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Fertilization Ability (fertilization + ability)

Distribution by Scientific Domains

Medical Sciences	40%
Earth and Environmental Science	40%

Selected Abstracts

Reproductive effects of the endocrine disruptor fenarimol on a Baltic amphipod Monoporeia affinis

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2006
Therese Jacobson
Abstract An endocrine disruptor, the fungicide fenarimol, was investigated regarding its effects on reproduction and hormone (ecdysteroid) levels in the deposit-feeding amphipod Monoporeia affinis. In addition, the influence of food shortage, both by itself and in combination with fenarimol, on reproduction was examined. Field-collected amphipods were exposed in flow-through microcosms during the period of sexual maturation and mating in four treatment series: Control with low food, fenarimol with low food, control with high food, and fenarimol with high food. Fenarimol was added at a concentration of 0.3 mg/L in two pulses/week. Results show that fenarimol has a negative effect on fertilization rate and male mating ability. Results were supported by a tendency toward delayed male sexual development. Food shortage decreased weight in both sexes and retarded female oocyte development. Higher ecdysteroid levels were recorded in males than in females, and food shortage increased male ecdysteroid levels. No effect of fenarimol exposure on ecdysteroid levels was observed. No synergistic effects of fenarimol and food shortage could be distinguished in any variable examined. Thus, M. affinis was vulnerable to reproductive impairment by fenarimol, with effects on the next generation (i.e., a disturbed sexual development and fertilization ability). Food shortage has negative effects on M. affinis, but it does not enhance the effects of fenarimol. [source]

The aetiology of sperm protamine abnormalities and their potential impact on the sperm epigenome

INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 6 2008
Douglas T. Carrell
Summary During the elongating spermatid stage of spermatogenesis, there is a step-wise replacement of nuclear histones with protamines 1 and 2. In fertile men, the ratio of protamine 1/protamine 2 (P1/P2) is within the narrow range of 0.8,1.2. Ratios above or below that range are associated with infertility, exhibiting a wide range of defects including decreased sperm counts, morphology, fertilization ability, and embryo implantation capacity. In this review, we highlight studies evaluating potential causes of abnormal protamine expression, including the sequencing of genes relevant to protamine expression in both affected patients and controls. While the variants of the protamine genes themselves do not appear to be responsible for most observed defects, variants of the Contrin gene, a transcription factor and translation repressor, appear to be contributory to some cases of abnormal expression. Additionally, we explore the potential effects of abnormal protamine replacement on the epigenome of human sperm. Ongoing studies are evaluating the role of retained histones and DNA methylation in sperm, which may be affected in sperm with aberrant protamine replacement. This important area of epigenetic research has profound clinical implications. [source]

The current status of sperm cryopreservation of the endangered Probarbus jullieni (Sauvage) in Malaysia

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 5 2010
P. C. Chew
Summary The objective of this study was to develop a cryopreservation method in Probarbus jullieni sperm, an endangered riverine fish species in Southeast Asia, including the optimization of an extender solution (14 extender formulations were tested) and selecting a cryoprotectant (five types of agents and methanol were used at concentrations (v/v) of 5, 7.5, 9, 10, 12, 15 and 20%). The semen to diluent ratios tested were as follow: 1 : 1, 1 : 2, 1 : 3, 1 : 4, 1 : 5, 1 : 7, 1 : 9, 1 : 14, 1 : 19, 1 : 24 and 1 : 49. Vapour exposure duration was set at 5, 10, 15 and 20 min while the distance between sample and liquid nitrogen (LN2) during the vapour exposure was designed at 3, 3.5, 4, 5 and 6 cm. Further, the time frame for thawing was set at 6, 7, 8, 10, 20 and 30 s. The optimum protocol was by using CF-HBSS (pH 7.5, osmolality 285 ± 10 mOsmol kg,1) in combination with methanol at 9% (v/v); sperm to diluents ratio between 1 : 3 to 1 : 5; vapour exposure for 5 min or 10 min, with samples placed at 3.5 cm or 4 cm above LN2 and thawing at 40°C for 7 s. The mean of pre-frozen and post-thaw sperm motility was 80.1 ± 13.6% (n = 43) and 49.6 ± 16.4% (n = 43) respectively. The reproductive characteristics of P. jullieni during its spawning season were addressed in present work. Cryopreserved sperm was found to have lower fertilization ability (4.2 ± 2.5%, n = 1050) and hatching rate (1.6 ± 1.2%, n = 1050) compared with fresh sperm (fertilization 77.7 ± 6.2%, n = 1050; hatching 64.7 ± 7.7%, n = 1050). The resulted problems and constraints encountered in the process of sperm cryopreservation of the species studied were also reported in this paper. [source]

In vitro Effect of Zearalenone and , -Zearalenol on Boar Sperm Characteristics and Acrosome Reaction

REPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2006
IA Tsakmakidis
Contents This study was conducted to determine the in vitro effects of three different concentrations (125, 187.5 and 250 ,m in diluted semen) of zearalenone (zen) and , -zearalenol (, -zen) on boar sperm. Semen parameters such as motility, viability and spontaneous acrosome reaction were evaluated. From the results it was shown that both zen and , -zen affected the sperm characteristics significantly (p < 0.05), except for , -zen at the low concentration which did not decrease the percentage of live reacted spermatozoa significantly. In conclusion, zen and , -zen are directly toxic when they affect boar semen in vitro and consequently decrease the fertilization ability of the sperm. The higher the concentration of mycotoxin tested, the greater the decline of sperm parameters noticed. The influence of mycotoxins was found to be time- and dose-dependent. [source]

Cryopreservation of silver barb Puntius gonionotus (Bleeker) spermatozoa: effect of extender composition, cryoprotective agents and freezing rate on their postthawing fertilization ability

AQUACULTURE RESEARCH, Issue 15 2008
Padmanav Routray
Abstract The effects of extender composition, cryoprotectant concentration and freezing and thawing on the fertilization efficiency of cryopreserved spermatozoa of Puntius gonionotus were evaluated. Computer-aided motility analysis of semen was conducted to check the suitability of spermatozoa for cryopreservation after mixing with different extenders and cryoprotective agents (CPAs). Extender-4 with an osmolality 260 mOsmol kg,1and pH 7.6 was used for the cryopreservation study. Among the CPAs, dimethyl sulphoxide (DMSO) was least toxic and more than 60% fertilization was achieved when used at 1.4 M at 0 °C for 10 and 30 min, whereas the toxicity of all CPAs to spermatozoa was evident when tested at 30 °C. Semen frozen at ,16 °C min,1 with 1.4 M DMSO showed 70% fertilization, which was significantly higher (P<0.05) than other freezing rates. Samples thawed at 35 °C water showed a fertilization rate comparable with that of fresh semen. Computer-assisted semen analysis of fresh and frozen semen after thawing showed variations in different types of motility in spermatozoa and in their class. There was no significant difference in motility before or after cryopreservation; however, significant differences could be observed in the average path velocity (VAP), straight line velocity (VSL) and curve linear velocity (VCL). Semen of silver barb could be cryopreserved with extender-4 by addition of 1.4 M DMSO to a final cryopreservation medium (MED 2) cooled at a rate of ,16 °C min,1, stored in liquid nitrogen (,196 °C) and utilized after thawing at 35±2 °C. [source]