Restriction digests of the clone give the following sizes (kb): BamHI--4.8, 0.6; EcoRI--3.2, 2.2. The vector contains modified luciferase (luc+) gene from the firefly Photinus pyralis in order to increase the yield of recoverable luciferase activity after transfection and to eliminate potential cryptic regulatory elements. The vector contains the human cytomegalovirus (CMV) enhancer upstream of the tk promoter. This combination confers strong transcriptional activation not only in a variety of vertebrate cell lines, but also in vivo in whole fish embryos injected with the vector DNA. The optimized luciferase reporter gene vectors (ATCC 87630 - 87633) provide valuable tools for the analysis of eukaryotic regulatory DNA elements. |