Effect of DNA loop anchorage regions (LARs) and microinjection timing on expression of beta-galactosidase gene injected into one-cell rabbit embryos.

摘要

The conditions favoring expression of a reporter gene microinjected into a male pronucleus of naturally ovulated and fertilized rabbit eggs have been studied. Injection of the reporter gene during S phase of the cell-cycle allows the highest level of expression of the gene. Incorporation of DNA loop anchorage regions (LARs) into constructs upstream and/or downstream of the reporter gene significantly increased the efficiency of expression. In all cases the expression of the microinjected gene started after a period of transcriptional quiescence, i.e., together with the expression of the host genome. Correct targeting of microinjected constructs within the nuclei via interaction of LAR elements with receptor sites on the nucleoskeleton may facilitate expression of injected DNA constructs as well as their integration into host cell DNA.