Analysis of the mouse CSF-1 gene promoter in a transgenic mouse model.
CSF-1 stimulates monocyte and osteoclast populations. However, the molecular mechanisms involved in regulating CSF-1 gene expression are unclear. To identify regulatory regions that control normal CSF-1 gene expression, a -774/+183-bp fragment of the murine CSF-1 promoter was analyzed in vitro and in vivo. Transcriptional activity was high in cultured osteoblasts that express CSF-1 mRNA compared to ARH-77 B cells that lack CSF-1 gene expression. Transient transfection of osteoblasts with promoter deletion constructs showed that the -774-bp fragment conferred the highest transcriptional activity and contained activator and repressor sequences. To assess the ability of the CSF-1 promoter to confer normal tissue expression of CSF-1, transgenic mice containing the -774/+183-bp region driving the E. coli beta-galactosidase (lacZ) reporter gene were generated. beta-Gal analysis of whole tissue extracts showed transgene expression in all tissues tested except liver and kidney. At the cellular level, the pattern of beta-gal expression in the spleen, thymus, bone, lung, and testes of adult transgenic mice mimicked normal endogenous CSF-1 mRNA expression in non-transgenic littermates detected by in situ hybridization. This region also directed appropriate transgene expression to sites in other tissues known to synthesize CSF-1, with the exception of the liver and kidney. These findings indicate that the -774-bp fragment contains cis-acting elements sufficient to direct CSF-1 gene expression in many tissues. CSF-1 promoter/lacZ mice may be useful for studying the transcriptional mechanisms involved in regulating CSF-1 gene expression in tissues throughout development.
Abboud
Sherry L
SL
South Texas Veterans Health Care System, Audie L. Murphy Division, and the Department of Pathology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78284, USA. abbouds@uthscsa.edu
Bunegin
Maria
M
Ghosh-Choudhury
Nandini
N
Woodruff
Kathleen
K
D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D017930:Genes, Reporter; D017403:In Situ Hybridization; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009928:Organ Specificity; D010006:Osteoblasts / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051381:Rats; D014020:Tissue Extracts; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D014020:Tissue Extracts; D016173:Macrophage Colony-Stimulating Factor; D001616:beta-Galactosidase