Testes-specific transgene expression in insulin-like growth factor-I transgenic mice.

Insulin-like growth factor-I (IGF-I) is a low molecular weight peptide that mediates the cell proliferating actions of growth hormone. Evidence exists indicating that IGF-I is produced by various cell types and this growth factor has been implicated in a variety of reproductive processes. To investigate the effect of IGF-I over-expression on reproductive systems, we generated three independent lines of transgenic mice harbouring a human IGF-I cDNA (hIGF-I) under the control of a Cytomegalovirus immediate early (CMV) promoter.