Growth factors sustain primordial germ cell survival, proliferation and entering into meiosis in the absence of somatic cells

In the present paper, we identified a cocktail of soluble growth factors, namely KL, LIF, BMP-4, SDF-1, bFGF and compounds (N-acetyl-l-cysteine, forskolin, retinoic acid) able to sustain the survival and self-renewal of mouse PGCs in the absence of somatic cell support. We show that under culture conditions allowing PGC adhesion to an acellular substrate, such growth factors and compounds were able to prevent the occurrence of significant levels of apoptosis in PGCs for 2 days, stimulate their proliferation and, when LIF was omitted from the cocktail, allow most of them to enter into and progress through meiotic prophase I. These results consent for the first time to establish culture conditions for purified mammalian PGCs in the absence of somatic cell support and should make easier the molecular dissection of the processes governing the development of such cells crucial for early gametogenesis.