Background: Failed fertilization after intracytoplasmic sperm injection (ICSI) can be due to a reduced oocyte-activation capacity caused by reduced concentrations and abnormal localization of the oocyte-activation factor phospholipase C (PLC) zeta. Patients with this condition can be helped to conceive by artificial activation of oocytes after ICSI with calcium ionophore (assisted oocyte activa...

In the game of evolutionary fitness, males must maximize the chance that their sperm successfully fertilize oocytes. Speciesspecific strategies include making more, bigger, or faster sperm, or producing seminal fluid that does more than serve as a vehicle for sperm transfer [1]. Importantly, seminal fluid components not only modulate sperm function and promote their competitiveness and long-ter...

Egg activation, which is the first step in the initiation of embryo development, involves both completion of meiosis and progression into mitotic cycles. In mammals, the fertilizing sperm delivers the activating signal, which consists of oscillations in free cytosolic Ca(2+) concentration ([Ca(2+)](i)). Intracytoplasmic sperm injection (ICSI) is a technique that in vitro fertilization clinics u...

It has long been appreciated that spermiogenesis, the cellular transformation of sessile spermatids into motile spermatozoa, occurs in the absence of new DNA transcription. However, few studies have addressed whether the physical presence of a sperm nucleus is required either during spermiogenesis or for subsequent sperm functions during egg activation and early zygotic development. To determin...

background: globozoospermia is a rare (incidence of 0.1% among andrological patients) and poorly understood condition, but a severe disorder in male infertility. this case report detailed the course of treatment and protocol of a patient with type 1 globozoospermia using intracytoplasmic sperm injection (icsi) and oocyte activation by calcium ionophore, which yielded conception and birth of a h...

Seminal fluid proteins have been shown to play important roles in male reproductive success, but the mechanisms for this regulation remain largely unknown. In Caenorhabditis elegans, sperm differentiate from immature spermatids into mature, motile spermatozoa during a process termed sperm activation. For C. elegans males, sperm activation occurs during insemination of the hermaphrodite and is t...

Caspases are central components in the apoptosis signaling cascade. The family of cysteine proteases transduces and enhances the apoptosis signal, and activation of effector caspases results in controlled cellular degradation. Although initially the presence of caspases in spermatozoa was controversially discussed in recent years, many studies demonstrated their activation in male germ cells. A...

This study investigated the relationship between acrosin activation and pig sperm proacrosin binding protein (sp32) phosphorylation levels. Differently processed pig spermatozoa (fresh semen sperm, capacitation sperm, acrosome reaction sperm, capacitation-like sperm, and thawed sperm) were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot analysis. The fres...

Adenylyl cyclase (AC) is a key enzyme that synthesizes cyclic AMP (cAMP) at the onset of the signaling pathway to activate sperm motility. Here, we showed that both transmembrane AC (tmAC) and soluble AC (sAC) are distinctly involved in the regulation of sperm motility in the ascidian Ciona intestinalis. A tmAC inhibitor blocked both cAMP synthesis and the activation of sperm motility induced b...