However, molecular mechanisms underlying germ cell migration and niche establishment are largely unknown.
Krüppel-associated box zinc finger genes (KRAB-ZFPs) constitute the largest individual family of mammalian transcriptional repressors and play pleiotropic roles, including imprint establishment, germ cell differentiation, and retrotransposon repression (Jacobs et al., 2014; Nowick et al., 2013).
If such a mechanism functions during germ cell development and/or the establishment of heterochromatin in early embryogenesis, it should be able to repair heterochromatin partly disrupted by stress.
Our studies indicate that the processes responsible for the formation of female germline cysts and the establishment of germ cell polarity are highly conserved between invertebrates and vertebrates.
This study provides not only further evidence for the remarkable plasticity of SSCs but also a potential system for dissecting molecular and epigenetic regulations in germ cell fate determination and imprinting establishment during gametogenesis.
Finally, although leukemia inhibitory factor (LIF) has a major role in maintaining pluripotency of ES cells and facilitates the establishment of germ cell colonies from the newborn testis, increased proliferation of mouse and rat SSCs was not seen with addition of LIF either to serum-containing media or to GDNF-dependent serum-free cultures [ 49, 54, 64, 65].
To determine whether the correct cycle of germ cell imprint erasure and re-establishment occurs in vitro in the absence of Dazl, we examined methylation at the H19 DMR in germ cells differentiated from male wildtype and Dazl-null mESC lines.
This is a surprising result for gcl and pum because the requirements for gcl in germline for establishment of the germ cell lineage and of pum for posterior patterning and germ cell maintenance are well-established (Asaoka-Taguchi et al. 1999; Parisi and Lin 1999; Robertson et al. 1999).
A critical step in the establishment of elaborate germ cell lineages during early embryogenesis in nematodes, fly, fish and frog is the temporal and spatial regulation of several proteins via mechanisms that are dependent on the 3'UTR of maternal mRNAs including nanos [1], [2], [3], [4].
Published: July 5 , 2012Expression of Blimp1, the key regulator of PGC specification, is obligatory for the establishment of the germ cell lineage in mice (Ohinata et al., 2005; Vincent et al., 2005).
