An experimental assessment of reproductive isolation and its consequences for seasonal hybridization dynamics
An experimental assessment of reproductive isolation and its consequences for seasonal hybridization dynamics
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DOI：
10.1093/biolinnean/bly177
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发表时间：
2019-02-01
影响因子：
1.9
通讯作者：
Pfenninger, Markus
中科院分区：
文献类型：
--
作者：
Foucault, Quentin;Wieser, Andreas;Pfenninger, Markus
虽然杂交的空间方面已经深入研究，时间方面还没有。本文分析了一对多化性非叮咬性摇蚊姊妹种--河岸摇蚊和河摇蚊的季节性杂交动态。猪。我们调查了不同温度条件下F1代杂种和所有可能的第一代回交杂种的育性和适合度。基于微卫星标记，我们推断存在不同的混合类在季节性的现场样品（春季和秋季）从现场的共同出现在连续两年。所有的实验杂种表现出降低的生育力，虽然没有一个特定的温度效应。在一个F-1方向上的适应性为零，但在另一个方向上没有减少。未观察到性别比例失真。然而，健身减少在所有回交，表明杂交应该是罕见的领域。在季节性样品中，C.猪只在秋季个体中发现。所有359个基因分型个体均归因于任一纯种。然而，几个人的秋季样本进行了后代渐渗的迹象，表明实际的杂交必须在夏季反复发生。因此，我们提出的证据表明，季节性的环境变化可以驱动杂交动态和长期经常性杂交不需要影响物种的完整性。
While the spatial aspect of hybridization has been investigated in depth, the temporal aspect has not. We analysed the seasonal hybridization dynamics of a multivoltine non-biting midge sister species pair, Chironomus riparius and C. piger. We investigated the fertility and fitness of F-1 hybrids, and all possible first-generation backcross hybrids, under different temperature conditions. Based on microsatellite markers, we then inferred the presence of different hybrid classes in seasonal field samples (spring and autumn) from a site of co-occurrence over two consecutive years. All experimental hybrids showed reduced fertility albeit without a specific temperature effect. Fitness was zero in one F-1 direction, but not reduced in the other. No sex ratio distortion was observed. However, fitness was reduced in all backcrosses, indicating that hybridization should be rare in the field. In the seasonal samples, C. piger was found only in autumn individuals. All 359 genotyped individuals were attributed to either of the pure species. However, several individuals of the autumn samples carried signs of later generation introgression, indicating that actual hybridization must take place recurrently during summer. We thus present evidence that seasonal environmental changes can drive hybridization dynamics and that long-term recurrent hybridization need not affect species integrity.