Science.gov

Sample records for increased sperm production

  1. Exposure to constant light during testis development increases daily sperm production in adult Wistar rats.

    PubMed

    Rocha, D C; Debeljuk, L; França, L R

    1999-06-01

    Testis histometry and daily sperm production (DSP) were evaluated in adult (160-day-old) Wistar rats exposed to constant light for the first 25 days after birth, and compared with control animals which were exposed to a 12 h-light-12 h-dark light regimen. Significantly greater (P < 0.05) numbers of Sertoli cell nucleoli and round spermatids per cross-section of seminiferous tubule were found in animals exposed to constant light. In addition, epididymis weight, DSP per testis and per gram of testis, as well as Leydig cell compartment volume, were significantly increased in treated animals. Although there was a clear trend toward an increased Sertoli cell population per testis in animals exposed to constant light, this difference was not statistically significant (P < 0.05). The number of round spermatids as expressed per Sertoli cell was the same in both groups. Surprisingly, the diameter and volume of round spermatid nucleus at stages I and VII of the cycle of seminiferous epithelium were significantly lower (P < 0.05) in treated animals. In conclusion, constant illumination during neonatal testis development increased sperm production and Leydig cell compartment volume in adult rats probably through a mechanism involving elevated follicle stimulating hormone and luteinizing hormone during the prepubertal period. To our knowledge, this is the first study showing that altering the light regimen can affect sperm production in non-seasonal breeders.

  2. Inhibition of ROS production through mitochondria-targeted antioxidant and mitochondrial uncoupling increases post-thaw sperm viability in yellow catfish.

    PubMed

    Fang, Lu; Bai, Chenglian; Chen, Yuanhong; Dai, Jun; Xiang, Yang; Ji, Xiaoping; Huang, Changjiang; Dong, Qiaoxiang

    2014-12-01

    Reactive oxygen species (ROS) are one of the main causes for decreased viability in cryopreserved sperm. Many studies have reported the beneficial effect of antioxidant supplements in freezing media for post-thaw sperm quality. In the present study, we explored two new approaches of ROS inhibition in sperm cryopreservation of yellow catfish, namely mitochondrial-targeted antioxidant and metabolic modulator targeting mitochondrial uncoupling pathways. Our study revealed that addition of MitoQ, a compound designed to deliver ubiquinone into mitochondria, significantly decreased ROS production, as well as lipid peroxidation, and increased post-thaw viability. Similarly, sperm incubated with 2,4-dinitrophenol (DNP), a chemical protonophore that induces mitochondrial uncoupling, also had reduced ROS production, as well as lipid peroxidation, and increased post-thaw sperm viability. Conversely, activation of uncoupling protein (UCP2) by 4-hydroxynonenal (HNE) neither reduced ROS production nor increased post-thaw sperm viability. Our findings indicate that ROS inhibition through mitochondrial-targeted antioxidant or mild mitochondrial uncoupling is beneficial for sperm cryopreservation in yellow catfish. Our study provides novel methods to mitigate oxidative stress induced damage in cryopreserved sperm for future applications.

  3. Enhanced early-life nutrition of Holstein bulls increases sperm production potential without decreasing postpubertal semen quality.

    PubMed

    Dance, Alysha; Thundathil, Jacob; Blondin, Patrick; Kastelic, John

    2016-08-01

    Enhanced early-life nutrition (∼130% of required energy and protein) increased testes size and weight (∼20-25%) and reduced age at puberty (∼1 month) in beef and dairy bulls, compared with those fed 70% of dietary requirements. The objective was to determine effects of early-life (2-31 weeks) nutritional modulation on feed costs, predicted number of harvestable sperm and doses of semen, and semen quality. Calves (∼1 week old) were randomly allocated into three groups that were fed 4, 6, or 8 L/day of milk (low [n = 8], medium [n = 9], and high groups [n = 9], respectively) from ages 2 to 8 weeks. Thereafter, they were weaned, transitioned onto barley silage-based diets, to receive ∼70, 100, or 130% of recommended amounts of energy and protein (feed costs were ∼CDN$280 more per bull to feed high versus low diets from 2 to 31 weeks). After 31 weeks, all bulls were fed a medium diet. Semen was collected, by electroejaculation, from 51 to 73 weeks, extended, chilled, and cryopreserved. Bulls fed high nutrition were numerically younger (P = 0.45) at sexual maturity (sperm with ≥30% progressive motility, ≥70% morphologically normal, and ≤20% abnormal heads), first acceptable post-chill sperm motility (>50%; P = 0.66) and first acceptable post-thaw motility (>25% progressive; P = 0.25) than bulls in the low-nutrition group. Semen from three bulls per group was used for in vitro fertilization (total of 1249 bovine oocytes); there were no significant differences among groups in fertilization percentage (mean ± SEM of 68.0 ± 8.7, 77.1 ± 3.5, and 68.7 ± 4.5% for low, medium, and high, respectively) or blastocyst yield (31.5 ± 5.6, 41.4 ± 4.9, and 33.7 ± 4.6%). On the basis of analysis of 2D gels of sperm proteins, 380 spots were identified on the fused master gel, but no spots were differentially expressed across groups. Overall, there were no significant differences in semen quality or sperm function among bulls fed

  4. Reproductive function of the male obese Zucker rats: alteration in sperm production and sperm DNA damage.

    PubMed

    Vendramini, V; Cedenho, A P; Miraglia, S M; Spaine, D M

    2014-02-01

    Obesity has been considered a public health issue in many countries and is of increasing concern for authorities over the past 6 years. The Zucker rat is a good experimental model for obesity and diabetes studies due to its metabolic characteristics that are similar to those developed by humans. A total of 12 obese Zucker rats and their lean littermates were killed in pubertal and young adult phases for assessing organ weights (testis and epididymis), testicular histomorphometric and stereological analyses, daily sperm production, and transit time in the epididymis. Sperm integrity was also investigated in the adult animals using the Comet assay. Alterations in organ weights, seminiferous epithelium architecture, sperm production, and transit time were noticed in the pubertal fatty rats. The volume density of the lymphatic space was decreased in both the ages. Adult animals had a significant increase in the extent of damage found in sperm DNA. Our results show for the first time that leptin receptor deficiency compromises sperm production during puberty and that genetic obese Zucker rats have increased sperm DNA fragmentation.

  5. Processes involved in assisted reproduction technologies significantly increase sperm DNA fragmentation and phosphatidylserine translocation.

    PubMed

    Balasuriya, A; Serhal, P; Doshi, A; Harper, J C

    2014-03-01

    Sperm preparation techniques in assisted reproduction technologies (ART) are potential generators of exogenous stresses that cause additional DNA damage. DNA fragmentation tests, such as the sperm chromatin structure assay, involve freezing sperm samples in the absence of cryoprotectant. Thermal, oxidative stress (OS) and freezing are detrimental to sperm DNA fragmentation and phosphatidylserine (PS) translocation. The primary aim of this study was to subject mature sperm to environmental insults that normally occur during ART. We tested the hypotheses that OS, thermal stress and freeze-thawing caused sperm nuclear and membrane damage and that a positive correlation exists between PS translocation and DNA fragmentation. Sperm DNA integrity deteriorates in semen samples from men with advancing age and a sperm concentration of <15 m ml(-1) . The significant increase in sperm DNA fragmentation at 37 °C after merely 1 h is important clinically as semen liquefaction and short-term sperm storage in an ART cycle involve incubating samples at this temperature. Freezing without a cryoprotectant significantly increases the level of sperm nuclear damage, so it is important not to freeze neat semen prior to DNA fragmentation testing. This study highlights the importance of minimising the production of exogenous stresses during sperm preparation in ART.

  6. Phenotypic engineering of sperm-production rate confirms evolutionary predictions of sperm competition theory

    PubMed Central

    Sekii, Kiyono; Vizoso, Dita B.; Kuales, Georg; De Mulder, Katrien; Ladurner, Peter; Schärer, Lukas

    2013-01-01

    Sperm production is a key male reproductive trait and an important parameter in sperm competition theory. Under sperm competition, paternity success is predicted to depend strongly on male allocation to sperm production. Furthermore, because sperm production is inherently costly, individuals should economize in sperm expenditure, and conditional adjustment of the copulation frequency according to their sperm availability may be expected. However, experimental studies showing effects of sperm production on mating behaviour and paternity success have so far been scarce, mainly because sperm production is difficult to manipulate directly in animals. Here, we used phenotypic engineering to manipulate sperm-production rate, by employing dose-dependent RNA interference (RNAi) of a spermatogenesis-specific gene, macbol1, in the free-living flatworm Macrostomum lignano. We demonstrate (i) that our novel dose-dependent RNAi approach allows us to induce high variability in sperm-production rate; (ii) that a reduced sperm-production rate is associated with a decreased copulation frequency, suggesting conditional adjustment of mating behaviour; and (iii) that both sperm production and copulation frequency are important determinants of paternity success in a competitive situation, as predicted by sperm competition theory. Our study clearly documents the potential of phenotypic engineering via dose-dependent RNAi to test quantitative predictions of evolutionary theory. PMID:23446521

  7. Mass-Specific Metabolic Rate Influences Sperm Performance through Energy Production in Mammals.

    PubMed

    Tourmente, Maximiliano; Roldan, Eduardo R S

    2015-01-01

    Mass-specific metabolic rate, the rate at which organisms consume energy per gram of body weight, is negatively associated with body size in metazoans. As a consequence, small species have higher cellular metabolic rates and are able to process resources at a faster rate than large species. Since mass-specific metabolic rate has been shown to constrain evolution of sperm traits, and most of the metabolic activity of sperm cells relates to ATP production for sperm motility, we hypothesized that mass-specific metabolic rate could influence sperm energetic metabolism at the cellular level if sperm cells maintain the metabolic rate of organisms that generate them. We compared data on sperm straight-line velocity, mass-specific metabolic rate, and sperm ATP content from 40 mammalian species and found that the mass-specific metabolic rate positively influences sperm swimming velocity by (a) an indirect effect of sperm as the result of an increased sperm length, and (b) a direct effect independent of sperm length. In addition, our analyses show that species with higher mass-specific metabolic rate have higher ATP content per sperm and higher concentration of ATP per μm of sperm length, which are positively associated with sperm velocity. In conclusion, our results suggest that species with high mass-specific metabolic rate have been able to evolve both long and fast sperm. Moreover, independently of its effect on the production of larger sperm, the mass-specific metabolic rate is able to influence sperm velocity by increasing sperm ATP content in mammals.

  8. Sound production in neonate sperm whales (L)

    NASA Astrophysics Data System (ADS)

    Madsen, P. T.; Carder, D. A.; Au, W. W. L.; Nachtigall, P. E.; Møhl, B.; Ridgway, S. H.

    2003-06-01

    Acoustic data from two sperm whale neonates (Physeter macrocephalus) in rehabilitation are presented and implications for sound production and function are discussed. The clicks of neonate sperm whale are very different from usual clicks of adult specimens in that neonate clicks are of low directionality [SL anomaly (0°-90°) <8 dB], long duration (2-12 ms), and low frequency (centroid frequency between 300 and 1700 Hz) with estimated SLs between 140 and 162 dB//1 μPa (rms). Such neonate clicks are unsuited for biosonar, but can potentially convey homing information between calves and submerged conspecifics in open ocean waters at ranges of some 2 km. Moreover, it is demonstrated that sperm whale clicks are produced at the anterior placed monkey lips, thereby substantiating a key point in the modified Norris and Harvey theory and supporting the unifying theory of sound production in odontocetes.

  9. Upregulation of uncoupling protein Ucp2 through acute cold exposure increases post-thaw sperm quality in zebrafish.

    PubMed

    Wang, Gongfa; Kang, Ning; Gong, Hongmei; Luo, Yan; Bai, Chenglian; Chen, Yuanhong; Ji, Xiaoping; Huang, Changjiang; Dong, Qiaoxiang

    2015-12-01

    Oxidative stress plays an important role in sperm damage during cryopreservation. Mild mitochondrial uncoupling has been shown to reduce excessive reactive oxygen species (ROS) and thus mitigate oxidative stress. Uncoupling protein (Ucp2) regulates mitochondrial uncoupling and can be induced by temperature fluctuation. In the present study, we explored a novel approach of acute cold exposure on Ucp2 activation and its association with oxidative damage and post-thaw sperm quality in zebrafish. Our study revealed that acute cold exposure of zebrafish at 18 °C for 24 h led to significant increase of ucp2 mRNA and Ucp2 protein in zebrafish fresh sperm as well as thawed sperm after cryopreservation. Although cold exposure had no effect on fresh sperm quality except for decreasing lipid peroxidation, sperm collected from cold-exposed zebrafish exhibited higher resistance to cryodamage, which was demonstrated by increased post-thaw motility, decreased lipid peroxidation, increased ATP production, and ultimately increased fertilization success. However, except for reduced lipid peroxidation, we did not observe any significant ROS reduction associated with increased Ucp2 activation in cold-exposed group, suggesting mechanisms other than mitochondrial uncoupling could have contributed to cold exposure associated benefits in post-thaw sperm survival. Nevertheless, our findings indicate that acute cold exposure prior to sperm cryopreservation is beneficial for post-thaw sperm survival in zebrafish, and this novel approach may be used to improve post-thaw sperm quality for other aquatic species.

  10. Sperm cells as vectors in the production of transgenic animals

    SciTech Connect

    Prince, R.M.

    1993-04-28

    Transgenic animals are used in industry and in biomedical research in order to provide in vivo experimental model systems. Sperm cells have been reported used as vectors in the production of transgenic animals before, however no approach has of yet proven to be successful. Fertilizing eggs with genetically modified sperm would be advantageous in that sperm are readily accessible and stable, and eggs can be fertilized by modified sperm cells in vivo. Recent elucidations regarding the unique manner of DNA packaging in sperm chromatin by protamines has provided us with the insight for developing a method of introducing foreign DNA into sperm which is likely to succeed where others have failed. We have developed a method for mimicking the in vivo system of sperm chromatin toroid subunits in vitro, concentrating these toroids, and fluorescent visualization. Our present work concerns development of a method to successfully deliver DNA across the cell membranes and into the nucleus.

  11. Increased aneuploidy rate in sperm with fragmented DNA as determined by the sperm chromatin dispersion (SCD) test and FISH analysis.

    PubMed

    Muriel, Lourdes; Goyanes, Vicente; Segrelles, Enrique; Gosálvez, Jaime; Alvarez, Juan G; Fernández, José Luis

    2007-01-01

    Previous studies suggest that sperm DNA fragmentation may be associated with aneuploidy. However, currently available tests have not made it possible to simultaneously perform DNA fragmentation and chromosomal analyses on the same sperm cell. The recently introduced sperm chromatin dispersion (SCD) test allows users to determine this relationship. Semen samples from 16 males, including 4 fertile donors, 7 normozoospermic, 3 teratozoospermic, 1 asthenozoospermic, and 1 oligoasthenoteratozoospermic, were processed for DNA fragmentation analysis by the SCD test using the Halosperm kit. Three-color fluorescence in situ hybridization (FISH) was performed on SCD-processed slides to determine aneuploidy for chromosomes X, Y, and 18. Spermatozoa with DNA fragmentation showed a 4.4 +/- 1.9-fold increase in diploidy rate and a 5.9 +/- 3.5-fold increase in disomy rate compared to spermatozoa without DNA fragmentation. The overall aneuploidy rate was 4.6 +/- 2.0-fold higher in sperm with fragmented DNA (Wilcoxon rank test: P < .001 in the 3 comparisons). A higher frequency of DNA fragmentation was found in sperm cells containing sex chromosome aneuploidies originated in both first and second meiotic divisions. The observed increase in aneuploidy rate in sperm with fragmented DNA may suggest that the occurrence of aneuploidy during sperm maturation may lead to sperm DNA fragmentation as part of a genomic screening mechanism developed to genetically inactivate sperm with a defective genomic makeup.

  12. Reactive oxygen species production and antioxidant enzyme activity during epididymal sperm maturation in Corynorhinus mexicanus bats.

    PubMed

    Arenas-Ríos, Edith; Rosado García, Adolfo; Cortés-Barberena, Edith; Königsberg, Mina; Arteaga-Silva, Marcela; Rodríguez-Tobón, Ahiezer; Fuentes-Mascorro, Gisela; León-Galván, Miguel Angel

    2016-03-01

    Prolonged sperm storage in the epididymis of Corynorhinus mexicanus bats after testicular regression has been associated with epididymal sperm maturation in the caudal region, although the precise factors linked with this phenomenon are unknown. The aim of this work is to determine the role of reactive oxygen species (ROS) and changes in antioxidant enzymatic activity occurring in the spermatozoa and epididymal fluid over time, in sperm maturation and storage in the caput, corpus and cauda of the bat epididymis. Our data showed that an increment in ROS production coincided with an increase in superoxide dismutase (SOD) activity in epididymal fluid and with a decrease in glutathione peroxidase (GPX) activity in the spermatozoa in at different time points and epididymal regions. The increase in ROS production was not associated with oxidative damage measured by lipid peroxidation. The results of the current study suggest the existence of a shift in the redox balance, which might be associated with sperm maturation and storage.

  13. Sperm Competition, Sperm Numbers and Sperm Quality in Muroid Rodents

    PubMed Central

    Gómez Montoto, Laura; Magaña, Concepción; Tourmente, Maximiliano; Martín-Coello, Juan; Crespo, Cristina; Luque-Larena, Juan José

    2011-01-01

    Sperm competition favors increases in relative testes mass and production efficiency, and changes in sperm phenotype that result in faster swimming speeds. However, little is known about its effects on traits that contribute to determine the quality of a whole ejaculate (i.e., proportion of motile, viable, morphologically normal and acrosome intact sperm) and that are key determinants of fertilization success. Two competing hypotheses lead to alternative predictions: (a) sperm quantity and quality traits co-evolve under sperm competition because they play complementary roles in determining ejaculate's competitive ability, or (b) energetic constraints force trade-offs between traits depending on their relevance in providing a competitive advantage. We examined relationships between sperm competition levels, sperm quantity, and traits that determine ejaculate quality, in a comparative study of 18 rodent species using phylogenetically controlled analyses. Total sperm numbers were positively correlated to proportions of normal sperm, acrosome integrity and motile sperm; the latter three were also significantly related among themselves, suggesting no trade-offs between traits. In addition, testes mass corrected for body mass (i.e., relative testes mass), showed a strong association with sperm numbers, and positive significant associations with all sperm traits that determine ejaculate quality with the exception of live sperm. An “overall sperm quality” parameter obtained by principal component analysis (which explained 85% of the variance) was more strongly associated with relative testes mass than any individual quality trait. Overall sperm quality was as strongly associated with relative testes mass as sperm numbers. Thus, sperm quality traits improve under sperm competition in an integrated manner suggesting that a combination of all traits is what makes ejaculates more competitive. In evolutionary terms this implies that a complex network of genetic and

  14. Increased sperm ubiquitination correlates with abnormal chromatin integrity.

    PubMed

    Hodjat, M; Akhondi, M A; Al-Hasani, S; Mobaraki, M; Sadeghi, M R

    2008-09-01

    Ubiquitin, a 8.5 kDa peptide that marks other proteins for proteasomal degradation, tags defective spermatozoa during epididymal passage and is proposed as a biomarker for sperm quality. The present study was designed to evaluate the relationships between sperm ubiquitination, sperm chromatin integrity and semen parameters. Semen samples from 63 couples were collected and analysed according to World Health Organization criteria. Each sample was evaluated for sperm ubiquitination by the direct immunofluorescence method, using anti-ubiquitin antibodies. Chromatin integrity of the same samples was analysed using acridine orange (AO) and toluidine blue (TB) tests. A positive correlation was found between ubiquitinated spermatozoa and the percentage of spermatozoa with abnormal chromatin (AO: r = 0.58, P < 0.001 and TB: r = 0.48, P < 0.001). Negative correlations were obtained between sperm ubiquitination and: sperm count (r = -0.2, P = 0.048), sperm morphology (r = -0.36, P = 0.003), rapidly progressive motility (r = -0.25, P = 0.044) and slow progressive motility (r = -0.28, P = 0.022). Sperm ubiquitination was positively correlated with the percentage of immotile spermatozoa. These results show that among semen parameters, chromatin abnormality is more closely associated with sperm ubiquitination and further validate sperm ubiquitination as a suitable marker for sperm quality.

  15. Increases in morphologically abnormal sperm in rats exposed to Co60 irradiation.

    PubMed

    Lock, L F; Soares, E R

    1980-01-01

    We have investigated the effects of testicular exposure to different doses of Co60 radiation on sperm morphology in F-344 rats. The results indicate that from 150 rad to 500 rad gamma irradiation causes statistically significant, dose-related increased in 1) the percent of morphologically aberrant sperm and 2) the frequency of tailless sperm. Both of these effects were detectable in sperm which were derived from treated spermatid, spermatocytes, and spermatogonial cells. These data indicate that the development of a sperm morphology assay in rats is feasible.

  16. Fluorescence In-Situ Hybridization Detects Increased Sperm Aneuploidy in Men with Recurrent Pregnancy Loss

    PubMed Central

    Ramasamy, Ranjith; Scovell, Jason M.; Kovac, Jason R.; Cook, Peter J.; Lamb, Dolores J.; Lipshultz, Larry I.

    2015-01-01

    Objective To investigate, in men presenting with recurrent pregnancy loss (RPL), the prevalence of sperm autosome and sex chromosome aneuploidy. Design Retrospective Study. Setting Male infertility clinic at a tertiary referral center. Patients 140 men with recurrent pregnancy loss provided semen samples and five normozoospermic controls provided 140 semen samples for comparison. RPL, documented in the female partners, was defined as a prior miscarriage and/or recurrent IVF/ICSI failure. Interventions Fluorescent In situ hybridization (FISH) was used to detect numerical abnormalities in sex chromosomes (X,Y) and autosomes (13, 18, 21) in ejaculated sperm. Main Outcome Measures Sperm aneuploidy in men with RPL and normozoospermic controls. Results Men with RPL had a greater percentage of sperm aneuploidy within the sex chromosomes, chromosomes 18 and 13/21 (1.04% vs. 0.38%; 0.18% vs. 0.03%; 0.26% vs. 0.08%). In total, 40% of men with normal sperm density and motility had abnormal sperm aneuploidy in the all the chromosomes analyzed. Men with abnormal sperm density and motility had a higher proportion of sperm sex chromosome aneuploidy than men with normal density/motility (62% vs. 45%). Men with normal strict morphology (>4%) had lower rates of sex chromosome and sperm aneuploidy than men with abnormal strict morphology (28% vs. 57%). There was no association between sperm DNA fragmentation and sperm aneuploidy. Conclusions Men with RPL have increased sperm aneuploidy compared to controls. A total of 40% of men with RPL and normal sperm density/motility had abnormal sperm aneuploidy. Men with oligoasthenozoospermia and abnormal strict morphology had greater percentage of sperm aneuploidy compared to men with normal semen parameters. PMID:25707335

  17. Reduction of centrifugation force in discontinuous percoll gradients increases in vitro fertilization rates without reducing bovine sperm recovery.

