Table 3. IGF-I, GHR, PI3KR1, CTSL2, and atrogin 1 gene expression of broilers from the starter period.

		IGFI-I 2		GHR		PI3KR1		CTSL2		Atrogin1 3
		Mean	SE	Mean	SE	Mean	SE	Mean	SE	Mean	SE
Comfort	MD 1	0.90	0.07	1.89	0.21	0.036	0.00	0.019	0.001	1.56	0.34
	DL1	1.14	0.15	3.33	0.62	0.059	0.02	0.012	0.001	1.21	0.24
	DL2	0.90	0.27	4.95	1.17	0.051	0.01	0.014	0.001	0.63	0.16
Stress	MD	0.47	0.14	1.84	0.66	0.050	0.00	0.050	0.008	1.61	0.43
	DL1	1.06	0.26	2.53	0.73	0.054	0.00	0.027	0.004	1.37	0.25
	DL2	0.88	0.13	4.70	1.87	0.039	0.00	0.031	0.002	0.92	0.14
Main effects
Environment	Comfort	0.98	0.18	3.39	1.79	0.049	0.02	0.015 b	0.007	1.14	0.57
	Stress	0.80	0.23	3.02	2.34	0.048	0.03	0.036 a	0.013	1.30	0.56
Diet	MD	0.68 b	0.17	1.87 b	0.47	0.043	0.02	0.035 a	0.011	1.59 a	0.37
	DL1	1.10 a	0.20	2.93 b	0.69	0.057	0.01	0.019 b	0.006	1.29 a	0.24
	DL2	0.89 ab	0.20	4.82 a	1.49	0.045	0.01	0.023 b	0.006	0.78 b	0.17
Probabilities
Environment		NS		NS		NS		<0.0001		NS
Diet		0.0144		0.0011		NS		0.0004		0.0012
Interaction		NS		NS		NS		NS		NS

^{a, b} Mean values within a column with different superscript letters are significantly different (P<0.05).

¹MD, methionine deficient; DL1, recommended level of methionine supplementation; DL2, methionine supplementation in excess.

²CTSL2, cathepsin L2; GHR, growth hormone receptor; IGF-I, insulin-like growth factor I; PI3KR1, phosphatidylinositol 3-kinase, regulatory 1.

³Expressed as arbitrary units (AU).

NS, non significant.