After James Watson and Francis Crick announced the double helix structure of DNA in 1953, other researchers pursued how DNA's instructions were actually carried out. Khorana devised techniques to find more about the genetic code of small “messenger” molecules of transfer ribonucleic acid (RNAs) and their codons which controlled protein building. In 1972, he was the first scientist to synthesize a wholly artificial gene from laboratory chemicals. In the 1980s, Khorana synthesized the gene for rhodopsin, a protein involved in vision.