    PubMed

    Guimarães, A C G; Leivas, F G; Santos, F W; Schwengber, E B; Giotto, A B; Machado, C I U; Gonçalves, C G M; Folchini, N P; Brum, D S

    2014-05-01

    The objective of this study was to determine the effect of different centrifugation forces in bovine sperm separation by discontinuous Percoll gradients for in vitro fertilization IVF. The semen samples from each bull were pooled or each bull were centrifuged separately and centrifuged in discontinuous Percoll gradients (30, 60 and 90%) at different forces: F1 (9000×g), F2 (6500×g), F3 (4500×g) and F4 (2200×g), according experiment. The sperm samples were evaluated to determine the concentration, motility, vigor, morphology, reactive oxygen species (ROS), integrity of the plasma membrane, lipid peroxidation, antioxidants and embryo development were also evaluated. No difference was observed in the concentration of sperm submitted to different centrifugation forces. The total percentage of motile sperm was increased after centrifugation at F3 and F4, and the ROS production at F1 was greater than the other forces. When the bulls semen were processed individually, no significant differences were observed for the sperm quality parameters between F1 and F4, including lipid peroxidation, antioxidants, cleavage rate and average time to the first cleavage. This work demonstrated for the first time that centrifugation at 2200×g enhanced the sperm penetration and fertilization rates without reducing sperm recovery compared to the typical centrifugation force (9000×g) currently used by the commercial bovine IVF industry.

  18. Concentration-dependent Sildenafil citrate (Viagra) effects on ROS production, energy status, and human sperm function.

    PubMed

    Sousa, Maria Inês; Amaral, Sandra; Tavares, Renata Santos; Paiva, Carla; Ramalho-Santos, João

    2014-04-01

    Literature regarding the effects of sildenafil citrate on sperm function remains controversial. In the present study, we specifically wanted to determine if mitochondrial dysfunction, namely membrane potential, reactive oxygen species production, and changes in energy content, are involved in in vitro sildenafil-induced alterations of human sperm function. Sperm samples of healthy men were incubated in the presence of 0.03, 0.3, and 3 μM sildenafil citrate in a phosphate buffered saline (PBS)-based medium for 2, 3, 12, and 24 hours. Sperm motility and viability were evaluated and mitochondrial function, i.e., mitochondrial membrane potential and mitochondrial superoxide production were assessed using flow-cytometry. Additionally, adenosine triphosphate (ATP) levels were determined by high performance liquid chromatography (HPLC) analysis. Results show a decrease in sperm motility correlated with the level of mitochondria-generated superoxide, without a visible effect on mitochondrial membrane potential or viability upon exposure to sildenafil. The effect on both motility and superoxide production was higher for the intermediate concentration of sildenafil (0.3 µM) indicating that the in vitro effects of sildenafil on human sperm do not vary linearly with drug concentration. Adenosine triphosphate levels also decreased following sildenafil exposure, but this decrease was only detected after a decrease in motility was already evident. These results suggest that along with the level of ATP and mitochondrial function other factors are involved in the early sildenafil-mediated decline in sperm motility. However, the further decrease in ATP levels and increase in mitochondria-generated reactive oxygen species after 24 hours of exposure might further contribute towards declining sperm motility.

  19. Click production during breathing in a sperm whale (Physeter macrocephalus)

    NASA Astrophysics Data System (ADS)

    Wahlberg, Magnus; Frantzis, Alexandros; Alexiadou, Paraskevi; Madsen, Peter T.; Møhl, Bertel

    2005-12-01

    A sperm whale (Physeter macrocephalus) was observed at the surface with above- and underwater video and synchronized underwater sound recordings. During seven instances the whale ventilated its lungs while clicking. From this observation it is inferred that click production is achieved by pressurizing air in the right nasal passage, pneumatically disconnected from the lungs and the left nasal passage, and that air flows anterior through the phonic lips into the distal air sac. The capability of breathing and clicking at the same time is unique among studied odontocetes and relates to the extreme asymmetry of the sperm whale sound-producing forehead.

  20. Advancing age increases sperm chromatin damage and impairs fertility in peroxiredoxin 6 null mice

    PubMed Central

    Ozkosem, Burak; Feinstein, Sheldon I.; Fisher, Aron B.; O’Flaherty, Cristian

    2015-01-01

    Due to socioeconomic factors, more couples are choosing to delay conception than ever. Increasing average maternal and paternal age in developed countries over the past 40 years has raised the question of how aging affects reproductive success of males and females. Since oxidative stress in the male reproductive tract increases with age, we investigated the impact of advanced paternal age on the integrity of sperm nucleus and reproductive success of males by using a Prdx6−/− mouse model. We compared sperm motility, cytoplasmic droplet retention sperm chromatin quality and reproductive outcomes of young (2-month-old), adult (8-month-old), and old (20-month-old) Prdx6−/− males with their age-matched wild type (WT) controls. Absence of PRDX6 caused age-dependent impairment of sperm motility and sperm maturation and increased sperm DNA fragmentation and oxidation as well as decreased sperm DNA compaction and protamination. Litter size, total number of litters and total number of pups per male were significantly lower in Prdx6−/− males compared to WT controls. These abnormal reproductive outcomes were severely affected by age in Prdx6−/− males. In conclusion, the advanced paternal age affects sperm chromatin integrity and fertility more severely in the absence of PRDX6, suggesting a protective role of PRDX6 in age-associated decline in the sperm quality and fertility in mice. PMID:25796034

  1. First Production of Larvae Using Cryopreserved Sperm: Effects of Preservation Temperature and Cryopreservation on European Eel Sperm Fertilization Capacity.

    PubMed

    Asturiano, J F; Sørensen, S R; Pérez, L; Lauesen, P; Tomkiewicz, J

    2016-08-01

    Sperm cryopreservation is a useful tool in captive fish reproduction management, that is to synchronize gamete production, especially in the case of species as the European eel, where the time of female spawning readiness is unpredictable. Several protocols to cryopreserve sperm of this species have been described, but until recently fertilization trials were not feasible. This study evaluated the effect of cold storage of diluted sperm prior to fertilizations and tested whether a previously defined protocol for European eel sperm cryopreservation can be successfully applied in fertilization trials to produce viable offspring. In our experiment, the sperm motility was evaluated after the extraction and the best samples were selected and pooled. Until stripping of eggs and fertilization, diluted sperm samples were maintained at either 4 or 20°C, or cryopreserved, following existing protocols. Fertilization of two egg batches was attempted. Diluted sperm caused a similar percentage of fertilized eggs and a similar number of embryos and larvae, independently of storage temperature (4 or 20°C). The cryopreserved sperm resulted in a lower percentage of fertilized eggs, but embryos developed and a few larvae ('cryolarvae') were obtained 55 h after fertilization in one of the two egg batches. This result evidences that the tested cryopreservation protocol is applicable for eel reproduction management, although improvements will be required to enhance fertilization success.

  2. Sperm Cryopreservation in Live-Bearing Xiphophorus Fishes: Offspring Production from Xiphophorus variatus and Strategies for Establishment of Sperm Repositories

    PubMed Central

    Cuevas-Uribe, Rafael; Savage, Markita G.; Walter, Ronald B.; Tiersch, Terrence R.

    2012-01-01

    Abstract Cryopreservation of sperm from Xiphophorus fishes has produced live young in three species: X. hellerii, X. couchianus, and X. maculatus. In this study, the goal was to establish protocols for sperm cryopreservation and artificial insemination to produce live young in X. variatus, and to identify needs for repository development. The objectives were to: 1) collect basic biological characteristics of males; 2) cryopreserve sperm from X. variatus, 3) harvest live young from cryopreserved sperm, and 4) discuss the requirements for establishment of sperm repositories. The 35 males used in this study had a body weight of 0.298±0.096 g (mean±SD), body length of 2.5±0.2 cm, and testis weight of 6.4±3.4 mg. The sperm production per gram of testis was 2.33±1.32×109 cells. After freezing, the post-thaw motility decreased significantly to 37%±17% (ranging from 5% to 70%) (p=0.000) from 57%±14% (40%–80%) of fresh sperm (N=20). Artificial insemination of post-thaw sperm produced confirmed offspring from females of X. hellerii and X. variatus. This research, taken together with previous studies, provides a foundation for development of strategies for sperm repositories of Xiphophorus fishes. This includes: 1) the need for breeding strategies for regeneration of target populations, 2) identification of minimum fertilization capacity of frozen samples, 3) identification of fish numbers necessary for sampling and their genetic relationships, 4) selection of packaging containers for labeling and biosecurity, 5) assurance of quality control and standardization of procedures, 6) information systems that can manage the data associated with cryopreserved samples, including the genetic data, 7) biological data of sampled fish, 8) inventory data associated with frozen samples, and 9) data linking germplasm samples with other related materials such as body tissues or cells saved for DNA and RNA analyses. PMID:22924335

  3. Polychlorinated biphenyls and dibenzofurans increased abnormal sperm morphology without alterations in aneuploidy: The Yucheng study.

    PubMed

    Hsu, Ping-Chi; Li, Ming-Chieh; Lee, Yeu-Chin; Kuo, Pao-Lin; Guo, Yueliang Leon

    2016-12-01

    In 1979, more than 2000 persons ingested rice oil contaminated with polychlorinated biphenyls and polychlorinated dibenzofurans; this event was called the "Yucheng accident." An increased percentage of oligospermia, reduced ability of sperm to penetrate oocytes, and reduced percentage of male offspring were reported in Yucheng men. This study examined whether the sperm sex ratio and chromosome aneuploidy are responsible for our observed findings in Yucheng men. In 1999-2000, Yucheng men and their neighborhood referents aged 37-50 years were recruited for physical examination, followed by semen analysis. The semen samples were analyzed for chromosomal aneuploidy through fluorescent in situ hybridization according to an established procedure in our laboratory. A total of 50 Yucheng men and 34 neighborhood referents volunteered to participate in the study. Although abnormal morphology was mildly increased, no differences were observed in sperm percentages, with normal numbers of chromosomes X, Y, and 8 in the two groups. The percentage of sperm with aneuploidy of the sex chromosomes or chromosome 8 and of that with diploidy did not vary between both groups. The normal X/Y sperm ratio was not different between the groups. However, among Yucheng men, 8% had a normal X/Y sperm ratio of >1.4, and no neighborhood referent showed such an elevated X/Y ratio. Chromosomal aneuploidy was not elevated in Yucheng men. The mechanisms underlying the reduced sperm capability of oocyte penetration and changed offspring sex ratio in Yucheng men remain undetermined.

  4. Cholesterol-Loaded Cyclodextrin Increases the Cholesterol Content of Goat Sperm to Improve Cold and Osmotic Resistance and Maintain Sperm Function after Cryopreservation.

    PubMed

    Salmon, Vianney M; Leclerc, Pierre; Bailey, Janice L

    2016-04-01

    The success of semen cryopreservation depends on sperm membrane integrity and function after thawing. Cholesterol-loaded cyclodextrin (CLC) is used for in vitro incorporation of cholesterol to protect cells against cold temperatures. We hypothesized that CLC treatment also enhances sperm cholesterol content to increase tolerance to osmotic shock and cryoresistance, thereby improving fertility. We confirmed the fact that treatment of goat semen with 3 mg/ml CLC increases sperm cholesterol content using both the Liebermann-Burchard approach and filipin III labeling of membrane cholesterol. Sperm were then treated with or without CLC and cryopreserved. After thawing, sperm cholesterol dramatically fell, even in the presence of CLC, which explains the mechanism of cryocapacitation. CLC treatment, however, maintained a normal prefreeze cholesterol level in sperm after cryopreservation. Furthermore, fresh sperm treated with CLC and subjected to either cold shock or incubated in hypo-, iso-, and hyperosmotic media, designed to mimic stresses associated with freezing/thawing, displayed increased temperature and osmotic tolerance. CLC treatment also improved sperm viability, motility, and acrosome integrity after thawing. Furthermore, CLC treatment did not affect the sperm's ability to undergo in vitro capacitation according to chlortetracycline fluorescence and protein tyrosine phosphorylation. A pilot field trial demonstrated that artificial insemination with sperm that underwent increased cholesterol levels following CLC treatment yielded higher fertility ( ITALIC! P< 0.1) and proliferation ( ITALIC! P< 0.05) rates in vivo than untreated semen from the same ejaculate samples. These observations suggest that CLC treatment could be used to improve cryoprotection during the freezing and thawing of goat sperm.

  5. Partial and total fish meal replacement by agricultural products in the diets improve sperm quality in African catfish (Clarias gariepinus).

    PubMed

    Nyina-Wamwiza, L; Milla, S; Pierrard, M-A; Rurangwa, E; Mandiki, S N M; Van Look, K J W; Kestemont, P

    2012-01-01

    This study investigated the long-term effects of total and partial replacement of dietary fish meal (FM) by a mixture of agricultural products on sperm quality of African catfish Clarias gariepinus. Four isonitrogenous and isoenergetic diets were formulated containing graded levels of either 50% FM and maize meal (diet 1); 25% FM mixed with crude sunflower oil cake (SFOC) and bean meal (BM) (diet 2); 12.5% FM mixed with sunflower oil cake, BM and ground nut oil cake (GOC) (diet 3) and 0% FM mixed with de-hulled sunflower oil cake (SFOCD), BM and ground nut oil cake (diet 4). Gonadosomatic index (GSI), sperm quality, plasma sex steroids (11-keto testosterone [11-KT]; testosterone [T]; estradiol-17beta [E2]) were evaluated on 10 to 24 fish fed on each diet. Sperm quality was assessed using computer-assisted sperm analysis (CASA). Total replacement of fish meal by plant products markedly increased sperm volume, spermatocrit, spermatozoa integrity, and sperm motility. Fish fed diet 3 (12.5% fish meal) provided intermediate results on sperm quality whereas the lowest values were obtained in fish fed diets 1 and 2. In fish fed 0% fish meal (diet 4), androgen levels were higher and estrogen levels were lower than in fish fed fish meal diets. Based on dietary lipid and fatty acid analyses, these results suggest a positive impact of short chain n-6 fatty acids on androgen synthesis and sperm quality. In conclusion, a combination of ground nut oil cake, bean meal and sunflower oil cake (preferably when the sunflower is dehulled) in African catfish diet improves the sperm quality.

  6. Increasing productivity: Another approach

    SciTech Connect

    Norton, F.J.

    1996-06-10

    An engineering information (EI) and information technology (IT) organization that must improve its productivity should work to further its business goals. This paper explores a comprehensive model for increasing EI/IT productivity by supporting organizational objectives.

  7. Reduced metabolic rate and oxygen radicals production in stored insect sperm.

    PubMed

    Ribou, Anne-Cécile; Reinhardt, Klaus

    2012-06-07

    Females of internally fertilizing species can significantly extend sperm lifespan and functionality during sperm storage. The mechanisms for such delayed cellular senescence remain unknown. Here, we apply current hypotheses of cellular senescence developed for diploid cells to sperm cells, and empirically test opposing predictions on the relationship between sperm metabolic rate and oxygen radical production in an insect model, the cricket Gryllus bimaculatus. Using time-resolved microfluorimetry, we found a negative correlation between metabolic rate (proportion of protein-bound NAD[P]H) and in situ intracellular oxygen radicals production in freshly ejaculated sperm. In contrast, sperm stored by females for periods of 1 h to 26 days showed a positive correlation between metabolic rate and oxygen radicals production. At the same time, stored sperm showed a 37 per cent reduced metabolic rate, and 42 per cent reduced reactive oxygen species (ROS) production, compared with freshly ejaculated sperm. Rank differences between males in ROS production and metabolic rate observed in ejaculated sperm did not predict rank differences in stored sperm. Our method of simultaneously measuring ROS production and metabolic rate of the same sample has the advantage of providing data that are independent of sperm density and any extracellular antioxidants that are proteins. Our method also excludes effects owing to accumulated hydrogen peroxide. Our results unify aspects of competing theories of cellular ageing and suggest that reducing metabolic rate may be an important means of extending stored sperm lifespan and functionality in crickets. Our data also provide a possible explanation for why traits of ejaculates sampled from the male may be rather poor predictors of paternity in sexual selection studies and likelihood of pregnancy in reproductive medicine.

  8. Organophosphorous pesticide exposure increases the frequency of sperm sex null aneuploidy.

    PubMed Central

    Recio, R; Robbins, W A; Borja-Aburto, V; Morán-Martínez, J; Froines, J R; Hernández, R M; Cebrián, M E

    2001-01-01

    It has been estimated that 4 of 1,000 live births and 35% of spontaneous abortions are aneuploid and that an important proportion of embryo and newborn aneuploidy is of paternal origin. Exposure to organophosphorous pesticides (OP) has been associated with sperm hyperploidy/polyploidy. Therefore, we aimed to assess the frequency of sperm aneuploidy (X, Y, and 18) and its relationship with urinary OP metabolites in agricultural workers. We performed multicolor fluorescence in situ hybridization on samples from nine men obtained before and during the pesticide spraying season to assess sperm aneuploidy. We measured urinary OP metabolite levels by gas-liquid chromatography. Aneuploidies were found in 0.67% of total sperm nuclei. The most frequent aneuploidy was the lack of a sexual chromosome or sex null (0.19%), followed by XY18 (0.15%) and XY18-18 (0.06%). OP metabolites detected at higher concentrations were dimethylthiophosphate, dimethyldithiophosphate, and diethylphosphate (DEP). There were no differences in average aneuploidy frequency or urinary metabolite levels between samples collected before and after exposure. However, Poisson regression analysis adjusted for age, alcohol intake, and sperm concentration showed significant associations between OP metabolite concentrations and increased frequency of sperm aneuploidies. The association was more evident between DEP and sex null, and the risk increased further during the spraying season. Thus, OP exposure could interfere with sperm chromosome segregation and increase the risk for genetic syndromes, such as Turner's. Further studies are required to assess the prevalence of spontaneous abortions, birth defects, and genetic syndromes in agricultural communities. PMID:11748030

  9. Addition of D-penicillamine, hypotaurine, and epinephrine (PHE) mixture to IVF medium maintains motility and longevity of bovine sperm and enhances stable production of blastocysts in vitro.

    PubMed

    Kang, Sung-Sik; Koyama, Keisuke; Huang, Weiping; Yang, Yinghua; Yanagawa, Yojiro; Takahashi, Yoshiyuki; Nagano, Masashi

    2015-01-01

    The present study aimed to establish an efficient system for bovine embryo production by in vitro fertilization (IVF) that can achieve stable normal fertilization and blastocyst developmental rates in any bull without optimization of the sperm concentration in IVF medium. We examined the effects of a PHE mixture (20 μM D-penicillamine, 10 μM hypotaurine and 1 μM epinephrine), theophylline (2.5 mM), and sperm concentration (1, 2 or 5 × 10(6) cells/ml) on fertilization and blastocyst developmental rates. High cleavage rates (78.3 to 92.4%) and blastocyst developmental rates (31.9 to 62.0%) at day 7 were obtained in the presence of PHE and theophylline in IVF medium with a sperm concentration of 2 × 10(6) cells/ml using sperm from 9 bulls. In addition, the synergistic effect of PHE and theophylline on normal fertilization (2 pronuclei) was clarified at 12 h after IVF with a sperm concentration of 1 × 10(6) cells/ml. Moreover, high linearity, high flagellar beat cross frequency, and low amplitude of lateral head of motile sperm were found by computer-assisted sperm analysis. In conclusion, the combination of the PHE mixture and theophylline synergistically accelerates sperm motility and sperm penetration of bovine oocytes. Theophylline activates sperm motility with increasing intracellular cAMP. However, PHE prevents an excessive increase of cAMP and maintains sperm motility without hyperactivation. When the combination of PHE and theophylline is added to IVF medium at a sperm concentration of 2 × 10(6) cells/ml, we can achieve stable normal fertilization and blastocyst development in any bull.

  10. Addition of D-penicillamine, hypotaurine, and epinephrine (PHE) mixture to IVF medium maintains motility and longevity of bovine sperm and enhances stable production of blastocysts in vitro

    PubMed Central

    KANG, Sung-Sik; KOYAMA, Keisuke; HUANG, Weiping; YANG, Yinghua; YANAGAWA, Yojiro; TAKAHASHI, Yoshiyuki; NAGANO, Masashi

    2014-01-01

    The present study aimed to establish an efficient system for bovine embryo production by in vitro fertilization (IVF) that can achieve stable normal fertilization and blastocyst developmental rates in any bull without optimization of the sperm concentration in IVF medium. We examined the effects of a PHE mixture (20 μM D-penicillamine, 10 μM hypotaurine and 1 μM epinephrine), theophylline (2.5 mM), and sperm concentration (1, 2 or 5 × 106 cells/ml) on fertilization and blastocyst developmental rates. High cleavage rates (78.3 to 92.4%) and blastocyst developmental rates (31.9 to 62.0%) at day 7 were obtained in the presence of PHE and theophylline in IVF medium with a sperm concentration of 2 × 106 cells/ml using sperm from 9 bulls. In addition, the synergistic effect of PHE and theophylline on normal fertilization (2 pronuclei) was clarified at 12 h after IVF with a sperm concentration of 1 × 106 cells/ml. Moreover, high linearity, high flagellar beat cross frequency, and low amplitude of lateral head of motile sperm were found by computer-assisted sperm analysis. In conclusion, the combination of the PHE mixture and theophylline synergistically accelerates sperm motility and sperm penetration of bovine oocytes. Theophylline activates sperm motility with increasing intracellular cAMP. However, PHE prevents an excessive increase of cAMP and maintains sperm motility without hyperactivation. When the combination of PHE and theophylline is added to IVF medium at a sperm concentration of 2 × 106 cells/ml, we can achieve stable normal fertilization and blastocyst development in any bull. PMID:25501343

  11. A Specific Transitory Increase in Intracellular Calcium Induced by Progesterone Promotes Acrosomal Exocytosis in Mouse Sperm.

