Gender-specific selection on codon usage in plant genomes

BMC Genomics

Table 4 Mean GC3 values for short genes (less than or equal to 200 amino acids in the homologous Arabidopsis thaliana protein), medium length genes (more than 200 amino acids and less than or equal to 400) and long genes (more 400 amino acids), and for genes encoding very long proteins only (equal to or more than 1000 amino acids) for female-specific and male-specific genes in Zea mays and Triticum aestivum and for male-specific and flower-specific genes in Brassica napus.

	Short			Medium			Long			Very long only ^a
	Female	Male	P-value	Female	Male	P-value	Female	Male	P-value	Female	Male	P-value
Zea mays	0.702	0.632	<1.0 × 10 ^-16	0.635	0.542	<1.0 × 10 ^-16	0.593	0.483	<1.0 × 10 ^-16	0.505	0.656	*0.044*
Triticum aestivum	0.768	0.729	*0.015*	0.677	0.617	<1.0 × 10 ^-16	0.612	0.526	<1.0 × 10 ^-16	0.518	0.436	<1.0 × 10 ^-16
Brassica napus	Male	Flower		Male	Flower		Male	Flower		Male	Flower
	0.523	0.501	0.002	0.489	0.472	0.0002	0.469	0.448	<1.0 × 10 ^-16	0.441	0.423	0.340

P-values are those for the Mann-Whitney Rank Sum Test (t-tests yielded similar P-values). P-values less than 0.05 are in bold. P-values not remaining statistically significant after Bonferroni correction among these contrasts are bold italics. For P-values of comparisons between protein length categories [see Additional data file 1 (Table 4)].
^a, Sample sizes are relatively small for this group, influencing P-values for Z. mays and B. napus; the direction and magnitude of the differences are maintained for each comparison (see text). Mean protein lengths (± Standard Error) for this category are as follows. Z. mays sperm 1556.0 (± 63), Z. mays egg 1485.2 (± 112), T. aestivum anther 1377.0 (± 24.7), T. aestivum ovary 1334.7 (± 72.8), B. napus microspore 1370.5 (± 70.6), B. napus flower 1361.4 (± 34.0). Other mean protein length values are presented in Table 3.

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