TABLE 2.

Expression ratio between homeologous gene pairs

Groupa	Expression ratiob				No. of homeolog pairsc		P valued	% of homeolog pairs with unbalanced expressione
	Mean	Median	SD	Skew	Ab	aB
C18	0.500	0.500	0.079	−0.045	2,077	2,059	1	13.8
LA18	0.503	0.505	0.113	−0.009	2,151	1,985	0.041	31.0
C42	0.501	0.501	0.089	−0.146	2,088	2,048	1	18.7
LA42	0.500	0.503	0.115	−0.085	2,119	2,017	0.465	33.4

^aC18, control condition at 18 h; LA18, lactic acid condition at 18 h; C42, control condition at 42 h; LA42, lactic acid condition at 42 h.

^bMean, median, standard deviation (SD), and skew refer to the A/(A+B) expression ratios for 4,136 homeologous gene pairs, as described in Materials and Methods.

^cAb, homeolog pair in which the A gene shows higher expression; aB, homeolog pair in which the B gene shows higher expression.

^dP values refer to the comparison between the number of Ab homeolog pairs and the number of aB homeolog pairs under each of the four conditions. P values were obtained from two-sided exact binomial tests of the null hypothesis that the numbers of Ab and aB loci are equal and were corrected for multiple testing using the Bonferroni method.

^eExpression ratio values of ≤0.4 and ≥0.6 are categorized as unbalanced expression.