    PubMed

    Romarowski, Ana; Sánchez-Cárdenas, Claudia; Ramírez-Gómez, Héctor V; Puga Molina, Lis del C; Treviño, Claudia L; Hernández-Cruz, Arturo; Darszon, Alberto; Buffone, Mariano G

    2016-03-01

    During capacitation, sperm acquire the ability to undergo the acrosome reaction (AR), an essential step in fertilization. Progesterone produced by cumulus cells has been associated with various physiological processes in sperm, including stimulation of AR. An increase in intracellular Ca(2+) ([Ca(2+)]i) is necessary for AR to occur. In this study, we investigated the spatiotemporal correlation between the changes in [Ca(2+)]i and AR in single mouse spermatozoa in response to progesterone. We found that progesterone stimulates an [Ca(2+)]i increase in five different patterns: gradual increase, oscillatory, late transitory, immediate transitory, and sustained. We also observed that the [Ca(2+)]i increase promoted by progesterone starts at either the flagellum or the head. We validated the use of FM4-64 as an indicator for the occurrence of the AR by simultaneously detecting its fluorescence increase and the loss of EGFP in transgenic EGFPAcr sperm. For the first time, we have simultaneously visualized the rise in [Ca(2+)]i and the process of exocytosis in response to progesterone and found that only a specific transitory increase in [Ca(2+)]i originating in the sperm head promotes the initiation of AR.

  12. Disruption of Maternal DNA Repair Increases Sperm-DerivedChromosomal Aberrations

    SciTech Connect

    Marchetti, Francesco; Essers, Jeroun; Kanaar, Roland; Wyrobek,Andrew J.

    2007-02-07

    The final weeks of male germ cell differentiation occur in aDNA repair-deficient environment and normal development depends on theability of the egg to repair DNA damage in the fertilizing sperm. Geneticdisruption of maternal DNA double-strand break repair pathways in micesignificantly increased the frequency of zygotes with chromosomalstructural aberrations after paternal exposure to ionizing radiation.These findings demonstrate that radiation-induced DNA sperm lesions arerepaired after fertilization by maternal factors and suggest that geneticvariation in maternal DNA repair can modulate the risk of early pregnancylosses and of children with chromosomal aberrations of paternalorigin.

  13. Current status of plant products reported to inhibit sperm.

    PubMed

    Farnsworth, N R; Waller, D P

    1982-06-01

    This report reviews research on plant-derived agents that prevent sperm production if taken orally by the male or that incapacitate or kill sperm on contact if used vaginally by the female. It would be of great value to develop fertility inhibitors that are totally selective for reproductive systems and enzymes, and there is a possibility that a plant-derived drug may have this effect. Plants that have been studied for their fertility inhibiting effects in the male include: Aristolochia indica L. (Aristolochiaceae); Azadirachta indica A. Juss (Meliaceae); Balanites roxburghii Planch. (Zygophyllaceae); Calotropis procera (Ait) R.Br. (Asclepiadaceae); Carica papaya L. (Caricaceae); Catharanthus roseus (L.) G. Don (Apocynaceae); Dieffenbachia seguine (Jacquin) Schott. (Araceae); Ecaballium elaterium A. Richard (Cucurbitaceae); Gossypium species (Malvaceae); Hibiscus rosa-sinensis L. (Malvaceae); Hippophae salicifolia D. Don (Elaeagnaceae); Leucaena glauca (L.) Benth. (Leguminosae); Lonicera ciliosa Poir. (Caprifoliaceae); Lupinus termis Forsk. (Leguminosae); Malvaviscus conzattii Greenm. (Malvaceae); Momordica charantia L. (Curcurbitaceae); Ocimum sanctum L. (Labiatae); Prunus emarginata Walp. (Rosaceae); and Withania somnifera (L.) Dunal (Solanaceae). A large number of plants have been randomly selected and screened for spermicidal activity "in vitro" and several seem promising. Those species found to be active and the nature of the active principle(s), when known, are presented in a table as are plant-derived chemical substances of known or partially known structure reported to be spermicidal "in vitro." Plants warrant systematic study as potential sources of sperm-agglutinating compounds. Of 1600 Indian plants tested, 90 showed positive semen coagulating properties. There seems to be a lack of correlation among experimental results obtained by different groups of investigators, between data obtained "in vitro" and "in vivo," and between experimental results and

  14. Sperm competition and the evolution of precopulatory weapons: Increasing male density promotes sperm competition and reduces selection on arm strength in a chorusing frog.

    PubMed

    Buzatto, Bruno A; Roberts, J Dale; Simmons, Leigh W

    2015-10-01

    Sperm competition theory assumes a trade-off between precopulatory traits that increase mating success and postcopulatory traits that increase fertilization success. Predictions for how sperm competition might affect male expenditure on these traits depend on the number of competing males, the advantage gained from expenditure on weapons, and the level of sperm competition. However, empirical tests of sperm competition theory rarely examine precopulatory male expenditure. We investigated how variation in male density affects precopulatory sexual selection on male weaponry and the level of sperm competition in the chorusing frog Crinia georgiana, where males use their arms as weapons in male-male combat. We measured body size and arm girth of 439 males, and recorded their mating success in the field. We found density-dependent selection acting on arm girth. Arm girth was positively associated with mating success, but only at low population densities. Increased male density was associated with higher risk and intensity of sperm competition arising from multimale amplexus, and a reversal in the direction of selection on arm girth. Opposing patterns of pre- and postcopulatory selection may account for the negative covariation between arm girth and testes across populations of this species.

  15. Reactive oxygen species production and redox state in parthenogenetic and sperm-mediated bovine oocyte activation.

    PubMed

    Morado, S; Cetica, P; Beconi, M; Thompson, J G; Dalvit, G

    2013-05-01

    The knowledge concerning redox and reactive oxygen species (ROS)-mediated regulation of early embryo development is scarce and remains controversial. The aim of this work was to determine ROS production and redox state during early in vitro embryo development in sperm-mediated and parthenogenetic activation of bovine oocytes. Sperm-mediated oocyte activation was carried out in IVF-modified synthetic oviductal fluid (mSOF) with frozen-thawed semen. Parthenogenetic activation was performed in TALP plus ionomycin and then in IVF-mSOF with 6-dimethylaminopurine plus cytochalasin B. Embryos were cultured in IVF-mSOF. ROS and redox state were determined at each 2-h interval (7-24 h from activation) by 2',7'-dichlorodihydrofluorescein diacetate and RedoxSensor Red CC-1 fluorochromes respectively. ROS levels and redox state differed between activated and non-activated oocytes (P<0.05 by ANOVA). In sperm-activated oocytes, an increase was observed between 15 and 19 h (P<0.05). Conversely, in parthenogenetically activated oocytes, we observed a decrease at 9 h (P<0.05). In sperm-activated oocytes, ROS fluctuated throughout the 24 h, presenting peaks around 7, 19, and 24 h (P<0.05), while in parthenogenetic activation, peaks were detected at 7, 11, and 17 h (P<0.05). In the present work, we found clear distinctive metabolic patterns between normal and parthenogenetic zygotes. Oxidative activity and ROS production are an integral part of bovine zygote behavior, and defining a temporal pattern of change may be linked with developmental competence.

  16. Ameliorative effect of quercetin against arsenic-induced sperm DNA damage and daily sperm production in adult male rats.

    PubMed

    Jahan, Sarwat; Rehman, Saima; Ullah, Hizb; Munawar, Asma; Ain, Qurat Ul; Iqbal, Tariq

    2016-01-01

    In this study, the protective effect of quercetin was evaluated against arsenic induced reproductive ailments in male rats. For this purpose, male rats (n = 5/group) weighing 180-250 g were used. First group served as control, second group received arsenic (50 ppm) in drinking water. Third group was treated with quercetin (50 mg/kg) alone, while fourth group received arsenic + quercetin. All treatments were carried out for 49 days. After treatment, animals were killed by decapitation; testis and epididymis were dissected out. Right epididymis was minced immediately for comet assay, while left epididymis was processed for histology. Similarly, right testis was homogenized for estimation of daily sperm production (DSP) and detection of metal concentration. The results of our research revealed that arsenic treatment did not cause any significant change in body weight and testicular volume. Quercetin treatment significantly prevented tissue deposition of arsenic within the testis. Arsenic treatment caused a significant reduction in DSP, however, in the arsenic + quercetin-treated group and quercetin alone-treated group, DSP was significantly high as compared to the arsenic-treated group. Histological study of epididymis showed empty lumen in arsenic-treated group while in arsenic + quercetin-treated group and quercetin alone-treated group, lumen were filled with sperm and were comparable to control. Sperm DNA damage, induced by arsenic, was significantly reversed toward control levels by supplementation of quercetin. These results suggest that quercetin not only prevents deposition of arsenic in tissues, but can also protect the sperm DNA damage.

  17. Decreased activity of superoxide dismutase in the seminal plasma of infertile men correlates with increased sperm deoxyribonucleic acid fragmentation during the first hours after sperm donation.

    PubMed

    Wdowiak, Artur; Bakalczuk, Szymon; Bakalczuk, Grzegorz

    2015-07-01

    Sperm DNA fragmentation varies between individuals and is more pronounced with increased patient age and time after sperm donation. The intensification of DNA fragmentation depends on the balance of the oxidoreductive system, which is regulated mainly by two enzymes - superoxide dismutase (SOD) and catalase. The objective of this study was to determine the relationship between sperm DNA fragmentation dynamics, fertility and seminal SOD and catalase activity. The study was conducted in 2013 and 2014 at the Non-Public Health Care Unit 'Ovum Reproduction and Andrology' in Lublin, Lublin, Poland, and covered 218 men aged 25-35 (85 fertile and 133 patients treated for infertility). Percentage of fragmented DNA was measured in a modified chromatin dispersion test at four time points after sperm donation (t = 0, 3, 6, 12 h). SOD and catalase activities were determined spectrophotometrically. We confirmed that the activity of SOD in the seminal plasma of men with reproductive disorders was lower compared with fertile men. Conversely, no significant correlations were found between fertility and catalase activity. Sperm DNA of infertile males was initially more fragmented than fertile male sperm DNA. SOD and catalase activity did not correlate with the degree of DNA fragmentation in fertile men. In men with reproductive disorders, the rate of DNA fragmentation was slow within first 3 h after sperm donation and then increased between 6 and 12 h. In this group of infertile men, those with higher SOD activity had a lower DNA fragmentation index (DFI) after 12 h, and a reduced rate of intensity of fragmentation from 6 to 12 h. Alternatively, higher catalase activity among men treated for infertility was accompanied by higher initial DFI and higher rate of DNA fragmentation from 6 to 12 h. These results highlight the importance of determining a proper time window between sperm donation and procedures of assisted reproductive technology.

  18. Productivity increases in science

    SciTech Connect

    Danko, J.E.; Young, J.K.; Molton, P.M.; Dirks, J.A.

    1993-02-01

    The study quantifies the impact on the cost of experimentation of synergistic advancements in instrumentation, theory, and computation over the last two decades. The study finds that the productivity of experimental investigation (experimental results/$) is increasing as science is transformed from a linear, isolated approach to a hierarchical, multidisciplinary approach. Developments such as massively parallel processors coupled with instrumental systems with multiple probes and diverse data analysis capabilities will further this transformation and increase the productivity of scientific studies. The complexities and scale of today's scientific challenges are much greater than in the past, however, so that the costs of research are increasing. Even though science is much more productive in terms of the experimental results, the challenges facing scientific investigators are increasing at an even faster pace. New approaches to infrastructure investments must capitalize on the changing dynamics of research and allow the scientific community to maximize gains in productivity so that complex problems can be attacked cost-effectively. Research strategies that include user facilities and coordinated experimental, computational, and theoretical research are needed.

  19. Productivity increases in science

    SciTech Connect

    Danko, J.E.; Young, J.K.; Molton, P.M.; Dirks, J.A.

    1993-02-01

    The study quantifies the impact on the cost of experimentation of synergistic advancements in instrumentation, theory, and computation over the last two decades. The study finds that the productivity of experimental investigation (experimental results/$) is increasing as science is transformed from a linear, isolated approach to a hierarchical, multidisciplinary approach. Developments such as massively parallel processors coupled with instrumental systems with multiple probes and diverse data analysis capabilities will further this transformation and increase the productivity of scientific studies. The complexities and scale of today`s scientific challenges are much greater than in the past, however, so that the costs of research are increasing. Even though science is much more productive in terms of the experimental results, the challenges facing scientific investigators are increasing at an even faster pace. New approaches to infrastructure investments must capitalize on the changing dynamics of research and allow the scientific community to maximize gains in productivity so that complex problems can be attacked cost-effectively. Research strategies that include user facilities and coordinated experimental, computational, and theoretical research are needed.

  20. The relationship of increased susceptibility of sperm DNA to denaturation and fertility in the stallion.

    PubMed

    Love, C C; Kenney, R M

    1998-10-15

    The relationship between fertility and susceptibility of sperm DNA to denaturation was determined in a group of 84 actively breeding, clinically fertile stallions. Susceptibility of DNA to denaturation was determined using the sperm chromatin structure assay (SCSA). The SCSA measures, mean of alpha-t (mean alpha t), standard deviation of alpha-t (SD alpha t), and the COMP of alpha-t (cells outside the main population)] were significantly correlated with the percentage seasonal pregnancy rate (SPR; mean alpha t, r = -0.24, P < or = 0.05; % COMP alpha t, r = -0.27, P < or = 0.05); percentage pregnant per first cycle (FCP; SD alpha t, r = -0.30, P < or = 0.01; % COMP alpha t, r = -0.42, P < or = 0.0001); and the percentage pregnant per cycle (PC; mean alpha t, r = -0.31, P < or = 0.01; SD alpha t, r = -0.32, P < or = 0.01; % COMP alpha t, r = -0.41, P < or = 0.0001). This study describes detectable intrinsic variation in sperm chromatin structure among fertile stallions (SPR, mean = 83%; FCP, mean = 58%; PC, mean = 57%) in an active breeding population (number of mares bred/stallion/year, mean = 37), in the absence of overt reproductive abnormalities and apparent diseases such that an increase in the susceptibility of sperm DNA to denaturation is associated with reduced fertility, both in terms of efficiency of reproduction (FCP and PC) and seasonal pregnancy rate (SPR). Both COMP alpha t and mean alpha t were useful indicators of fertility, with COMP alpha t being the only SCSA value able to identify mean differences between fertility groupings for SPR and FCP, and overall it was the most reliable indicator of fertility in this group of stallions. The SCSA is able to evaluate a compartment of the spermatozoa which is different from that of traditional tests for sperm quality such as motility and morphology.

  1. Testes Mass, but Not Sperm Length, Increases with Higher Levels of Polyandry in an Ancient Sex Model

    PubMed Central

    Vrech, David E.; Olivero, Paola A.; Mattoni, Camilo I.; Peretti, Alfredo V.

    2014-01-01

    There is strong evidence that polyandrous taxa have evolved relatively larger testes than monogamous relatives. Sperm size may either increase or decrease across species with the risk or intensity of sperm competition. Scorpions represent an ancient direct mode with spermatophore-mediated sperm transfer and are particularly well suited for studies in sperm competition. This work aims to analyze for the first time the variables affecting testes mass, ejaculate volume and sperm length, according with their levels of polyandry, in species belonging to the Neotropical family Bothriuridae. Variables influencing testes mass and sperm length were obtained by model selection analysis using corrected Akaike Information Criterion. Testes mass varied greatly among the seven species analyzed, ranging from 1.6±1.1 mg in Timogenes dorbignyi to 16.3±4.5 mg in Brachistosternus pentheri with an average of 8.4±5.0 mg in all the species. The relationship between testes mass and body mass was not significant. Body allocation in testes mass, taken as Gonadosomatic Index, was high in Bothriurus cordubensis and Brachistosternus ferrugineus and low in Timogenes species. The best-fitting model for testes mass considered only polyandry as predictor with a positive influence. Model selection showed that body mass influenced sperm length negatively but after correcting for body mass, none of the variables analyzed explained sperm length. Both body mass and testes mass influenced spermatophore volume positively. There was a strong phylogenetic effect on the model containing testes mass. As predicted by the sperm competition theory and according to what happens in other arthropods, testes mass increased in species with higher levels of sperm competition, and influenced positively spermatophore volume, but data was not conclusive for sperm length. PMID:24736525

  2. A Review of New Technologies that may Become Useful for in vitro Production of Boar Sperm.

    PubMed

    Gadella, B M; Ferraz, M A

    2015-07-01

    Making sperm cells outside the original testicular environment in a culture dish has been considered for a long time as impossible due to the very complicated process of spermatogenesis and sperm maturation, which altogether, encompasses a 2-month period. However, new approaches in complex three-dimensional co-cell cultures, micro-perfusion and micro-fluidics technologies, new knowledge in the functioning, culturing and differentiation of spermatogonial stem cells (SSC) and their precursor cells have revolutionized this field. Furthermore, the use of better molecular markers as well as stimulatory factors has led to successful in vitro culture of stem cells either derived from germ line stem cells, from induced pluripotent stem cells (iPSC) or from embryonic stem cells (ESC). These stem cells when placed into small seminiferous tubule fragments are able to become SSC. The SSC beyond self-renewal can also be induced into haploid sperm-like cells under in vitro conditions. In mouse, this in vitro produced sperm can be injected into a mature oocyte and allow post-fertilization development into an early embryo in vitro. After transferring such obtained embryos into the uterus of a recipient mouse, they can further develop into healthy offspring. Recently, a similar approach has been performed with combining selected cells from testicular cell suspensions followed by a complete in vitro culture of seminiferous cords producing sperm-like cells. However, most of the techniques developed are laborious, time-consuming and have low efficiency, placing questionable that it will become useful used for setting up an efficient in vitro sperm production system for the boar. The benefits and drawbacks as well as the likeliness of in vitro pig sperm production to become applied in assisted technologies for swine reproduction are critically discussed. In this contribution, also the process of sperm production in the testis and sperm maturation is reviewed.

  3. Sperm wars and the evolution of male fertility.

    PubMed

    Simmons, Leigh W; Fitzpatrick, John L

    2012-11-01

    Females frequently mate with several males, whose sperm then compete to fertilize available ova. Sperm competition represents a potent selective force that is expected to shape male expenditure on the ejaculate. Here, we review empirical data that illustrate the evolutionary consequences of sperm competition. Sperm competition favors the evolution of increased testes size and sperm production. In some species, males appear capable of adjusting the number of sperm ejaculated, depending on the perceived levels of sperm competition. Selection is also expected to act on sperm form and function, although the evidence for this remains equivocal. Comparative studies suggest that sperm length and swimming speed may increase in response to selection from sperm competition. However, the mechanisms driving this pattern remain unclear. Evidence that sperm length influences sperm swimming speed is mixed and fertilization trials performed across a broad range of species demonstrate inconsistent relationships between sperm form and function. This ambiguity may in part reflect the important role that seminal fluid proteins (sfps) play in affecting sperm function. There is good evidence that sfps are subject to selection from sperm competition, and recent work is pointing to an ability of males to adjust their seminal fluid chemistry in response to sperm competition from rival males. We argue that future research must consider sperm and seminal fluid components of the ejaculate as a functional unity. Research at the genomic level will identify the genes that ultimately control male fertility.

  4. Increased N6-methyladenosine in Human Sperm RNA as a Risk Factor for Asthenozoospermia.

    PubMed

    Yang, Ying; Huang, Wei; Huang, Jing-Tao; Shen, Fan; Xiong, Jun; Yuan, Er-Feng; Qin, Shan-shan; Zhang, Ming; Feng, Yu-Qi; Yuan, Bi-Feng; Liu, Song-Mei

    2016-04-13

    Male infertility is a worldwide medical problem. Asthenozoospermia is a common cause of infertility. Epigenetic modifications of DNA and histones have been shown to influence human infertility, but no research has explored whether N(6)-methyladenosine (m(6)A) level in RNA is associated with asthenozoospermia. Here, we collected a total of 52 semen samples, including 20 asthenozoospermia patients and 32 healthy controls. An LC-ESI-MS/MS method was used to detect m(6)A contents in sperm RNA, and real-time PCR was performed to determine the mRNA expression of demethylase (FTO, ALKBH5), methyltransferase (METTL3, METTL14, WTAP) and an m(6)A-selective-binding protein (YTHDF2). We found that m(6)A content (p = 0.033) and the mRNA expression of METTL3 (p = 0.016) and METTL14 (p = 0.025) in asthenozoospermia patients were significantly higher than those of controls. Increased m(6)A content was a risk factor for asthenozoospermia (odds ratio (OR) 3.229, 95% confidence interval (CI) 1.178 - 8.853, p = 0.023). Moreover, m(6)A content was correlated with the expression of METTL3 (r = 0.303, p = 0.032) and with sperm motility (progressive motility: r = -0.288, p = 0.038; non-progressive motility: r = -0.293, p = 0.037; immotility: r = 0.387, p = 0.005). Our data suggest that increased m(6)A content is a risk factor for asthenozoospermia and affects sperm motility. Methyltransferases, particularly METTL3, play key roles in increasing m(6)A contents in sperm RNA.

  5. Increased N6-methyladenosine in Human Sperm RNA as a Risk Factor for Asthenozoospermia

    PubMed Central

    Yang, Ying; Huang, Wei; Huang, Jing-Tao; Shen, Fan; Xiong, Jun; Yuan, Er-Feng; Qin, Shan-shan; Zhang, Ming; Feng, Yu-Qi; Yuan, Bi-Feng; Liu, Song-Mei

    2016-01-01

    Male infertility is a worldwide medical problem. Asthenozoospermia is a common cause of infertility. Epigenetic modifications of DNA and histones have been shown to influence human infertility, but no research has explored whether N6-methyladenosine (m6A) level in RNA is associated with asthenozoospermia. Here, we collected a total of 52 semen samples, including 20 asthenozoospermia patients and 32 healthy controls. An LC-ESI-MS/MS method was used to detect m6A contents in sperm RNA, and real-time PCR was performed to determine the mRNA expression of demethylase (FTO, ALKBH5), methyltransferase (METTL3, METTL14, WTAP) and an m6A-selective-binding protein (YTHDF2). We found that m6A content (p = 0.033) and the mRNA expression of METTL3 (p = 0.016) and METTL14 (p = 0.025) in asthenozoospermia patients were significantly higher than those of controls. Increased m6A content was a risk factor for asthenozoospermia (odds ratio (OR) 3.229, 95% confidence interval (CI) 1.178 – 8.853, p = 0.023). Moreover, m6A content was correlated with the expression of METTL3 (r = 0.303, p = 0.032) and with sperm motility (progressive motility: r = −0.288, p = 0.038; non-progressive motility: r = −0.293, p = 0.037; immotility: r = 0.387, p = 0.005). Our data suggest that increased m6A content is a risk factor for asthenozoospermia and affects sperm motility. Methyltransferases, particularly METTL3, play key roles in increasing m6A contents in sperm RNA. PMID:27072590

  6. Elevated dietary intake of Zn-methionate is associated with increased sperm DNA fragmentation in the boar.

    PubMed

    García-Contreras, Adelfa; De Loera, Yasmin; García-Artiga, Carlos; Palomo, Antonio; Guevara, Jesús A; Herrera-Haro, José; López-Fernández, Carmen; Johnston, Steve; Gosálvez, Jaime

    2011-05-01

    Boars fed on ration of 200 ppm Zn methionate showed a significant increase (P < 0.001) in sperm DNA fragmentation when compared to animals fed on non-supplemented and rations containing 150 ppm Zn methionate. There was a positive correlation (R2 = 0.207; P = 0.002) between % sperm DNA fragmentation (SDF) and the concentration of Zn in spermatozoa. Increased Zn in the diet also resulted in a non-proportional increase in Zn concentration in the testis and spermatozoa but not in the epididymis; Zn in sperm accumulated at levels up to 50 times higher than that found in the seminal plasma and 10-13 times that found in the epididymis and testis, respectively. These results show that supplementation of dietary Zn at a concentration of 200 ppm had an adverse effect on boar sperm DNA quality and may be related to the ability of spermatozoa to accumulate Zn during spermiogenesis.

