COMBINED ACTION OF STEM-CELL FACTOR, LEUKEMIA INHIBITORY FACTOR, AND CAMP ON INVITRO PROLIFERATION OF MOUSE PRIMORDIAL GERM-CELLS

In the present paper we investigated the effects of stem cell factor/m astocyte growth factor (SCF/MGF), leukemia inhibitory factor/different iating inhibitory activity (LIF/DIA) (two growth factors known to affe ct primordial germ cell growth in vitro) and forskolin (FRSK) (an acti vator of-adenylate cyclase in many cell types) alone or in combination on the survival and proliferation of primordial germ cells (PGCs) obt ained from 8.5, 10.5, and 11.5 days post coitum (dpc) mouse embryos an d cultured without pre-formed cell feeder layers. The results showed t hat both at 1 and 3 days of culture the addition of 100 ng/ml SCF, 20 muM FRSK, or in some instances 20 ng/ml LIF alone caused a significant increase of PGC number as compared with controls. The highest effects were obtained when SCF and/or LIF were used together with FRSK. Moreo ver, we found that FRSK elevated cAMP levels in purified 11.5 dpc PGCs and that this compound, but not SCF and LIF, stimulated PGC prolifera tion, as assessed by 5-bromo-2'-deoxyuridin (BrdU) incorporation. Thes e results suggest a mechanism of combined action of cAMP with SCF and/ or LIF in the control of proliferation of mouse PGCs in vitro.