. 2017 Nov 23;5:e4083. doi: 10.7717/peerj.4083

Table 3. Association of 11 SNPs at DRD2 gene with egg production traits in Muscovy duck.

SNPs¹	Traits²	Least-squares mean ± SEM³			P-value
		CC(n = 387)	CT(n = 237)	TT(n = 31)
C+7T	FEA	272.95 ± 0.90^c	276.30 ± 1.15^b	295.94 ± 3.17^a	<0.0001
	E59W	74.62 ± 1.35^a	75.34 ± 1.73^a	61.13 ± 4.78^b	0.0187
	E300D	22.90 ± 0.71^a	21.81 ± 0.91^a	8.42 ± 2.51^b	<0.0001
		CC(n = 22)	CG(n = 239)	GG(n = 394)
C+364G	FEA	297.00 ± 3.80^a	275.64 ± 1.15^b	273.79 ± 0.90^b	<0.0001
	E59W	62.32 ± 5.67^b	77.15 ± 1.72^a	73.14 ± 1.34^ab	0.0193
	E300D	9.86 ± 3.01^b	22.37 ± 0.91^a	22.16 ± 0.71^a	0.0003
		TT(n = 130)	TC(n = 160)	CC(n = 410)
T+3024C	FEA	276.27 ± 1.75^a	275.21 ± 1.58^a	277.19 ± 0.98^a	0.5547
	E59W	79.02 ± 2.37^a	72.81 ± 2.13^ab	72.77 ± 1.33^b	0.0594
	E300D	21.94 ± 1.30^a	21.37 ± 1.17^a	20.80 ± 0.73^a	0.7271
		CC(n = 143)	AC(n = 182)	AA(n = 375)
A+3183C	FEA	276.84 ± 1.67^a	278.16 ± 1.48^a	275.67 ± 1.03^a	0.3816
	E59W	69.38 ± 2.25^b	72.85 ± 2.00^ab	76.21 ± 1.39^a	0.0301
	E300D	21.02 ± 1.24^a	19.98 ± 1.09^a	21.75 ± 0.76^a	0.4124
		GG(n = 205)	AG(n = 269)	AA(n = 226)
A+3262G	FEA	278.86 ± 1.39^a	276.85 ± 1.21^ab	274.15 ± 1.32^b	0.0466
	E59W	69.75 ± 1.88^b	73.88 ± 1.64^ab	77.80 ± 1.79^a	0.0084
	E300D	19.50 ± 1.03^b	21.06 ± 0.90^ab	22.72 ± 0.98^a	0.0766
		GG(n = 132)	CG(n = 231)	CC(n = 337)
C+3301G	FEA	272.05 ± 1.72^b	279.36 ± 1.30^a	276.42 ± 1.08^a	0.0033
	E59W	80.70 ± 2.34^b	73.11 ± 1.77^a	71.86 ± 1.46^a	0.0052
	E300D	24.77 ± 1.28^a	19.26 ± 0.96^b	21.01 ± 0.80^b	0.0028
		TT(n = 135)	TC(n = 245)	CC(n = 320)
T+3423C	FEA	277.77 ± 1.71^a	278.80 ± 1.27^a	274.35 ± 1.11^b	0.0226
	E59W	67.96 ± 2.31^b	73.13 ± 1.72^ab	77.08 ± 1.50^a	0.0038
	E300D	20.13 ± 1.27^ab	19.89 ± 0.94^b	22.53 ± 0.82^a	0.0730
		TT(n = 47)	TC(n = 154)	CC(n = 499)
T+3428C	FEA	270.64 ± 2.90^b	275.08 ± 1.60^ab	277.58 ± 0.89^a	0.0422
	E59W	85.72 ± 3.92^a	76.16 ± 2.16^b	72.14 ± 1.20^b	0.0022
	E300D	25.87 ± 2.15^a	22.16 ± 1.19^ab	20.38 ± 0.66^b	0.0317
		TT(n = 145)	AT(n = 141)	AA(n = 414)
A+3484T	FEA	272.65 ± 1.65^b	278.96 ± 1.67^a	277.13 ± 0.97^a	0.0183
	E59W	79.86 ± 2.23^a	74.19 ± 2.27^a	71.78 ± 1.32^b	0.0080
	E300D	24.17 ± 1.22^a	19.40 ± 1.24^b	20.67 ± 0.72^b	0.0141
		GG(n = 140)	AG(n = 218)	AA(n = 342)
A+3489G	FEA	278.66 ± 1.68^a	278.69 ± 1.34^a	274.35 ± 1.07^b	0.0159
	E59W	67.56 ± 2.27^b	72.51 ± 1.82^b	77.46 ± 1.45^a	0.0008
	E300D	19.99 ± 1.24^ab	19.56 ± 1.00^b	22.61 ± 0.80^a	0.0343
		GG(n = 198)	CG(n = 180)	CC(n = 322)
C+3545G	FEA	272.70 ± 1.41^b	276.78 ± 1.47^a	278.81 ± 1.10^a	0.0029
	E59W	79.74 ± 1.91^a	73.11 ± 2.00^b	70.84 ± 1.49^b	0.0011
	E300D	24.26 ± 1.04^a	21.02 ± 1.09^b	19.29 ± 0.82^b	0.0009

Notes.

Data are summarized as means ± SEM.

SNPs means single nucleotide polymorphisms, referred to covered regions, the first nucleotide of the translation start codon was designated +1, with the next upstream nucleotide being −1.

FEA, first egg age; E59W, egg number at age 59 weeks; E300D, egg number at age 300 days.

Values within a row with no common superscript differ significantly (P < 0.05) or are highly significant (P < 0.01).