Optimization and in vivo Expression of Chicken Oviduct- Specific Expression Vector

Abstract:

We modified a previously constructed vector pOV1 and compared expression difference among modified constructs. First. 5￠-and 3￠-regulatory regions of chicken ovalbumin gene were excised from the previously constructed vector pOV1 by endonuclease digestion and subcloned into modified pcDNA3.0, named as pOV2. Then only the 5′-regulatory region was subcloned into the same vector and this resulted in the third oviduct-specific expression vector pOV3. To compare expression property of the three constructs in hen oviduct, the LacZ reporter gene was subcloned at the down-stream of the 5′-regulatory region in vectors pOV1, pOV2 and pOV3, respectively. The resultant recombinant constructs pOV1LacZ, pOV2LacZ and pOV3LacZ were injected into laying hens via wing vein rout. RT-PCR of the vector-injected hen tissues showed that the LacZ gene was transcribed only in the oviduct, but not in the heart, liver, kidney and spleen tested. Similarly, β-galactosidase activity was detected only in the oviduct magnum, which was secreted into egg white of the injected hens and enhanced by injecting estrogen into the hens. Among the three vectors tested, expression of LacZ gene in pOV3LacZ-injected hen oviduct magnum was at a relatively higher level and thus pOV3 vector was selected for further studies.