Optimization of pest resistance genes using DNA shuffling

A method of obtaining an optimized recombinant pest resistance gene, the method comprising:

• (1) recombining a plurality of forms of a nucleic acid which comprise segments derived from a gene that confers resistance to a pest upon a plant in which the gene is effectively expressed, wherein the plurality of forms of the nucleic acid differ from each other in two or more nucleotides, to produce a library of recombinant genes, wherein the library includes at least one optmized recombinant pest resistance gene that confers resistance to a pest upon a plant in which the gene is effectively expressed, wherein the optimized recombinant pest resistance gene exhibits improved pest resistance capability compared to a non-recombinant pest resistance gene;
• (2) expressing members of the library of recombinant genes, thereby producing polypeptides encoded by the expressed members of the library of recombinant genes;
• and
• (3) assaying the polypeptides for the ability to confer pest resistance upon a plant, thereby identifying the optimized recombinant pest resistance gene;
• wherein the optimized recombinant pest resistance gene is identified by observation of the improved pest resistance capability of the polypeptide encoded by the optimized recombinant pest resistance gene compared to a polypeptide encoded by a non-recombinant pest resistance gene.