The Nuclear Pore Complex Facilitates Centriole-Nuclear Attachment in Spermatids

Area of Science:

• Cell Biology
• Reproductive Biology
• Molecular Biology

Background:

• The head-tail coupling apparatus (HTCA) is essential for sperm function and male fertility.
• The nuclear pore complex (NPC) has been implicated in male fertility, but its specific role in HTCA formation is unknown.

Purpose of the Study:

• To investigate the role of NPCs and their components in the development of the HTCA during spermiogenesis.
• To identify specific nucleoporins involved in HTCA formation and understand their mechanism of action.

Main Methods:

• A testis-specific RNAi screen was employed to target nucleoporins (NPC components).
• Functional assays were performed to assess HTCA development and centriole attachment following nucleoporin depletion.
• Immunofluorescence microscopy and biochemical analyses were used to examine protein localization and interactions, including dynein/dynactin recruitment.

Main Results:

• Nup133 and Nup107 were identified as critical regulators of HTCA development, required for the initial nucleus-centriole connection.
• Depletion of Nup133 and Nup107 led to HTCA defects due to the loss of nuclear envelope dynein/dynactin.
• Loss of Nup358, an NPC cytoplasmic filament component, resulted in severe centriole detachment, suggesting it acts as a dynein anchor.

Conclusions:

• NPCs play a critical role in the early stages of HTCA establishment during spermiogenesis.
• NPCs are required for the recruitment of dynein to the nuclear envelope, facilitating the connection between the nucleus and centriole.
• These findings highlight a novel function of NPCs in male reproductive processes and identify key components involved in sperm head-tail linkage.