Abstract: Methods and compositions for transposon-mediated transgenesis are provided herein. In some embodiments, methods are provided for generating a transgenic embryo containing a piggyBac-like transposon. In some embodiments, such methods can include: contacting a nucleic acid containing a transgene flanked by two terminal repeats with one of the group consisting of: a piggyBac-like transposase polypeptide and a nucleotide sequence encoding a piggyBac-like transposase to form a mixture; contacting the mixture with a sperm to form a composition; and introducing the composition into an unfertilized oocyte to form a transgenic embryo, wherein the piggyBac-like transposase catalyzes the integration of the transgene into the genome of the embryo. In some embodiments, the piggyBac-like transposase can be encoded by a nucleotide sequence on the same nucleic acid containing the transgene. In some embodiments, the nucleic acid encoding the piggyBac-like transposase can be an mRNA.