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Sperm Survival (sperm + survival)
Selected AbstractsMating triggers dynamic immune regulations in wood ant queensJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2009G. CASTELLA Abstract Mating can affect female immunity in multiple ways. On the one hand, the immune system may be activated by pathogens transmitted during mating, sperm and seminal proteins, or wounds inflicted by males. On the other hand, immune defences may also be down-regulated to reallocate resources to reproduction. Ants are interesting models to study post-mating immune regulation because queens mate early in life, store sperm for many years, and use it until their death many years later, while males typically die after mating. This long-term commitment between queens and their mates limits the opportunity for sexual conflict but raises the new constraint of long-term sperm survival. In this study, we examine experimentally the effect of mating on immunity in wood ant queens. Specifically, we compared the phenoloxidase and antibacterial activities of mated and virgin Formica paralugubris queens. Queens had reduced levels of active phenoloxidase after mating, but elevated antibacterial activity 7 days after mating. These results indicate that the process of mating, dealation and ovary activation triggers dynamic patterns of immune regulation in ant queens that probably reflect functional responses to mating and pathogen exposure that are independent of sexual conflict. [source] Effect of Carbohydrates on the Ability of Bull Sperm to Bind to Bovine Oviduct Epithelial CellsREPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2009Y Kon Contents In the present study, we investigated the effect of various carbohydrates on the ability of bovine spermatozoa to bind to the bovine oviduct epithelial cells (OECs). We also examined the fertilization competence and motility of spermatozoa that bind to OECs in the presence of carbohydrates. Frozen-thawed spermatozoa were incubated with OECs, with and without various carbohydrates. The sperms were then divided into two fractions: OEC-binding sperms (B-sperm) and non-OEC binding sperms (NB-sperm). The fertilization rate, ability to bind the zona pellucida, and membrane integrity of the spermatozoa as determined using a hypo-osmotic-swelling test (HOST) were lower in NB-sperm than in the unseparated spermatozoa (control). The motility of the B-sperm was maintained for a longer time than that of the control spermatozoa. The addition of N -acetyl- d -glucosamine (GlcNAc, 5 mm) to the sperm-OEC mixture increased the number of B-sperm. D -mannose (5 mm) and D -fucose (5 mm) had no effect on the number of B-sperm. The motility of B-sperm, which bound to OECs in the presence of GlcNAc, however, was not maintained. When either OECs or the spermatozoa were treated with GlcNAc prior to sperm-OEC co-incubation, only sperm-side treatment enhanced sperm-OEC binding, but B-sperm motility was not maintained. The motility of spermatozoa incubated with GlcNAc was lower than that of controls. These results indicate that GlcNAc enhances sperm binding to OECs, probably via sperm surface modification, but does not promote increased sperm survival. [source] Post-thaw Survival and Longevity of Bull Spermatozoa Frozen with an Egg Yolk-based or Two Egg Yolk-free Extenders after an Equilibration Period of 18 hREPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2007R Muiño Contents The aim of the present study was to determine the suitability of using two egg yolk-free commercial extenders, Andromed® and Biociphos Plus®, as compared with the Tris-egg yolk based diluent Biladyl®, for the cryopreservation of bull spermatozoa when the freezing protocol involved holding the extended semen at 4°C for 18 h before the freezing. Six ejaculates from each of 10 Holstein bulls were collected by using artificial vagina. The ejaculates were evaluated for volume, sperm concentration and motility, divided in to three equal volumes, and diluted, respectively, with the three extenders as specified above. Extended semen was equilibrated for 18 h at 4°C and frozen in 0.25-ml straws. After thawing, 100- ,l aliquots of semen were labelled with SYBR-14, PI and PE-PNA (Phycoerythrin-conjugated Peanut agglutinin) and analysed by flow cytometry at 0, 3, 6 and 9 h after incubation at 37°C. A General Lineal Model procedure for repeated measures was used to determine the effects of extender, bull, replicate and the interaction between them, on sperm viability and acrosomal integrity. Semen samples frozen with Biladyl® showed higher (p < 0.001) sperm survival after 0 h (47.9%) and 9 h (30.3%) of incubation than those frozen with Andromed® (38.5% and 17.3%, after 0 and 9 h respectively) or Biociphos Plus® (34.9% and 21.6%, after 0 and 9 h respectively). The bull and replicate had significant effects (p < 0.001) on both sperm viability and acrosomal integrity, but the interactions between bull and extender and between replicate and extender were not significant. It was concluded that, when holding the semen overnight before freezing, the use of Biladyl® results in higher sperm survival and longevity than