  7. Effects of dietary energy on sexual maturation and sperm production in Holstein bulls.

    PubMed

    Harstine, B R; Maquivar, M; Helser, L A; Utt, M D; Premanandan, C; DeJarnette, J M; Day, M L

    2015-06-01

    In prepubertal bulls and heifers of dairy and beef breeds, puberty can be induced to occur earlier than typical with targeted high-energy diets due to precocious activation of the endocrine mechanisms that regulate puberty. Precocious activation of puberty in bulls intended for use in the AI industry has the potential to hasten and perhaps increase sperm production. It was hypothesized that feeding bulls a high-energy diet beginning at 8 wk of age would advance the prepubertal rise in LH and lead to advanced testicular maturation and age at puberty. From 58 to 230 ± 0.3 d of age, Holstein bulls received either a high-energy diet (HE;n = 9; targeted ADG 1.5 kg/d) or a control diet (CONT;n = 10; targeted ADG 0.75 kg/d). Thereafter, all bulls were fed a similar diet. The HE treatment increased LH secretion at 125 d of age, testosterone concentrations from 181 to 210 d, and scrotal circumference (SC) from 146 to 360 d of age relative to the CONT treatment. Beginning at 241 ± 5 d of age, semen collection (artificial vagina) was attempted every 14 d in bulls from the HE (n = 8) and CONT (n = 7) treatment until each bull attained puberty (ejaculate containing 50 × 10 spermatozoa with 10% motility). To assess semen production as mature bulls, semen was collected thrice weekly beginning at 541 ± 5 d of age until slaughter at 569 ± 5 d of age. After slaughter, epididymal and testicular measurements were collected and testicular tissue was fixed to determine seminiferous tubule diameter. Age at puberty did not differ between treatments (310 ± 35 d). Although testis and epididymal weight and testis volume were greater (P < 0.05) in the HE than the CONT treatment, sperm production of mature bulls did not differ between treatments. Diameter of seminiferous tubules also did not differ between treatments. We conclude that the HE advanced aspects of sexual maturation and increased testes size, but this was not reflected in hastened puberty or sperm production in the present

  8. Increasing mobile radiography productivity.

    PubMed

    Wong, Edward; Lung, Ngan Tsz; Ng, Kris; Jeor, Patrick

    2013-01-01

    Mobile radiography using computed radiography (CR) cassettes is a common equipment combination with a workflow bottleneck limited by location of CR readers. Advent of direct digital radiography (DDR) mobile x-ray machines removes this limitation by immediate image review and quality control. Through the use of key performance indicators (KPIs), the increase in efficiency can be quantified.

  9. Plastic responses of male Drosophila melanogaster to the level of sperm competition increase male reproductive fitness

    PubMed Central

    Bretman, Amanda; Fricke, Claudia; Chapman, Tracey

    2009-01-01

    Evolutionary and plastic responses by males to the level of sperm competition (SC) are reported across widespread taxa, but direct tests of the consequences for male reproductive success in a competitive context are lacking. We varied male perception of SC to examine the effect on male competitive reproductive success and to test whether the outcomes were as predicted by theory. Exposure to rival males prior to mating increased a male's ejaculate investment (measured as mating duration); by contrast, exposure to rival males in the mating arena decreased mating duration. The results therefore suggested that SC intensity is important in shaping male responses to SC in this system, although the patterns were not strictly in accord with existing theory. We then tested whether males that responded to the level of SC had higher reproductive fitness in a competitive context. We found that males kept with rivals prior to mating again mated for longer; furthermore, they achieved significantly higher paternity share regardless of whether they were the first or second males to mate with a female. The plastic strategies employed by males therefore resulted in significantly increased reproductive success in a competitive context, even following subsequent rematings in which the majority of sperm were displaced. PMID:19324834

  10. Reduced curvilinear velocity of boar sperm on substrates with increased hydrophobicity.

    PubMed

    Mears, Matthew; Kennelly, Thomas M; Howse, Jonathan R; Tarmey, Drew S; Geoghegan, Mark; Pacey, Allan A

    2014-03-15

    The curvilinear velocity (VCL) of boar spermatozoa between standard microscopy glassware decreases when the slides are coated with the hydrophobic polymer polystyrene (PS) compared with the less hydrophobic poly(methyl methacrylate) (PMMA) coating. Sperm from three boars were observed and analyzed using particle tracking software. The VCL did not differ significantly between coatings of different thickness, indicating no penetration of the sperm into the coating and that only the surface layer of the polymer film interacts with the sperm and buffer medium. The VCL of sperm between PS-coated surfaces was significantly reduced compared with PMMA surfaces (P < 0.0001), and this was attributed to a stronger hydrophobic effect between PS and water. The size of this effect varied between different boars, perhaps as a consequence of variations in hydrophobicity of sperm from different boars or different ejaculates. The modification of surface properties in this way may improve our understanding of sperm behavior and may provide improvements to assisted conception techniques as animal or human sperm used in assisted conception are frequently manipulated in laboratory plastics as part of diagnostic procedures (e.g., semen analysis) or before injection into an oocyte or during the co-incubation with the oocyte in IVF. Controlling the velocity of sperm using the interaction properties of inert polymer coatings could lead to new sperm selection procedures for clinical use or the development of model systems to better understand sperm-surface interactions.

  11. Effects of increased paternal age on sperm quality, reproductive outcome and associated epigenetic risks to offspring.

    PubMed

    Sharma, Rakesh; Agarwal, Ashok; Rohra, Vikram K; Assidi, Mourad; Abu-Elmagd, Muhammad; Turki, Rola F

    2015-04-19

    Over the last decade, there has been a significant increase in average paternal age when the first child is conceived, either due to increased life expectancy, widespread use of contraception, late marriages and other factors. While the effect of maternal ageing on fertilization and reproduction is well known and several studies have shown that women over 35 years have a higher risk of infertility, pregnancy complications, spontaneous abortion, congenital anomalies, and perinatal complications. The effect of paternal age on semen quality and reproductive function is controversial for several reasons. First, there is no universal definition for advanced paternal ageing. Secondly, the literature is full of studies with conflicting results, especially for the most common parameters tested. Advancing paternal age also has been associated with increased risk of genetic disease. Our exhaustive literature review has demonstrated negative effects on sperm quality and testicular functions with increasing paternal age. Epigenetics changes, DNA mutations along with chromosomal aneuploidies have been associated with increasing paternal age. In addition to increased risk of male infertility, paternal age has also been demonstrated to impact reproductive and fertility outcomes including a decrease in IVF/ICSI success rate and increasing rate of preterm birth. Increasing paternal age has shown to increase the incidence of different types of disorders like autism, schizophrenia, bipolar disorders, and childhood leukemia in the progeny. It is thereby essential to educate the infertile couples on the disturbing links between increased paternal age and rising disorders in their offspring, to better counsel them during their reproductive years.

  12. Gamete Therapeutics: Recombinant Protein Adsorption by Sperm for Increasing Fertility via Artificial Insemination

    PubMed Central

    Alvarez-Gallardo, Horacio; Kjelland, Michael E.; Moreno, Juan F.; Welsh, Thomas H.; Randel, Ronald D.; Lammoglia, Miguel A.; Pérez-Martínez, Mario; Lara-Sagahón, Alma V.; Esperón-Sumano, A. Enrique; Romo, Salvador

    2013-01-01

    A decrease in fertility can have a negative economic impact, both locally and over a broader geographical scope, and this is especially the case with regard to the cattle industry. Therefore, much interest exists in evaluating proteins that might be able to increase the fertility of sperm. Heparin binding proteins (HBPs), specifically the fertility associated antigen (FAA) and the Type-2 tissue inhibitor of metalloproteinase (TIMP-2), act to favor the capacitation and acrosome reaction and perhaps even modulate the immune system’s response toward the sperm. The objective of this research was to determine the effect on fertility of adding recombinant FAA (rFAA) and recombinant TIMP-2 (rTIMP-2) to bovine semen before cryopreservation for use in an artificial insemination (AI) program in a tropical environment. For this experiment, 100 crossbred (Bos taurus x Bos indicus) heifers were selected based on their estrus cycle, body condition score (BCS), of 4 to 6 on a scale of 1 to 9, and adequate anatomical conformation evaluated by pelvic and genital (normal) measurements. Heifers were synchronized using estradiol benzoate (EB), Celosil® (PGF2α) (Shering-Plough) and a controlled internal drug release (CIDR) device was inserted that contained progesterone. Inseminations were performed in two groups at random, 50 animals per group. The control group was inseminated with conventional semen. The treatment group was inseminated with semen containing rFAA (25 µg/mL) and rTIMP-2 (25 µg/mL). In the control group a 16% pregnancy rate was obtained versus a 40% pregnancy rate for the HBP treatment group, resulting in a significant difference (P = 0.0037). Given the results herein, one may conclude that the HBPs can increase fertility and could be an option for cattle in tropical conditions; however, one needs to consider the environment, nutrition, and the genetic interaction affecting the final result in whatever reproductive program that is implemented. PMID:23762288

  13. The role of mitochondria in energy production for human sperm motility.

    PubMed

    Piomboni, P; Focarelli, R; Stendardi, A; Ferramosca, A; Zara, V

    2012-04-01

    Mitochondria of spermatozoa are different from the corresponding organelles of somatic cells, in both their morphology and biochemistry. The biochemical differences are essentially related to the existence of specific enzyme isoforms, which are characterized by peculiar kinetic and regulatory properties. As mitochondrial energy metabolism is a key factor supporting several sperm functions, these organelles host critical metabolic pathways during germ cell development and fertilization. Furthermore, spermatozoa can use different substrates, and therefore activate different metabolic pathways, depending on the available substrates and the physico-chemical conditions in which they operate. This versatility is critical to ensure fertilization success. However, the most valuable aspect of mitochondria function in all types of cells is the production of chemical energy in the form of ATP which can be used, in the case of spermatozoa, for sustaining sperm motility. The latter, on the other hand, represents one of the major determinants of male fertility. Accordingly, the presence of structural and functional alterations in mitochondria from asthenozoospermic subjects confirms the important role played by these organelles in energy maintenance of sperm motility. The present study gives an overview of the current knowledge on the energy-producing metabolic pathways operating inside human sperm mitochondria and critically analyse the differences with respect to somatic mitochondria. Such a comparison has also been carried out between the functional characteristics of human sperm mitochondria and those of other mammalian species. A deeper understanding of mitochondrial energy metabolism could open up new avenues of investigation in bioenergetics of human sperm mitochondria, both in physiological and pathological conditions.

  14. SIGNIFICANCE OF INCORPORATING MEASURES OF SPERM PRODUCTION AND FUNCTION INTO RAT TOXICOLOGY STUDIES

    EPA Science Inventory

    The rat is the preferred species for reproductive toxicity testing. The inclusion of measures of rat sperm quality, such as motility and morphology, into reproductive test protocols often increases the sensitivity of the test to detect effects, and provides the toxicologist and ...

  15. A Specific Transitory Increase in Intracellular Calcium Induced by Progesterone Promotes Acrosomal Exocytosis in Mouse Sperm1

    PubMed Central

    Romarowski, Ana; Sánchez-Cárdenas, Claudia; Ramírez-Gómez, Héctor V.; Puga Molina, Lis del C.; Treviño, Claudia L.; Hernández-Cruz, Arturo; Darszon, Alberto; Buffone, Mariano G

    2016-01-01

    During capacitation, sperm acquire the ability to undergo the acrosome reaction (AR), an essential step in fertilization. Progesterone produced by cumulus cells has been associated with various physiological processes in sperm, including stimulation of AR. An increase in intracellular Ca2+ ([Ca2+]i) is necessary for AR to occur. In this study, we investigated the spatiotemporal correlation between the changes in [Ca2+]i and AR in single mouse spermatozoa in response to progesterone. We found that progesterone stimulates an [Ca2+]i increase in five different patterns: gradual increase, oscillatory, late transitory, immediate transitory, and sustained. We also observed that the [Ca2+]i increase promoted by progesterone starts at either the flagellum or the head. We validated the use of FM4-64 as an indicator for the occurrence of the AR by simultaneously detecting its fluorescence increase and the loss of EGFP in transgenic EGFPAcr sperm. For the first time, we have simultaneously visualized the rise in [Ca2+]i and the process of exocytosis in response to progesterone and found that only a specific transitory increase in [Ca2+]i originating in the sperm head promotes the initiation of AR. PMID:26819478

  16. Effects of thymoquinone on testicular structure and sperm production in male obese rats.

    PubMed

    Tüfek, Nur Hande; Altunkaynak, Muhammad Eyüp; Altunkaynak, Berrin Zuhal; Kaplan, Süleyman

    2015-01-01

    Thymoquinone (TQ) is a phytochemical compound found in the plant Nigella sativa. It has antioxidant and anti-cancer effects. This study investigated the effects of TQ on obesity and testicular structure of high-fat-diet (HFD) fed rats. Obese control (OC) and obese thymoquinone (OT) groups were fed a special diet containing 40% of total calories from fat. Non-obese control (NC) and non-thymoquinone (NT) groups were fed a standard diet for nine weeks. Then, intraperitoneal TQ injections were carried out to the OT and NT groups for six weeks and testes were removed. Catalase and myeloperoxidase activity were determined in rat testis tissue. Stereological, histopathological, and immunohistochemical changes were evaluated in the testes of the rats. In stereological studies, mean volumes of testis and seminiferous tubules, the number of spermatogenic cells and also Leydig cells in the OC group were reduced, but these values significantly increased in the OT group. Apoptotic cells were observed in the OC group in comparison to the OT group. The number of healthy sperms were reduced in the OC group, whereas the majority showed anomalies in the head, neck, and tail. The number of healthy sperm was increased and the anomalies significantly reduced by using TQ in both the NT, and especially the OT group. TQ like antioxidants may improve fertility by means of increasing the healthy sperm number and preventing sperm anomalies.

  17. Sperm production and quality in brill Scophthalmus rhombus L.: relation to circulating sex steroid levels.

    PubMed

    Hachero-Cruzado, Ismael; Forniés, Asunción; Herrera, Marcelino; Mancera, Juan Miguel; Martínez-Rodríguez, Gonzalo

    2013-04-01

    The aims of the present study were to characterize sperm quality and to quantify seasonal changes in sexual hormone (testosterone [T], 11-ketotestosterone [11-KT] and 17,20β-dihydroxypregn-4-en-3-one [17,20β-P]) levels in male brill (Scophthalmus rhombus) plasma, as well as to test a more intensive sampling strategy to establish relationships between sex steroid levels and sperm production parameters. Sperm concentration ranged from 0.5 to 3.1 × 10(9) spermatozoa mL(-1), and changes in sperm quality parameters depending on sampling date were observed. Plasma sexual steroid levels remained high and changed in parallel during the spawning season and afterwards decreased to very low levels in summer. The analysis of annual changes of 11-KT and T ratios suggests that 11-KT can be the main circulating androgen for stimulating spermatogenesis in S. rhombus and that T could be involved in the beginning of spermatogenesis through the positive feedback on brain-pituitary-gonad axis. Finally, daily 11-KT and T levels showed similar patterns of variation in males sampled, whereas 17,20β-P amounts showed somewhat opposite trends. These differences could be related with the different role of androgens and progestin during the spermatogenesis.

  18. Production of transgenic piglets using ICSI-sperm-mediated gene transfer in combination with recombinase RecA.

    PubMed

    García-Vázquez, Francisco A; Ruiz, Salvador; Matás, Carmen; Izquierdo-Rico, M José; Grullón, Luis A; De Ondiz, Aitor; Vieira, Luis; Avilés-López, Karen; Gutiérrez-Adán, Alfonso; Gadea, Joaquín

    2010-08-01

    Sperm-mediated gene transfer (SMGT) is a method for the production of transgenic animals based on the intrinsic ability of sperm cells to bind and internalize exogenous DNA molecules and to transfer them into the oocyte at fertilization. Recombinase-A (RecA) protein-coated exogenous DNA has been used previously in pronuclear injection systems increasing integration into goat and pig genomes. However, there are no data regarding transgene expression after ICSI. Here, we set out to investigate whether the expression of transgenic DNA in porcine embryos is improved by recombinase-mediated DNA transfer and if it is possible to generate transgenic animals using this methodology. Different factors which could affect the performance of this transgenic methodology were analyzed by studying 1) the effect of the presence of exogenous DNA and RecA protein on boar sperm functionality; 2) the effect of recombinase RecA on in vitro enhanced green fluorescent protein (EGFP)-expressing embryos produced by ICSI or IVF; and 3) the efficiency of generation of transgenic piglets by RecA-mediated ICSI. Our results suggested that 1) the presence of exogenous DNA and RecA-DNA complexes at 5 microg/ml did not affect sperm functionality in terms of motility, viability, membrane lipid disorder, or reactive oxygen species generation; 2) EGFP-expressing embryos were obtained with a high efficiency using the SMGT-ICSI technique in combination with recombinase; however, the use of IVF system did not result in any fluorescent embryos; and 3) transgenic piglets were produced by this methodology. To our knowledge, this is the first time that transgenic pigs have been produced by ICSI-SGMT and a recombinase.

  19. Performance of Rodent Spermatozoa Over Time Is Enhanced by Increased ATP Concentrations: The Role of Sperm Competition.

    PubMed

    Tourmente, Maximiliano; Villar-Moya, Pilar; Varea-Sánchez, María; Luque-Larena, Juan J; Rial, Eduardo; Roldan, Eduardo R S

    2015-09-01

    Sperm viability, acrosome integrity, motility, and swimming velocity are determinants of male fertility and exhibit an extreme degree of variation among closely related species. Many of these sperm parameters are associated with sperm ATP content, which has led to predictions of trade-offs between ATP content and sperm motility and velocity. Selective pressures imposed by sperm competition have been proposed as evolutionary causes of this pattern of diversity in sperm traits. Here, we examine variation in sperm viability, acrosome integrity, motility, swimming velocity, and ATP content over time, among 18 species of closely related muroid rodents, to address the following questions: (a) Do sperm from closely related species vary in ATP content after a period of incubation? (b) Are these differences in ATP levels related to differences in other sperm traits? (c) Are differences in ATP content and sperm performance over time explained by the levels of sperm competition in these species? Our results revealed a high degree of interspecific variability in changes in sperm ATP content, acrosome integrity, sperm motility and swimming velocity over time. Additionally, species with high sperm competition levels were able to maintain higher levels of sperm motility and faster sperm swimming velocity when they were incubated under conditions that support sperm survival. Furthermore, we show that the maintenance of such levels of sperm performance is correlated with the ability of sperm to sustain high concentrations of intracellular ATP over time. Thus, sperm competition may have an important role maximizing sperm metabolism and performance and, ultimately, the fertilizing capacity of spermatozoa.

  20. Increased cervical electrical activity during oestrus in progestagen treated ewes: Possible role in sperm transport.

    PubMed

    Cavaco-Gonçalves, S; Marques, C C; Horta, A E M; Figueroa, J P

    2006-07-01

    The aim of this investigation was to characterize the pattern of cervical myoelectrical activity (EMG) in the sheep, during the periovulatory period, after synchronization of oestrus with progestagen and eCG. EMG was measured with a computerised modular system in five ewes previously fitted with a pair of monopolar Teflon needle electrodes in the muscle layers of the cervix. Each ewe was submitted to oestrus synchronization treatment with intravaginal progestagen sponge during 12 days, and the administration of 500 IU of eCG at the withdrawal of sponge. EMG was recorded in each animal during 19 h, starting 44 h after withdrawal of sponge. The number and duration of events were determined every hour during the experiment. Two distinct event durations were identified: one lasting less than 200 s and another lasting between 300 and 500 s. The two types of events analysed (less than 200 s and lasting between 300 and 500 s) had a similar pattern during the period of observation although they were not in synchrony. For events lasting less than 200 s, activity increased between 48 and 50 h after sponge withdrawal, with the peak of activity being observed between 51 and 53 h. For events of 300-500 s duration, the peak of activity was observed between 48 and 50h after sponge withdrawal and activity was maintained until 51-53 h. The increase in cervical motility observed in progestagen-eCG treated ewes is in keeping with the increase in cervical activity observed by others in natural cycling animals, and suggests that exogenous hormones used in synchronization protocols had no deleterious action on cervical motility during periovulatory period. The enhanced activity of cervical muscle layer found around the time of mating and/or AI suggests it may play an important role as a regulatory mechanism of sperm transport. Taking advantage of the cervical responsiveness to various drugs, experimental modulation of cervical activity could be used to facilitate cervical sperm

  1. Relationships of testicular iron and ferritin concentrations with testicular weight and sperm production in boars.

    PubMed

    Wise, T; Lunstra, D D; Rohrer, G A; Ford, J J

    2003-02-01

    The inverse relationship of testicular size and circulating follicle-stimulating hormone (FSH) concentrations has been documented, and accompanying this relationship is the change in color of the parenchymal tissue of the testes. Large testes (300 to 400 g) are pink to light red and small testes (100 g) are dark maroon with color gradations for weights in between. It was hypothesized that this color most likely represented an iron protein. Chromatographic analysis of testicular tissue indicated that the Fe was associated primarily with ferritin, and immunohistochemistry showed that Leydig cells were the primary location of ferritin storage within the testes. Concentrations of Fe and ferritin were higher in small testes and decreased as testes weight increased (P < 0.05). As testicular Fe concentrations increased, daily sperm production (DSP) and total DSP declined (P < 0.05). Genotyping six generations of Meishan x White composite boars (n = 288) for a quantitative trait locus that is indicative of elevated FSH and small testes in boars indicated that the Meishan genotype had elevated testicular iron concentrations and darker color in conjunction with reduced total DSP (P < 0.01). It is not thought the elevated iron concentrations affect testicular weights but are probably a result of elevated FSH and FSH inducement of Fe transport. The storage of Fe in Leydig cells may provide a reservoir of Fe for easy access by Sertoli and germ cells, but still provide a degree of protection to germ cells from ionic iron.

