The Adaptive Significance of Natural Genetic Variation in the DNA Damage Response of Drosophila melanogaster
PC (Panama, 8°N), MX (Mexico, 19°N), FL (Florida, 30°N), VA (Virginia, 37°N), RI (Rhode Island, 41°N), and ME (Maine, 44°N). We scored hatch rate for 20,328 UV-unexposed embryos (control) and for 30,853 UV-exposed embryos from 111 isofemale lines (sample sizes are: NPC = 25; NMX = 14; NFL = 15; NVA = 16; NRI = 18; NME = 23). Panel (A) Regression of population mean UV sensitivity index (reduction in egg hatch rate after UV exposure) over latitude (R2 = 0.94, p = 0.001). Error bars represent the standard error of the mean (s.e.m.). Panel (B) Regression over latitude of population-mean (± s.e.m.) egg hatch rate from controls (UV-unexposed; in green; primary y-axis) and of population-mean (± s.e.m.) egg hatch rate of UV-exposed embryos (in blue; secondary y-axis). Both regressions are significant (R2 = 0.78, p = 0.019; and R2 = 0.73, p = 0.029, respectively).