What are the implications of genetic engineering for kashrus?

Transplantation of a few genes from a non-kosher creature into a kosher creature doesn't make it unkosher, because its basic identity hasn't changed. (Also, gene transplantation isn't cross-breeding, and isn't forbidden under the laws of kilayim.) The situation would be more problematic if the transplantation resulted in a hybrid creature, but this would require transplantation of very many genes, and won't be feasible in the near future. Ask a follow-up question