Thermal plasticity of melanin pigmentation patterns in Drosophila species has been studied as a model to investigate developmental mechanisms of phenotypic plasticity. The developmental process of melanin pigmentation patterns on wings of Drosophila is divided into two parts, prepattern specification during the pupal period and wing vein-dependent transportation of melanin precursors after eclosion. Which part can be affected by thermal changes? To address this question, we used polka-dotted melanin spots on wings of Drosophila guttifera, whose spot areas are specified by wingless morphogen. In this research, we reared D. guttifera at different temperatures to test whether wing spots show thermal plasticity. We found that wing size becomes larger at lower temperature and that different spots have different reaction norms. Furthermore, we changed the rearing temperature in the middle of the pupal period and found that the most sensitive developmental periods for wing size and spot size are different. The results suggest that the size control mechanisms for the thermal plasticity of wing size and spot size are independent. We also found that the most sensitive stage for spot size was part of the pupal period including stages at which wingless is expressed in the polka-dotted pattern. Therefore, it is suggested that temperature change might affect the prepattern specification process and might not affect transportation through wing veins.

果蝇物种黑色素色素沉着模式的热可塑性已作为研究表型可塑性发育机制的模型进行了研究。果蝇翅膀上黑色素色素沉着模式的发育过程分为两个部分，蛹期的前模式规范和羽化后黑色素前体依赖翼脉的运输。哪些部分会受到热变化的影响？为了解决这个问题，我们在果蝇翅膀上使用了圆点黑色素斑点，其斑点区域由无翼形态发生素指定。在这项研究中，我们饲养了D. guttifera在不同温度下测试翼斑是否表现出热塑性。我们发现，在较低的温度下，翅膀的尺寸会变大，并且不同的点有不同的反应规范。此外，我们改变了蛹期中期的饲养温度，发现对翅膀大小和斑点大小最敏感的发育时期是不同的。结果表明，翼尺寸和光斑尺寸的热塑性的尺寸控制机制是独立的。我们还发现，对光斑大小最敏感的阶段是蛹期的一部分，包括以圆点图案表达无翅的阶段。因此，表明温度变化可能会影响预图案规范过程，但可能不会影响通过翼脉的运输。