Gene-rich UV sex chromosomes harbor conserved regulators of sexual development

Authors: Sarah B. Carey, Jerry Jenkins, John T. Lovell, Florian Maumus, Avinash Sreedasyam, Adam C. Payton, Shengqiang Shu, George P. Tiley, Noé Fernández‐Pozo, Adam Healey, Kerrie Barry, Cindy Chen, Mei Wang, Anna Lipzen, Chris Daum, Christopher Saski, Jordan McBreen, Roth E. Conrad, Leslie M. Kollar, Sanna Olsson, Sanna Huttunen, Jacob B. Landis, J. Gordon Burleigh, Norman J. Wickett, Matthew G. Johnson, Stefan A. Rensing, Jane Grimwood, Jeremy Schmutz, Stuart F. McDaniel - Science Advances 2021 cited by 105

to test for degeneration in the bryophyte UV sex chromosomes. We show that the moss sex chromosomes evolved over 300 million years ago and expanded via two chromosomal fusions. Although the sex chromosomes exhibit weaker purifying selection than autosomes, we find that suppressed recombination alone is insufficient to drive degeneration. Instead, the U and V sex chromosomes harbor thousands of broadly expressed genes, including numerous key regulators of sexual development across land plants.