Comprehensive analysis of CCCH-type zinc finger family genes facilitates functional gene discovery and reflects recent allopolyploidization event in tetraploid switchgrass

Table 1 Purifying and diversifying selection of PvC3Hs

Duplicated pairs	Chromosomal locations	Ks	Ka	Ka/Ks	Evolutionary Selection	Duplication type	Divergence Time (Mya)
PvC3H29/39	Chr5a/5b	0.000	0.041	N/A	Diversifying	Homeologous	N/A
PvC3H34/45	Chr5a/5b	0.000	0.036	N/A	Diversifying	Homeologous	N/A
PvC3H62/66	Chr9a/9b	0.000	0.018	N/A	Diversifying	Homeologous	N/A
PvC3H54/57	Chr7a/7b	0.039	0.052	1.316	Diversifying	Homeologous	3
PvC3H33/41	Chr5a/5b	0.041	0.019	0.459	Purifying	Homeologous	3.1
PvC3H6/7	Chr1a/1b	0.046	0.075	1.649	Diversifying	Homeologous	3.5
PvC3H61/65	Chr9a/9b	0.047	0.03	0.638	Purifying	Homeologous	3.6
PvC3H32/42	Chr5a/5b	0.06	0.006	0.104	Purifying	Homeologous	4.6
PvC3H35/44	Chr5a/5b	0.065	0.044	0.672	Purifying	Homeologous	5
PvC3H1/9	Chr1a/1b	0.073	0.061	0.841	Purifying	Homeologous	5.6
PvC3H31/43	Chr5a/5b	0.076	0.066	0.874	Purifying	Homeologous	5.8
PvC3H10/15	Chr2a/2b	0.082	0.092	1.119	Diversifying	Homeologous	6.3
PvC3H30/40	Chr5a/5b	0.102	0.084	0.825	Purifying	Homeologous	7.9
PvC3H20/23	Chr3a/3b	0.131	0.064	0.489	Purifying	Homeologous	10.1
PvC3H46/51	Chr6a/6b	0.151	0.013	0.087	Purifying	Homeologous	11.6
PvC3H5/6	Chr1a/1a	0.163	0.06	0.367	Purifying	Tandem	12.5
PvC3H17/50	Chr3a/6b	0.237	0.03	0.128	Purifying	Paralogous	18.2
PvC3H32/33	Chr5a/5a	0.282	0.444	1.575	Diversifying	Tandem	21.7
PvC3H41/42	Chr5b/5b	0.287	0.464	1.616	Diversifying	Tandem	22.1

Ks: number of synonymous substitutions per synonymous site; Ka: number of nonsynonymous substitutions per nonsynonymous site. When Ka/Ks = 1, neutral evolution; Ka/Ks < 1, purifying selection; Ka/Ks > 1, diversifying selection. Genes in duplicated pairs are in tandem duplication (Tandem), in homeologous chromosomes (Homeologous) or were simply paralogous.

ISSN: 1471-2164