Iyengar Vikram K, Reeve H Kern, Eisner Thomas
Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14850, USA.
Nature. 2002 Oct 24;419(6909):830-2. doi: 10.1038/nature01027.
Females of the arctiid moth Utetheisa ornatrix mate preferentially with larger males, receiving both direct phenotypic and indirect genetic benefits. Here we demonstrate that the female's mating preference is inherited through the father rather than the mother, indicating that the preference gene or genes lie mostly or exclusively on the Z sex chromosome, which is strictly paternally inherited by daughters. Furthermore, we show that the preferred male trait and the female preference for that trait are correlated, as females with larger fathers have a stronger preference for larger males. These findings are predicted by the protected invasion theory, which asserts that male homogametic sex chromosome systems (ZZ/ZW) found in lepidopterans and birds promote the evolution of exaggerated male traits through sexual selection. Specifically, the theory predicts that, because female preference alleles arising on the Z chromosome are transmitted to all sons that have the father's attractive trait rather than to only a fraction of the sons, such alleles will experience stronger positive selection and be less vulnerable to chance loss than would autosomal alleles.
灯蛾科蛾类Utetheisa ornatrix的雌性优先与体型较大的雄性交配，从而获得直接的表型益处和间接的遗传益处。在此，我们证明雌性的交配偏好是通过父亲而非母亲遗传的，这表明偏好基因主要或仅位于Z性染色体上，而女儿严格从父亲那里继承该染色体。此外，我们表明偏好的雄性特征与雌性对该特征的偏好是相关的，因为父亲体型较大的雌性对体型较大的雄性有更强的偏好。这些发现是由受保护的入侵理论预测的，该理论断言，在鳞翅目昆虫和鸟类中发现的雄性同配性别染色体系统（ZZ/ZW）通过性选择促进了夸张的雄性特征的进化。具体而言，该理论预测，由于在Z染色体上出现的雌性偏好等位基因会传递给所有具有父亲吸引性状的儿子，而不是仅传递给一部分儿子，因此与常染色体等位基因相比，此类等位基因将经历更强的正选择，并且更不容易因偶然因素而丢失。
