评估了植物群中的 Solanum 物种之间的数量性状基因座（QTL）的积累情况，发现杂种种子不育 QTL 的积累速度快于线性，因此经验性地评估和证实了这一理论预测。相比之下，与杂种不育无关的性状的基因座在物种之间没有加速积累的证据。
