Testicular failure (TF) is referring to the condition of testicles which are unable to produce sperm or testosterone. Testosterone is the essential androgen (male sex hormone) for male reproductive function that allows for the development of male genitalia, secondary sex characteristics in prepubescent males, and the maintenance of secondary sex characteristics, initiation and maintenance of sp...

Parthenogenetic lineages that arise in a hermaphroditic, sexual population will inherit the male function from their sexual progenitors. Natural selection then acts to reduce male allocation of the parthenogens, freeing resources presumably for the female function. Depending on age and the available genetic variation, one therefore expects to find reduced male allocation in naturally occurring ...

spermatozoa generate reactive oxygen species (ros) in physiological amounts which play a role in sperm functions during sperm capacitation acrosome reaction (ar) and oocyte fusion. in addition damaged sperm are likely to be the source of ros. the most important ros produced by human sperm are hydrogen peroxide superoxide anion and hydroxyl radicals. besides human seminal plasma and sperm posses...

Testicular failure (TF) is referring to the condition of testicles which are unable to produce sperm or testosterone. Testosterone is the essential androgen (male sex hormone) for male reproductive function that allows for the development of male genitalia, secondary sex characteristics in prepubescent males, and the maintenance of secondary sex characteristics, initiation and maintenance of sp...

A number of reproductive parameters were evaluated in 12 adult indigenous boars. The seminal vesicles, prostate and bulbourethral glands had masses of 184.41 +/- 18.00 g, 16.69 +/- 2.42 g and 142.05 +/- 16.12 g, respectively, while the penile length measured 45.71 +/- 4.49 cm. The testes and epididymides had masses of 211.82 +/- 26.74 g and 108.81 +/- 11.49 g. The number of sperm averaged 2.78 ...

Testicular failure (TF) is referring to the condition of testicles which are unable to produce sperm or testosterone. Testosterone is the essential androgen (male sex hormone) for male reproductive function that allows for the development of male genitalia, secondary sex characteristics in prepubescent males, and the maintenance of secondary sex characteristics, initiation and maintenance of sp...

In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS) plays a key role in causing cells to undergo a massive acrosome reaction (AR). Astaxanthin (Asta), a photo-protective red pigment belonging to the carotenoid family,...

The yield of flow cytometric sorted Xand Y-chromosome-bearing sperm in a given time period is an important factor in the strategies used for fertilization and the production of sex-preselected offspring. This yield is dependent on the efficiency with which the modified flow cytometer/cell sorter analyzes the DNA of spermatozoa. The efficiency is directly related to the number of sperm with the ...

Recent studies suggest that sperm production and transfer may have significant costs to males. Male sperm investment into a current copulation may therefore influence resources available for future matings, which selects for male strategic mating investment. In addition, females may also benefit from actively or passively altering the number of sperm transferred by males. In the scorpionfly Pan...