Fig. 1.
Extreme QTL mapping in Flyland. (A) The Flyland population was generated by a round robin crossing design. Progeny of these crosses was mixed and outcrossed randomly for 70 generations. The last generation constituted the Flyland population. (B) For starvation resistance, a random sample of 300 and the 300 longest-living female flies constituted the sequenced pools. (C) Distribution of startle response for 2,000 phenotyped female flies in Flyland. (D) Distribution of chill coma recovery for 2,000 female flies in Flyland. The top (red) and bottom (blue) 15% scoring flies were pooled and sequenced. Allele frequencies were estimated in the high and low pools and compared to identify QTLs. (E) Plots of significance (−log10P; left axis) and allele frequency differences (ΔQ95; right axis) for extreme QTL mapping. Points of dark color indicate significant SNPs. The dark-colored lines connect consecutive sliding windows of 50 kb, with a step size of 5 kb. In each window, the 95% quantile of the absolute allele frequency difference is plotted.