title: Fibroblast growth factor requirements for in vitro development of bovine embryos.
abstract: The overall goal was to describe the importance of fibroblast growth factors (FGFs) during development of the bovine embryo. An inhibitor of FGF receptor kinase activity (SU5402) was used to examine whether FGF signaling is required for embryo development. Addition of 20 μM SU5402 on Day 0 (Day of IVF) reduced (P = 0.04) the percentage of oocytes becoming blastocysts on Day 7 compared to controls (5.9 ± 2.1 vs 16.9 ± 2.4; average ± SEM). Also, Day-8 blastocysts placed into individual culture drops of medium containing SU5402 tended to have decreased (P = 0.08) blastomere numbers at Day 11 (211.1 ± 27.5 vs 297.8 ± 25.0). A second series of studies determined if supplemental FGF2 enhances development in vitro. There was no effect of FGF2 on cleavage or blastocyst development rates when 5 or 100 ng/mL FGF2 was provided immediately after fertilization. Also, FGF2 supplementation beginning on Day 5 post-fertilization did not significantly affect blastocyst rates or the number of trophoblast and inner cell mass cells. However, addition of 500 ng/mL FGF2 at both Day 0 and Day 4 increased (P = 0.03) the percentage of oocytes that became blastocysts on Day 7 compared with controls (27.4 ± 1.3 vs 19.7 ± 1.3). In a final study, the thermal-protective ability of FGF2 was examined by adding FGF2 1 h before exposing Day 5 embryos to heat shock. Addition of FGF2 did not significantly influence embryo thermal-tolerance. In conclusion, FGF receptor activation was important for optimal blastocyst formation and FGF2 supplementation increased bovine blastocyst formation when provided at high concentrations.
authors.affiliation: Department of Animal Sciences, University of Florida, Gainesville, FL, USA.
authors.forename: Sarah D
authors.initials: SD
authors.lastname: Fields
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hansen
authors.forename: Alan D
authors.initials: AD
authors.lastname: Ealy
mesh_terms: D000818:Animals; D002417:Cattle / Q000196:embryology*; D004305:Dose-Response Relationship, Drug; D047108:Embryonic Development / Q000187:drug effects; D005307:Fertilization in Vitro / Q000662:veterinary*; D005346:Fibroblast Growth Factors / Q000378:metabolism / Q000494:pharmacology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D006358:Hot Temperature; D007370:Interferon Type I / Q000235:genetics / Q000378:metabolism; D011257:Pregnancy Proteins / Q000235:genetics / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011758:Pyrroles / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000378:metabolism
chemical_list: D007370:Interferon Type I; D011257:Pregnancy Proteins; D011758:Pyrroles; D012333:RNA, Messenger; D017468:Receptors, Fibroblast Growth Factor; C105686:SU 5402; C020947:interferon tau; D005346:Fibroblast Growth Factors; D011505:Protein-Tyrosine Kinases