The evolution of centriole degradation in mouse sperm
Sushil Khanal, Ankit Jaiswal, Rajanikanth Chowdanayaka, Nahshon Puente, Katerina Turner, Kebron Yeshitela Assefa, Mohamad Nawras, Ezekiel David Back, Abigail Royfman, James P. Burkett, Soon Hon Cheong, Heidi S. Fisher, Puneet Sindhwani, John C. Gray, Nallur Basappa Ramachandra, Tomer Avidor‐Reiss
Abstract
Centrioles are subcellular organelles found at the cilia base with an evolutionarily conserved structure and a shock absorber-like function. In sperm, centrioles are found at the flagellum base and are essential for embryo development in basal animals. Yet, sperm centrioles have evolved diverse forms, sometimes acting like a transmission system, as in cattle, and sometimes becoming dispensable, as in house mice. How the essential sperm centriole evolved to become dispensable in some organisms is unclear. Here, we test the hypothesis that this transition occurred through a cascade of evolutionary changes to the proteins, structure, and function of sperm centrioles and was possibly driven by sperm competition. We found that the final steps in this cascade are associated with a change in the primary structure of the centriolar inner scaffold protein FAM161A in rodents. This information provides the first insight into the molecular mechanisms and adaptive evolution underlying a major evolutionary transition within the internal structure of the mammalian sperm neck.