Fertilization is a cell-cell recognition process that occurs between two distinct cells: a small asymmetric and motile sperm cell and a large and nonmotile egg. The stages of fertilization can be divided into four processes: 1) sperm preparation, 2) sperm-egg recognition and binding, 3) sperm-egg fusion and 4) fusion of sperm and egg pronuclei and activation of the zygote. The specific structur...

background: there is a great concern for the possible adverse effects of radiofrequency radiations of cell phones. moreover, unwanted sound is one of the physical pollutants of current societies. thus, the present study was conducted to examine the effect of cell phone waves, sound, and simultaneous effect of cell phone waves and sound on sperm viability and total antioxidant capacity of blood ...

fertilization involves direct interaction of the sperm and oocyte, fusion of the cell membranes and :union: of male and female gamete genomes. the completion of this process and subsequent embryo development depend in part on the inherent integrity of the sperm dna. sperm genome quality has been emphasized for several years as playing a major role in early embryogenesis. there is clinical evide...

With the advent of human assisted reproduction in the year 1978 numerous techniques were developed to isolate spermatozoa capable to fertilize oocytes. While early methodologies only focused on the aim of isolating viable, motile spermatozoa, with further progress of assisted reproductive technology, particularly for ICSI, it rapidly became clear that these two parameters are insufficient for t...

background: multiple factors have been suggested for prediction of pregnancy in intracytoplasmic sperm injection (icsi) cycles such as the number of injected oocytes, fertilization rate, embryo morphology and quality of transferred embryos. predictive value of these factors is important in icsi outcome. objectives: to evaluate the role of embryo morphology for prediction of pregnancy in icsi cy...

In plants, each male meiotic product undergoes mitosis, and then one of the resulting cells divides again, yielding a three-celled pollen grain comprised of a vegetative cell and two sperm cells. Several genes have been found to act in this process, and DUO1 (DUO POLLEN 1), a transcription factor, plays a key role in sperm cell formation by activating expression of several germline genes. But h...

Background: Sperm cryopreservation-thawing process has damaging effects on the structure and function of sperm, namely cryoinjury. Calcium overload has been reported as a postulated mechanism for sperm damage during the first steps after thawing. This study was designed to assess the intracellular calcium (Ca2+i) after cryopreservation and to clarify the role of a calcium chelator ethylene glyc...

Storage of sperm inside the female genital tract is an integral phase of reproduction in many animal species. The sperm storage site constitutes the arena for sperm activation, sperm competition and female sperm choice. Consequently, to understand animal mating systems information on the processes that occur from sperm transfer to fertilization is required. Here, we focus on sperm activation in...

Background: Cysteine has been used as additive in cryopreservation extenders. It contains of thiol group which plays an antioxidant role to eliminate reactive oxygen species (ROS) during freeze -thaw procedure. Excessive ROS production cause DNA damage and subsequently reduce sperm fertility. On the other hand, protamine protein have high levels of cysteine which is critical in packaging and co...

sperm cells are one of the most stellar and fas-cinating cells in all species. one of the most distinctive characteristic of these cells is their movement dynamics which can be observed through a light microscope. the first paper regarding sperm cell biology that appeared on pubmed was pres-ented by dr. w.f. whitney (1). there, he showed the staining properties of spermatozoa and it was publish...