Sawyer L A, Hennessy J M, Peixoto A A, Rosato E, Parkinson H, Costa R, Kyriacou C P
Department of Genetics, University of Leicester, LE1 7RH, UK.
Science. 1997 Dec 19;278(5346):2117-20. doi: 10.1126/science.278.5346.2117.
The threonine-glycine (Thr-Gly) encoding repeat within the clock gene period of Drosophila melanogaster is polymorphic in length. The two major variants (Thr-Gly)17 and (Thr-Gly)20 are distributed as a highly significant latitudinal cline in Europe and North Africa. Thr-Gly length variation from both wild-caught and transgenic individuals is related to the flies' ability to maintain a circadian period at different temperatures. This phenomenon provides a selective explanation for the geographical distribution of Thr-Gly lengths and gives a rare glimpse of the interplay between molecular polymorphism, behavior, population biology, and natural selection.
果蝇生物钟基因周期内编码苏氨酸-甘氨酸（Thr-Gly）的重复序列长度具有多态性。两种主要变体（Thr-Gly）17和（Thr-Gly）20在欧洲和北非呈现出高度显著的纬度渐变分布。野生捕获个体和转基因个体的Thr-Gly长度变异都与果蝇在不同温度下维持昼夜节律周期的能力有关。这一现象为Thr-Gly长度的地理分布提供了一个选择性解释，并且罕见地揭示了分子多态性、行为、种群生物学和自然选择之间的相互作用。
