Table 4. IGF-I, GHR, PI3KR1, CTSL2, and atrogin 1 gene expression of broilers from the grower period.

		IGFI-I 2		GHR		PI3KR1		CTSL2		Atrogin 1 3
		Mean		SE	Mean	SE	Mean	SE		Mean	SE	Mean	SE
Comfort	MD 1	0.22	0.02	2.10 bc	0.24	0.017	0.002	0.024 cd	0.005	1.83	0.4
	DL1	0.28	0.04	3.69 b	0.69	0.014	0.005	0.015 d	0.003	1.42	0.2
	DL2	0.24	0.06	5.49 a	1.29	0.014	0.002	0.013 d	0.002	0.74	0.2
Stress	MD	0.14	0.07	2.04 c	0.74	0.012	0.001	0.074 a	0.010	2.34	0.5
	DL1	0.26	0.06	2.80 bc	0.80	0.013	0.002	0.034 bc	0.005	1.61	0.3
	DL2	0.22	0.03	2.26 bc	0.67	0.02	0.006	0.038 b	0.004	1.09	0.1
Main effects
Environment	Comfort	0.25	0.04	3.76	1.15	0.015	0.003	0.017	0.004	1.33	0.4
	Stress	0.21	0.06	2.37	0.72	0.015	0.006	0.049	0.012	1.68	0.4
Diet	MD	0.18	0.05	2.06	0.53	0.015	0.005	0.049	0.017	2.08 a	0.4
	DL1	0.27	0.05	3.25	0.77	0.013	0.004	0.024	0.007	1.51 b	0.2
	DL2	0.23	0.05	3.88	1.38	0.017	0.005	0.026	0.008	0.92 c	0.2
Probabilities
Environment		NS		0.0053		NS		<0.0001		NS
Diet		NS		0.0113		NS		<0.0001		<0.0001
Interaction		NS		0.0252		NS		0.0011		NS

^{a, b, c, d} 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.