Low and/or total failed fertilization following ICSI is a disappointing effect that some couples may face during their treatment which may have severe social and economic consequences for these infertile couples. This phenomenon has been mainly attributed to failed oocyte activation post ICSI. Researchers have regarded this failure due to the absence or deficiency of sperm associated to oocyte ...

Sperm of salmonid fishes are quiescent in the presence of millimolar concentrations of extracellular K+, but motility initiation occurs when sperm are suspended in K+-free medium. In this study, glycerol (CH2OHCHOHCH2OH) treatment of intact sperm in the presence of K+ induced the initiation of motility even though a large amount of K+ was present. Another organic alcohol, erythritol (CH2OH(CHOH...

Sperm motility analysis of aquatic model species is important yet challenging due to the small sample volume, necessity activate with water, and short duration motility. To achieve standardization sperm activation, microfluidic mixers have shown improved reproducibility over activation by hand, but challenges remain in optimizing simplifying use these microdevices for greater adoption. The devi...

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...

In pigs, intracytoplasmic sperm injection (ICSI) efficiency is still poor. The inadequate decondensation of the sperm chromatin, its transformation into the male pronucleus (MPN) together with the subsequent inability to activate the oocyte, seem to be the main causes of the low ICSI efficiency. In order to improve the MPN formation we took two different approaches. On the one hand, the in vitr...

The effects of reduced doses of OvaprimTM (GnRHa + domperidone) on sperm release of Brycon orbignyanus and Prochilodus lineatus were evaluated. Furthermore, sperm quality was compared among fresh, equilibrated and postthaw samples. Males received a single and reduced dose of OvaprimTM (0.125 or 0.25 ml/kg); control males received pituitary extract (cPE; 3 mg/kg). Fresh sperm was evaluated for v...

BACKGROUND Sexual reproduction in animals requires the production of highly specialized motile sperm cells that can navigate to and fertilize ova. During sperm differentiation, nonmotile spermatids are remodeled into motile spermatozoa through a process known as spermiogenesis. In nematodes, spermiogenesis, or sperm activation, involves a rapid cellular morphogenesis that converts unpolarized r...

One important result of egg activation is the establishment of blocks to prevent polyspermic fertilization; these blocks are established on the zona pellucida and the egg plasma membrane. This study examines what the sperm brings to the egg to induce the establishment of the membrane block to polyspermy, building on past evidence that membrane block establishment does not occur in response to p...

Plasma membrane-anchored proteases have key roles in cell signaling, migration and refashioning the cell surface and its surroundings. We report the first example of a plasma membrane-anchored protease on mature sperm, testase 1 (ADAM 24). Unlike other studied sperm ADAMs (fertilin alpha and beta, cyritestin) whose metalloprotease domains are removed during sperm development, we found testase 1...