DPPA3 has several aliases, including STELLA, STELLAR and PGC7. It was initially detected in preimplantation embryos, PGCs and oocytes of all stages of development in the mouse and deemed to be an excellent marker of cells of early germline lineage (Saitou et al., 2002). More precisely, in the post-implantation embryo it is expressed from the time of PGC specification through PGC migration until embryonic day 13.5 (E13.5) whereupon it is downregulated until birth, when immature oocytes begin to express it again (Saitou et al., 2002). Despite the timing of the onset of its expression, a knock-out study demonstrated that it is not required for germ cell specification (Bortvin et al., 2004). As it is not expressed in mature sperm (Saitou et al., 2002), Dppa3 is therefore a maternal factor of embryogenesis and it has been shown to be essential in protecting the early mouse embryo from premature DNA methylation (Nakamura et al., 2007). As such, it allows correct genomic imprinting and epigenetic modifications which are critical for normal development.

Its human homologue is expressed on chromosome 12 (Bowles et al., 2003) and, although it is expressed at low levels in hESCs, its expression is upregulated in hESCs undergoing germ cell differentiation (Wongtrakoongate et al., 2013). Expression is restricted to the fetal ovary by the second half of pregnancy (Clark et al., 2004) and it appears to be expressed at the same stage of differentiation as POU5F1 and PRDM1 (Lin et al., 2014). Post-natally, both primordial follicles and mature, metaphase II (MII) oocytes express DPPA3 in humans (Grondahl et al., 2013). DPPA3 is also abundant in bovine oocytes and preimplantation embryos and its role in preventing early DNA demethylation has been recapitulated in bovine embryos, thus it could be hypothesised that a similar process occurs in early human embryos (Bakhtari and Ross, 2014). In larger animal models, DPPA3 therefore appears to be a marker of germ cells at a slightly later stage in development than LIN28 and NANOG.