• PMID: 30328350
• Gene Name: EQTN
• Condition: Associated with male fertility and sperm-egg adhesion
• Association: Associated
• Sex: Male
• Infertility type: Male infertility

Deletion of Eqtn in mice reduces male fertility and sperm-egg adhesion

Ito C, Yamatoya K, Yoshida K, Fujimura L, Sugiyama H, Suganami A, Tamura Y, Hatano M, Miyado K, Toshimori K.

A number of sperm proteins are involved in the processes from gamete adhesion to fusion, but the underlying mechanism is still unclear. Here, we established a mouse mutant, the EQUATORIN-knockout (EQTN-KO, Eqtn - / - ) mouse model and found that the EQTN-KO males have reduced fertility and sperm-egg adhesion, while the EQTN-KO females are fertile. Eqtn - / - sperm were normal in morphology and motility. Eqtn - / - -Tg (Acr-Egfp) sperm, which were produced as the acrosome reporter by crossing Eqtn - / - with Eqtn +/+ -Tg(Acr-Egfp) mice, traveled to the oviduct ampulla and penetrated the egg zona pellucida of WT females. However, Eqtn - / - males mated with WT females showed significant reduction in both fertility and the number of sperm attached to the zona-free oocyte. Sperm IZUMO1 and egg CD9 behaved normally in Eqtn - / - sperm when they were fertilized with WT egg. Another acrosomal protein, SPESP1, behaved aberrantly in Eqtn - / - sperm during the acrosome reaction. The fertility impairment of EQTN/SPESP1-double KO males lacking Eqtn and Spesp1 (Eqtn/Spesp1 - / - ) was more severe compared with that of Eqtn - / - males. Eqtn - / - -Tg (Eqtn) males, which were generated to rescue Eqtn - / - males, restored the reduced fertility. FAU - Ito, Chizuru AU - Ito C AD - Department of Functional Anatomy, Reproductive Biology and Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan. FAU - Yamatoya, Kenji AU - Yamatoya K AD - Department of Functional Anatomy, Reproductive Biology and Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan. AD - Biomedical Research Center, Chiba University, Chiba, Japan. FAU - Yoshida, Keiichi AU - Yoshida K AD - Department of Functional Anatomy, Reproductive Biology and Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan. FAU - Fujimura, Lisa AU - Fujimura L AD - Biomedical Research Center, Chiba University, Chiba, Japan. FAU - Sugiyama, Hajime AU - Sugiyama H AD - Department of Bioinformatics, Graduate School of Medicine, Chiba University, Chiba, Japan. FAU - Suganami, Akiko AU - Suganami A AD - Molecular Chirality Research Center, Chiba University, Chiba Japan. FAU - Tamura, Yutaka AU - Tamura Y AD - Molecular Chirality Research Center, Chiba University, Chiba Japan. FAU - Hatano, Masahiko AU - Hatano M AD - Department of Biomedical Science, Graduate School of Medicine, Chiba University, Chiba, Japan. FAU - Miyado, Kenji AU - Miyado K AD - Department of Reproductive Biology, National Center for Child Health and Development, Tokyo, Japan.