Study on the Vesiculation during Mouse Sperm Acrosome Reaction

The location Of the mono-membrane and the bi-membrane vesicles of mouse sperm wasidentified using Con A in conjugation with the colloidal gold. The observation showed that bothmono-membrane vesicles and outer layer of the bi-membrane vesicles come from the outeracrosome membrane.The inner membrane layer of the bi-member vesicles and residual membrane distributed among the vesicles are really foe plasmalemma.It is suggested that the outeracrosome membrane did not fuse with the plasmalemma during mouse sperm acrosome reaction and that both the mono-membrane and the bi-membrane vesicles of mouse sperm wereformed due to winding of the outer acrosome membrane.

Vlouse sperm acquire a new structure on the apical hoo Juring epididymal maturation

Spermatozoa emerging from the testis undergo a maturation process in the epididymis during which they change morphologically, biochemically and physiologically to gain motility and the ability to fertilize ova. We examined mouse epididymal sperm with immunostaining and transmission electron microscopy （EM） and identified a previously unknown structure on the apical hook. The structure has a coiled configuration around 11 nm in thickness and is present at the tip of each corner of the triangular-rod shaped perforatorium. Surveying sperm isolated from various regions of the epididymis indicated that mouse sperm acquire the hook rim （HR） structure during its passage through the proximal two-thirds of the caput epididymidis. The structure withstands vigorous sonication and harsh chemical treatments and remains intact after the acrosome reaction. Its location and sturdiness suggest a function in protecting the apical hook from mechanical wear during fertilization. Our EM images of epididymal sperm also revealed additional novel structures as well as lateral asymmetry of the sperm head, indicating that mouse sperm head has a structure more complex than previously recognized.