Assessing the impact of comparative genomic sequence data on the functional annotation of the Drosophilagenome

Table 2 Rates of amino-acid (K_a) and silent (K_s) substitution in Drosophila genes

Species	All genes			Known genes			Predicted genes			p-value
	K_a	K_s	N	K_a	K_s	N	K_a	K_s	N	K_a	K_s
D. erecta	0.057	0.357	53	0.042	0.366	25	0.071	0.349	28	0.0001	0.1299
D. pseudoobscura	0.146	2.313	41	0.071	1.830	17	0.199	2.655	24	0.0009	0.0262
D. willistoni	0.220	2.627	39	0.089	2.225	15	0.302	2.878	24	0.0001	0.0735
D. littoralis	0.170	2.166	31	0.126	1.923	14	0.206	2.366	17	0.1315	0.6058

Rates of substitution per site between D. melanogaster and D. erecta, D. pseudooobscura, D. willistoni, or D. littoralis are estimated using the method of Yang and Nielsen [81]. Shown are the average rates of substitution per site (and sample sizes) of all, known or predicted genes. p-values are the results of Mann-Whitney U-tests for differences in the distribution of K_a and K_s values between known and predicted genes for a given pairwise comparison. Values in bold represent significant differences in rates of evolution between known and predicted genes at the 0.006 (= 0.05/8) level.

ISSN: 1474-760X