Researchers from the University of Wisconsin-Madison have sequenced the genome for the Phalangium opilio, also known as the daddy long leg spider. The ultimate goal of the study was to learn more about arachnid genome evolution and how these genes gave rise to such features as fangs and pinchers. While researching this, they took the genome and used RNA interference to turn off the genes associated with leg development in these spider embryos. The result was that six of their eight legs came out shorter than normal and were closer to a pedipalp appendage, which is used for food. The researchers next plan is to develop the first transgenic P. opilio, from this genome.