This paper describes the fine structure of the spermatozoan apex and its morphological changes during the process of fertilization in Ciona intestinalis. At the apex of the head an acrosome is present in the form of a flattened vesicle containing moderately electron-dense material with an electron-dense plate in its centre. Contiguous to the acrosome, an apical substance is located in the anter...

Successful fertilization requires gametes to complete several stages, beginning with maturation and transport along the male and female reproductive tracts and ending with the interaction between the sperm and the egg. This last step involves sperm-egg adhesion and membrane fusion. ADAMs (disintegrin and metalloprotease domain proteins) are a family of membrane-anchored glycoproteins that are t...

This study investigates the effect of supplementing bovine follicular fluids (FF) to rabbit sperm motility, acrosome reaction and transaminases activities. Ovarian FF were collected from 46 pairs of bovine ovaries. Normal follicles were classified, according to their diameters, into small (SFF, ≤4 mm), medium (MFF,>4-8 mm), large (LFF,> 8 mm) and cystic (CSTFF,>20 mm). Rabbit semen was collecte...

We have developed an assay for detecting the acrosome reaction in mouse sperm using chlortetracycline (CTC) as a fluorescent probe . Sperm known to be intact with nonreacted acrosomes show CTC fluorescence in the presence of Ca" over the anterior portion of the sperm head on the plasma membrane covering the acrosome . Sperm which have undergone the acrosome reaction do not show fluorescence on ...

We have identified a possible role for the KIFC1 motor protein in formation of the acrosome, an organelle unique to spermatogenesis. KIFC1, a C-terminal kinesin motor, first appears on membrane-bounded organelles (MBOs) in the medulla of early spermatids followed by localization to the acrosomal vesicle. KIFC1 continues to be present on the acrosome of elongating spermatids as it flattens on th...

BACKGROUND Nitric oxide (NO) is a signaling molecule produced by intracellular nitric oxide synthase (NOS) enzymes. This free radical appears to affect sperm capacitation, a maturation step preceding acrosome reaction. Recent studies have reported leptin ability to promote capacitation and acrosome reaction in pig male gametes. METHODS This study has investigated nitric oxide production in le...

The acrosome reaction in vertebrate sperm has been shown to be essential for fertilisation [ 11. The process involves fusion and vesiculation of sperm head plasma membranes and the underlying outer acrosomal membrane, resulting in the exocytotic release of acrosomal enzymes. Yanagamachi and Usui have demonstrated that sperm have an absolute requirement for Ca*’ during the acrosome reaction [2]....

The present was conducted to separate heparin binding proteins (HBP) of capacitated sperm extracts and determine their relationship with acrosome reaction and semen fertility of bulls (n=30). Fourteen immunoreactive bands in capacitated spermatozoa of bulls (135, 100, 75, 70, 65, 55, 48, 45, 33, 31, 26, 24, 20 and 18 kDa) were detected in western blots following incubation with anti-HBP antibod...

Flow cytometry was utilised to determine whether short-term (Day 1) or long-term hypothermic liquid storage (Day 5), or cryopreservation of boar spermatozoa (1) caused changes in plasma membrane phospholipid disorder (MPLD) and acrosome exocytosis (AE), indicative of an advanced stage of capacitation or acrosome status, and (2) facilitated or inhibited the induction of capacitation and the acro...

In certain Australian marsupials including the tammar wallaby (Macropus eugenii) and the brushtail possum (Trichosurus vulpecula), formation of the acrosome is not completed in the testis but during a complex differentiation process as spermatozoa pass through the epididymis. Using transmission and scanning electron microscopy this paper defined the process of acrosome formation in the epididym...