A defective recombinant adenovirus was constructed that carried the ge
ne of a ribozyme cleaving the mRNA for secreted alkaline phosphatase (
SEAP). The ribozyme gene was under control of the regulatory elements
of the virus-associated RNA gene of fowl adenovirus CELO. The SEAP gen
e was expressed in another defective recombinant adenovirus. Coinfecti
on of HeLa cells resulted in a decline in SEAP activity in the culture
medium. RT-PCR assays proved specific mRNA cleavage in infected cells
.