Novaluron Has Detrimental Effects on Sperm Functions

Although novaluron is an insect growth regulator with a low mammalian acute toxicity and a low risk to the environment and nontarget organisms, toxic effects of novaluron have been reported. However, no studies have yet evaluated the effect of novaluron on reproduction. Therefore, we examined the effects of novaluron on sperm functions. The spermatozoa of ICR mice were incubated with various concentrations of novaluron to induce capacitation. Then, sperm motion parameters and capacitation status were evaluated using CASA program and H33258/chlortetracycline staining. In addition, PKA activity and tyrosine phosphorylation were evaluated by Western blotting. After exposure, various sperm motion parameters were significantly decreased in a dose-dependent manner. The acrosome reaction was also significantly decreased in the high concentration groups. Sperm viability was significantly reduced at the highest concentration. In addition, PKA activity and tyrosine phosphorylation were also significantly altered. Thus, novaluron affects sperm viability, sperm motility, and motion kinematics during capacitation. Furthermore, it may promote the reduction in acrosome reactions. The physiological suppression of sperm function may depend on abnormal tyrosine phosphorylation via the alteration of PKA activity. Therefore, we suggest that it is necessary to consider reproductive toxicity when using novaluron as a pesticide.

Composition of Stallion Seminal Plasma and Its Impact on Oxidative Stress Markers and Spermatozoa Quality

The composition of seminal plasma of individual sires varies and so does the fertilizing ability. Micro and macro elements along with seminal enzymes, hormones, proteins, and lipids contained in seminal plasma are essential for the proper physiological function of spermatozoa. However, elevated levels against the normal physiological values, especially in the case of trace metals, result in the production of reactive oxygen species. The deficiency of antioxidants in the seminal plasma that could scavenge free radicals causes an impairment of spermatozoa quality. Ejaculates were obtained from 19 stallions. The fresh semen was analyzed to evaluate qualitative parameters of spermatozoa in terms of the motility, viability, and integrity of DNA. Separated seminal plasma underwent the assessment of the chemical and biochemical composition and RedOx markers. Based on the obtained concentrations of individual chemical elements, the correlation analysis suggested a negative impact of Cu in seminal plasma on the SOD, GPx, and LPO. Contrary, positive correlation was detected between FRAP and motility features. While Cu negatively correlated with sperm motion parameters, the adverse effect on viability was suggested for Cd. Our data suggest that seminal plasma has a potential due to its availability to become the potential biomarker of the reproductive health of farm animals.

Sperm migration in the genital tract—In silico experiments identify key factors for reproductive success

Sperm migration in the female genital tract controls sperm selection and, therefore, reproductive success as male gametes are conditioned for fertilization while their number is dramatically reduced. Mechanisms underlying sperm migration are mostly unknown, since in vivo investigations are mostly unfeasible for ethical or practical reasons. By presenting a spatio-temporal model of the mammalian female genital tract combined with agent-based description of sperm motion and interaction as well as parameterizing it with bovine data, we offer an alternative possibility for studying sperm migration in silico. The model incorporates genital tract geometry as well as biophysical principles of sperm motion observed in vitro such as positive rheotaxis and thigmotaxis. This model for sperm migration from vagina to oviducts was successfully tested against in vivo data from literature. We found that physical sperm characteristics such as velocity and directional stability as well as sperm-fluid interactions and wall alignment are critical for success, i.e. sperms reaching the oviducts. Therefore, we propose that these identified sperm parameters should be considered in detail for conditioning sperm in artificial selection procedures since the natural processes are normally bypassed in reproductive in vitro technologies. The tremendous impact of mucus flow to support sperm accumulation in the oviduct highlights the importance of a species-specific optimum time window for artificial insemination regarding ovulation. Predictions from our extendable in silico experimental system will improve assisted reproduction in humans, endangered species, and livestock.

Glutathione supplementation in semen extender improves rabbit sperm attributes during refrigeration

In the present study, we evaluated the sustaining effect of various glutathione (GSH) concentrations in extender on rabbit sperm attributes during storage at 5°C for 24 h. Semen was collected from regular donor rabbit bucks using an artificial vagina and initially evaluated for sperm quality. The qualifying ejaculates were diluted with one of the extenders having 0, 1, 2, 4 or 8 mM GSH, to achieve a final concentration of 1×108 sperm/mL. The extended samples were stored at 5°C for 24 h. Sperm motility, motion kinetics, acrosome integrity and viability were assessed after 3, 6, 12 and 24 h of storage. The results showed that total sperm motility and sperm motion kinetics (oscillation index of the sperm, straightness index and beat cross frequency) were influenced (<em>P</em>&lt;0.05) by glutathione dose and refrigeration time. An interaction of (<em>P</em>&lt;0.05) GSH concentrations and refrigeration time was observed for sperm viability and acrosome reaction rate. In conclusion, the 4 mM GSH supplemented extender’s protective influence was remarkable to maintainrabbit sperm quality for 24 h 5°C.

Curvature in the reproductive tract alters sperm–surface interactions

The fallopian tube is lined with a highly complex folded epithelium surrounding a lumen that progressively narrows. To study the influence of this labyrinthine complexity on sperm behavior, we use droplet microfluidics to create soft curved interfaces over a range of curvatures corresponding to the in vivo environment. We reveal a dynamic response mechanism in sperm, switching from a progressive surface-aligned motility mode at low curvatures (larger droplets), to an aggressive surface-attacking mode at high curvatures (smaller droplets of <50 µm-radius). We show that sperm in the attacking mode swim ~33% slower, spend 1.66-fold longer at the interface and have a 66% lower beating amplitude than in the progressive mode. These findings demonstrate that surface curvature within the fallopian tube alters sperm motion from a faster surface aligned locomotion in distal regions to a prolonged physical contact with the epithelium near the site of fertilization, the latter being known to promote capacitation and fertilization competence.

