Jonathan Hodgkin was one of the earliest researchers to explore the genetics of development in the nematode worm Caenorhabditis elegans. He first unpicked the genetic and maturational events that determine the sex of individual worms before extending his interest to other developmental pathways, behaviour and immunity.

Most C. elegans worms are hermaphrodite, with two X chromosomes, but they also exist as males, with only one. Jonathan used genetic mutation in this tiny, fast-breeding species to define the regulatory cascade of genes that controls the development of male or hermaphrodite characteristics — providing a model for approaching development in other species.

Since 2000, Jonathan has focused on the nematode’s response to attack by bacteria, exploring highly conserved pathways of innate immunity that are also relevant to development. Through microarray analysis, he has identified antibacterial factors produced by the worm that could be candidates for new antibiotics. He has also discovered novel pathogenic bacteria that attack nematodes, which may have potential as biocontrol agents against parasitic nematodes. In 2011, he received the Genetics Society Medal.