Combining two Meishan F2 crosses improves the detection of QTL on pig chromosomes 2, 4 and 6

Table 2 QTL detected in the two independent and the combined pedigrees by the single QTL detection analysis with significance level <10%

Pedigree	Trait	SSC	Position (cM)	LRT	Threshold	Number of segregating sires	QTL effect	References
French	BFT	2	0 [0-8]	47.2	+	2	+ 0.25	[8]
French	loin	2	0 [0-3]	58.4	**	3	- 0.30	[8]
French	IMF	4	0 [0-12]	37.0	+	3	- 0.009	/
French	BFT	4	61 [55-66]	45.5	+	4	+ 0.19	[8]
French	LWG	4	66 [56-71]	69.6	**	2	- 0.18	[6]
French	x2	4	14 [6-23]	47.0	+	2	- 0.006	/
French	head weight	4	42 [17-49]	44.6	+	3	- 0.25	/
French	birth weight	4	53 [45-58]	61.3	**	4	- 0.07	[6]
French	belly weight	4	55 [48-61]	56.9	**	2	- 0.04	[8]
French	teat number	6	110 [98-130]	46.0	+	3	+ 0.03	[15]
French	loin weight	6	99 [92-108]	46.6	+	3	+ 0.22	/
French	midriff weight	6	144 [137-150]	59.1	**	4	- 0.15	/
Dutch	weaning weight	2	21 [17-24]	46.2	+	5	+ 0.03	/
Dutch	BFT	2	28 [18-46]	60.4	**	9	+ 0.22	[11]
Dutch	meat	2	30 [19-47]	63.8	**	8	- 0.31	/
Dutch	a*	2	26 [19-36]	51.2	*	10	+ 0.02	[10]
Dutch	IMF	4	0 [0-6]	47.0	+	9	+ 0.14	[11]
Dutch	birth weight	6	136 [130-144]	47.4	+	8	- 0.13	/
Dutch	teat number	6	154 [146-161]	47.5	+	8	- 0.05	/
Dutch	L*	6	103 [91-118]	61.3	**	7	+ 0.20	/
Combined	BFT	2	1 [0-5]	95.6	*	12	+ 0.34
Combined	meat	2	32 [25-46]	97.8	**	10	- 0.32
Combined	IMF	4	0 [0-5]	84.0	*	12	+ 0.11
Combined	teat number	4	46 [37-51]	75.7	+	10	- 0.04
Combined	birth weight	4	53 [49-57]	82.1	*	9	- 0.10
Combined	LWG	4	83 [59-90]	98.6	**	11	- 0.30
Combined	teat number	6	104 [94-113]	84.8	*	11	- 0.01

Traits indicated in bold are common to the two independent pedigrees; LRT is the maximum Likelihood Ratio Test; the QTL effect is expressed in standard deviation units; the effect is given as Meishan - European alleles; +, *, ** are the 10%, 5% and 1% chromosome-wide significance levels respectively; the references of previously published data are given,/: when no previous result was available for this trait on the chromosome or when this QTL was not detected in the previous analysis.

ISSN: 1297-9686