Potential Anti-Fouling Properties of Extracts from the Mediterranean Sponge Ircinia Oros: An Ecotoxicological Screening

The phylum Porifera and their symbionts produce a wide variety of bioactive compounds, playing a central role in their ecology and evolution. In this study, four different extracts (obtained by non-polar and semi-polar extraction methodologies) from the Mediterranean sponge Ircinia oros were tested for their potential antifouling purposes. The evaluation was performed using three different target species, associated with three different endpoints: the marine bacterium Aliivibrio fischeri (inhibition of bioluminescence), the marine diatom Phaeodactylum tricornutum (inhibition of growth) and different development stages of the brackish-water serpulid Ficopomatus enigmaticus (gametes: sperm motion, vitality inhibition and cellular damage; larvae: development; adults: AChE (acetylcholinesterase)-inhibitory activity). Effects of extracts were species-specific and did not vary among different extraction methodologies. In particular, no significant reduction of bioluminescence of A. fischeri was observed for all tested samples. By contrast, extracts inhibited P. tricornutum growth and had toxic effects on different F. enigmaticus’ developmental stages. Obtained results suggest that the proposed test battery can be considered a suitable tool as bioactivity screening of marine natural products.

27 Cryopreservation of bovine semen using cell-permeating antioxidant and protein-free extender

Effective semen extenders are those with defined composition that promote sperm longevity. Generation of reactive oxygen species during semen cryopreservation results in sperm membrane lipid peroxidation and reduced longevity. Recent studies demonstrated that small cell permeating dimethyl tyrosine conjugated peptides, such as SS-31, translocate to the mitochondria and scavenge excess reactive oxygen species. The present study was conducted to test the hypothesis that the addition of SS-31 improves the post-thaw quality and fertility potential of bovine semen. The effect of SS-31 was tested in combination with two extenders: (1) conventional tris-egg yolk-glycerol (TEYG, control) and (2) cholesterol-cyclodextrin+tris-glycerol (CC+TG, a defined protein-free extender). Fifteen ejaculates were collected from 5 Black Angus bulls. Ejaculates were diluted to 400×106 spermmL−1 with tris-citric acid buffer, and treated with 0, 50, or 100 µmolmL−1 SS-31 for 15min at 32°C. Semen aliquots were diluted further with TEYG, 0.5mgmL−1 CC+TG, or 1mgmL−1 CC+TG extender to a final concentration of 50×106 spermmL−1. Semen was then cooled to 4°C and frozen in a programmable freezer. Post-thaw sperm motion parameters were evaluated at 0, 2, 4, 6 and 24h with CASA. Semen fertility was determined by fixed-time AI using Hereford-cross cows (n=100). Synchronized cows were inseminated once with semen extended in TEYG, 1mgmL−1 CC+TG, or 1mgmL−1 CC+TG + 100 µmolmL−1 SS-31. Pregnancy was diagnosed by ultrasonography at 27 days post-insemination. Post-thaw sperm motion parameters were compared by ANOVA for repeated-measures, and pregnancy rates were compared using binomial linear mixed-model ANOVA. No differences in sperm motion parameters were detected among SS-31 treatments within extenders. Semen extended in TEYG or 1mgmL−1 CC+TG had greater total and progressive motilities at 0 and 2h post-thaw than semen extended in 0.5mgmL−1 CC+TG (P&lt;0.05). Pregnancy rates after fixed-time insemination did not differ among semen extender groups [TEYG: 15/25 (60%), 1mgmL−1 CC+TG: 19/34 (56%), 100 µmolmL−1 SS-31+1mgmL−1 CC+TG: 21/37 (57%)]. Addition of the cell permeating antioxidant SS-31 did not improve post-thaw semen quality or fertility. The CC+TG extender was as robust as conventional egg yolk extender in protecting bovine sperm during cryopreservation. This research was supported by NSERC Canada, the Government of Saskatchewan, and Agriculture and Agri-Food Canada.

Effects of Sub Lethal Concentrations of Sodium Fluoride on Sperm Activity and on the level of Sex Hormones of Adult Male Albino Rats

In recent years, fluorosis caused many problems in humans and animals bodies. Dental fluorosis, skeletal fluorosis, bone fractures, decreased birth rates, adverse effects on the male genital system, like damaging the structure of testes and epididymis and loosing fertilization ability can be considered as good examples of fluorosis. Thus, the current study aimed to determine the toxicity of sodium fluoride (NaF) on the activity of sperm and the level of sex hormones including testosterone, follicle stimulating hormone, and luteinizing hormone. For achieving this purpose, thirty adult albino male rats, aged between 90-100 days, were divided randomly into two treated groups with 10 rats for each group which were treated with 150, 300 ppm of sodium fluoride,respectively. In addition, 10 rats were kept as a control group. Sodium fluoride was offered to the treated groups in the drinking water to evaluate the toxic effect of NaF on male reproductive system, sperm concentration, sperm motion, and sperm velocity compared with control group. The findings revealed a significant decrease in the sperm concentration, sperm count, sperm motion, sperm velocity and the level of sexual hormones in comparison with the control group. It can be concluded that NaF may reduce the efficiency of male reproductive system, and reduce the levels of sexual hormones in rats