The northern white rhinoceros is one of the rarest animals on Earth, with just two females left and no natural way for the species to reproduce. Now, an international team of scientists at Scripps Research, the San Diego Zoo Wildlife Alliance, Max Planck Institute for Molecular Genetics, and other collaborators have mapped the entire genome of a northern white rhino. This represents a crucial step toward bringing the critically endangered species back from the edge using advanced reproductive technologies. The complete genome can be used as a reference to analyze the health of previously developed northern white rhinoceros stem cells. Eventually, those stem cells may be able to generate sperm and eggs to yield new rhinos.

The researchers discovered that a highly branched neuron called PVD, previously characterized in hermaphrodites, forms a different structure in males. Moreover, while in hermaphrodites, PVD functions primarily in pain sensing, in males, it has an additional role during mating; when its development is disrupted, males are slower and less coordinated. This discovery provides a unique example of sexual dimorphism in the structure of a single neuron, which is linked to behavioral differences.