BACKGROUND The increasing prevalence of cancer survivors who are infertile due to gonadal failure highlights the importance of fertility preservation prior to gonadotoxic treatments. Adolescent cancer patients may not be mature enough to produce sperm by masturbation, leading to the use of alternative methods for obtaining sperm for cryopreservation. The aim of the current study was to evaluate...

We have reported recently the first birth after intrauterine transfer of embryos obtained by injection of round spermatids into oocytes in cases of unexpected azoospermia. Here we provide a complete documentation of the series of 11 cases in which this novel method of infertility treatment was employed. In four of these cases, elongated spermatids were identified in the ejaculate, and it was de...

In species where females mate promiscuously, the reproductive success of males depends both on their ability to acquire mates (pre-copulatory sexual selection) and ability of their ejaculates to outcompete those of other males (post-copulatory sexual selection). Sperm competition theory predicts a negative relationship between investment in body traits favouring mate acquisition (secondary sexu...

As commonly observed among closely related species within a variety of taxa, Drosophila species differ considerably in whether they exhibit sexual dimorphism in coloration or morphology. Those Drosophila species in which male external sexual characters are minimal or absent tend, instead, to have exaggerated ejaculate traits such as sperm gigantism or seminal nutrient donations. Underlying expl...

The objective of this study was to scale-up the procedure for Single Layer Centrifugation (SLC) through Androcoll(TM)-P, as a preliminary step towords processing the whole ejaculate. The first experiment compared Single Layer Centrifugation using 4.5 mL and 15 mL extended ejaculate (SLC-4.5 and SLC-15, resp.), assessing sperm quality by objective motility analysis, morphology, viability, and th...

Although alternative mating tactics are found in males of many species, little is known about tactic-specific adaptations to sperm competition and the mechanism by which fertilization success is obtained. We now report on the sperm investment patterns of males that use alternative mating tactics in bluegill sunfish (Lepomis macrochirus). Bluegill males are characterized by three alternative mat...

The aim of the study was to determine the effect of growth rate and lean meat content in Pietrain×Duroc and Duroc×Pietrain hybrid boars on their semen characteristics. On the basis of the results of performance testing carried out on the 180 day of life, the boars were divided into four groups according to their daily weight gain (I: 750–800 g; II: 801–850 g; III: 851–900 g; and IV: >900 g), an...

The aim of this investigation was to evaluate the semen quality traits of purebred male rabbits and their crosses under subtropical Egyptian conditions. A full 3 x 3 diallel crossing was performed for producing the first generation progeny of New Zealand White (N), Flander (F) and Rex (R) breeds. The highest ejaculate volume (p< 0.05) and percentage of live sperms (p<0.01) with the lowest perce...

BACKGROUND In its 1993 report the Canadian Royal Commission on New Reproductive Technologies challenged the effectiveness of in vitro fertilization for severe male infertility. To address the Commission's concern, the authors compared the relative effectiveness of in vitro fertilization combined with intracytoplasmic sperm injection for severe male infertility and conventional in vitro fertiliz...

Sperm motility is, for its relation to cell viability and fertility, a central component of the spermiogram, where consideration of motion patterns allows discrimination of sub-populations among boar spermatozoa. Extension and cryo-preservation imposes changes in these patterns in connection to handling, additives, temperature changes and the removal of boar seminal plasma (BSP) which apparentl...