Hepatic mRNA expression and plasma levels of insulin-like growth factor-I (IGF-I) in broiler chickens selected for different growth rates

Abstract

The hepatic expression and plasma concentrations of IGF-I were investigated in three broiler chicken strains selected for different growth rates (HP-Hubbard-Pettersen, a fast growing strain; NN-Naked-neck, a strain with an intermediate growth rate and a heterozygous genotype, and C-Caipira, a slow growing crossbred strain). The chickens were studied at 1, 21 and 42 days of age and had free access to food throughout the study. Hepatic IGF-I mRNA expression was assessed by dot blot analysis using a randomly labeled chicken IGF-I cDNA as the probe and plasma IGF-I concentrations were assayed by radioimmunoassay. The hepatic levels of IGF-I mRNA increased from 1 to 21 days of age in all strains, with NN chickens showing a higher (p < 0.05) IGF-I expression than the other strains. Plasma IGF-I concentrations increased (p < 0.05) with broiler chicken age, but there were no significant differences among the strains. These results indicate that despite differences in the growth rates among the strains, the changes in the expression of IGF-I mRNA in liver and in the plasma levels of IGF-I were independent of broiler chicken strain, but varied with chicken age.

Insulin‐like growth factor 1 and growth rate in nestlings of a wild passerine bird

“…; Giachetto et al . ). Our results, in great tits, show somewhat different pattern to that described in chickens.…”

“…However, while this accumulated evidence shows that IGF‐1 is essential during growth and development, a direct correlation between the IGF‐1 and post‐natal body weight is often reported to be absent (Buyse & Decuypere ; Giachetto et al . ; Rahimi ).…”

“…In ovo injections of IGF-1 has been shown to promote overall body weight increase during the pre-and post-natal periods (Kocamis et al 1998;Liu et al 2011;Wang et al 2012). Furthermore, in chickens, which were divergently selected for high and low post-natal growth rates, the faster growing strain was shown to have increased plasma IGF-1 levels and hepatic IGF-1 mRNA expression rates, when compared to the strain with the lower growth rate (Beccavin et al 2001;Giachetto et al 2004). However, while this accumulated evidence shows that IGF-1 is essential during growth and development, a direct correlation between the IGF-1 and post-natal body weight is often reported to be absent (Buyse & Decuypere 1999;Giachetto et al 2004;Rahimi 2005).…”

Domestication and growth hormone transgenesis cause similar changes in gene expression in coho salmon ( Oncorhynchus kisutch )

“…In domestic dogs, elevated GH (during early life) and IGF1 are associated with large dog breeds (44,45), and the IGF1 locus has been associated with variation influencing body size (46). Extensive work in domestic chickens and turkeys has found GH and IGF1 to be variably correlated with growth rate or to have an ability to further stimulate organismal or cellular growth (47)(48)(49)(50). In fish, fast-growing strains of rainbow trout have not been found to possess elevated plasma or pituitary GH or plasma IGF1 (51), and fast-growing Atlantic salmon showed no change in IGF1 but pituitary and plasma GH were elevated when examined across stages (52).…”

Expression Profiles of Somatotropic Axis Genes in Lines of Chickens Divergently Selected for 56-Day Body Weight

“…Lines of chickens selected for high or low growth rates were respectively associated with high and low circulating IGF-1 levels (17). In contrast, Giachetto et al (18) reported that hepatic IGF-1 mRNA and plasma IGF-1 levels were similar for chickens with different growth rates. For the Virginia Tech growth selected lines, the concentration of plasma GH is less and IGF-1 is greater in HWS than LWS chickens (19).…”