  2. Sperm competition leads to functional adaptations in avian testes to maximize sperm quantity and quality.

    PubMed

    Lüpold, Stefan; Wistuba, Joachim; Damm, Oliver S; Rivers, James W; Birkhead, Tim R

    2011-05-01

    The outcome of sperm competition (i.e. competition for fertilization between ejaculates from different males) is primarily determined by the relative number and quality of rival sperm. Therefore, the testes are under strong selection to maximize both sperm number and quality, which are likely to result in trade-offs in the process of spermatogenesis (e.g. between the rate of spermatogenesis and sperm length or sperm energetics). Comparative studies have shown positive associations between the level of sperm competition and both relative testis size and the proportion of seminiferous (sperm-producing) tissue within the testes. However, it is unknown how the seminiferous tissue itself or the process of spermatogenesis might evolve in response to sperm competition. Therefore, we quantified the different germ cell types and Sertoli cells (SC) in testes to assess the efficiency of sperm production and its associations with sperm length and mating system across 10 species of New World Blackbirds (Icteridae) that show marked variation in sperm length and sperm competition level. We found that species under strong sperm competition generate more round spermatids (RS)/spermatogonium and have SC that support a greater number of germ cells, both of which are likely to increase the maximum sperm output. However, fewer of the RS appeared to elongate to mature spermatozoa in these species, which might be the result of selection for discarding spermatids with undesirable characteristics as they develop. Our results suggest that, in addition to overall size and gross morphology, testes have also evolved functional adaptations to maximize sperm quantity and quality.

  3. Production of F1 interspecies hybrid offspring with cryopreserved sperm from a live-bearing fish, the swordtail Xiphophorus helleri.

    PubMed

    Yang, Huiping; Hazlewood, Leona; Heater, Sheila J; Guerrero, Paula A; Walter, Ronald B; Tiersch, Terrence R

    2007-03-01

    Despite study of sperm cryopreservation in more than 200 fish species, production of broods from cryopreserved sperm in live-bearing fish has not been demonstrated. This has not been due to a lack of effort, but instead is a result of the unique morphology, biology, and biochemistry of reproduction in viviparous fishes. For example, sperm of Xiphophorus helleri have a cylindrical nucleus, can swim for days after being activated, have glycolytic capabilities, and can reside in the female reproduction tract for months before fertilization. These traits are not found in fishes with external fertilization. The long-standing research use of the genus Xiphophorus has led to development of over 60 pedigreed lines among the 26 species maintained around the world. These species and lines serve as contemporary models in medical research, although they must be maintained as live populations. Previous attempts at establishing sperm cryopreservation protocols for Xiphophorus have not produced live young. To address this we have been studying the parameters surrounding cryobiology of Xiphophorus sperm and applying this information to an improved understanding of internal fertilization and reproduction. Here we report the first successful fertilization and offspring production by cryopreserved sperm in any live-bearing fish. This claim is supported by our use of artificial insemination between two species that yield distinct hybrid offspring to verify paternity via cryopreserved sperm. We provide a practical approach for preservation of valuable genetic resources from live-bearing fish species, a group that is rapidly being lost due to destruction of native habitats.

  4. Small testicles with impaired production of sperm in adult male survivors of childhood malignancies

    SciTech Connect

    Siimes, M.A.; Rautonen, J. )

    1990-03-15

    Testicular size has been studied in 66 adult men who survived leukemia (n = 14) or cancer (n = 52) in childhood. Mean follow-up time was 14.5 years. The testicular size was measured as the length and breadth in mm; testicular volume index was calculated. Serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and prolactin were measured. A sperm sample was obtained from 46 men. The patients had smaller testicles than healthy medical students; 51 had small testicles. The size was the smallest in patients who survived leukemia. Multivariate analysis showed that the variables with independent effects on testicular size were cranial and testicular irradiation and therapy with cyclophosphamide. Sperm production was dependent on testicular size. We conclude that determination of serum FSH combined with testicular size may offer a practical approach for predicting the subsequent testicular damage in boys with malignancies.

  5. Metabolic rate limits the effect of sperm competition on mammalian spermatogenesis.

    PubMed

    delBarco-Trillo, Javier; Tourmente, Maximiliano; Roldan, Eduardo R S

    2013-01-01

    Sperm competition leads to increased sperm production in many taxa. This response may result from increases in testes size, changes in testicular architecture or changes in the kinetics of spermatogenesis, but the impact of each one of these processes on sperm production has not been studied in an integrated manner. Furthermore, such response may be limited in species with low mass-specific metabolic rate (MSMR), i.e., large-bodied species, because they cannot process energy and resources efficiently enough both at the organismic and cellular levels. Here we compare 99 mammalian species and show that higher levels of sperm competition correlated with a) higher proportions of seminiferous tubules, b) shorter seminiferous epithelium cycle lengths (SECL) which reduce the time required to produce sperm, and c) higher efficiencies of Sertoli cells (involved in sperm maturation). These responses to sperm competition, in turn, result in higher daily sperm production, more sperm stored in the epididymides, and more sperm in the ejaculate. However, the two processes that require processing resources at faster rates (SECL and efficiency of Sertoli cells) only respond to sperm competition in species with high MSMR. Thus, increases in sperm production with intense sperm competition occur via a complex network of mechanisms, but some are constrained by MSMR.

  6. Nerve growth factor promotes human sperm motility in vitro by increasing the movement distance and the number of A grade spermatozoa.

    PubMed

    Lin, Kai; Ding, Xue-Feng; Shi, Cui-Ge; Zeng, Dan; QuZong, SuoLang; Liu, Shu-Hong; Wu, Yan; LuoBu, GeSang; Fan, Ming; Zhao, Y-Q

    2015-11-01

    Nerve growth factor (NGF) was first found in the central nervous system and is now well known for its multiple pivotal roles in the nervous system and immune system. However, more and more evidences showed that NGF and its receptors TrkA and p75 were also found in the head and tail of spermatozoa, which indicate the possible effect of NGF on the sperm motility. Nevertheless, the exact role of NGF in the human sperm motility remains unclear until now. In this study, we investigated the effect of NGF on human sperm motility, and the results showed that NGF could promote human sperm motility in vitro by increasing the movement distance and the number of A grade spermatozoa. Further analysis demonstrated that NGF promoted the sperm motility in a dose-dependent manner in vitro. These results may facilitate the further studies on human fertility and assisted reproduction techniques.

  7. Effect of increasing paternal body mass index on pregnancy and live birth rates in couples undergoing intracytoplasmic sperm injection.

    PubMed

    Umul, M; Köse, S A; Bilen, E; Altuncu, A G; Oksay, T; Güney, M

    2015-04-01

    In this study, our purpose was to investigate the possible effect of paternal obesity on intracytoplasmic sperm injection (ICSI) outcomes on the basis of clinical pregnancy outcome. Antropometric measurements of 155 couples, referred to our infertility clinic and who underwent an ICSI cycle, have been evaluated. The study sample were divided into three groups with respect to paternal body mass index (BMI), as normal weight (BMI: 20-24.9), overweight (BMI: 25-29.9) and obese (BMI ≥ 30). Results of conventional semen analysis were also analysed. Clinical pregnancy data, including fertilisation rate, implantation rate, clinical pregnancy rate and live birth rate, were evaluated. Paternal obesity was a significant negative factor for sperm concentration and sperm motility (P = 0.03 and P = 0.01 respectively). A significant decrease of clinical pregnancy rate and live birth rate was associated with increased paternal BMI (P = 0.04 and P = 0.03 respectively). We have not determined a significant difference among groups in terms of fertilisation rate and implantation rate. This study demonstrates that increasing paternal BMI has a negative influence on ICSI success, including clinical pregnancy rate and live birth rate. There is a need for further studies to point the importance of lifestyle changes in order to overcome the negative influence of paternal obesity on couple's fertility.

  8. Treatment of GnRHa-implanted Senegalese sole (Solea senegalensis) with 11-ketoandrostenedione stimulates spermatogenesis and increases sperm motility.

    PubMed

    Agulleiro, Maria J; Scott, Alexander P; Duncan, Neil; Mylonas, Constantinos C; Cerdà, Joan

    2007-08-01

    The effect of 11-ketoandrostenedione (OA) on plasma concentrations of sexual steroids and spermatogenesis of Senegalese sole (Solea senegalensis) implanted with gonadotropin-releasing hormone agonist (GnRHa) was investigated. Males were treated with saline (control) or with GnRHa implants (50 mug kg(-1)) in the presence or absence of OA (2 or 7 mg kg(-1)) during twenty eight days. Treatment with GnRHa alone slightly stimulated spermatogenesis and milt production with respect to controls, and this was associated with a transient elevation of plasma 11-ketotestosterone (11-KT) at day seven and an increase of 5beta-reduced metabolite(s) of 17,20beta-dihydroxy-pregn-4-en-3-one (17,20betaP) at day twenty eight. However, treatment with GnRHa+OA increased plasma concentrations of 11-KT and free+sulphated 5beta-reduced metabolites of 17,20betaP at days seven, fourteen and twenty one. After twenty eight days, the testis of GnRHa+OA-treated fish showed a lower number of spermatogonia B and spermatocytes I, and a higher number of spermatids, than fish treated with GnRHa alone. In addition, the motility of spermatozoa produced by GnRHa+OA males was enhanced by 2-fold with respect to controls or GnRHa males. These results suggest that treatment of Senegalese sole with GnRHa+OA stimulates spermatogenesis resulting in more motile sperm. Such effects could be mediated by an increased synthesis of 11-KT and/or 17,20betaP in the testis but further studies will be required to elucidate the specific mechanism involved.

  9. [How to increase food production?].

    PubMed

    Gahamanyi, L

    1984-12-01

    Pressure of population on cultivable land, serious soil erosion, and low productivity due to scarcity of inputs have hampered efforts to provide an adequate diet for the population of Rwanda. Until the present, production has increased about as rapidly as population, but Rwanda is not totally self-sufficient in food, future climatic conditions may be less favorable than those of the past, technical and resource constraints are likely to increase, and little new land will be available for cultivation. Between 1970-80, hectares devoted to bananas and beans have increased considerably, but the marginal nature of much new land has seriously lowered productivity. Sweet potatoes are more extensively grown but their productivity is limited, and productivity of manioc has stagnated despite efforts to increase it. Peas are less frequently cultivated because the fallow land on they they are grown has almost disappeared due to population pressure. Agriculture in Rwanda has always been associated with herding, but population pressure is eliminating pastureland. Firewood for cooking is also becoming more scarce and reforestation is not proceeding rapidly enough to fill projected demand. Between 1978-80 and the year 2000, preliminary goals are to increase production in tons from 2,005,900 to 3,375,000 for bananas, from 177,400 to 330,000 for beans, from 15,200 to 45,500 for ground nuts, from 4000 to 25,000 for soybeans, from 174,800 to 288,000 for sorghum, from 81,300 to 250,000 for maize, from 3700 to 45,000 for rice, from 837,100 to 2,148,000 for sweet potatoes, from 506,600 to 1,200,000 for manioc, and from 216,000 to 600,000 for potatoes. Reaching these goals will require doubling of overall productivity per hectare. Different strategies will be required for increasing the yields of the principal crops. Priority should be given to developing strains of beans that will grow well in the poor soils, dry or cold regions, and acidic soils where they are usually planted in Rwanda

  10. Increase Productivity Through Knowledge Management

    NASA Astrophysics Data System (ADS)

    Gavrikova, N. A.; Dolgih, I. N.; Dyrina, E. N.

    2016-04-01

    Increase in competition level requires companies to improve the efficiency of work force use characterized by labor productivity. Professional knowledge of staff and its experience play the key role in it. The results of Extrusion Line operator’s working time analysis are performed in this article. The analysis revealed that the reasons of working time ineffective use connected with inadequate information exchange and knowledge management in the company. Authors suggest the way to solve this problem: the main sources of knowledge in engineering enterprise have been defined, the conditions of success and the stages of knowledge management control have been stated.

  11. Spermatogenic cycle length and sperm production in the freshwater turtle Kinosternon scorpioides.

    PubMed

    Sousa, Alana Lislea; Campos-Junior, Paulo Henrique Almeida; Costa, Guilherme Mattos Jardim; de França, Luiz Renato

    2014-02-01

    Kinosternon scorpioides is a Brazilian freshwater turtle that belongs to the class Reptilia, encompassing almost 10,000 species. Nevertheless, very little is known about the testicular quantitative parameters, particularly those related to spermatogenesis, in this vertebrate class. Our main objectives were to investigate in detail the structure and function of the testis in K. scorpioides, particularly the aspects related to spermatogenic cycle length and Sertoli cell (SC) and spermatogenic efficiencies. Nine sexually mature turtles were examined, and intraperitoneal bromodeoxyuridine injections were administered to estimate duration of spermatogenesis. Based on the acrosome development in spermatids and the overall germ cell associations, 10 stages of the seminiferous epithelium cycle were characterized. Similar to birds, humans, and some primate species, several stages were observed per seminiferous tubule cross-sections. One spermatogenic cycle and the entire spermatogenic process lasted, respectively, 12 and 53 days. The SC efficiency (number of round spermatids per SC) and daily sperm production per gram of testis were, respectively, 20 and 40 million spermatids. As established for mammals, our findings suggest that SC efficiency is also a critical determinant of sperm production in reptiles. To our knowledge, this is the first study to investigate the kinetics of spermatogenesis and testis function in any reptilian species. Besides allowing a better understanding of reproductive biology in reptiles, these data will be useful in comparative studies. Moreover, these results could provide the basis for investigations related to the evaluation of spermatogonial stem cell physiology niche in Kinosternon scorpioides.

  12. The secretory products of Trichomonas vaginalis decrease fertilizing capacity of mice sperm in vitro.

    PubMed

    Roh, Jaesook; Lim, Young-Su; Seo, Min-Young; Choi, Yuri; Ryu, Jae-Sook

    2015-01-01

    Trichomonas vaginalis infection is one of the most prevalent sexually transmitted infections in humans and is now recognized as an important cause of infertility in men. There is little information about the effect of extracellular polymeric substances (EPS) from T. vaginalis on sperm, but previous reports do not provide a conclusive description of the functional integrity of the sperm. To investigate the impact of EPS on the fertilizing capacity of sperm, we assessed sperm motility, acrosomal status, hypo-osmotic swelling, and in vitrofertilization rate after incubating the sperm with EPS in vitrousing mice. The incubation of sperm with EPS significantly decreased sperm motility, viability, and functional integrity in a concentration and time-dependent manner. These effects on sperm quality also resulted in a decreased fertilization rate in vitro. This is the first report that demonstrates the direct negative impact of the EPS of T. vaginalis on the fertilization rate of sperm in vitro. However, further study should be performed using human sperm to determine if EPS has similar negative impact on human sperm fertilizing capacity in vitro.

  13. In Utero Exposure to Benzo[a]Pyrene Increases Mutation Burden in the Soma and Sperm of Adult Mice

    PubMed Central

    Meier, Matthew J.; O’Brien, Jason M.; Beal, Marc A.; Allan, Beverly; Yauk, Carole L.; Marchetti, Francesco

    2016-01-01

    Background: Mosaicism, the presence of genetically distinct cell populations within an organism, has emerged as an important contributor to disease. Mutational events occurring during embryonic development can cause mosaicism in any tissue, but the influence of environmental factors on levels of mosaicism is unclear. Objectives: We investigated whether in utero exposure to the widespread environmental mutagen benzo[a]pyrene (BaP) has an impact on the burden and distribution of mutations in adult mice. Methods: We used the Muta™Mouse transgenic rodent model to quantify and characterize mutations in the offspring of pregnant mice exposed to BaP during postconception days 7 through 16, covering the major period of organogenesis in mice. Next-generation DNA sequencing was then used to determine the spectrum of mutations induced in adult mice that were exposed to BaP during fetal development. Results: Mutation frequency was significantly increased in the bone marrow, liver, brain, and sperm of first filial generation (F1) males. Developing embryos accumulated more mutations and exhibited higher proportions of mosaicism than exposed adults, particularly in the brain. Decreased sperm count and motility revealed additional negative impacts on the reproductive function of F1 males. Conclusion: In utero exposure to environmental mutagens contributes to somatic and germline mosaicism, permanently affecting both the genetic health of the F1 and the population gene pool. Citation: Meier MJ, O’Brien JM, Beal MA, Allan B, Yauk CL, Marchetti F. 2017. In utero exposure to benzo[a]pyrene increases mutation burden in the soma and sperm of adult mice. Environ Health Perspect 125:82–88; http://dx.doi.org/10.1289/EHP211 PMID:27448386

  14. Male-biased sex ratio does not promote increased sperm competitiveness in the seed beetle, Callosobruchus maculatus

    PubMed Central

    McNamara, Kathryn B.; Robinson, Stephen P.; Rosa, Márta E.; Sloan, Nadia S.; van Lieshout, Emile; Simmons, Leigh W.

    2016-01-01

    Sperm competition risk and intensity can select for adaptations that increase male fertilisation success. Evolutionary responses are examined typically by generating increased strength of sexual selection via direct manipulation of female mating rates (by enforcing monandry or polyandry) or by alteration of adult sex ratios. Despite being a model species for sexual selection research, the effect of sexual selection intensity via adult sex-ratio manipulation on male investment strategies has not been investigated in the seed beetle, Callosobruchus maculatus. We imposed 32 generations of experimental evolution on 10 populations of beetles by manipulating adult sex ratio. Contrary to predictions, males evolving in male-biased populations did not increase their testes and accessory gland size. This absence of divergence in ejaculate investment was also reflected in the fact that males from male-biased populations were not more successful in either preventing females from remating, or in competing directly for fertilisations. These populations already demonstrate divergence in mating behaviour and immunity, suggesting sufficient generations have passed to allow divergence in physiological and behavioural traits. We propose several explanations for the absence of divergence in sperm competitiveness among our populations and the pitfalls of using sex ratio manipulation to assess evolutionary responses to sexual selection intensity. PMID:27306351

  15. Male-biased sex ratio does not promote increased sperm competitiveness in the seed beetle, Callosobruchus maculatus.

    PubMed

    McNamara, Kathryn B; Robinson, Stephen P; Rosa, Márta E; Sloan, Nadia S; van Lieshout, Emile; Simmons, Leigh W

    2016-06-16

    Sperm competition risk and intensity can select for adaptations that increase male fertilisation success. Evolutionary responses are examined typically by generating increased strength of sexual selection via direct manipulation of female mating rates (by enforcing monandry or polyandry) or by alteration of adult sex ratios. Despite being a model species for sexual selection research, the effect of sexual selection intensity via adult sex-ratio manipulation on male investment strategies has not been investigated in the seed beetle, Callosobruchus maculatus. We imposed 32 generations of experimental evolution on 10 populations of beetles by manipulating adult sex ratio. Contrary to predictions, males evolving in male-biased populations did not increase their testes and accessory gland size. This absence of divergence in ejaculate investment was also reflected in the fact that males from male-biased populations were not more successful in either preventing females from remating, or in competing directly for fertilisations. These populations already demonstrate divergence in mating behaviour and immunity, suggesting sufficient generations have passed to allow divergence in physiological and behavioural traits. We propose several explanations for the absence of divergence in sperm competitiveness among our populations and the pitfalls of using sex ratio manipulation to assess evolutionary responses to sexual selection intensity.

  16. Production of F1 Offspring with Vitrified Sperm from a Live-Bearing Fish, the Green Swordtail Xiphophorus hellerii

    PubMed Central

    Cuevas-Uribe, Rafael; Yang, Huiping; Daly, Jonathan; Savage, Markita G.; Walter, Ronald B.

    2011-01-01

    Abstract This study reports the first production of offspring with vitrified sperm from a live-bearing fish Xiphophorus hellerii. The overall goal of this study was to develop streamlined protocols for integration into a standardized approach for vitrification of aquatic species germplasm. The objectives were to (1) estimate acute toxicity of cryoprotectants, (2) evaluate vitrification solutions, (3) compare different thawing methods, (4) evaluate membrane integrity of post-thaw sperm vitrified in different cryoprotectants, and (5) evaluate the fertility of vitrified sperm. Nine cryoprotectants and two commercial vitrification additives were tested for acute toxicity and glass forming ability, alone and in combination. Two vitrification solutions, 40% glycerol (Gly) and 20% Gly+20% ethylene glycol (EG) in 500 mOsmol/kg Hanks' balanced salt solution (HBSS), were selected for vitrification of 10 μL sperm samples using inoculating loops plunged into liquid nitrogen. Samples were thawed at 24°C (one loop in 5 μL of HBSS or three loops in 500 μL of HBSS). Samples thawed in 500 μL were concentrated by centrifugation (1000 g for 5 min at 4°C) into 5 μL for artificial insemination. Offspring were produced from virgin females inseminated with sperm vitrified with 20% Gly+20% EG and concentrated by centrifugation. PMID:21883000

  17. Procurement of exogenous ammonia by the swallowtail butterfly, Papilio polytes, for protein biosynthesis and sperm production.

    PubMed

    Honda, Keiichi; Takase, Hiroyuki; Ômura, Hisashi; Honda, Hiroshi

    2012-09-01

    How to acquire sufficient quantity of nitrogen is a pivotal issue for herbivores, particularly for lepidopterans (butterflies and moths) of which diet quality greatly differs among their life stages. Male Lepidoptera often feed from mud puddles, dung, and carrion, a behavior known as puddling, which is thought to be supplementary feeding targeted chiefly at sodium. During copulation, males transfer a spermatophore to females that contains, besides sperm, nutrients (nuptial gifts) rich in sodium, proteins, and amino acids. However, it is still poorly understood how adults, mostly nectarivores, extract nitrogen from the environment. We examined the availability of two ubiquitous inorganic nitrogenous ions in nature, viz. ammonium (or ammonia) and nitrate ions, as nutrients in a butterfly, and show that exogenous ammonia ingested by adult males of the swallowtail, Papilio polytes, can serve as a resource for protein biosynthesis. Feeding experiments with (15)N-labeled ammonium chloride revealed that nitrogen was incorporated into eupyrene spermatozoa, seminal protein, and thoracic muscle. Ammonia uptake by males significantly increased the number of eupyrene sperms in the reproductive tract tissues. The females also had the capacity to assimilate ammonia into egg protein. Consequently, it is evident that acquired ammonia is utilized for the replenishment of proteins allocable for reproduction and somatic maintenance. The active exploitation of exogenous ammonia as a nutrient by a butterfly would foster better understanding of the foraging and reproductive strategies in insects.

