Factors affecting penetration of zona-free hamster ova

Clinical assessment of the male fertility

The evaluation of infertility in males consists of physical examination and semen analyses. Standardized semen analyses depend on the descriptive analysis of sperm motility, morphology, and concentration, with a threshold level that must be surpassed to be considered a fertile spermatozoon. Nonetheless, these conventional parameters are not satisfactory for clinicians since 25% of infertility cases worldwide remain unexplained. Therefore, newer tests methods have been established to investigate sperm physiology and functions by monitoring characteristics such as motility, capacitation, the acrosome reaction, reactive oxygen species, sperm DNA damage, chromatin structure, zona pellucida binding, and sperm-oocyte fusion. After the introduction of intracytoplasmic sperm injection technique, sperm maturity, morphology, and aneuploidy conditions have gotten more attention for investigating unexplained male infertility. In the present article, recent advancements in research regarding the utilization of male fertility prediction tests and their role and accuracy are reviewed.

Capacitation status of stored boar spermatozoa is related to litter size of sows

Semen parameters can be considered useful predictors of sperm fertility. The objective of this study was to address the question of whether differences in in vivo fertility after the use of different ejaculates could be predicted using sperm kinematics, capacitation status, and sperm penetration ability under commercial pig production conditions. The percentage of capacitated sperm, as assessed by chlortetracycline (CTC) staining, was positively correlated with litter size (p<0.01). Our data suggest that litter size increases in proportion to the number of capacitated spermatozoa. When all semen parameters (kinematics, sperm capacitation status, and sperm penetration ability) and litter size were included in a multiple linear regression analysis, significant associations were found between the percentage of capacitated sperm (B-type), the sperm fertility index as assessed by a sperm penetration assay (SPA), and litter size. This relationship between capacitated sperm and litter size, however, was more predictive for smaller litter groups than larger ones. We found that the percentage of B-type sperm was significantly correlated with historic average litter size. However, there was no significant correlation between the percentage of B-type sperm and historic farrowing rates. To determine the normal range for B-type sperm, the lower limits were established as 30% for small litters (<8 piglets) and 35% for large litters. The overall accuracy of the assay was 92% and 83% for small and large litters, respectively. These results indicate that capacitation status as measured by CTC staining is a useful predictor of sperm fertility, equivalent to SPA. Moreover, original capacitation status exhibited better predictive ability for small litters than for large ones. Therefore, subfertile boars can be identified primarily by capacitation status.

Effects of human follicular fluid on spermatozoa that have been cocultured with human oviductal cells

OBJECTIVE

To investigate the sequential effects of human oviductal cells and human follicular fluid (hFF) on various sperm functions.

DESIGN

Laboratory experimental study.

SETTING

University gynecology unit.

PATIENT(S)

Fallopian tubes were from patients undergoing tubal ligation or hysterectomy. Semen was from men attending the subfertility clinics.

INTERVENTION(S)

Spermatozoa were treated with [1] 6 hours in Earle's balanced salt solution (EBSS-BSA; control); [2] 5 hours in EBSS-BSA and 1 hour with hFF (hFF); [3] 5 hours with oviductal cells and 1 hour in EBSS-BSA (coculture); and [4] 5 hours with oviductal cells and 1 hour with hFF (sequential).

MAIN OUTCOME MEASURE(S)

Motility, acrosome reaction, zona binding, and oocyte fusion.

RESULT(S)

Groups II and III spermatozoa had similar motility and were better than that of group I. Group IV displayed higher motility parameters than the other groups. Human follicular fluid induced acrosome reaction. The incidence of acrosome reaction in group IV was significantly lower than that in group II. Group III did not affect the acrosome reaction. Spermatozoa in groups II-IV had lower zona binding capacity than those in group I. Human follicular fluid stimulated oocyte penetration, whereas oviductal cells suppressed this effect of hFF.

CONCLUSION(S)

Oviductal cells maintained the fertilizing capacity of spermatozoa, whereas hFF facilitated the fertilization process of oviductal spermatozoa.

Recent advances in reproductive genetic technologies

New possibilities for the diagnosis and treatment of reproductive and genetic disorders are becoming available as a result of a series of recent technical advances. Intracytoplasmic sperm injection (ICSI) allows treatment of numerous infertile men whose sperm cannot penetrate the egg to initiate fertilization. Molecular genetic testing provides clients of reproductive age with additional information that permits prevention of genetic diseases such as fragile X syndrome, the leading cause of inherited mental retardation. Preimplantation genetic testing (PGT) offers couples who carry genetic disorders the prospect of having children with a greatly decreased risk of initiating a pregnancy involving an affected individual. Flow-cytometric sperm separation offers a new, effective approach for prevention of X-linked genetic disorders. Two major causes of recurrent pregnancy loss (RPL) involve recurrent trisomies and immunological disorders. Of the latter, 70% of studied populations of patients can attain live births with simple treatment protocols. Maternal serum assays involving multiple markers reduce both false positives and false negatives in detection of trisomies. Despite these advances in research, many safe and effective methods of diagnosis and treatment remain under-utilized in the clinical arena.