Table 1. Unbiased estimates of percent genetic variance explained by detected QTLs, in real and simulated data.

Variance explained	Data	Four-locus model	Best model
0–10	0.26	0.11	0.2
10–20	0.15	0.27	0.18
20–30	0.14	0.33	0.16
30–40	0.13	0.2	0.12
40–50	0.09	0.07	0.09
50–60	0.07	0.02	0.06
>60	0.16	0.004	0.2
Median	0.27	0.24	0.27

Numbers in each cell represent the fraction of QTLs in a given data set that explain a percent of genetic variance in a given range. Data: QTLs detected across all real transcripts. QTLs detected in the subset of highly heritable transcripts were not significantly different (data not shown). Four-locus model: QTLs simulated under a model of four additive loci of equal effect. Best model: QTLs simulated under the best-fit additive model for highly heritable transcripts. QTLs with negative estimates were not included. When transcripts linked to multiple loci, results are for the QTL with the most significant P value in the linkage test.