Exploring the genetic variants of insulin-like growth factor II gene and their associations with two production traits in Langshan chicken

Figures & data

Table 1. Genotypic and allelic frequencies of the IGF2 gene I2 locus in Langshan chicken.

Genotypic frequencies (observed genotype numbers)			Allelic frequencies
CC	CG	GG	C	G	Locus equilibrium χ^2 test (p value)
0.467 (140)	0.343 (103)	0.190 (57)	0.638	0.362	χ^2 = 19.990 (p = .000008)

Table 2. Population genetic parameters for the IGF2 gene I2 locus in Langshan chicken.

Observed heterozygosity (Ho)	Expected heterozygosity (He)	Effective allele numbers (Ne)	Polymorphic information content (PIC)
0.3433	0.4617	1.8579	0.3551

Table 3. Least squares means of genotypic effects and additive and dominance effects for two production traits.

Genotype	Number	Traits
		Body weight at 16-week old (kg)	Egg numbers of 300 days
CC	140	1.553^ab ± 0.013	85.060^B ± 1.542
CG	103	1.522^b ± 0.015	89.660^B ± 1.948
GG	57	1.593^a ± 0.017	100.810^A ± 2.455
Additive effect		0.020	7.875
Dominance effect		−0.051	−3.275
Ratio		−2.550	−0.416

Note: Different small letters (a and b) in the same column indicated significant deviation (p < .05), while different capital letters (A and B) meant highly significant deviation (p < .01); Ratio is the ratio of the dominance effect to the absolute value of the additive effect.