Abstract: We describe here an in vitro method of increasing complementarity in a heteroduplex polynucleotide sequence. The method uses annealing of opposite strands to form a polynucleotide duplex with mismatches. The heteroduplex polynucleotide is combined with an effective amount of enzymes having strand cleavage activity, 3′ to 5′ exonuclease activity, and polymerase activity, and allowing sufficient time for the percentage of complementarity to be increased within the heteroduplex. Not all heteroduplex polynucleotides will necessarily have all mismatches resolved to complementarity. The resulting polynucleotide is optionally ligated. Several variant polynucleotides result. At sites where either of the opposite strands has templated recoding in the other strand, the resulting percent complementarity of the heteroduplex polynucleotide sequence is increased. The parent polynucleotides need not be cleaved into fragments prior to annealing heterologous strands. Therefore, no reassembly is required.

Abstract: The present invention relates to foreign peptide sequences fused to the N-terminal of plant viral structural proteins and a method of their production. Fusion proteins are economically synthesized in plants at high levels by biologically contained tobamoviruses. The foreign peptide sequences can be cleaved from the fusion proteins by proteolytic enzymes or chemical reagents. The foreign peptide sequences of the invention have many uses. Such uses include use as antigens for inducing the production of antibodies having desired binding properties, e.g., protective antibodies, for use as vaccine antigens for the induction of protective immunity, including immunity against parasitic infections, for use as a protein involved in hormonal activity, or for use as a protein involved in immunoregulatory activity.

Abstract: This invention is directed to a plus strand RNA viral vector for transformation of a host organism with a foreign RNA, and expression of said foreign RNA. The foreign RNA is inserted into an infective RNA viral segment containing cis-acting viral replication elements, and allowed to infect the host organism. The RNA vector is modified to obtain infectivity by including an intervening sequence between the cap and the 5′ end. The modified RNA is able to tolerate the exogeneous RNA segment without disrupting the replication of the modified RNA, in the absence of a trans-acting viral replication element in a single component plant virus host cell.

Abstract: This invention is directed to a plus strand RNA viral vector for transformation of a host organism with a foreign RNA, and expression of said foreign RNA. The foreign RNA is inserted into an infective RNA viral segment containing cis-acting viral replication elements, and allowed to infect the host organism. The RNA vector is modified to obtain infectivity by not incorporating a cap at the 5′ end of the genome. The modified RNA is able to tolerate the exogenous RNA segment without disrupting the replication of the modified RNA, in the absence of a trans-acting viral replication element in a single component plant virus host cell.

Abstract: A method of suppressing virus gene expression in plants using untranslatable plus sense RNA is disclosed. The method is useful for the production of plants that are resistant to virus infection.