  18. Procurement of exogenous ammonia by the swallowtail butterfly, Papilio polytes, for protein biosynthesis and sperm production

    NASA Astrophysics Data System (ADS)

    Honda, Keiichi; Takase, Hiroyuki; Ômura, Hisashi; Honda, Hiroshi

    2012-09-01

    How to acquire sufficient quantity of nitrogen is a pivotal issue for herbivores, particularly for lepidopterans (butterflies and moths) of which diet quality greatly differs among their life stages. Male Lepidoptera often feed from mud puddles, dung, and carrion, a behavior known as puddling, which is thought to be supplementary feeding targeted chiefly at sodium. During copulation, males transfer a spermatophore to females that contains, besides sperm, nutrients (nuptial gifts) rich in sodium, proteins, and amino acids. However, it is still poorly understood how adults, mostly nectarivores, extract nitrogen from the environment. We examined the availability of two ubiquitous inorganic nitrogenous ions in nature, viz. ammonium (or ammonia) and nitrate ions, as nutrients in a butterfly, and show that exogenous ammonia ingested by adult males of the swallowtail, Papilio polytes, can serve as a resource for protein biosynthesis. Feeding experiments with 15N-labeled ammonium chloride revealed that nitrogen was incorporated into eupyrene spermatozoa, seminal protein, and thoracic muscle. Ammonia uptake by males significantly increased the number of eupyrene sperms in the reproductive tract tissues. The females also had the capacity to assimilate ammonia into egg protein. Consequently, it is evident that acquired ammonia is utilized for the replenishment of proteins allocable for reproduction and somatic maintenance. The active exploitation of exogenous ammonia as a nutrient by a butterfly would foster better understanding of the foraging and reproductive strategies in insects.

  19. Porcine embryo production following in vitro fertilization and intracytoplasmic sperm injection from vitrified immature oocytes matured with a granulosa cell co-culture system.

    PubMed

    Casillas, Fahiel; Ducolomb, Yvonne; Lemus, Ana E; Cuello, Cristina; Betancourt, Miguel

    2015-10-01

    This study was designed to evaluate the capacity of vitrified-warmed porcine immature oocytes to mature and to be fertilized using in vitro fertilization or intracytoplasmic sperm injection, and to determine the subsequent embryo development. Immature oocytes were vitrified using ethylene glycol and dimethylsulphoxide as cryoprotectants and the Cryolock method. After warming oocytes were cultured 44 h for maturation. Oocytes were randomly distributed in three treatment groups and subjected to in vitro fertilization (Experiment 1) or intracytoplasmic sperm injection (Experiment 2) procedures. The results indicate that the embryo development was higher in denuded oocytes co-cultured with granulosa cells (NkO-CC group) fertilized by in vitro fertilization or intracytoplasmic sperm injection compared to cumulus-cell oocyte complexes (COCs group), showing no significant differences with control. Vitrified denuded oocytes matured with a co-culture system NkO-CC group, displayed higher cleavage rate and blastocyst production than vitrified COCs group. Blastocysts were successfully obtained after IVF and ICSI procedures; however, the development to the blastocyst stage was better after IVF. These results show that the vitrification-warming media, the employment of a granulosa cell co-culture system and the Cryolock method during vitrification, increased the nuclear and cytoplasmic maturation of vitrified porcine immature oocytes. Further experiments are required to enhance porcine embryo production after vitrification.

  20. Competition between the sperm of a single male can increase the evolutionary rate of haploid expressed genes.

    PubMed

    Ezawa, Kiyoshi; Innan, Hideki

    2013-07-01

    The population genetic behavior of mutations in sperm genes is theoretically investigated. We modeled the processes at two levels. One is the standard population genetic process, in which the population allele frequencies change generation by generation, depending on the difference in selective advantages. The other is the sperm competition during each genetic transmission from one generation to the next generation. For the sperm competition process, we formulate the situation where a huge number of sperm with alleles A and B, produced by a single heterozygous male, compete to fertilize a single egg. This "minimal model" demonstrates that a very slight difference in sperm performance amounts to quite a large difference between the alleles' winning probabilities. By incorporating this effect of paternity-sharing sperm competition into the standard population genetic process, we show that fierce sperm competition can enhance the fixation probability of a mutation with a very small phenotypic effect at the single-sperm level, suggesting a contribution of sperm competition to rapid amino acid substitutions in haploid-expressed sperm genes. Considering recent genome-wide demonstrations that a substantial fraction of the mammalian sperm genes are haploid expressed, our model could provide a potential explanation of rapid evolution of sperm genes with a wide variety of functions (as long as they are expressed in the haploid phase). Another advantage of our model is that it is applicable to a wide range of species, irrespective of whether the species is externally fertilizing, polygamous, or monogamous. The theoretical result was applied to mammalian data to estimate the selection intensity on nonsynonymous mutations in sperm genes.

  1. Why mammalian lineages respond differently to sexual selection: metabolic rate constrains the evolution of sperm size.

    PubMed

    Gomendio, Montserrat; Tourmente, Maximiliano; Roldan, Eduardo R S

    2011-10-22

    The hypothesis that sperm competition should favour increases in sperm size, because it results in faster swimming speeds, has received support from studies on many taxa, but remains contentious for mammals. We suggest that this may be because mammalian lineages respond differently to sexual selection, owing to major differences in body size, which are associated with differences in mass-specific metabolic rate. Recent evidence suggests that cellular metabolic rate also scales with body size, so that small mammals have cells that process energy and resources from the environment at a faster rate. We develop the 'metabolic rate constraint hypothesis' which proposes that low mass-specific metabolic rate among large mammals may limit their ability to respond to sexual selection by increasing sperm size, while this constraint does not exist among small mammals. Here we show that among rodents, which have high mass-specific metabolic rates, sperm size increases under sperm competition, reaching the longest sperm sizes found in eutherian mammals. By contrast, mammalian lineages with large body sizes have small sperm, and while metabolic rate (corrected for body size) influences sperm size, sperm competition levels do not. When all eutherian mammals are analysed jointly, our results suggest that as mass-specific metabolic rate increases, so does maximum sperm size. In addition, species with low mass-specific metabolic rates produce uniformly small sperm, while species with high mass-specific metabolic rates produce a wide range of sperm sizes. These findings support the hypothesis that mass-specific metabolic rates determine the budget available for sperm production: at high levels, sperm size increases in response to sexual selection, while low levels constrain the ability to respond to sexual selection by increasing sperm size. Thus, adaptive and costly traits, such as sperm size, may only evolve under sexual selection when metabolic rate does not constrain cellular

  2. Effect of neonatal or adult heat acclimation on testicular and epididymal morphometry and sperm production in rats.

    PubMed

    Kurowicka, B; Dietrich, G J; Kotwica, G

    2015-03-01

    The accessory gland weight, testicular and epididymal morphometry and sperm production were analyzed in four groups of rats housed at 20 or 34°C: (1) control rats (CR) kept at 20°C from birth to day 90; (2) adult heat-acclimated rats (AHA) kept at 20°C from birth to day 45 followed by 34°C to day 90; (3) neonatal heat-acclimated rats (NHA) kept at 34°C from birth to day 90 and (4) de-acclimated rats (DA) kept at 34°C from birth to day 45 followed by 20°C to day 90. In NHA and DA rats, accessory gland weight was higher than in controls. Despite the lack of differences in testicular and epididymal morphometry, curvilinear velocity of spermatozoa was lower in the NHA group compared to controls. Areas of seminiferous tubules were lower in the DA than in CR and NHA groups, however, sperm concentration and motility were not affected by the treatment in this group. In AHA rats, epithelium of approximately 20% of seminiferous tubules was degenerated and Sertoli cell number was lower in the remaining tubules. In contrast to sperm motility, epididymal duct area, area of the duct occupied by spermatozoa and cauda epididymis sperm concentration were lower in AHA rats than in the other groups. In conclusion, neonatal heat acclimation did not affect the testicular morphometry and epididymal sperm concentration, suggesting adjustment to high ambient temperature. On the contrary, adult heat acclimation of rats affected the examined parameters, leading to decreased sperm concentration.

  3. Efficient production of intersubspecific hybrid mice and embryonic stem cells by intracytoplasmic sperm injection.

    PubMed

    Shinmen, Akie; Honda, Arata; Ohkawa, Mika; Hirose, Michiko; Ogonuki, Narumi; Yuzuriha, Misako; Miki, Hiromi; Mochida, Keiji; Inoue, Kimiko; Abe, Kuniya; Ito, Masao; Ogura, Atsuo

    2007-09-01

    Recently, mice and embryonic stem (ES) cells with allelic polymorphisms have been used extensively in the field of genetics and developmental biology. In this study, we examined whether intersubspecific hybrid mice and ES cells with these genotypes can be efficiently produced by intracytoplasmic sperm injection (ICSI). Frozen-thawed spermatozoa from wild-derived strains, JF1 (Mus musculus molossinus), MSM (M. m. molossinus), HMI (M. m. castaneus), and SWN (M. m. spp.), were directly injected into mature oocytes from laboratory mice ([C57BL/6 x DBA2]F1; M. m. domesticus). The in vitro and in vivo developmental capacity of F1 embryos was not significantly different among the groups (P > 0.05), and term offspring were efficiently obtained in all groups (27%-34% of transferred embryos). However, the mean body and placental weights of the offspring differed significantly with genotype (P < 5 x 10(-10)), with the HMI hybrid greatest in both body and placental weights. In an application study using these F1 offspring, we analyzed their mitochondrial DNA using intersubspecific polymorphisms and found the consistent disappearance of sperm mitochondrial DNA in the F1 progeny. In a second series of experiments, we generated F1 blastocysts by injecting MSM spermatozoa into C57BL/6 oocytes and used them to generate hybrid ES cell lines. The ES cell lines were established at a high efficiency (9 lines from 20 blastocysts) and their allelic polymorphisms were confirmed. Thus, ICSI using cryopreserved spermatozoa allows the efficient and immediate production of a number of F1 hybrid mice and ES cell lines, which can be used for polymorphic analysis of mouse genetics.

  4. Duration of spermatogenesis and daily sperm production in the jaguar (Panthera onca).

    PubMed

    Costa, G M J; Chiarini-Garcia, H; Morato, R G; Alvarenga, R L L S; França, L R

    2008-10-15

    The jaguar, like most wild felids, is an endangered species. Since there are few data regarding reproductive biology for this species, our main goal was to investigate basic aspects of the testis and spermatogenesis. Four adult male jaguars were utilized; to determine the duration of spermatogenesis, two animals received an intratesticular injection of H(3)-thymidine. Mean (+/-SEM) testis weight and the gonadosomatic index were 17.7+/-2.2g and 0.05+/-0.01%, respectively, whereas the seminiferous tubules and the Leydig cells volume density were 74.7+/-3.8 and 16.7+/-1.6%. Eight stages of spermatogenesis were characterized, according to the tubular morphology system and acrosome development. Each spermatogenic cycle and the entire spermatogenic process (based on 4.5 cycles) lasted approximately 12.8+/-0.01 and 57.7+/-0.07 d. The number of Sertoli and Leydig cells per gram of testis was 29+/-4 x 10(6) and 107+/-12 x 10(6). Based on the number of round spermatids per pachytene spermatocyte (2.8+/-0.3:1; meiotic index); significant cell loss (30%) occurred during the two meiotic divisions. There were approximately eight spermatids for each Sertoli cell (Sertoli cell efficiency), whereas the daily sperm production per gram of testis was 16.9+/-1.2 x 10(6). We expect that in the near future, the knowledge obtained in the present investigation will facilitate, utilizing germ cell transplantation, preservation of the germinal epithelium and the ability to generate sperm from jaguars in testes of domestic cats.

  5. Comparative evidence for the evolution of sperm swimming speed by sperm competition and female sperm storage duration in passerine birds.

    PubMed

    Kleven, Oddmund; Fossøy, Frode; Laskemoen, Terje; Robertson, Raleigh J; Rudolfsen, Geir; Lifjeld, Jan T

    2009-09-01

    Sperm swimming speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm swimming speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm swimming speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm swimming speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm swimming speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm swimming speed.

  6. Redox regulation of mammalian sperm capacitation

    PubMed Central

    O’Flaherty, Cristian

    2015-01-01

    Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of reactive oxygen species (ROS) that will trigger and regulate a series of events including protein phosphorylation, in a time-dependent fashion. The identity of the sperm oxidase responsible for the production of ROS involved in capacitation is still elusive, and several candidates are discussed in this review. Interestingly, ROS-induced ROS formation has been described during human sperm capacitation. Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon. Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation. Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans. Lactate dehydrogenase, glucose-6-phospohate dehydrogenase, and isocitrate dehydrogenase are responsible in supplying NAD (P) H for sperm capacitation. Peroxiredoxins (PRDXs) are newly described enzymes with antioxidant properties that can protect mammalian spermatozoa; however, they are also candidates for assuring the regulation of redox signaling required for sperm capacitation. The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility. PMID:25926608

  7. Sperm number trumps sperm size in mammalian ejaculate evolution

    PubMed Central

    Fitzpatrick, John L.

    2015-01-01

    Postcopulatory sexual selection is widely accepted to underlie the extraordinary diversification of sperm morphology. However, why does it favour longer sperm in some taxa but shorter in others? Two recent hypotheses addressing this discrepancy offered contradictory explanations. Under the sperm dilution hypothesis, selection via sperm density in the female reproductive tract favours more but smaller sperm in large, but the reverse in small, species. Conversely, the metabolic constraint hypothesis maintains that ejaculates respond positively to selection in small endothermic animals with high metabolic rates, whereas low metabolic rates constrain their evolution in large species. Here, we resolve this debate by capitalizing on the substantial variation in mammalian body size and reproductive physiology. Evolutionary responses shifted from sperm length to number with increasing mammalian body size, thus supporting the sperm dilution hypothesis. Our findings demonstrate that body-size-mediated trade-offs between sperm size and number can explain the extreme diversification in sperm phenotypes. PMID:26582027

  8. A quality assurance initiative for commercial-scale production in high-throughput cryopreservation of blue catfish sperm.

    PubMed

    Hu, E; Liao, T W; Tiersch, T R

    2013-10-01

    Cryopreservation of fish sperm has been studied for decades at a laboratory (research) scale. However, high-throughput cryopreservation of fish sperm has recently been developed to enable industrial-scale production. This study treated blue catfish (Ictalurus furcatus) sperm high-throughput cryopreservation as a manufacturing production line and initiated quality assurance plan development. The main objectives were to identify: (1) the main production quality characteristics; (2) the process features for quality assurance; (3) the internal quality characteristics and their specification designs; (4) the quality control and process capability evaluation methods, and (5) the directions for further improvements and applications. The essential product quality characteristics were identified as fertility-related characteristics. Specification design which established the tolerance levels according to demand and process constraints was performed based on these quality characteristics. Meanwhile, to ensure integrity throughout the process, internal quality characteristics (characteristics at each quality control point within process) that could affect fertility-related quality characteristics were defined with specifications. Due to the process feature of 100% inspection (quality inspection of every fish), a specific calculation method, use of cumulative sum (CUSUM) control charts, was applied to monitor each quality characteristic. An index of overall process evaluation, process capacity, was analyzed based on in-control process and the designed specifications, which further integrates the quality assurance plan. With the established quality assurance plan, the process could operate stably and quality of products would be reliable.

  9. Strain preference in donor and recipient for production of W-bearing sperm in mixed-sex germline chimeric chickens.

    PubMed

    Kagami, Hiroshi; Iwata, Junko; Yasuda, Jun; Ono, Tamao

    2002-02-01

    To elucidate the strain preference in donor and recipient for the production of W-bearing sperm, mixed-sex germline chimeric chickens were produced. The combination of donor and recipient was White Leghorn (WL) and Barred Plymouth Rock (BPR), and vice versa. Four sets of mixed-sex chimeras that had the male phenotype at sexual maturity were subjected to analysis: group 1, a female WL donor and a male BPR recipient; group 2, a male WL donor and a female BPR recipient; group 3, a female BPR donor and a male WL recipient; group 4, a male BPR donor and a female WL recipient. The mean number of W-bearing sperm detected by in situ hybridization among 10000 sperm observed was 135, 158, 26 and 71 in groups 1, 2, 3 and 4, respectively. The number in group 1 was significantly higher than that of group 3 (P<0.05). And the number in group 2 was significantly higher than those of groups 3 and 4 (P<0.05). It is suggested that the combination of a WL donor and a BPR recipient produced W-bearing sperm more efficiently than the reverse combination.

  10. PLCzeta(zeta): a sperm protein that triggers Ca2+ oscillations and egg activation in mammals.

    PubMed

    Swann, K; Saunders, C M; Rogers, N T; Lai, F A

    2006-04-01

    At fertilization in mammals, the sperm activates development by causing a prolonged series of intracellular Ca(2+) oscillations that are generated by increased production of inositol trisphosphate (InsP(3)). It appears that the sperm initiates InsP(3) generation via the introduction of a sperm factor into the egg after gamete membrane fusion. We recently identified a sperm-specific form of phospholipase C (PLC), referred to as PLCzeta(zeta). We review the evidence that PLCzeta represents the sperm factor that activates development of the egg and discuss the characteristics of PLCzeta that distinguish it from the somatic forms of PLC.

  11. Genetic sperm defects.

    PubMed

    Chenoweth, Peter J

    2005-08-01

    Genetic sperm defects are specific sperm defects, which have been shown to have a genetic mode of transmission. Such genetic linkage, either direct or indirect, has been associated with a number of sperm defects in different species, with this number increasing with improved diagnostic capabilities. A number of sperm defects, which have proven or suspected genetic modes of transmission are discussed herein, with particular emphasis on cattle. These include: 1. Acrosome defects (knobbed, ruffled and incomplete); 2. Head defects (abnormal condensation, decapitated, round head, rolled head, nuclear crest); 3. Midpiece abnormalities ("Dag" defect, "corkscrew" defect, "pseudo-droplet" defect); 4. Tail defects ("tail stump" defect, primary ciliary dyskinesia).

  12. Lactate and Pyruvate Are Major Sources of Energy for Stallion Sperm with Dose Effects on Mitochondrial Function, Motility, and ROS Production.

    PubMed

    Darr, Christa R; Varner, Dickson D; Teague, Sheila; Cortopassi, Gino A; Datta, Sandipan; Meyers, Stuart A

    2016-08-01

    Stallion sperm rely primarily on oxidative phosphorylation for production of ATP used in sperm motility and metabolism. The objective of the study was to identify which substrates included in Biggers, Whitten, and Whittingham (BWW) media are key to optimal mitochondrial function through measurements of sperm motility parameters, mitochondrial oxygen consumption, and cellular reactive oxygen species (ROS) production. It was expected that mitochondrial substrates, pyruvate and lactate, would support sperm motility and mitochondrial function better than the glycolytic substrate, glucose, due to direct utilization within the mitochondria. Measurements were performed after incubation in modified BWW media with varying concentrations of lactate, pyruvate, and glucose. The effects of media and duration of incubation on sperm motility, ROS production, and oxygen consumption were determined using a linear mixed-effects model. Duplicate ejaculates from four stallions were used in three separate experiments to determine the effects of substrate availability and concentration on sperm motility and mitochondrial function and the relationship of oxygen consumption with cellular ROS production. The present results indicate that lactate and pyruvate are the most important sources of energy for stallion sperm motility and velocity, and elicit a dose-dependent response. Additionally, lactate and pyruvate are ideal for maximal mitochondrial function, as sperm in these media operate at a very high level of their bioenergetic capability due to the high rate of energy metabolism. Moreover, we found that addition of glucose to the media is not necessary for short-term storage of equine sperm, and may even result in reduction of mitochondrial function. Finally, we have confirmed that ROS production can be the result of mitochondrial dysfunction as well as intense mitochondrial activity.

  13. Environmental chemicals impact dog semen quality in vitro and may be associated with a temporal decline in sperm motility and increased cryptorchidism

    PubMed Central

    Lea, Richard G.; Byers, Andrew S.; Sumner, Rebecca N.; Rhind, Stewart M.; Zhang, Zulin; Freeman, Sarah L.; Moxon, Rachel; Richardson, Holly M.; Green, Martin; Craigon, Jim; England, Gary C. W.

    2016-01-01

    Adverse temporal trends in human semen quality and cryptorchidism in infants have been associated with exposure to environmental chemicals (ECs) during development. Here we report that a population of breeding dogs exhibit a 26 year (1988–2014) decline in sperm quality and a concurrent increased incidence of cryptorchidism in male offspring (1995–2014). A decline in the number of males born relative to the number of females was also observed. ECs, including diethylhexyl phthalate (DEHP) and polychlorinated bisphenol 153 (PCB153), were detected in adult dog testes and commercial dog foods at concentrations reported to perturb reproductive function in other species. Testicular concentrations of DEHP and PCB153 perturbed sperm viability, motility and DNA integrity in vitro but did not affect LH stimulated testosterone secretion from adult testis explants. The direct effects of chemicals on sperm may therefore contribute to the decline in canine semen quality that parallels that reported in the human. PMID:27503122

  14. Comparative responses of sperm cells and embryos of Pacific oyster (Crassostrea gigas) to exposure to metolachlor and its degradation products.

    PubMed

    Mai, Huong; Gonzalez, Patrice; Pardon, Patrick; Tapie, Nathalie; Budzinski, Hélène; Cachot, Jérôme; Morin, Bénédicte

    2014-02-01

    Metolachlor is one of the most intensively used chloroacetanilide herbicides in agriculture. Consequently, it has been frequently detected in coastal waters as well as its major degradation products, metolachlor ethane sulfonic acid (MESA) and metolachlor oxanilic acid (MOA) which are encountered at higher concentrations than metolachlor. Although a few studies of metolachlor toxicity have been conducted on marine organisms, little is known about the environmental toxicity of metolachlor degradation products. In this study, the deleterious effects of metolachlor and its degradation products on spermatozoa and embryos of Crassostrea gigas have been compared using biomarkers of developmental defects, DNA damage and gene transcription levels. After 24h exposure, significant increases in the percentage of abnormal D-larvae and DNA damage were observed from 0.01 μg L(-1) for S-metolachlor and 0.1 μg L(-1) for MESA and MOA. Results showed that S-metolachlor was more embryotoxic and genotoxic than its degradation products. Oyster sperm was also very sensitive to metolachlor exposure and followed the pattern: metolachlor (0.01 μg L(-1))>MOA (0.1 μg L(-1))>MESA (1 μg L(-1)). Metolachlor and MESA mainly triggered variations in the transcription level of genes encoding proteins involved in oxidative stress responses (mitochondrial superoxide dismutase and catalase). Overall, no significant variation in transcription levels could be detected in C. gigas embryos exposed to MOA. This study demonstrates that metolachlor and its main degradation products have the potential to impact several steps of oyster development and therefore recruitment in coastal areas exposed to chronic inputs of pesticides.