the use of Andromed® or Biociphos Plus®. [source] OC1 Effects of Cryopreservation on the Expression of Glut-3, Glut-5 and As-A Proteins in Iberian Boar Sperm MembranesREPRODUCTION IN DOMESTIC ANIMALS, Issue 2006S Sancho In order to determine the injure produced in boar spermatozoa through cryopreservation process, we analyzed the expression of the hexose transporters Glut-3 and Glut-5 and the zona pellucida binding protein As-A (P68) in three different steps of the freezing-thawed protocol: at 17°C (fresh BTS-diluted semen, 1 : 2 v/v, step 1), at 5°C (after glycerol addition; step 2), and post-thawing (step 3). All sperm analyses were carried out with immunogold techniques under electronic microscopy. For this study eight healthy post-pubertal Iberian boars were submitted to a collection of twice per week through 3 months, evaluating two ejaculates from each boar. Glut-3 maintains the expression in the acrosome region post-thawing but not along the tail where is reduced. The expression of Glut-5 and As-A is majority located at the post-acrosome region of the spermatozoa at step 1, but in step 2 and step 3 this expression is relocated to sperm tail area. In conclusion, while cryopreservation affects the localization and the expression of Glut-3 and Glut-5, its fertilizing capacity is not significantly reduced. The stabilization of boar semen at 5°C was found to be the most crucial step for sperm survival. [source] Update on Semen Technologies for Animal Breeding,REPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2006JM Morrell Contents Despite the scale of the livestock breeding industry, where many millions of insemination doses are prepared each year, sperm preparation techniques are used infrequently in animal assisted reproduction compared with its human counterpart. However, some of the techniques used for human sperm preparation, for example, density gradient centrifugation, improve the quality of sperm preparations which is, in turn, reflected by an increased conception rate. The preparation technique separates motile spermatozoa with normal morphology and intact DNA from the total sperm population, leaving behind immature or senescent spermatozoa, morphologically abnormal ones and those with damaged DNA. Furthermore, the motile spermatozoa are removed from the seminal plasma which carries cells, cellular debris and reactive oxygen species, as well as pathogens. Gradient-prepared spermatozoa survive longer, either in liquid storage or when cryopreserved, and are free of bacteria and viral infectivity if prepared carefully. Preparation techniques such as density gradient centrifugation, or the simplified single layer centrifugation technique, have considerable potential for aiding sperm preparation from poor quality semen samples, such as may be obtained from unselected semen donors in captive breeding programmes, or from performance horses. Moreover, the removal of pathogens has important implications, both for disease control and for avoiding the use of antibiotics in semen extenders, which can be detrimental to sperm survival. [source] Prostate cancer: a newly discovered route for testosterone to reach the prostateANDROLOGIA, Issue 5 2009Treatment by super-selective intraprostatic androgen deprivation Summary The prostate, an androgen-regulated exocrine gland, is an integral part of the male reproductive system which has an essential function in sperm survival and motility in its long hostile route to meet and fertilise the egg in the Fallopian tube. Testosterone is known to be the key, obligatory regulator of the prostate that promotes the development and progression of prostate cancer (PCa). Yet, the pathophysiological mechanism of PCa remains unclear and its causal relation to serum testosterone has not been established. Here, we report on the discovery of a previously unrecognized route of flow of free testosterone (FT), at a concentration of 130 times the physiological levels, reaching the prostate via the testicular and prostate venous drainage systems, bypassing the systemic circulation. This condition results from the malfunction of the vertically oriented testicular venous drainage system in humans, a phenomenon with a prevalence that increases rapidly with age, which causes deviation of the testicular venous flow from its normal route. Early results of an interventional radiological procedure, super-selective intraprostatic androgen deprivation therapy are discussed. This treatment has resulted in decrease in prostate volume, and serum PSA, with disappearance of cancerous cells on repeat biopsies in five of six patients. Some of the unresolved biological enigmatic questions associated with PCa are discussed. We conclude that pathological flow of FT from the testes directly to the prostate in an extremely high concentration via the testicular-prostate venous drainage systems was identified may explain the mechanism for the development of PCa. We suggest a time-window for eradication of localised, androgen-sensitive, PCa cells. We anticipate that this treatment may retard, stop or even reverse the development of the disease. A mechanism for the evolution of PCa is discussed. [source] | ||||||||||