title: Developmental changes in amniotic and allantoic fluid insulin-like growth factor (IGF)-I and -II concentrations of avian embryos.
abstract: In the literature, IGFs in the developing embryo are usually determined by blood serum concentrations. For this study, IGF-I/-II was quantified in the amniotic and allantoic fluids of fertile commercial broiler chicken (Gallus domesticus) (n=222), Pekin duck (Anas platyrhyncha) (n=250), and turkey (Meleagridis gallopavo) eggs (n= 200) during incubation. Amniotic and allantoic fluids were collected from embryos starting at 6 days of incubation for chickens and 8 days of incubation for ducks and turkeys. IGF concentrations within the fluids were determined by radioimmunoassay. Chicken amniotic IGF-I concentration at stage 29 of development was significantly higher (P< or =0.05) than the duck or turkey. At stage 36 of development the concentration of IGF-II in the amniotic fluid was 2.8 times greater in the chicken versus the duck (P< or =0.05) and 2 times greater than in the turkey (P< or =0.05). Within species, chicken IGF-I concentration in the amniotic fluid had a cubic trend (P< or =0.001), duck IGF-I increased linearly (P< or =0.001), and turkey concentrations declined quadratically (P< or =0.001) throughout development. In all species, the IGF-II concentration was higher than the IGF-I concentration in the amniotic and allantoic fluids.
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA. dkarcher@purdue.edu
authors.forename: D M
authors.initials: DM
authors.lastname: Karcher
authors.forename: J P
authors.initials: JP
authors.lastname: McMurtry
authors.forename: T J
authors.initials: TJ
authors.lastname: Applegate
mesh_terms: D000482:Allantois / Q000737:chemistry / Q000378:metabolism*; D000653:Amniotic Fluid / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D002642:Chick Embryo; D004372:Ducks / Q000196:embryology / Q000378:metabolism*; D004625:Embryo, Nonmammalian; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000032:analysis / Q000378:metabolism*; D011863:Radioimmunoassay; D013045:Species Specificity; D014422:Turkeys / Q000196:embryology / Q000378:metabolism*
chemical_list: D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II