Interleukin-4 (IL-4), a pleiotropic cytokine, stimulates a dose-depend
ent increase in the number of mouse primordial germ cells in culture.
Results from bromodeoxyuridine incorporation assays suggest that IL-4
acts as a survival factor rather than as a mitogen for primordial germ
cells in this system. Studies on the embryonic expression patterns of
IL-4 and its receptors, using RT-PCR and ELISA, show that IL-4 and it
s receptors are present at the correct time and place to influence PGC
numbers in vivo. (C) 1996 Academic Press, Inc.