Rapid evolution of chemosensory receptor genes in a pair of sibling species of orchid bees (Apidae: Euglossini)

Table 2 Nucleotide polymorphisms and patterns of selection between orthologous genes

	ORs	GRs	IRs	OBPs	CSPs	Total	NC
Unique genes^a	74	1	4	10	5	94	3091
Variable genes^b	36 (0.49)	1 (1.0)	2 (0.5)	2 (0.2)	1 (0.2)	42 (0.45)	387 (0.13)
Total variable sites	194	3	13	10	1	218	989
Total polymorphic^c
synonymous	55	0	2	3	1	61	479
non-synonymous	50	3	2	4	0	56	134
Total fixed^c
synonymous	23	0	1	1	0	25	277
non-synonymous	66	0	8	2	0	76	99
Genes fixed^d	21	0	2	1	0	24	157
Mean d_N ^e	0.0034857	0	0.0026	0.006000	0	0.0035167	0.0005127
Mean d_S ^e	0.0037524	0	0.00105	0.011600	0	0.0038542	0.0042777
Mean d_N/d_S ^e	0.9289340	-	2.4761905	0.5172414	-	0.9124324	0.1198630
d_N/d_S > 1^e,f	10 (1)	-	2 (0)	0 (0)	-	12 (1)	23 (0)
S ratio [%]^g	13.51	0	50	0	0	12.77	0.74

^aHomologous genes identified independently in the antennal transcriptomes of E. dilemma and E. viridissima with ≥10-fold mean per-base coverage
^bGenes with fixed differences between the two species. In brackets: relative amount of all unique genes
^cTotal polymorphic/ fixed sites of all variable sites
^dGenes with fixed differences between the two species
^e d _N /d _S calculations are based on genes containing fixed differences
^fNumber of pairwise d _N /d _S estimates significantly higher than 1 in brackets
^gRatio of orthologous genes with fixed differences among all orthologous genes detected per gene set

ISSN: 2730-7182