  15. Effects of pulse-modulated microwave radiation and conventional heating on sperm production

    SciTech Connect

    Lebovitz, R.M.; Johnson, L.; Samson, W.K.

    1987-01-01

    The effects on testicular function of pulse-modulated microwave radiation (PM MWR, 1.3 GHz) and of conventional heating were studied in the rat. Anesthetized adult males (Sprague-Dawley, 400-500 g) were treated then killed at specific intervals with respect to the 13-day cycle of the seminiferous epithelium. PM MWR at 7.7 mW/g (90 min) yielded a modest decline in daily sperm production (DSP) that derived primarily from effects on primary spermatocytes. PM MWR at 4.2 mW/g was ineffective. The mean intratesticular temperature during the former reached 40 degrees C and did not exceed 38 degrees C during the latter. MWR considerably in excess of 7.7 mW/g yielded decrements in virtually all germ cell types, with primary spermatocytes again being most markedly affected. Using conventional heating, intratesticular temperatures in excess of 39 degrees C for 60 min were required for significant decrements in DSP. Levels of circulating follicle-stimulating hormone and of leutinizing hormone were resistant to either treatment. We conclude that the damage threshold and the differential sensitivity of immature germ cells to PM MWR can be adequately explained by the consequent macroscopic heating.

  16. Seminal quality and sperm production in beef bulls with chronic dietary vitamin A deficiency and subsequent re-alimentation.

    PubMed

    Rode, L M; Coulter, G H; Kastelic, J P; Bailey, D R

    1995-05-01

    Sixteen Hereford bulls (16 mo of age, 462 kg average body weight) were used in each of 2 yr to evaluate the effects of hypovitaminosis A on seminal quality and sperm production. Bulls were fed a high-concentrate diet with (+VIT) or without (-VIT) supplemental Vitamin A until the apparent onset of hypovitaminosis A (28 and 32 wk in Year 1 and 2, respectively). Half of the bulls on each treatment were then slaughtered and those remaining were re-alimented with Vitamin A. Plasma retinol concentration in -VIT bulls reached a nadir at approximately 25 wk. In Year 1, the proportion of progressively motile spermatozoa was lower in -VIT bulls after 17 wk but returned to that of the +VIT group after re-alimentation. The proportion of spermatozoa with primary morphological defects appeared to be greater in -VIT bulls compared to +VIT bulls by 26 and 24 wk in Year 1 and 2, respectively. The incidence of these defects declined in -VIT bulls upon re-alimentation, and approached the incidence observed in +VIT bulls by 8 to 12 wk of re-alimentation. Hypovitaminosis A decreased paired testes weight, daily sperm production, and epididymal sperm reserves but did not affect daily gain. Prolonged dietary Vitamin A deficiency impaired semen quality and sperm production in the absence of other clinical symptoms. However, under practical feeding conditions, diets that result in long-term, marginal Vitamin A deficiency or a relatively short-term absence of Vitamin A intake probably would have minimal effects on spermatogenesis.

  17. In vitro production of cattlexbuffalo hybrid embryos using cattle oocytes and African buffalo (Syncerus caffer caffer) epididymal sperm.

    PubMed

    Owiny, O D; Barry, D M; Agaba, M; Godke, R A

    2009-04-01

    Interspecies hybridization of bovids occurs between domestic cattle and at least three other species; American bison (Bison bison), yak (Bos grunniens) and banteng (Bos banteng). Birth of a cattlexbuffalo (Bubalus bubalis) hybrid has reportedly occurred in Russia and in China, but these reports were not authenticated. Such hybrids could be important in improving livestock production and management of diseases that impede production in tropical Africa. This study investigated hybridization between cattle and its closest African wild bovid relative, the African buffalo (Syncerus caffer caffer). In an attempt to produce cattlexbuffalo hybrid embryos in vitro, matured cattle oocytes were subjected to a standard in vitro fertilization (IVF) procedure with either homologous cattle (n=1166 oocytes) or heterologous African buffalo (n=1202 oocytes) frozen-thawed epididymal sperm. After IVF, 67.2% of the oocytes inseminated with the homologous cattle sperm cleaved. In contrast, fertilization with buffalo sperm resulted in only a 4.6% cleavage rate. The cleavage intervals were also slower in hybrid embryos than in the IVF-derived cattle embryos. Of the cleaved homologous cattle embryos 52.2% progressed to the morula stage compared with 12.7% for the buffalo hybrid embryos. No hybrid embryos developed beyond the early morula stage, while 40.1% of the cleaved cattlexcattle embryos developed to the blastocyst stage. Transfer of buffalo hybrid IVF embryos to domestic cattle surrogates resulted in no pregnancies at 60 days post-transfer. This study indicates that interspecies fertilization of cattle oocytes with African buffalo epididymal sperm can occur in vitro, and that a barrier to hybridization occurs in the early stages of embryonic development. Chromosomal disparity is likely the cause of the fertilization abnormalities, abnormal development and subsequent arrest impairing the formation of hybrid embryos beyond the early morula stage. Transfer of the buffalo hybrid embryos

  18. Low Sperm Count

    MedlinePlus

    ... unknown, it might be related to abnormal testicular temperature regulation. Varicoceles result in reduced quality of the ... can be permanently reduced. Overheating the testicles. Elevated temperatures impair sperm production and function. Although studies are ...

  19. Low seminal zinc bound to high molecular weight proteins in asthenozoospermic patients: evidence of increased sperm zinc content in oligoasthenozoospermic patients.

    PubMed

    Carpino, A; Siciliano, L; Petroni, M F; De Stefano, C; Aquila, S; Andó, S; Petrone, M F

    1998-01-01

    Total seminal zinc concentration, seminal zinc fraction bound to high molecular weight proteins (HMW-Zn%) and zinc content in spermatozoa were assayed in the ejaculates of 90 asthenozoospermic patients subdivided into two study groups: normoasthenozoospermics (group I: n = 50) and oligoasthenozoospermics (group II: n = 40). The zinc concentrations of patients were compared with those of a control group of donors showing normal semen parameters. All samples were also investigated for their sperm membrane functional integrity by the hypo-osmotic swelling test (HOS). The results showed normal total zinc concentrations but very low HMW-Zn% values (P < 0.001) in seminal plasma of the two groups of asthenozoospermic patients compared to the controls. Furthermore higher zinc amounts (P < 0.001) were measured in spermatozoa of oligoasthenozoospermic patients compared to group I and to the control group. Oligoasthenozoospermics also displayed a lower HOS score (P < 0.001) compared to the other two groups. These data suggest that the increased unbound seminal zinc could contribute to the decrease of sperm motility in normoasthenozoospermic and oligoasthenozoospermic patients. A further impairment in sperm motility could occur in the oligoasthenozoospermic patients where the increase of seminal free zinc was followed by a major zinc uptake by spermatozoa. The higher intrasperm zinc content in these patients could be a reflection of their low sperm membrane functionality.

  20. Sex-Sorted Boar Sperm - An Update on Related Production Methods.

    PubMed

    Rath, D; Tiedemann, D; Gamrad, L; Johnson, L A; Klein, S; Kues, W; Mancini, R; Rehbock, C; Taylor, U; Barcikowski, S

    2015-07-01

    As in other mammals, sex sorting of pig sperm is based on quantitative flow cytometry. A major disadvantage of the technique is the relatively low efficiency to produce enough sorted sperm for artificial insemination. However, several approaches are on the way to make sexed pig sperm available for commercial application. In this context, for example, the growing field of nanotechnology may significantly contribute to these developments, as it provides highly efficient bio-nanoprobes, for example, based on plasmonic nanoparticles. Independent of the method, further development requires enormous investments and set-up of logistics to get the technology into the practical pig market. Only global players will be able to establish the necessary research projects, but in the end, a significant shift of sex ratios will be available for pig producers as it is already the case for the dairy industry.

  1. Sperm competition and sperm cooperation: the potential role of diploid and haploid expression.

    PubMed

    Immler, Simone

    2008-03-01

    Sperm competition is a powerful selective force driving the evolution of sperm shape and function. Recent findings suggest that sperm cooperation is a potential evolutionary response to sperm competition. Sperm cooperation may enhance the performance of the ejaculate increasing a male's chance to outcompete rival males in competition for fertilisation. Whether and how sperm cooperation may evolve is the focal point of this review. The relative importance of haploid and diploid gene expression for the evolution of sperm cooperation and the potential conflict of interest between (i) haploid sperm and diploid male and (ii) among sibling sperm, since sibling sperm only share an average of 50% of their genes in a diploid organism, are discussed. Furthermore, sperm cooperation is defined and the literature for empirical evidence of sperm cooperation is reviewed in light of the author's definitions.

  2. Off-axis effects on the multipulse structure of sperm whale usual clicks with implications for sound production

    NASA Astrophysics Data System (ADS)

    Zimmer, Walter M. X.; Madsen, Peter T.; Teloni, Valeria; Johnson, Mark P.; Tyack, Peter L.

    2005-11-01

    Sperm whales (Physeter macrocephalus) produce multipulsed clicks with their hypertrophied nasal complex. The currently accepted view of the sound generation process is based on the click structure measured directly in front of, or behind, the whale where regular interpulse intervals (IPIs) are found between successive pulses in the click. Most sperm whales, however, are recorded with the whale in an unknown orientation with respect to the hydrophone where the multipulse structure and the IPI do not conform to a regular pulse pattern. By combining far-field recordings of usual clicks with acoustic and orientation information measured by a tag on the clicking whale, we analyzed clicks from known aspects to the whale. We show that a geometric model based on the bent horn theory for sound production can explain the varying off-axis multipulse structure. Some of the sound energy that is reflected off the frontal sac radiates directly into the water creating an intermediate pulse p1/2 seen in off-axis recordings. The powerful p1 sonar pulse exits the front of the junk as predicted by the bent-horn model, showing that the junk of the sperm whale nasal complex is both anatomically and functionally homologous to the melon of smaller toothed whales.

  3. Production of fertile sperm from in vitro propagating enriched spermatogonial stem cells of farmed catfish, Clarias batrachus.

    PubMed

    Nayak, Swapnarani; Ferosekhan, Shajahan; Sahoo, Sangram Ketan; Sundaray, Jitendra Kumar; Jayasankar, Pallipuram; Barman, Hirak Kumar

    2016-12-01

    Spermatogenesis is a highly co-ordinated and complex process. In vitro propagation of spermatogonial stem cells (SSCs) could provide an avenue in which to undertake in vivo studies of spermatogenesis. Very little information is known about the SSC biology of teleosts. In this study, collagenase-treated testicular cells of farmed catfish (Clarias batrachus, popularly known as magur) were purified by Ficoll gradient centrifugation followed by magnetic activated cell sorting using Thy1.2 (CD90.2) antibody to enrich for the spermatogonial cell population. The sorted spermatogonial cells were counted and gave ~3 × 106 cells from 6 × 106 pre-sorted cells. The purified cells were cultured in vitro for >2 months in L-15 medium containing fetal bovine serum (10%), carp serum (1%) and other supplements. Microscopic observations depicted typical morphological SSC features, bearing a larger nuclear compartment (with visible perinuclear bodies) within a thin rim of cytoplasm. Cells proliferated in vitro forming clumps/colonies. mRNA expression profiling by qPCR documented that proliferating cells were Plzf + and Pou2+, indicative of stem cells. From 60 days onwards of cultivation, the self-renewing population differentiated to produce spermatids (~6 × 107 on day 75). In vitro-produced sperm (2260 sperm/SSC) were free swimming in medium and hence motile (non-progressive) in nature. Of those, 2% were capable of fertilizing and generated healthy diploid fingerlings. Our documented evidence provides the basis for producing fertile magur sperm in vitro from cultured magur SSCs. Our established techniques of SSC propagation and in vitro sperm production together should trigger future in vivo experiments towards basic and applied biology research.

  4. Glucose-6-phosphate dehydrogenase deficiency does not increase the susceptibility of sperm to oxidative stress induced by H2O2

    PubMed Central

    Roshankhah, Shiva; Rostami-Far, Zahra; Shaveisi-Zadeh, Farhad; Movafagh, Abolfazl; Shaveisi-Zadeh, Jila

    2016-01-01

    Objective Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect. G6PD plays a key role in the pentose phosphate pathway, which is a major source of nicotinamide adenine dinucleotide phosphate (NADPH). NADPH provides the reducing equivalents for oxidation-reduction reductions involved in protecting against the toxicity of reactive oxygen species such as H2O2. We hypothesized that G6PD deficiency may reduce the amount of NADPH in sperms, thereby inhibiting the detoxification of H2O2, which could potentially affect their motility and viability, resulting in an increased susceptibility to infertility. Methods Semen samples were obtained from four males with G6PD deficiency and eight healthy males as a control. In both groups, motile sperms were isolated from the seminal fluid and incubated with 0, 10, 20, 40, 60, 80, and 120 µM concentrations of H2O2. After 1 hour incubation at 37℃, sperms were evaluated for motility and viability. Results Incubation of sperms with 10 and 20 µM H2O2 led to very little decrease in motility and viability, but motility decreased notably in both groups in 40, 60, and 80 µM H2O2, and viability decreased in both groups in 40, 60, 80, and 120 µM H2O2. However, no statistically significant differences were found between the G6PD-deficient group and controls. Conclusion G6PD deficiency does not increase the susceptibility of sperm to oxidative stress induced by H2O2, and the reducing equivalents necessary for protection against H2O2 are most likely produced by other pathways. Therefore, G6PD deficiency cannot be considered as major risk factor for male infertility. PMID:28090457

  5. Individual adjustment of sperm expenditure accords with sperm competition theory.

    PubMed

    Pilastro, Andrea; Scaggiante, Marta; Rasotto, Maria B

    2002-07-23

    Sperm competition theory predicts that males should strategically allocate their sperm reserves according to the level of sperm competition, defined as the probability that the sperm of two males compete for fertilizing a given set of ova. Substantial evidence from numerous animal taxa suggests that, at the individual level, sperm expenditure increases when the risk of sperm competition is greater. In contrast, according to the "intensity model" of sperm competition [Parker, G. A., Ball, M. A., Stockley, P. & Gage, M. J. G. (1996) Proc. R. Soc. London Ser. B 263, 1291-1297], when more than two ejaculates compete during a given mating event, sperm expenditure should decrease as the number of competing males increases. Empirical evidence supporting this prediction, however, is still lacking. Here we measured sperm expenditure in two gobiid fishes, the grass (Zosterisessor ophiocephalus) and black goby (Gobius niger), in which up to six sneakers can congregate around the nest of territorial males and release their sperm when females spawn. We show that, in accordance with theory, sneaker males of both species release fewer sperm as the number of competitors increases.

  6. Sperm competition generates evolution of increased paternal investment in a sex role-reversed seed beetle.

    PubMed

    Booksmythe, I; Fritzsche, K; Arnqvist, G

    2014-12-01

    When males provide females with resources at mating, they can become the limiting sex in reproduction, in extreme cases leading to the reversal of typical courtship roles. The evolution of male provisioning is thought to be driven by male reproductive competition and selection for female fecundity enhancement. We used experimental evolution under male- or female-biased sex ratios and limited or unlimited food regimes to investigate the relative roles of these routes to male provisioning in a sex role-reversed beetle, Megabruchidius tonkineus, where males provide females with nutritious ejaculates. Males evolving under male-biased sex ratios transferred larger ejaculates than did males from female-biased populations, demonstrating a sizeable role for reproductive competition in the evolution of male provisioning. Although larger ejaculates elevated female lifetime offspring production, we found little evidence of selection for larger ejaculates via fecundity enhancement: males evolving under resource-limited and unlimited conditions did not differ in mean ejaculate size. Resource limitation did, however, affect the evolution of conditional ejaculate allocation. Our results suggest that the resource provisioning that underpins sex role reversal in this system is the result of male-male reproductive competition rather than of direct selection for males to enhance female fecundity.

  7. Sperm competition games: the risk model can generate higher sperm allocation to virgin females.

    PubMed

    Ball, M A; Parker, G A

    2007-03-01

    We examine the risk model in sperm competition games for cases where female fertility increases significantly with sperm numbers (sperm limitation). Without sperm competition, sperm allocation increases with sperm limitation. We define 'average risk' as the probability q that females in the population mate twice, and 'perceived risk' as the information males gain about the sperm competition probability with individual females. If males obtain no information from individual females, sperm numbers increase with q unless sperm limitation is high and one of the two competing ejaculates is strongly disfavoured. If males can distinguish between virgin and mated females, greater sperm allocation to virgins is favoured by high sperm limitation, high q, and by the second male's ejaculate being disfavoured. With high sperm limitation, sperm allocation to virgins increases and to mated females decreases with q at high q levels. With perfect information about female mating pattern, sperm allocation (i) to virgins that will mate again exceeds that to mated females and to virgins that will mate only once, (ii) to virgins that mate only once exceeds that for mated females if q is high and there is high second male disadvantage and (iii) to each type of female can decrease with q if sperm limitation is high, although the average allocation increases at least across low q levels. In general, higher sperm allocation to virgins is favoured by: strong disadvantage to the second ejaculate, high sperm limitation, high average risk and increased information (perceived risk). These conditions may apply in a few species, especially spiders.

  8. Processing and selection of surgically-retrieved sperm for ICSI: a review.

    PubMed

    Verheyen, Greta; Popovic-Todorovic, Biljana; Tournaye, Herman

    2017-01-01

    Although the technique of intracytoplasmic sperm injection (ICSI) has been a revolution in the alleviation of male infertility, the use of testicular sperm for ICSI was a formerly unseen breakthrough in the treatment of the azoospermic man with primary testicular failure. At the clinical level, different procedures of testicular sperm retrieval (conventional TESE, micro-TESE, FNA/TESA, MESA, PESA) are being performed, the choice is mainly based on the cause of azoospermia (obstructive versus non-obstructive) and the surgeon's skills. At the level of the IVF laboratory, mechanical procedures to harvest the sperm from the tissue may be combined with enzymatic treatment in order to increase the sperm recovery rates. A number of techniques have been developed for viable sperm selection in males with only immotile testicular sperm available. However, large, well-designed studies on the benefit and safety of one over the other technique are lacking. Despite all the available methods and combinations of laboratory procedures which have a common goal to maximize sperm recovery from testicular samples, a large proportion of NOA patients fail to father a genetically own child. Advanced technology application may improve recovery rates by detection of the testicular foci with active spermatogenesis and/or identification of the rare individual sperm in the testicular suspensions. On the other hand, in vitro spermatogenesis or sperm production from embryonic stem cells or induced pluripotent stem cells might be future options. The present review summarizes the available strategies which aim to maximize sperm recovery from surgically retrieved samples.

  9. In vitro production of haploid sperm cells from male germ cells of foetal cattle.

    PubMed

    Dong, Wu-Zi; Hua, Jin-Lian; Shen, Wen-Zheng; Dou, Zhong-Ying

    2010-04-01

    The purpose of this study was to isolate the foetal cattle male germ cells (mGCs) and then induce them into sperm cells. The mGCs were purified and enriched by a two-step plating method based on the different adherence velocities of mGCs and somatic cells. The percentage of the vasa and the c-kit positive cells were 95.34+/-2.25% and 53.3+/-1.03% by using flow cytometry analysis (FCA), respectively. In feeder-free culture system, the half-suspending cells appeared and formed a 16-cell rosary in medium after the mGCs were cultured for 6-8 days. On immunocytochemical staining during the second passage, some single cells adhering to the plate appeared to be both Oct-4 and alpha6-integrin positive. During the third passage, the mGCs were induced for 48 h by retinol acid (RA) on Sertoli cell-feeder layer, followed by 5-7 days culture in an RA-free medium. Some elongated sperm-like cells appeared in the medium at this stage. We found that the most effective concentration of RA for the inducement was 10(-7)moll(-1) (P<0.01). The haploid cells in suspension were identified by FCA. The elongated sperm-like cells showed proacrosome-like structure and the flagellum with fibre construct under electron microscopy. The mRNA of outer dense fibre-3 (ODF-3) and transcription protein-1 (TP-1) could be detected in the suspended cells by using reverse transcription polymerase chain reaction (RT-PCR). About 23.1% bovine oocytes could be activated to perform cleavage by intracytoplasmic injection with the sperm-like cells, but embryos did not further develop. Our investigation further demonstrated that foetal cattle mGCs could be induced in vitro into haploid sperm in the short term.

  10. Tuning sperm chemotaxis.

    PubMed

    Guerrero, Adán; Wood, Christopher D; Nishigaki, Takuya; Carneiro, Jorge; Darszon, Alberto

    2010-10-01

    Sperm chemotaxis is a long-term puzzle and most of our knowledge comes from studying marine animals that are external fertilizers. Sperm are attracted by diffusible chemical factors (chemoattractants) released from the egg which redirect their swimming paths towards their source. This redirection is driven by increases in flagellar curvature that correlate with transient flagellar Ca(2+) increases. Recent experimental and modelling results provide insights into the signal flow underlying the translation of an external chemical gradient into an intracellular molecular and motor response. A fundamental element of sea-urchin sperm chemotaxis lies in the ability of these cells to suppress Ca(2+)-mediated increases in flagellar curvature while experiencing an increasing chemoattractant gradient. The article considers this new evidence and summarizes the known underlying cellular mechanisms and behavioural strategies that sperm use to locate and fertilize the oocyte.

  11. Fracturing high-permeability reservoirs increases productivity

    SciTech Connect

    Dusterhoft, R.G. ); Chapman, B.J. )

    1994-06-20

    Hydraulic fracturing of high-permeability reservoirs has increased long-term hydrocarbon production and reduced sand production in many areas of the world. A key element is the reduction of near well bore drawdown during production. Drawdown, the difference between reservoir and production pressures, is the driving force for flow into the well bore. As drawdown increases because of higher production rates or depletion, formation instability may cause fines and sand to migrate into the well bore region. A greater well bore radius reduces both radial velocity and drawdown. Fracturing beyond the well bore region effectively bypasses the damaged zone, increasing the effective radius of the well bore and enabling higher flow rates with lower drawdown pressures. In essence, the reservoir energy is used more efficiently because the conductive proppant bed bypasses the near well bore restrictions. The paper discusses candidate well selection; proppant selection; sand control; minifrac procedures; spurt losses; fracture design; equipment; case histories in West Africa and offshore Louisiana.

  12. Modified Withdrawal Slot Increases Silicon Production

    NASA Technical Reports Server (NTRS)

    Piotrowsky, P. A.; Duncan, C. S.

    1988-01-01

    New shape reduces ribbon breakage and resulting idle time. Shape for slot through which single-crystal silicon ribbon pulled from melt increases productivity. Reduces tendency of emerging ribbon to grow thin and break.

