Regulatory elements directing gut expression of the GATA6 gene during mouse early development

The GATA6 transcription factor, as well as GATA4 and GATA5, is expressed in a variety of mammalian tissues including the precardiac mesoderm and endoderm, and gut-related organs. Genetic studies have also implicated GATA factors as important regulators of gut endoderm development. Previously, we identified the promoter and a cardiac-specific enhancer of mouse GATA6 [Sun-Wada et al. (2000) J. Biochem. 127, 703-709], however, little is known about the regulatory elements that govern GATA6 expression in the primitive gut. Here, we identified a distal enhancer of the GATA6 gene directing expression in the gut by creating transgenic mice. A sequence of approximately 200 bp between -8.0 kb and -7.8 kb contains element(s) that enhance transcription in the gut during embryonic development, when linked to the hsp68 promoter/lacZ fusion gene. Our results also show that GATA6 expression is controlled by multiple regulatory regions including cardiac-specific and gut-specific enhancers.