The perinuclear theca protein Calicin helps shape the sperm head and maintain the nuclear structure in mice
Xiao-Zhen Zhang,
Lin-Lin Wei,
Hui-Juan Jin,
Xiao-Hui Zhang,
Su-Ren Chen
Affiliations
Xiao-Zhen Zhang
Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
Lin-Lin Wei
Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
Hui-Juan Jin
Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
Xiao-Hui Zhang
Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
Su-Ren Chen
Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing 100875, China; Corresponding author
Summary: The perinuclear theca (PT) is a cytoskeletal element encapsulating the sperm nucleus; however, our understanding of the physiological roles of PT in sperm is very limited. We show that Calicin interacts with itself and many other PT components, indicating it may serve as an organizing center of the PT assembly. Calicin is detectable first when surrounding the acrosome, then detected around the entire nucleus, and finally translocated to the postacrosomal region of spermatid heads. Intriguingly, loss of Calicin specifically causes surface subsidence of sperm heads in the nuclear condensation stage. Calicin interacts with inner acrosomal membrane (IAM) protein Spaca1 and nuclear envelope (NE) components to form an “IAM-PT-NE” structure. Intriguingly, Ccin-knockout sperm also exhibit DNA damage and failure of fertilization. Our study provides solid animal evidence to suggest that the PT encapsulating sperm nucleus helps shape the sperm head and maintain the nuclear structure.
