The role of exogenous growth-promoting factors and their receptors in organogenesis
Published: 1 April 1997
M K Pratten
Department of Human Anatomy and Cell Biology, The Medical School, Queens Medical Centre, Nottingham, United Kingdom. Margaret.Pratten@nottingham.ac.uk
The mechanisms involved in the regulation of early embryonic development are poorly understood. Certain growth promoting molecules are known to be produced within the embryo itself. It is clear, however, that at the early stages of embryonic development, many additional growth promoting factors have to be provided by the maternal system. Since the levels of factors such as epidermal growth factor and insulin in the maternal circulation are not linked with gestational age of the offspring, it is likely that regulation of receptors in the embryonic tissues may provide the key to the regulation of development. The expression of any receptor may depend on its synthetic rate, turnover or its distribution between the cell surface and intracellular pools. The study of the role of exogenous growth promoting molecules and receptor distribution and regulation for such growth factors, in particular insulin, insulin-like growth factor-I and epidermal growth factor, in embryos has been addressed using whole embryo culture, supported by anembryonic yolk sac culture and intravitelline injection of rat embryos.