Data from: A Z-linked sterility locus causes sexual abstinence in hybrid females and facilitates speciation in Spodoptera frugiperda

In the fall armyworm, Spodoptera frugiperda (Lepidoptera, Noctuidae), two sympatric strains have been recognized that have been termed corn strain (C) and rice strain (R), referring to their most common host plants. Both strains are reproductively isolated via a distinct prezygotic barrier as well as via an intriguing postzygotic phenomenon: when R females have mated with C males, the resulting RC hybrid females exhibit dramatically reduced fertility independent of their mating partner. Here we demonstrate that the reduced fertility is caused by the fact that these females refrain from mating, i.e. females are behaviorally sterile. We identified a Z-chromosomally linked sterility locus that is most likely incompatible with yet-to-be-identified autosomal (or cytoplasmic) factors leading to the observed sexual abstinence. Within-chromosome mapping revealed the sterility locus to be located in an area of strongly reduced inter-strain recombination.

在草地贪夜蛾（fall armyworm，学名Spodoptera frugiperda，隶属鳞翅目（Lepidoptera）夜蛾科（Noctuidae））中，目前已确认存在两个同域品系，二者依据其最常见的寄主植物分别被命名为玉米品系（C）与水稻品系（R）。这两个品系可通过独特的合子前生殖隔离屏障，以及一种引人关注的合子后生殖机制实现生殖隔离：当水稻品系雌虫与玉米品系雄虫交配后，所产生的RC杂交雌虫的生育力会显著下降，且该表型与其自身的交配对象无关。本研究证实，这种生育力下降源于此类雌虫拒绝交配，即这些雌虫存在行为不育现象。研究团队鉴定出一个Z染色体（Z-chromosome）连锁的不育位点，该位点极可能与尚未被探明的常染色体（autosomal）或细胞质（cytoplasmic）因子不兼容，进而引发了上述的性禁欲行为。染色体内部定位分析显示，该不育位点位于品系间重组率显著降低的区域。