Ejaculated mammalian sperm must acquire fertilization capacity after residing into the female reproductive tract, a process collectively known as capacitation. Cholesterol efflux was required for sperm maturation. Different from flagellated sperm, C. elegans sperm are crawling cells. C. elegans sperm are highly enriched with cholesterol though this animal species lacks biosynthetic pathway for ...

Motility parameters of the spermatozoa in most fish species spawning in fresh water like Rutilus kutum lasts for a short time after activation. Ovarian fluid significantly influenced sperm motility (motility duration period) and percent motility (progressive forward motile sperm). Both of these variables generally increased as the concentration of ovarian fluid increased from 33% to 50%, respec...

BACKGROUND Failed fertilization occurs in 2-3% of ICSI cycles and is mainly due to lack of oocyte activation. Heterologous ICSI of patient's sperm in mouse oocytes allows discrimination between sperm- and oocyte-related aetiologies of activation failure. Assisted oocyte activation (AOA) by Ca-ionophore treatment can initiate fertilization in subsequent therapeutic ICSI. We report on diagnosis a...

objective: the present study aimed to simultaneously evaluate the association between expression of three potential factors [post-acrosomal sheath ww domain-binding protein (pawp), phospholipase cζ (plcζ), and truncated form of the kit receptor (tr-kit)] as candidates of oocyte activation with fertilization rate and early embryonic development. materials and methods: in this experimental study,...

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...

Received: 21 January, 2014 Accepted: 30 March, 2014 Published: 20 April, 2014 A study was conducted to investigate the effect Gonadotropins supplied to culture medium on human sperm parameters and sperm DNA structure during in vitro sperm activation. Thirty infertile patients were included. Semen sample was divided into 3 aliquots. One mL of SMART medium either alone (control group) or supplied...

Sperm from trout, like other sperm, are immotile in the seminal tract and initiate motility upon dilution into an appropriate fertilizing environment. Trout sperm motility is inhibited by high extracellular [K+] and can be activated by dilution of extracellular [K+]. Activation of trout sperm by the dilution of extracellular [K+] suggests regulation by membrane potential. Using the membrane pot...

fertilization is triggered by changes in intracellular calcium concentration. in mammals, these transients in ooplasmic calcium concentration take the form of repetitive spikes, so called calcium oscillations (ca2+-oscillations). these oscillations are important for relieve of meiotic arrest and to induce all the other events of oocyte activation. although a surface mediated way of oocyte activ...

in human fertilization, the sperm centrosome nucleates a radial array of microtubules called the sperm aster. the sperm aster is responsible for apposition of male and female pronuclei, and later gives rise to the first meiotic spindle. the objective of this study was to determine microtubule assembly and chromatin configuration in rabbit oocytes following intracytoplasmic injection with human ...

Given limited resources for motility, sperm cell activation must be precisely timed to ensure the greatest likelihood of fertilization. Like those of most species, the sperm of C. elegans become active only after encountering an external signaling molecule. Activation coincides with spermiogenesis, the final step in spermatogenesis, when the spherical spermatid undergoes wholesale reorganizatio...