TABLE 3.

Codon bias in somatic and germline sex-biased genes

	Expression	Male	Female	Pa
N	Soma	145	137
ENC	Soma	52.62	43.42	3.9 × 10−17
FOP	Soma	0.455	0.598	2.1 × 10−17
N	Germ	1083	876
ENC	Germ	50.32	46.70	2.2 × 10−29
FOP	Germ	0.507	0.564	1.3 × 10−29

N, number of genes; ENC, effective number of codons (Wright 1990); F_OP, frequency of optimal codons (Ikemura 1981). Numbers represent the mean value for each category.

^aP-value of two-tailed Mann-Whitney test comparing male- and female-biased genes.