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Objective: To construct a plasmid vector with EGFP reporter gene for functional analysis of enhancers., Methods: EGFP DNA was amplified by PCR from plasmid pEGFP-N1 DNA and subcloned into plasmid PGL3-promoter backbone without luc(+) gene to construct the enhancer-identifying vector pEGFP-enhancer. Different copies of hypoxia response element (HRE) sequence were synthetized and subcloned into the multiple cloning site of the plasmid pEGFP-enhancer. Using Lipofectamine 2000, the recombined pEGFP-HRE and pEGFP-5HRE plasmids were transfected into the Hela cells respectively. After hypoxic or normoxic cell culture, EGFP expression in the cells was detected by flow cytometry and fluorescence microscopy., Results: After hypoxic exposure, the fluorescence intensity of EGFP in the Hela cells transfected with the plasmid increased with the enhancer HRE copies, while the fluorescence intensity underwent no significant changes after normoxic cell culture., Conclusion: we have successfully constructed the enhancer expression vector plasmid pEGFP-enhancer, which can identify the activity of the enhancers through EGFP expression.

Objective: To identify the labeled cells in the ependyma/subventricular zone (SVZ) of normal adult rats by DiI injected into the lateral ventricle., Methods: Fifty male Sprague-Dawley rats were divided randomly into five groups (10 per group). All of the rats were injected with 10 microL of 2 g/L fluorescence dye DiI into the right lateral ventricle. The five groups of rats were sacrificed at 6 h, 12 h, 24 h, 36 h or 48 h after injection respectively. Hoechst 33258 staining was used to identify nuclei and laser confocal microscopy was used to detect the DiI-labeled cells and to measure the thickness of the tissue with DiI fluorescence in the wall of the left lateral ventricle., Results: After injection of the DiI into the right lateral ventricle, DiI- Hoechst 33258 double positive cells were found in the ependymal layer of the left lateral ventricular wall at 24 h and in the SVZ at 48 h as well. The thickness of the tissue with DiI fluorescence in the left ependyma/septal subventricular zone (SVZspt) and ependyma/postnatal equivalent of the ganglionic eminences (SVZge) remained unchanged at 12 h and 24 h after DiI injection. The thickness of the tissue with DiI fluorescence in the left ependyma/SVZge was significantly greater than that in the ependyma/SVZspt at all of the time points (P<0.05)., Conclusion: The ependyma/SVZ cells can be labeled by Dil 24-48 h after injection (10 microL of 2 g/L) into the lateral ventricle.