Dynamic GATA6 expression in primitive endoderm formation and maturation in early mouse embryogenesis

Ovarian Cancer Programs, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA.
Developmental Dynamics (Impact Factor: 2.67). 10/2008; 237(10):2820-9. DOI: 10.1002/dvdy.21703
Source: PubMed

ABSTRACT The derivation of the primitive endoderm layer from the pluripotent cells of the inner cell mass is one of the earliest differentiation and morphogenic events in embryonic development. GATA4 and GATA6 are the key transcription factors in the formation of extraembryonic endoderms, but their specific contribution to the derivation of each endoderm lineage needs clarification. We further analyzed the dynamic expression and mutant phenotypes of GATA6 in early mouse embryos. GATA6 and GATA4 are both expressed in primitive endoderm cells initially. At embryonic day (E) 5.0, parietal endoderm cells continue to express both GATA4 and GATA6; however, visceral endoderm cells express GATA4 but exhibit a reduced expression of GATA6. By and after E5.5, visceral endoderm cells no longer express GATA6. We also found that GATA6 null embryos did not form a morphologically recognizable primitive endoderm layer, and subsequently failed to form visceral and parietal endoderms. Thus, the current study establishes that GATA6 is essential for the formation of primitive endoderm, at a much earlier stage then previously recognized, and expression of GATA6 discriminates parietal endoderm from visceral endoderm lineages.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Embryonic stem (ES) cells are characterized by their functional potency and capacity to self-renew in culture. Historically, ES cells have been defined as pluripotent, able to make the embryonic but not the extraembryonic lineages (such as the yolk sac and the placenta). The functional capacity of ES cells has been judged based on their ability to contribute to all somatic lineages when they are introduced into an embryo. However, a number of recent reports have suggested that under certain conditions, ES cells, and other reprogrammed cell lines, can also contribute to the extraembryonic lineages and, therefore, can be said to be totipotent. Here, we consider the molecular basis for this totipotent state, its transcriptional signature and the signalling pathways that define it.
    Philosophical Transactions of The Royal Society B Biological Sciences 12/2014; 369(1657). DOI:10.1098/rstb.2013.0549 · 6.31 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The presence of an air‐filled organ (AO), either lungs or a swimbladder, is a defining character of the Osteichthyes (bony vertebrates, including tetrapods). Despite the functional and structural diversity of AOs, it was not previously known whether the same group of developmental regulatory genes are involved in the early development of both lungs and swimbladders. This study demonstrates that a suite of genes (Nkx2.1, FoxA2, Wnt7b, GATA6), previously reported to be co‐expressed only in the tetrapod lung, is also co‐expressed in the zebrafish swimbladder. We document the expression pattern of these genes in the adult and developing zebrafish swimbladder and compare the expression patterns to those in the mouse lung. Early‐acting genes involved in endoderm specification are expressed in the same relative location and stage of AO development in both taxa (FoxA2 and GATA6), but the order of onset and location of expression are not completely conserved for the later acting genes (Nkx2.1 and Wnt7b). Co‐expression of this suite of genes in both tetrapod lungs and swimbladders of ray‐finned fishes is more likely due to common ancestry than independent co‐option, because these genes are not known to be co‐expressed anywhere except in the AOs of Osteichthyes. Any conserved gene product interactions may comprise a character identity network (ChIN) for the osteichthyan AO.
    Evolution & Development 03/2013; 15(2). DOI:10.1111/ede.12022 · 2.68 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Pluripotent stem cells hold great promise for cell-based therapies in regenerative medicine. However, critical to understanding and exploiting mechanisms of cell lineage specification, epigenetic reprogramming, and the optimal environment for maintaining and differentiating pluripotent stem cells is a fundamental knowledge of how these events occur in normal embryogenesis. The early mouse embryo has provided an excellent model to interrogate events crucial in cell lineage commitment and plasticity, as well as for embryo-derived lineage-specific stem cells and induced pluripotent stem (iPS) cells. Here we provide an overview of cell lineage specification in the early (preimplantation) mouse embryo focusing on the transcriptional circuitry and epigenetic marks necessary for successive differentiation events leading to the formation of the blastocyst.
    12/2011; 2(3):420-48. DOI:10.3390/genes2030420