Over-expression of GATA-6 in Xenopus embryos blocks differentiation of heart precursors

Abstract

Xenopus GATA-6 transcripts are first detected at the beginning of gastrulation in the mesoderm, and subsequent domains of expression include the field of cells shown to have heart-forming potential. In this region, GATA-6 expression continues only in those cells that go on to form the heart; however, a decrease occurs prior to terminal differentiation. Artificial elevation of GATA-6, but not GATA-1, prevents expression of both cardiac actin and heart-specific myosin light chain. This effect is heart-specific because cardiac actin expression is unaffected in somites. Expression of the earlier marker XNkx-2.5 was unaffected and morphological development of the heart was initiated independently of the establishment of the contractile machinery. We conclude that a reduction in the level of GATA-6 is important for the progression of the cardiomyogenic differentiation programme and that GATA-6 may act to maintain heart cells in the precursor state. At later stages, when the elevated GATA-6 levels had decayed, differentiation ensued but the number of cells contributing to the myocardium had increased, suggesting either that the blocked cells had proliferated or that additional cells had been recruited.

Activation of peroxisome proliferator‐activated receptor gamma suppresses mast cell maturation involved in allergic diseases

“…In contrast, it has also been reported that over-expression of GATA-6 blocks the late differentiation of precursor cells of heart in Xenopus embryos (22). These reports suggest that maintenance of high level GATA-6 expression inhibits the later phase of cell differentiation, although GATA-6 is necessary for the early phase of development.…”

Requirement of the transcription factor GATA4 for heart tube formation and ventral morphogenesis.

“…8). Furthermore, a recent study reported that GATA6 overexpression in Xenopus embryos was capable of delaying cardiomyocyte differentiation resulting in enlarged heart-forming regions, suggesting that GATA6 plays an important role in controlling cardiomyocyte differentiation (Gove et al 1997).…”

Different requirements for GATA factors in cardiogenesis are mediated by non‐canonical Wnt signaling

“…GATA proteins are transcription factors, which regulate diverse processes during embryogenesis and in adults (Patient and McGhee, 2002). The GATA4, 5, and 6 genes are all important in vertebrates for endoderm formation (Weber et al, 2000;Afouda et al, 2005) and are central regulators of heart development (Gove et al, 1997;Reiter et al, 1999;Peterkin et al, 2003Peterkin et al, , 2007Holtzinger and Evans, 2005;Afouda et al, 2008;Haworth et al, 2008;Takeuchi and Bruneau, 2009). They have overlapping spatial and temporal expression patterns and regulate cardiomyogenesis in a partially redundant manner (Holtzinger and Evans, 2007;Peterkin et al, 2007).…”