Ontogenic Changes in the Circulating Concentrations of Insulin-like Growth Factor (IGF)-I, IGF-II, and IGF-Binding Proteins in the Chicken Embryo

GRP94 Is Essential for Mesoderm Induction and Muscle Development Because It Regulates Insulin-like Growth Factor Secretion

“…When IGF-II expression was ablated genetically, mesoderm development was impaired (Morali et al, 2000). In both mouse and chicken embryogenesis, IGF-I is expressed at later stages than IGF-II Scanes et al, 1997). Thus, IGF-II and IGF1R are a relevant ligand-receptor pair for cell fate decisions during mesoderm induction, and if IGF secretion is dependent on GRP94, the observed phenotype is consistent with published work.…”

Morphogenesis and differentiation of the avian endocrine pancreas, with particular reference to experimental studies on the chick embryo

“…4) (Rawdon and Andrew, 1998), an increase that was significantly greater than that produced by insulin (17.3%). Insulin-like growth factor-I is present in the chick embryo from day 3 of incubation (Pèrez-Villamil et al, 1994) and by mid-embryogenesis is produced by the pancreas (Serrano et al, 1990); in the chick the serum concentration of IGF-I rises from a relatively low level at 9.5 days to peak at 14.5 days of incubation (Scanes et al, 1997). Thus, it is conceivable that endogenously produced IGF-I could promote development of insulin cells in vivo by binding to IGF-I receptors in the pancreas.…”

Potential role for insulin-like growth factor II and vitronectin in the endothelial–mesenchymal transition process

“…IGFII, whose actions are modulated by IGF‐binding proteins, has been characterized in the chicken embryo and shown to regulate chicken cell protein synthesis and cell growth (Kallincos et al, 1990; McMurtry et al, 1996; Allan et al, 2003). Of particular significance, high circulating levels of IGFII have been reported during midembryonic development of chicken embryos with a pattern similar to that observed for mammal species, suggesting that this growth factor has a significant activity in embryonic development (Scanes et al, 1997; McMurtry et al, 1998). IGFII levels decline in the neonatal period (Scanes et al, 1997; McMurtry et al, 1998).…”

“…Of particular significance, high circulating levels of IGFII have been reported during midembryonic development of chicken embryos with a pattern similar to that observed for mammal species, suggesting that this growth factor has a significant activity in embryonic development (Scanes et al, 1997; McMurtry et al, 1998). IGFII levels decline in the neonatal period (Scanes et al, 1997; McMurtry et al, 1998). In spite of these considerations, the mechanisms that modulate the effect of this growth factor during embryonic development, as well as in the development of vascular lesions, are unclear.…”