Which genetic phenomenon earned Barbara McClintock the 1983 Nobel Prize in Physiology or Medicine?

Transposable elements earned Barbara McClintock the 1983 Nobel Prize in Physiology or Medicine.

Transposable elements are DNA sequences that can move to new positions within a genome. McClintock discovered them through cytogenetic studies of maize chromosomes in the 1940s and 1950s. She identified controlling elements that could alter the activity of genes involved in kernel pigmentation.

Her findings challenged the prevailing view that genes occupied fixed, unchanging positions with limited interaction. The importance of mobile DNA became more widely appreciated decades later, when similar elements were found across plants, animals, and microorganisms.

Transposable elements can create mutations, change gene regulation, and reshape genomes. They are sometimes called jumping genes, but they do not always literally jump as intact units; different classes move through different molecular mechanisms. McClintock received the Nobel Prize alone in 1983.