Nucleic acid binding, DNA binding, Transcription factor
Comment
stemness
Cellular localization
Nuclear
Comment
Ovarian function
Early embryo development
Comment
Nanog, Pou5f1 and SoxB1 activate zygotic gene expression during the maternal-to-zygotic transition. Lee MT 2013 et al.
After fertilization, maternal factors direct development and trigger zygotic genome activation (ZGA) at the maternal-to-zygotic transition (MZT). In zebrafish, ZGA is required for gastrulation and clearance of maternal messenger RNAs, which is in part regulated by the conserved microRNA miR-430. However, the factors that activate the zygotic program in vertebrates are unknown. Here we show that Nanog, Pou5f1 (also called Oct4) and SoxB1 regulate zygotic gene activation in zebrafish. We identified several hundred genes directly activated by maternal factors, constituting the first wave of zygotic transcription. Ribosome profiling revealed that nanog, sox19b and pou5f1 are the most highly translated transcription factors pre-MZT. Combined loss of these factors resulted in developmental arrest before gastrulation and a failure to activate >75% of zygotic genes, including miR-430. Our results demonstrate that maternal Nanog, Pou5f1 and SoxB1 are required to initiate the zygotic developmental program and induce clearance of the maternal program by activating miR-430 expression.
/////////////////////////
Expression regulated by
Comment
Ovarian localization
Primordial Germ Cell, Oocyte
Comment
Nanog expression in mouse germ cell development. Yamaguchi S et al. Nanog is a newly identified transcriptional factor bearing a homeodomain and expressed in pluripotential cells of preimplantation and early postimplantation embryos, and embryonic stem (ES) and embryonic germ (EG) cells. Knockout experiments indicate that Nanog functions as a key player in maintaining the pluripotency of stem cells. Importantly, Nanog expression is highly expressed in primordial germ cells (PGCs) of E11.5 and E12.5 mouse embryos. However, its temporal and spatial expression pattern and function in germ cells are largely unknown. To address these issues, whole embryos and cryosections of embryos were immunostained with anti-NANOG and anti-STELLA/PGC7 antibodies. NANOG expression, repressed in colonized PGCs of E7.25-E7.5 embryos, became detectable in migrating PGCs of E7.75-E8.0 embryos. Both male and female PGCs migrating in E9.5 and E10.5 embryos and colonizing the genital ridges of E11.5 and E12.5 embryos were positive for NANOG immunostaining, while the NANOG expression pattern differed between the sexes in the later developmental stage. In female gonadal PGCs of E13.5 and E14.5 embryos, NANOG became undetectable in germ cells positive for the synaptonemal complex-specific protein SCP3, while in male PGCs of E14.5-E16.5 embryos, the number of NANOG-positive germ cells drastically decreased during the mitotic arrest. No germ cells positive for NANOG were detectable in testes and ovaries of adult mice. Thus, in germ cell development, NANOG is expressed in proliferating germ cells, in which nuclear reprogramming is progressing.
Follicle stages
Comment
Expression of pluripotent stem cell markers in the human fetal ovary. Kerr CL et al. BACKGROUND Human primordial germ cells (PGCs) can give rise to pluripotent stem cells such as embryonal carcinoma cells (ECCs) and embryonic germ cells (EGCs). METHODS In order to determine whether PGCs express markers associated with pluripotency in EGCs and ECCs, the following study cross examines the expression patterns of multiple pluripotent markers in the human fetal ovary, 5.5-15 weeks post-fertilizaton (pF) and relates this expression with the ability to derive pluripotent EGCs in vitro. RESULTS Specific subpopulations were identified which included OCT4(+)/Nanog(+)/cKIT(+)/VASA(+) PGCs and oogonia. Interestingly, these cells also expressed SSEA1 and alkaline phosphatase (AP) and SSEA4 expression occurred throughout the entire gonad. Isolation of SSEA1(+) cells from the gonad resulted in AP(+) EGC colony formation. The number of OCT4(+) or Nanog(+) expressing cells peaked by week 8 and then diminished after week 9 pF, as oogonia enter meiosis. In addition, the efficiency of EGC derivation was associated with the number of OCT4(+) cells. TRA-1-60 and TRA-1-81 were only detected in the lining of the mesonephric ducts and occasionally in the gonad. CONCLUSIONS These results demonstrate that PGCs, a unipotent cell, express most, but not all, of the markers associated with pluripotent cells in the human fetal ovary.