School of Life Sciences, Arizona State University, Tempe, Arizona 85287-4601, USA.
Evolution. 2011 Jul;65(7):2098-110. doi: 10.1111/j.1558-5646.2011.01285.x. Epub 2011 Mar 30.
Studies of compound eyes have revealed that variation in eye structure can substantially affect visual performance. Here, we investigate the degree to which a stressful rearing environment, which decreases body size, affects the eye phenotype. Full siblings of the Orange Sulphur butterfly, Colias eurytheme, were collected from known parents and split within families among two diet treatments that varied in quality. In both sexes, individuals reared on the high-quality diet had larger eye height and anterior facet diameter, and therefore, by inference, superior vision. However, relative to their reduced body size, individuals reared on low-quality diet had proportionally larger eyes and facets than individuals reared on high-quality diet. We interpret this finding as evidence that butterflies encountering nutritional stress increased proportional investment in eye development to reduce loss of visual performance. We also found significant broad-sense genetic variation underlying eye structure in both males and females, and report novel heritability estimates for eye height and facet diameter. Surprisingly, there was greater genetic variation in eye height among males than among females, despite apparently stronger directional selection on male vision. We discuss the implications of these data for our understanding of eye development and evolution.
对复眼的研究表明，眼睛结构的变化会显著影响视觉表现。在这里，我们研究了紧张的饲养环境（会降低体型）对眼睛表型的影响程度。我们从已知的父母那里收集了橙色硫磺蝶（Colias eurytheme）的全同胞，并在两个饮食处理组中按家庭内部分配，这两个饮食处理组在质量上有所不同。在雌雄两性中，在高质量饮食中饲养的个体眼高和前表面直径较大，因此可以推断出它们的视觉更优越。然而，与它们的体型缩小相比，在低质量饮食中饲养的个体的眼睛和前表面比例比在高质量饮食中饲养的个体更大。我们将这一发现解释为，遇到营养压力的蝴蝶会增加对眼睛发育的比例投资，以降低视觉表现的损失。我们还发现了眼睛结构在雌雄两性中都存在显著的广义遗传变异，并报告了眼高和前表面直径的新遗传力估计值。令人惊讶的是，尽管雄性视觉受到更强的定向选择，但雄性眼睛高度的遗传变异比雌性更大。我们讨论了这些数据对我们理解眼睛发育和进化的意义。
