Genome-wide mapping of Quantitative Trait Loci for fatness, fat cell characteristics and fat metabolism in three porcine F2 crosses

Table 5 Combined analysis of significant QTL positions ^a

					Single locus^c				Combined loci^d
Trait^b, Cross	SSC	Position (cM)	F ratio	P	VF₂ (%)	r² (%)	Additive effect	F ratio	P	Additive effect
SEFW, W × M	1	71.0	17.3	< 0.001	4.8	18.0	-0.11	4.3	0.039	-0.05
	1	137.1	21.9	< 0.001	6.1	19.1	-0.12	16.4	< 0.001	-0.10
	5	73.0	18.2	< 0.001	5.0	18.2	0.10	15.0	< 0.001	0.08
	7	85.9	18.1	< 0.001	5.0	18.2	-0.10	18.8	< 0.001	-0.09
	X	90.0	15.3	< 0.001	4.2	17.5	-0.11	15.4	< 0.001	-0.11
			Initial model: r² (%) 13.6 Combined loci: VF₂ (%) 20.2; r² (%) 32.1
FD10, W × M	1	112.9	19.3	< 0.001	5.3	14.9	-2.18	14.9	< 0.001	-1.76
	2	46.5	13.7	< 0.001	3.8	13.5	-1.95	12.6	< 0.001	-1.70
	7	78.8	33.9	< 0.001	9.2	18.4	2.73	35.3	< 0.001	2.60
	X	90.0	20.5	< 0.001	5.7	15.2	-2.98	20.2	< 0.001	-2.71
			Initial model: r² (%) 9.8 Combined loci: VF₂ (%) 19.4; r² (%) 30.2
FMR, M × P	1	166.3	25.5	< 0.001	7.4	29.0	0.09	23.7	< 0.001	0.08
	2	0.0	14.7	< 0.001	4.3	26.6	0.06	9.5	0.002	0.04
	2	63.4	17.1	< 0.001	5.4	27.2	0.07	14.5	< 0.001	0.06
	6	96.9	35.6	< 0.001	10.1	31.1	0.10	32.3	< 0.001	0.09
			Initial model: r² (%) 23.1 Combined loci: VF₂ (%) 22.8; r² (%) 41.4
FV146, W × P	2	96.3	9.8	0.002	3.0	17.9	-2.96	11.3	< 0.001	-3.00
	4	76.9	19.3	< 0.001	6.0	20.4	4.35	17.7	< 0.001	4.00
	7	105.4	9.9	0.002	3.0	17.9	-3.71	8.9	0.003	-3.32
	X	0.0	9.5	0.002	2.9	17.8	3.06	11.9	< 0.001	3.23
			Initial model: r² (%) 15.0 Combined loci: VF₂ (%) 14.4; r² (%) 28.3
FVCM, M × P	1	207.3	8.7	0.003	2.7	16.0	-8.23	11.0	0.001	-8.48
	2	59.4	10.1	0.002	3.0	16.4	-5.34	13.6	< 0.001	-5.71
	7	74.8	37.1	< 0.001	10.8	23.2	10.31	42.3	< 0.001	10.56
	X	3.0	7.4	0.014	2.1	15.7	5.26	5.3	0.022	4.08
			Initial model: r² (%) 13.6 Combined loci: VF₂ (%) 18.6; r² (%) 30.6

Examples are given for some traits and show the results gained by including several genome-wide significant QTL across chromosomes
^a multiple position models were included together with the same environmental independent variables as in the initial model; ^b trait acronym, for definition see Table 2; ^c each QTL position was analyzed separately for trait association; F ratio: mean square estimates of the additive and dominant components in relation to the error variance of the model; VF₂: proportion of error variance reduction by inclusion of additive and dominant components in the initial model; r²: determination coefficient; ^d QTL positions analyzed in combination

ISSN: 1297-9686