A CONSTRUCT CAPABLE OF RELEASE IN CLOSED CIRCULAR FORM FROM A LARGER NUCLEOTIDE SEQUENCE PERMITTING SITE SPECIFIC EXPRESSION AND/OR DEVELOPMENTALLY REGULATED EXPRESSION OF SELECTED GENETIC SEQUENCES

摘要

The present invention relates generally to constructs and in particular genetic constructs comprising polynucleotide sequences capable of release in covalently closed, circular form from a larger nucleotide sequence such as, but not limited to, a genome of a eukaryotic cell. Preferably, once released, a polynucleotide sequence is reconstituted in a form which permits expression of the polynucleotide sequence. In one embodiment, the reconstituted polynucleotide sequence comprises a coding sequence with all or part of an extraneous nucleotide such as, but not limited to, intronic sequence or other splice signal inserted therein. Expression and in particular transcription of the coding sequence involves splicing out the extraneous sequence. The release and circularization is generally in response to a stimulus such as a protein-mediated stimulus. More particularly, the protein is a viral or prokaryotic or eukaryotic derived protein or developmentally and/or tissue specific regulated protein. The construct of the present invention is particularly useful in conferring genetic resistance against pathogens or inducing apoptosis or other cell death mechanisms useful, for example, in treating cancer or inducing male or female sterility in plants. The constructs permit, therefore, site specific expression and/or developmentally regulated expression of selected genetic sequences.