Adaptive evolution of the osmoregulation-related genes in cetaceans during secondary aquatic adaptation

Table 1 CODEML analysis of osmoregulatory genes (11 genes) and evidence of positive selection on the ACE, AGT, SLC14A2, REN, AQP2, and AVP genes in mammals and cetaceans

Genes	Models	-lnL	2ΔLnL	P value^a	ω values
ACE	Site model
(1033aa)	Dataset I: All mammals (28 sequences)
	M8a	20856.619			ω = 1
	M8	20853.691	5.856	0.016	ω = 2.077
	Dataset II: cetaceans (11 sequences)
	M8a	5910.391			ω = 1
	M8	5905.151	10.480	0.001	ω = 4.855
	Branch site model
	Dataset I: All mammals (28 sequences)
	Branch n (terminal branch of Grampus griseus)
	Null	21017.590			ω0 = 0.070, ω1 = 1, ω2 = 1
	Alternative	21010.004	15.172	0.002	ω0 = 0.070, ω1 = 1, ω2 = 258.836
AGT	Site model
(324aa)	Dataset II: cetaceans (10 sequences)
	M8a	2017.713			ω = 1
	M8	2014.489	6.448	0.011	ω = 4.134
	Branch site model
	Dataset I: All mammals (30 sequences)
	Branch n (terminal branch of G. griseus)
	Null	10615.771			ω0 = 0.154, ω1 = 1, ω2 = 1
	Alternative	10601.717	28.107	<0.001	ω0 = 0.154, ω1 = 1, ω2 = 952.146
SLC14A2	Site model
(861aa)	Dataset I: All mammals (28 sequences)
	M8a	15199.892			ω = 1
	M8	15197.706	4.372	0.037	ω = 1.529
	Dataset II: cetaceans (10 sequences)
	M8a	4602.652			ω = 1
	M8	4597.947	9.410	0.002	ω = 2
REN	Site model
(407aa)	Dataset I: All mammals (25 sequences)
	M8a	7542.944			ω = 1
	M8	7531.661	22.565	<0.001	ω = 16.110
AQP2	Branch site model
(202aa)	Dataset I: All mammals (27 sequences)
	Branch c (ancestral toothed whales)
	Null	3827.416			ω0 = 0.037, ω1 = 1, ω2 = 1
	Alternative	3822.989	8.854	0.074	ω0 = 0.038, ω1 = 1, ω2 = 999

Note: a, likelihood ratio test p-values were adjusted for multiple testing with a Benjamini & Hochberg’s procedure [63, 64] and threshold of 0.05.

ISSN: 2730-7182