February 19, 2021 In the same way that Lego pieces can be arranged in new ways to build a variety of structures, genetic elements can be mixed and matched to create new genes, according to new research. A long-proposed mechanism for creating genes, called exon shuffling, works by shuffling functional blocks of DNA sequences into new genes that express proteins. A study, “Recurrent Evolution of Vertebrate Transcription Factors by Transposase Capture,” published Feb. 19 in Science, investigates how genetic elements called transposons, or “jumping genes,” are added into the mix during evolution to assemble new genes through exon shuffling. Transposons, first discovered in the 1940s by Cornell alum and Nobel Prize-winner Barbara McClintock ’23, M.A. ’25, Ph.D. ’27, are abundant components of genomes – they make up half of human DNA – and have the ability to hop and replicate selfishly in the genome. Some transposons contain their own genes that code for enzymes called transposase proteins, which cut and paste genetic material from one chromosomal location to another.