ADAM3 was absent from Clgn-/- sperm and disappeared from the Triton X-114 detergent-enriched phase in Ace-/- sperm, explaining their inability to bind to the zona pellucida.
Male mice deficient for the calmegin (Clgn) or the angiotensin-converting enzyme (Ace) gene show impaired sperm migration into the oviduct and loss of sperm-zona pellucida binding ability in vitro. Since CLGN is a molecular chaperone for membrane transport of target proteins and ACE is a membrane protein, we looked for ACE on the sperm membranes from Clgn-/- mice. ACE was present and showed normal activity, indicating that CLGN is not involved in transporting ACE to the sperm membranes. The ablation of the Adam2 and Adam3 genes generated animals whose sperm did not bind the zona pellucida, which led us to examine the presence of ADAM2 and ADAM3 in Clgn-/- and Ace-/- sperm. ADAM3 was absent from Clgn-/- sperm. In the Ace-/- mice, while ADAM2 was found normally in the sperm, ADAM3 disappeared from the Triton X-114 detergent-enriched phase after phase separation, which suggests that ACE is involved in distributing ADAM3 to a location where it can participate in sperm-zona pellucida binding. This diminished amount of ADAM3 in the Triton X-114 detergent-enriched phase may explain the inability of Clgn-/- and Ace-/- sperm to bind to the zona pellucida.
Yamaguchi et al. (Thu,) conducted a other in Impaired sperm migration and loss of sperm-zona pellucida binding ability. Clgn or Ace gene deficiency was evaluated on Presence and distribution of ADAM3 in sperm. ADAM3 was absent from Clgn-/- sperm and disappeared from the Triton X-114 detergent-enriched phase in Ace-/- sperm, explaining their inability to bind to the zona pellucida.