Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2005
Publication Date: N/A
Interpretive Summary: The present work describes the use of a recombinant virus (Avian Adeno-Associated virus) to express a reporter gene in different tissues of chickens to which said recombinant virus was applied by injection in-ovo. Expression of the reporter gene was investigated in various tissue samples obtained at different sampling times, from the inoculated birds. The authors demonstrated that the recombinant virus was able to induce the production of the reporter gene in tissues derived from the inoculated birds.
Technical Abstract: Recombinant avian adeno-associated virus coding for the LacZ gene were used to inoculate embryonating chicken eggs, to assess the usefulness of the system for the expression of a transgene in vivo. The results obtained indicate significantly higher levels of expression of the reporter gene at various time intervals in the embryos inoculated with the recombinant virus in comparison with the mock inoculated controls. At the embryo level, significant differences were evident at 120 hr post inoculation, while hatched chicks showed transgene expression up to 14 days of age. In a second experiment, different cell line cultures were transfected with plasmids encoding for a reporter gene flanked by the avian adeno-associated virus inverted terminal repeats (ITR), either alone or in the presence of the major non structural proteins of the virus (Rep 78/68) to assess the ability of these proteins and DNA elements to enhance gene expression. Results indicate that the inclusion of the viral ITR alone or during co-expression of the Rep proteins significantly enhance the expression of the transgene in all cell lines tested, as evidenced by the detection of the Beta galactosidase protein through chemiluminescence reactions and staining of transfected monolayers.