Background: To clarify the mechanism of sperm penetration through the zona pellucida, the flagellar force generated by a hyperactivated spermatozoon was evaluated using the resistive force theory applied to the hyperactivated flagellar waves that were obtained from the mammalian spermatozoa. Materials and Methods: The hydrodynamic calculation of the flagellar force of the activated (non-hyperac...

The mouse oocyte can be activated by injection of a single, intact mouse spermatozoon or its isolated head. Isolated tails are unable to activate the oocyte. Active sperm-borne oocyte-activating factor(s) (SOAF) appears during transformation of the round spermatid into the spermatozoon. The action of SOAF is not highly species-specific: mouse oocytes are activated by injection of spermatozoa fr...

To clarify the physiological changes of sperm morphology in active Thoroughbred stallions during the breeding season, we examined the dismount semen collected from the penile urethra immediately after service. The spermatozoa were analyzed for relationships between the morphology and the stallion's age or the number of services. Seasonal variation was apparent in the rate of the sperm tail abno...

BACKGROUND One of the semen quality parameters use to determine fertility is the percentage of sperm that express normal morphology. Sperm head morphometry is also correlated with fertility. The objectives of this study were 1) to investigate the sperm morphology and normal sperm head morphometry of Thai native crossbred stallions, and 2) to compare our results with the characteristics of prove...

Commercial ostrich farming is constrained by the absence of a formal animal recording and evaluation scheme as well as by current farming practices. Artificial insemination may have an important role in overcoming these limitations, but requires a thorough knowledge of sperm morphology. Although the morphological characteristics of normal ostrich sperm have been documented, little information i...

Sperm morphology is unique among the known cells and 3 major parts can be immediately distinguished: head, midpiece and tail. Normal sperm exhibit an oval-shaped head with a regular outline and a cap (acrosome) covering more than one-third of the head surface. The midpiece is slender, less than one third of the width of the head, straight and regular in outline. The tail is slender, uncoiled an...

BACKGROUND Standard semen parameters have proven poor at predicting the outcomes of IVF treatment cycles. As recent studies suggest that the male genome may play an important role in early embryogenesis, this study attempts to correlate the level of sperm DNA damage in fresh semen and prepared sperm with the outcomes of conventional IVF treatment cycles. METHODS Forty patients embarking on IV...

The aim of this study was to investigate the eff ect of boar age on quality traits and fertility of liquid-stored semen. Boars were allocated into 3 age groups: 7-10 months (young), 18-33 months (mature), 51-61 months (old). Ejaculates of ≥ 200x106 sperm/ml and 85% total motile sperm were extended to 30x106 sperm/ml, stored at 17-18 °C and used within 12-24 h for artifi cial insemination (AI) o...

The objective of the present study was to evaluate the protective effect of Phyllanthus emblica against clastogenicity induced by lead nitrate on the incidence of sperm head abnormalities in the germ cells of mice. At higher concentration of lead, a significant increase in the percentage of sperm head abnormalities was noted but when animals primed with Phyllanthus fruit extract (PFE), a reduct...

The effects of acute restraint stress on sperm motility and reproductive endocrinology were investigated in adult rats. Sperm motility was determined by computer-assisted sperm analysis. Acute restraint stress reduced sperm motility starting after 30 min, and the sperm motility parameters, percentage of motile spermatozoa (%), straight-line velocity, curvilinear velocity, deviation of the sperm...