A genome sequence for the flatworm Schmidtea mediterranea reveals a chromosome that might be primed to become a sex chromosome. The finding offers a remarkable chance to study the evolution of sex determination.

Article p.329 doi: 10.1038/s41586-022-04757-3

News & Views p.257 doi: 10.1038/d41586-022-01129-9

Sign up for Nature Research e-alerts to get the lastest research in your inbox every week.

Subscribe to the world's leading scientific publications

Register for free weekly e-alerts!

How to publish your research in Nature

High-quality language editing and scientific editing

A global indicator of high-quality research

© 2022 Nature Japan K.K. Part of Springer Nature Group.