ABSTRACT
We previously reported that the mouse GATA-2 gene is regulated by two alternative promoters (Minegishi et al, J Biol Chem, 273:3625, 1998). Although the more proximal IG (general) promoter is active in almost all GATA-2-expressing cells, the distal IS (specific) promoter activity was selectively detected in hematopoietic tissues but not in other mesodermal tissues. We report here in vivo analysis of the GATA-2 locus and its regulatory characteristics in hematopoietic tissues of transgenic mice. Transgenes containing 6 or 7 kbp of sequence flanking the 5' end of the IS first exon direct expression of beta-galactosidase or green fluorescent protein (GFP) reporter genes specifically to the para-aortic splanchnopleura, aorta-gonads, and mesonephros (AGM) region, and in the neural tissues. In situ hybridization analysis showed that reporter gene expression specifically recapitulates the endogenous expression profile of GATA-2 in these tissues. The flk-1, CD34, c-kit, and CD45 antigens were identified in the GFP-positive cells from the AGM region and fetal liver, indicating that GATA-2 is expressed in immature hematopoietic cells. Deletion of 3.5 kbp from the 5' end of the 6.0 kbp IS promoter construct, including one of the DNase I hypersensitive sites, completely abolished hematopoietic expression. These experiments describe an early developmental GATA-2 hematopoietic enhancer located between 6.0 and 2.5 kbp 5' to the IS exon.
Subject(s)
DNA-Binding Proteins/genetics , Embryo, Mammalian/metabolism , Gene Expression , Hematopoiesis , Transcription Factors/genetics , Animals , Deoxyribonuclease I/metabolism , GATA2 Transcription Factor , Green Fluorescent Proteins , In Situ Hybridization , Liver/chemistry , Liver/embryology , Luminescent Proteins/analysis , Luminescent Proteins/genetics , Mesentery/chemistry , Mesentery/embryology , Mesonephros/chemistry , Mice , Mice, Transgenic , Nerve Tissue/chemistry , Nerve Tissue/embryology , Para-Aortic Bodies/chemistry , Pleura/chemistry , Pleura/embryology , RNA, Messenger/analysis , Spleen/chemistry , beta-Galactosidase/geneticsABSTRACT
We have analyzed the perinatal development of galanin-like immunoreactivity (GAL-LI) and catecholamines (CA) in the paraaortal paraganglia (PGGL) and adrenal glands. In the PGGL, the tissue content of GAL-LI was highest on the day of birth and decreased postnatally. The fetal levels were lower than at birth. In contrast, the content of CA in the PGGL increased with age. In the adrenal glands, the contents of both GAL-LI and CA also increased with age. During the first postnatal week the contents of both GAL-LI and CA in the PGGL were markedly higher than in the adrenal glands. Chromatographic analysis of GAL-LI in extracts of fetal and postnatal rabbit PGGL, respectively, indicated that most of the GAL-LI from both age groups co-eluted with synthetic porcine GAL. An additional, apparently more polar, component was also detected at both ages, which may represent a differently processed form of the peptide. The high content of GAL-LI in the PGGL at birth may reflect an enhanced synthesis associated with birth.
