Research article

A highly conserved regulatory element controls hematopoietic expression of GATA-2 in zebrafish

Zhongan Yang¹ , Hong Jiang¹ , Fang Zhao² , Deepa B Shankar³ , Kathleen M Sakamoto³ , Michael Q Zhang² and Shuo Lin¹

¹  Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California 90095-1606, USA

²  Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA

³  Division of Hematology-Oncology and Pathology and Laboratory Medicine, Gwynne Hazen Cherry Memorial Laboratories, David Geffen School of Medicine at UCLA, Los Angeles, California 90095-1752, USA

author email corresponding author email

BMC Developmental Biology 2007, 7:97doi:10.1186/1471-213X-7-97

Published:	20 August 2007

Abstract

Background

GATA-2 is a transcription factor required for hematopoietic stem cell survival as well as for neuronal development in vertebrates. It has been shown that specific expression of GATA-2 in blood progenitor cells requires distal cis-acting regulatory elements. Identification and characterization of these elements should help elucidating transcription regulatory mechanisms of GATA-2 expression in hematopoietic lineage.

Results

By pair-wise alignments of the zebrafish genomic sequences flanking GATA-2 to orthologous regions of fugu, mouse, rat and human genomes, we identified three highly conserved non-coding sequences in the genomic region flanking GATA-2, two upstream of GATA-2 and another downstream. Using both transposon and bacterial artificial chromosome mediated germline transgenic zebrafish analyses, one of the sequences was established as necessary and sufficient to direct hematopoietic GFP expression in a manner that recapitulates that of GATA-2. In addition, we demonstrated that this element has enhancer activity in mammalian myeloid leukemia cell lines, thus validating its functional conservation among vertebrate species. Further analysis of potential transcription factor binding sites suggested that integrity of the putative HOXA3 and LMO2 sites is required for regulating GATA-2/GFP hematopoietic expression.

Conclusion

Regulation of GATA-2 expression in hematopoietic cells is likely conserved among vertebrate animals. The integrated approach described here, drawing on embryological, transgenesis and computational methods, should be generally applicable to analyze tissue-specific gene regulation involving distal DNA cis-acting elements.