Table 2. Theoretical predictions of the genomic location of sex-biased genes in aphids.

	Theoretical predictions:			Empirical test of Predictions 3: Genomic location of sex-biased genes
	Predictions 1: Preferred location for mutations with antagonistic effects (based on the analytical model and on our simulations)	Predictions 2: Expression pattern of sexually antagonist mutations after the evolution of modifiers of gene expression	Predictions 3: Combination of Predictions 1 and 2	Random expectations: All genes: #X∶#A = 497∶3215, f (X) = 0.13Genes with >5 reads: #X∶#A = 390∶2930, f (X) = 0.12
Fitness effect of the mutation				threshold for expression bias	#X∶#A	f(X)	% deviation	X2 test P-value
sm>0, sf<0, sa<0	X	M+F−A−	M+F−A−: enriched on the X	2-fold	63∶205	0.24	+100%	<10−8
				5-fold	54∶118	0.31	+167%	<10−14
				10-fold	44∶87	0.34	+186%	<10−14
sm>0, sf>0, sa<0	X	M+F+A−	M+F+A−: enriched on the X	2-fold	6∶17	0.26	+122%	0.033
				5-fold	6∶6	0.50	+326%	0.0001
				10-fold	4∶3	0.57	+386%	0.0002
sm<0, sf>0, sa>0	A	M−F−A+	M−F−A+: depleted on the X	2-fold	11∶153	0.07	−43%	0.045
				5-fold	4∶104	0.04	−68%	0.009
				10-fold	3∶81	0.04	−70%	0.020
sm<0, sf>0, sa>0	A	M−F+A+	M−F+A+: depleted on the X	2-fold	2∶69	0.03	−76%	0.019
				5-fold	1∶21	0.05	−61%	0.29
				10-fold	1∶12	0.08	−35%	0.65
sm<0, sf>0, sa<0	Slight bias towards A	M−F+A−	M−F+A−: slight bias towards A	2-fold	19∶193	0.09	−24%	0.21
				5-fold	8∶72	0.10	−15%	0.63
				10-fold	3∶40	0.07	−41%	0.33
sm>0, sf<0, sa>0	Slight bias towards X	M+F−A+	M+F−A+: slight bias towards X	2-fold	7∶73	0.09	−26%	0.41
				5-fold	3∶51	0.06	−53%	0.16
				10-fold	2∶22	0.08	−29%	0.60

The preferred chromosomal locations of sexually antagonistic mutations (Prediction 1) are based on the simulations presented in Figure 2. Prediction 2: Predicted evolution of expression pattern of a gene bearing a sexually antagonist mutation after the evolution of a modifier that reduces the expression in the harmed sex (M, F and A refer to male, sexual female and asexual female, respectively, and the sign represents relative expression in each morph). The genomic locations of sex-biased genes (Predictions 3) were obtained by combining Predictions1 and 2. Theoretical predictions 3 were then tested with empirical data by looking at the genomic location of sex-biased genes, when considering different levels of fold-change in expression (2-, 5-, 10-fold difference). Observed number of genes for X and autosomes, frequency of X-linkage, % deviation from random expectation of X-linkage (f _(X) = 0.12) and its significance (Chi-square tests) are also given.