Sperm motility

About: Sperm motility is a research topic. Over the lifetime, 13874 publications have been published within this topic receiving 416587 citations. The topic is also known as: sperm movement & GO:0097722.

Calcium-induced quiescence in reactivated sea urchin sperm.

Abstract: Sperm flagella of the sea urchin Tripneustes gratilla beat with asymmetrical bending waves after demembranation with Triton X-100 in the presence of EGTA and reactivation at pH 81 with 1 mM ATP in the presence of 2 mM MgSO4 Addition of 01--02 mM free Ca2+ to these reactivated sperm induces 70--95% of them to become quiescent This quiescence can be reversed by reduction of the free Ca2% concentration with EGTA, or by dilution to reduce the MgATP2- concentration below 03 mM The quiescent waveform is characterized by a sharp principal bend of approximately 56 rad in the proximal region of the flagellum, a slight reverse bend in the midregion that averages approximately 03 rad, and a principal bend of approximately 11 rad in the tip The quiescent sperm are highly fragile mechanically, and disruption, including microtubule sliding, occurs spontaneously at a slow rate upon standing or immediately upon gentle agitation Mild digestion by trypsin causes a gradual appearance of normal, symmetrical flagellar beating Addition of increasing concentrations of vanadate to quiescent sperm causes a graded decrease in the proximal bend angle, with 50 micrometers vanadate reducing it to approximately 26 rad In the presence of 01 mM free Ca2% and 10 micrometers vanadate, a characteristic, crescented stationary bend is induced in the demembranated sperm, without intermediate oscillatory beating, by the addition of either 01 or 1 mM ATP In the absence of vanadate, these two concentrations of ATP produce asymmetric beating and quiescence, respectively The results support the hypothesis that quiescence in live sperm is induced by an elevated concentration of intracellular Ca2% In addition, they demonstrate that bending can occur in flagella in which oscillatory beating is inhibited and emphasize the close relationship between asymmetric beating and quiescence

Relationship between sperm mitochondrial membrane potential, sperm motility, and fertility potential

Abstract: Aim To analyze the relationship between sperm mitochondrial membrane potential and sperm motility parameters by means of a computer-assisted sperm analyzer (CASA) and in-vitro fertilization rate(%FR). Methods Semen samples were obtained from 26 men undergoing in vitro fertilization-embryo transfer (IVF-ET). Informed consent was obtained from all men prior to the study. Samples were prepared using wash and swim-up method in HEPES-HTF medium. The sperm motility (%MOT), progressive motility (%PMOT), average path velocity (VAP) microm/s), straight line velocity (VSL) (micro m/s), curvilinear velocity (VCL) (microm/s) and %hyperactivated sperm (%HA), and the %FR were assessed. The samples were incubated in the presence of 2.0 mciromol/L of 5,5',6,6'-tetra-chloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) for 30 min at 37 degrees C in air and washed in PBS before flow cytometry (FACSCalibur: Becton Dickinson) analysis. The mitochondrial probe JC-1 was used to identify the mitochondrial membrane potential. The sperm was divided into three populations according to the fluorescence pattern as follows: the high mitochondrial membrane potential group (n=8), the moderate group (n=5), and the low group (n=13). Statistical analysis was performed using unpaired t-test. Results Significant differences were found between the high and the low groups in %MOT (91.1+/-8.5 vs 63.0+/-32.7, mean+/-SD), VAP (73.0+/-14.2 vs 52.1+/-12.5), VCL (127.0+/-28.1 vs 87.0+/-22.6), %HA (27.3+/-23.6 vs 7.2+/-9.0) and %FR [73.2 (48/56) vs 59.0 (69/117)]. No significant differences were found in other CASA parameters. Conclusion When the sperm mitochondrial membrane potential increases, sperm motility parameters and fertility potential will also increase. The JC-1 dye method is useful to predict sperm fertility potential.

Intracellular calcium increases with hyperactivation in intact, moving hamster sperm and oscillates with the flagellar beat cycle.

Abstract: At some time before fertilization, mammalian sperm undergo a change in movement pattern, termed hyperactivation. There is evidence that hyperactivation offers an advantage to sperm for detaching from the oviductal mucosa, for penetrating viscoelastic substances in the oviduct, and for penetrating the zona pellucida. Hyperactivation is known to require extracellular calcium, but little else is known about the mechanisms by which calcium affects sperm movement. The calcium-sensitive fluorescent dye indo-1 was used to follow intracellular calcium levels ([Ca2+]i) in individual moving sperm. Sperm were loaded with 10 microM of the acetoxymethyl ester form of the dye and then rinsed. The dye was excited at 340 nm by using a filtered xenon stroboscope, and images at the 405-nm and 490-nm excitation maxima were simultaneously digitized at 30 per sec for 2.1 sec. [Ca2+]i was significantly higher in the acrosomal and postacrosomal regions of the head and in the flagellar midpiece (the principal piece could not be measured) in hyperactivated than in nonhyperactivated sperm (P < 0.0001). [Ca2+]i oscillations were detected in the proximal half of the midpiece that were identical in frequency to the flagellar-beat-cycle frequency in 12 of 17 hyperactivated sperm (median, 3.5 Hz). Rapid [Ca2+]i oscillations were also detected in the acrosomal and postacrosomal regions, as well as in the distal midpiece. Oscillations were not eliminated by dampening the flagellar bending with methyl cellulose. The [Ca2+]i oscillations detected in sperm are significantly more rapid than oscillations detected in other cell types.

Sperm DNA damage in male infertility: Etiologies, assays, and outcomes

Abstract: Male factor infertility is the sole cause of infertility in approximately 20% of infertile couples, with an additional 30% to 40% secondary to both male and female factors. Current means of evaluation of male factor infertility remains routine semen analysis including seminal volume, pH, sperm concentration, motility, and morphology. However, approximately 15% of patients with male factor infertility have a normal semen analysis and a definitive diagnosis of male infertility often cannot be made as a result of routine semen analysis. Attention has focused on the role of sperm nuclear DNA integrity in male factor infertility. Here we review the structure of human sperm chromatin, the etiology and mechanisms of sperm DNA damage, current tests available to assess sperm DNA integrity, and effect of sperm DNA integrity on reproductive outcomes.