TABLE 2

Codon bias in X-linked and autosomal genes

ChromosomeMaleFemaleNon-sexPMFaPMNaPFNa
N  X 144 331 823
ENC  X  48.87  45.65  46.117.9 × 10−71.8 × 10−60.250
FOP  X   0.515   0.568   0.5532.0 × 10−74.8 × 10−50.013
N  Auto114911123712
ENC  Auto  50.50  48.75  48.403.8 × 10−81.7 × 10−320.003
FOP  Auto   0.506   0.536   0.5343.5 × 10−186.3 × 10−100.531
  • a P-value of two-tailed Mann-Whitney test for comparisons among male- (M), female- (F), and non-sex-biased (N) genes.

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