  13. Diploid males, diploid sperm production, and triploid females in the ant Tapinoma erraticum

    NASA Astrophysics Data System (ADS)

    Cournault, Laurent; Aron, Serge

    2009-12-01

    Under complementary sex determination (CSD), females of Hymenoptera arise from diploid, fertilized eggs and males from haploid, unfertilized eggs. Incidentally, fertilized eggs that inherit two identical alleles at the CSD locus will develop into diploid males. Diploid males are usually unviable or sterile. In a few species, however, they produce diploid sperm and father a triploid female progeny. Diploid males have been reported in a number of social Hymenoptera, but the occurrence of triploid females has hardly ever been documented. Here, we report the presence of triploid females, diploid males, and diploid sperm (produced by diploid males and stored in queen spermathecae) in the ant Tapinoma erraticum. Moreover, we show variations in the frequency of triploids among female castes: Triploid females are more frequent among workers than virgin queens; they are absent among mated, reproductive queens. The frequency of triploid workers also varies between populations and between nests within populations.

  14. Laser radiation and motility patterns of human sperm

    SciTech Connect

    Lenzi, A.; Claroni, F.; Gandini, L.; Lombardo, F.; Barbieri, C.; Lino, A.; Dondero, F. )

    1989-01-01

    Human sperm were exposed in vitro to laser radiation. An increase in progressive sperm motility was associated with a faster rate of sperm ATP consumption. Computer-assisted analysis of sperm motility confirmed the positive effect of laser irradiation on velocity and linearity of sperm.

  15. The effects of four insect growth-regulating (IGR) insecticides on honeybee (Apis mellifera L.) colony development, queen rearing and drone sperm production.

    PubMed

    Thompson, Helen M; Wilkins, Selwyn; Battersby, Alastair H; Waite, Ruth J; Wilkinson, David

    2005-10-01

    This study assessed the effects of exposure to IGRs on the long-term development of the honeybee colony, viability of queens and sperm production in drones and integrated the data into a honeybee population model. Colonies treated with diflubenzuron resulted in a short-term reduction in the numbers of adult bees and brood. Colonies treated with fenoxycarb declined during the season earlier and started the season slower. The number of queens that successfully mated and laid eggs was affected in the fenoxycarb treatment group but there were no significant differences in the drone sperm counts between the colonies. An existing honeybee population model was modified to include exposure to IGRs. In the model, fenoxycarb reduced the winter size of the colony, with the greatest effects following a June or an August application. Assuming a 'larvae per nurse bee' ratio of 1.5 for brood rearing capability, the reduction in winter size of a colony following a fenoxycarb application was at its worst about 8%. However, even if only those bees reared within 2 weeks of the IGR being applied are subject to premature ageing, this might significantly reduce the size of over-wintering colonies, and increase the chance of the bee population dwindling and dying in late winter or early spring.

  16. Fires increase Amazon forest productivity through increases in diffuse radiation

    NASA Astrophysics Data System (ADS)

    Rap, A.; Spracklen, D. V.; Mercado, L.; Reddington, C. L.; Haywood, J. M.; Ellis, R. J.; Phillips, O. L.; Artaxo, P.; Bonal, D.; Restrepo Coupe, N.; Butt, N.

    2015-06-01

    Atmospheric aerosol scatters solar radiation increasing the fraction of diffuse radiation and the efficiency of photosynthesis. We quantify the impacts of biomass burning aerosol (BBA) on diffuse radiation and plant photosynthesis across Amazonia during 1998-2007. Evaluation against observed aerosol optical depth allows us to provide lower and upper BBA emissions estimates. BBA increases Amazon basin annual mean diffuse radiation by 3.4-6.8% and net primary production (NPP) by 1.4-2.8%, with quoted ranges driven by uncertainty in BBA emissions. The enhancement of Amazon basin NPP by 78-156 Tg C a-1 is equivalent to 33-65% of the annual regional carbon emissions from biomass burning. This NPP increase occurs during the dry season and acts to counteract some of the observed effect of drought on tropical production. We estimate that 30-60 Tg C a-1 of this NPP enhancement is within woody tissue, accounting for 8-16% of the observed carbon sink across mature Amazonian forests.

  17. An Extract of Pomegranate Fruit and Galangal Rhizome Increases the Numbers of Motile Sperm: A Prospective, Randomised, Controlled, Double-Blinded Trial

    PubMed Central

    Fedder, Maja D. K.; Jakobsen, Henrik B.; Giversen, Ina; Christensen, Lars P.; Parner, Erik T.; Fedder, Jens

    2014-01-01

    Pomegranate fruit (Punica granatum) and galangal (Alpinia galanga) have separately been shown to stimulate spermatogenesis and to increase sperm counts and motility in rodents. Within traditional medicine, pomegranate fruit has long been used to increase fertility, however studies on the effect on spermatogenesis in humans have never been published. With this study we investigated whether oral intake of tablets containing standardised amounts of extract of pomegranate fruit and powder of greater galangal rhizome (Punalpin) would increase the total number of motile spermatozoa. The study was designed as a prospective, randomized, controlled, double-blinded trial. Enrolment was based on the mean total number of motile spermatozoa of two ejaculates. The participants delivered an ejaculate after 4–8 days of tablet intake and two ejaculates just before they stopped taking the tablets. Seventy adult men with a semen quality not meeting the standards for commercial application at Nordic Cryobank, but without azoospermia, were included in the study. Participants were randomized to take tablets containing extract of pomegranate fruit (standardised with respect to punicalagin A+B, punicalin and ellagic acid) and freeze-dried rhizome of greater galangal (standardised with respect to 1′S-1′-acetoxychavicol acetate) or placebo on a daily basis for three months. Sixty-six participants completed the intervention (active treatment: n = 34; placebo: n = 32). After the intervention the total number of motile spermatozoa was increased in participants treated with plant extracts compared with the placebo group (p = 0.026). After three months of active treatment, the average total number of motile sperm increased by 62% (from 23.4 to 37.8 millions), while for the placebo group, the number of motile sperm increased by 20%. Sperm morphology was not affected by the treatment. Our findings may help subfertile men to gain an improved amount of motile ejaculated sperm by

  18. A diet supplemented with L-carnitine improves the sperm quality of Piétrain but not of Duroc and Large White boars when photoperiod and temperature increase.

    PubMed

    Yeste, M; Sancho, S; Briz, M; Pinart, E; Bussalleu, E; Bonet, S

    2010-03-15

    It has been reported that a diet supplemented with L-carnitine can improve sperm quality in some mammalian species. Against this background, the current study seeks to determine the effects of feeding L-carnitine (625 mg day(-1)) on boar semen characteristics (ejaculate volume, sperm concentration, sperm viability, acrosome and mitochondrial sheath integrity, sperm motility, sperm morphology, and osmotic resistance of spermatozoa) in three different porcine breeds (Sus domesticus) (Piétrain, Duroc, and Large White) exposed to natural environmental changes in temperature and photoperiod over a 20-wk period (February to July 2007). One hundred twenty boars (40 per breed) were randomly separated into two groups (60 boars each): the first (20 boars per breed) was fed a control diet and the second (also 20 males per breed) the same diet supplemented with L-carnitine (625 mg day(-1)). Whereas the L-carnitine supplement did not affect ejaculate volume, concentration, motility, viability, or the osmotic resistance of spermatozoa, it did improve sperm morphology in Piétrain boars by reducing the percentage of immature spermatozoa when the temperature and the photoperiod increased. Conversely, no effect on sperm morphology from supplementing feed with L-carnitine was observed in both Duroc and Large White breeds. We can therefore conclude that the addition of L-carnitine to the diet of males may maintain the level of normal sperm morphology in Piétrain boars when a drop in sperm quality occurs (due to increases in photoperiod and temperature), without affecting the other sperm quality parameters.

  19. Cryotolerance of stallion spermatozoa is related to ROS production and mitochondrial membrane potential rather than to the integrity of sperm nucleus.

    PubMed

    Yeste, M; Estrada, E; Rocha, L G; Marín, H; Rodríguez-Gil, J E; Miró, J

    2015-03-01

    Although cryopreservation of stallion spermatozoa allows long-term preservation of spermatozoa from particular stallions and facilitates international trade, it is understood to inflict damages on sperm cells that may finally reduce their fertilizing ability. In addition, individual differences are known to exist in the sperm ability to withstand freeze-thawing protocols. To date, these differences have mainly been reported on the basis of sperm motility and membrane integrity. For this reason, the present work sought to determine differences between good (good freezability ejaculates: GFE) and poor (poor freezability ejaculates: PFE) freezability stallion ejaculates in other sperm parameters, including peroxide and superoxide levels, potential of mitochondrial membrane and nuclear integrity. With this purpose, a total of 24 stallion ejaculates were cryopreserved and classified into two groups (GFE vs. PFE), depending on their sperm membrane integrity and motility after freeze-thawing. From the total of 24 ejaculates, 13 were classified as GFE and the other 11 were classified as PFE. Apart from differences in sperm membrane permeability and lipid disorder after freeze-thawing, GFE presented significantly (p < 0.05) higher percentages of viable spermatozoa with high content of peroxides and of superoxides than PFE. In contrast, and despite cryopreservation of stallion spermatozoa increasing DNA fragmentation and disrupting disulphide bonds in sperm head proteins, no significant differences between GFE and PFE were seen. We can thus conclude that good and poor freezability stallion ejaculates differ in their reactive oxygen species levels after cryopreservation, but not in the damage extent on sperm nucleus.

  20. Increasing productivity through Total Reuse Management (TRM)

    NASA Technical Reports Server (NTRS)

    Schuler, M. P.

    1991-01-01

    Total Reuse Management (TRM) is a new concept currently being promoted by the NASA Langley Software Engineering and Ada Lab (SEAL). It uses concepts similar to those promoted in Total Quality Management (TQM). Both technical and management personnel are continually encouraged to think in terms of reuse. Reuse is not something that is aimed for after a product is completed, but rather it is built into the product from inception through development. Lowering software development costs, reducing risk, and increasing code reliability are the more prominent goals of TRM. Procedures and methods used to adopt and apply TRM are described. Reuse is frequently thought of as only being applicable to code. However, reuse can apply to all products and all phases of the software life cycle. These products include management and quality assurance plans, designs, and testing procedures. Specific examples of successfully reused products are given and future goals are discussed.

  1. The Effect of Ambient Air Pollution on Sperm Quality

    PubMed Central

    Hansen, Craig; Luben, Thomas J.; Sacks, Jason D.; Olshan, Andrew; Jeffay, Susan; Strader, Lillian; Perreault, Sally D.

    2010-01-01

    Background Research has suggested an association with ambient air pollution and sperm quality. Objectives We investigated the effect of exposure to ozone (O3) and particulate matter < 2.5 μm in aerodynamic diameter (PM2.5) on sperm quality. Methods We reexamined a previous cohort study of water disinfection by-products to evaluate sperm quality in 228 presumed fertile men with different air pollution profiles. Outcomes included sperm concentration, total sperm per ejaculate (count), and morphology, as well as DNA integrity and chromatin maturity. Exposures to O3 and PM2.5 were evaluated for the 90–day period before sampling. We used multivariable linear regression, which included different levels of adjustment (i.e., without and with season and temperature) to assess the relationship between exposure to air pollutants during key periods of sperm development and adverse sperm outcomes. Results Sperm concentration and count were not associated with exposure to PM2.5, but there was evidence of an association (but not statistically significant) with O3 concentration and decreased sperm concentration and count. Additionally, a significant increase in the percentage of sperm cells with cytoplasmic drop [β = 2.64; 95% confidence interval (CI), 0.21–5.06] and abnormal head (β = 0.47; 95% CI, 0.03–0.92) was associated with PM2.5 concentration in the base model. However, these associations, along with all other sperm outcomes, were not significantly associated with either pollutant after controlling for season and temperature. Overall, although we found both protective and adverse effects, there was generally no consistent pattern of increased abnormal sperm quality with elevated exposure to O3 or PM2.5. Conclusions Exposures to O3 or PM2.5 at levels below the current National Ambient Air Quality Standards were not associated with statistically significant decrements in sperm outcomes in this cohort of fertile men. However, some results suggested effects on sperm

  2. Variability in sperm form and function in the context of sperm competition risk in two Tupinambis lizards.

    PubMed

    Blengini, Cecilia S; Sergio, Naretto; Gabriela, Cardozo; Giojalas, Laura C; Margarita, Chiaraviglio

    2014-11-01

    In polyandrous species, sperm morphometry and sperm velocity are under strong sexual selection. Although several hypotheses have been proposed to explain the role of sperm competition in sperm trait variation, this aspect is still poorly understood. It has been suggested that an increase in sperm competition pressure could reduce sperm size variation or produce a diversity of sperm to maximize male fertilization success. We aim at elucidating the variability of sperm morphometric traits and velocity in two Tupinambis lizards in the context of sperm competition risk. Sperm traits showed substantial variation at all levels examined: between species, among males within species, and within the ejaculate of individual males. Sperm velocity was found to be positively correlated with flagellum: midpiece ratio, with relatively longer flagella associated with faster sperm. Our results document high variability in sperm form and function in lizards.

  3. Variability in sperm form and function in the context of sperm competition risk in two Tupinambis lizards

    PubMed Central

    Blengini, Cecilia S; Sergio, Naretto; Gabriela, Cardozo; Giojalas, Laura C; Margarita, Chiaraviglio

    2014-01-01

    In polyandrous species, sperm morphometry and sperm velocity are under strong sexual selection. Although several hypotheses have been proposed to explain the role of sperm competition in sperm trait variation, this aspect is still poorly understood. It has been suggested that an increase in sperm competition pressure could reduce sperm size variation or produce a diversity of sperm to maximize male fertilization success. We aim at elucidating the variability of sperm morphometric traits and velocity in two Tupinambis lizards in the context of sperm competition risk. Sperm traits showed substantial variation at all levels examined: between species, among males within species, and within the ejaculate of individual males. Sperm velocity was found to be positively correlated with flagellum: midpiece ratio, with relatively longer flagella associated with faster sperm. Our results document high variability in sperm form and function in lizards. PMID:25505535

  4. Exploring Increased Productivity Through Employee Engagement

    NASA Astrophysics Data System (ADS)

    Richards, Wayne K., Jr.

    Disengaged employees cost U.S. companies billions of dollars annually in lowered productivity, a cost which has been compounded by the difficult economic situations in the country. The potential for increasing productivity through increased employee engagement was examined in this study. Using personal engagement theory and the theory of planned behavior, the purpose of this phenomenological study was to explore how the experiences of salaried aerospace employees affected productivity and the financial performance of an organization. Interviews were conducted with a purposive sample of 20 aerospace employees whose responses were codified and analyzed to identify themes. The analysis indicated that (a) the lived experiences of employees influenced employee engagement, (b) employee engagement affects organizational commitment and performance, and (c) trust and respect and leadership are essential components to keep employees engaged. Eighty percent of the participants indicated that as employee engagement increases so too does organizational performance. The implications for positive social change include new insights for leaders seeking to increase productivity and financial performance, and to support employee engagement for maintaining sustainability, retaining talent, increasing profits, and improving the economy.

  5. Continued increases in Arctic Ocean primary production

    NASA Astrophysics Data System (ADS)

    Arrigo, Kevin R.; van Dijken, Gert L.

    2015-08-01

    Dramatic declines in sea-ice cover in the Arctic Ocean in recent decades have the potential to fundamentally alter marine ecosystems. Here we investigate changes in sea ice between the years 1998 and 2012 at regional and basin scales and how these have impacted rates of phytoplankton net primary production (NPP). Annual NPP increased 30% over the Arctic Ocean during our study period, with the largest increases on the interior shelves and smaller increases on inflow shelves. Increased annual NPP was often, but not always, associated with reduced sea-ice extent and a longer phytoplankton growing season (fewer days of ice cover). Spatial patterns of increased annual NPP suggest that increased nutrient fluxes may also play an important role. Outflow shelves either exhibited no change in annual NPP during our study period or a significant decline, perhaps indicating that nutrients had been consumed by increased NPP farther upstream.

  6. Sperm studies in anesthesiologists

    SciTech Connect

    Wyrobek, A.J.; Brodsky, J.; Gordon, l.; Moore, D.H., II; Watchmaker, G.; Cohen, E.N.

    1981-11-01

    Semen samples were collected from 46 anesthesiologists each of whom had worked a minimum of one year in hospital operating rooms ventilated with modern gas-scavenging devices. Samples collected from 26 beginning residents in anesthesiology served as controls. Concentrations of sperm and percentage of sperm having abnormal head shapes were determined for each sample. No significant differences were found between anesthesiologists and beginning residents. Limiting the analyses to men having no confounding factors (varicocele, recent illness, medications, heavy smoking, frequent sauna use) did not change the results. The sperm concentration and morphology in 13 men did not change signficantly after one year of exposure to anesthetic gases. However, the group of men who had one or more confounding factors (excluding exposure to anesthetic gases) showed significantly higher percentages of sperm abnormalities than did the group of men without such factors. These results suggest that limited exposure to anesthetic gases does not significantly affect sperm production as judged by changes in sperm concentration and morphology. These data are reassuring, but since the hospitals surveyed used modern gas-scavenging devices, men who are occupationally exposed to anesthetic gases without this protection should be studied for fuller assessment of the possible human spermatotoxic effects.

  7. Increasing Sales by Developing Production Consortiums.

    ERIC Educational Resources Information Center

    Smith, Christopher A.; Russo, Robert

    Intended to help rehabilitation facility administrators increase organizational income from manufacturing and/or contracted service sources, this document provides a decision-making model for the development of a production consortium. The document consists of five chapters and two appendices. Chapter 1 defines the consortium concept, explains…

  8. Increasing the availability of national mapping products.

    USGS Publications Warehouse

    Roney, J.I.; Ogilvie, B.C.

    1981-01-01

    A discussion of the means employed by the US Geological Survey to facilitate map usage, covering aspects of project Map Accessibility Program including special rolled and folded map packaging, new market testing, parks and campgrounds program, expanded map dealer program, new booklet-type State sales index and catalog and new USGS map reference code. The USGS is seen as the producer of a tremendous nation-wide inventory of topographic and related map products available in unprecedented types, formats and scales, and as endeavouring to increase access to its products. The new USGS map reference code is appended. -J.C.Stone

  9. Sperm shape abnormalities in carbaryl-exposed employees

    PubMed Central

    Wyrobek, A. J.; Watchmaker, G.; Gordon, L.; Wong, K.; Moore, D.; Whorton, D.

    1981-01-01

    Semen was collected from 50 men occupationally exposed to carbaryl (1-naphthyl methyl carbamate) in a produciton plant for durations of 1 to 18 years and compared to semen from a control group of 34 unexposed, newly-hired workers. Employment, fertility, health, personal data, and blood samples were collected for each individual. Semen samples were analyzed for changes in sperm count, morphology, and frequency of sperm carrying double flourescent bodies (YFF). As a group, the exposed workers showed a significantly higher proportion of sperm with abnormal head shapes than did the control group (p < 0.005). Age, smoking habits, and medical problems did not appear to affect this result. This finding appears to be limited to men working in the carbaryl production area at the time of sampling. Sperm count and YFF did not show similar differences, which may be because they are known to be statistically less sensitive to small changes. Formerly exposed workers (away from carbaryl for an average of 6.3 years) showed a marginally significant elevation in sperm abnormalities compared to controls (p < .05, one-tailed statistical analyses) suggesting that the increase in abnormal morphology may not be reversible. However, the question of reversibility is sensitive to confounding factors and small sample sizes and, therefore, requires further study. With these data a definitive link between carbaryl exposure and human seminal defects cannot be established. Although a distinct effect on sperm morphology was seen in the exposed group, the increases in sperm shape abnormalities were not related to exposure dose (estimated by number of years on the job or job classification during the year prior to semen collection). Inexplicably, the increases in sperm abnormalities were seen primarily in currently exposed men who had worked with carbaryl for less than approximately 6 years. These findings suggest the need for further study since other workplace-related factor(s) may be responsible

  10. Increased productivity in flight with voice commanding

    NASA Technical Reports Server (NTRS)

    Jordan, W. T.

    1985-01-01

    Automatic Speech Recognition technology has matured to the point where it can provide a viable means of increasing productivity by naturalizing the man-machine interface. With ever increasing workloads being placed on astronauts, speech recognition may provide an alternative means of system controlling that would reduce the task burden. Voice commanding, allowing hands-free operation, can be especially effective during operations requiring simultaneous system control. A flight experiment is under development to demonstrate the operational effectiveness of voice control by commanding the Space Shuttle's Closed Circuit Television (CCIV) system. This experiment will help direct future applications of voice entry to space operations.

  11. Increased Fertilization Rates after In Vitro Culture of Frozen-Thawed Testicular Immotile Sperm in Nonobstructive Azoospermic Patients

    PubMed Central

    Nuñez-Calonge, R.; Cortes, S.; Gago, M.; López, P.; Caballero-Peregrin, P.

    2012-01-01

    Objective. To optimise the use of freeze/thaw testicular immotile spermatozoa from nonobstructive azoospermia patients and to analyse the outcome of intracytoplasmic sperm injection (ICSI) of such spermatozoa. Methods. Testicular specimens were retrieved and cryopreserved from forty patients with nonobstructive azoospermia and underwent one cycle with thawed spermatozoa (Group I) that led to pregnancy in sixteen cases. Twenty-four patients of group I underwent treatment with the same batch of thawed spermatozoa (Group II). For the first ICSI attempt, injection was performed when motile spermatozoa were found. In group II, injection was performed when maximum motility was reached. We compared mean of fertilization rate, embryo quality, clinical pregnancy rate and embryo implantation rate. Results. The mean percentage of motility was significantly higher in the group II than in the group I (18, 6 versus 8, 2). Group I showed a significant decrease in fertilization rates when compared with cryopreserved testicular spermatozoa in group II (54% versus 72%, P < 0.05). No difference was noted between the cleavage rate, embryo quality, clinical pregnancy rates and implantation rates among group II and I. Conclusion. Fecundation rate can be significantly improved after in-vitro culture and sperm selection of frozen-thawed immotile testicular spermatozoa in patients with nonobstructive azoospermia. PMID:22567413

  12. Similarities and differences between the sperm quality index and sperm mobility index of broiler breeder semen.

    PubMed

    Dumpala, P R; Parker, H M; McDaniel, C D

    2006-12-01

    The sperm quality index (SQI) and sperm mobility index (SMI) both predict sperm motility. Previous research was conducted comparing the SMI with the SQI; however, semen was diluted improperly for the SQI (40-fold). For an accurate comparison, semen must be diluted 10-fold for the SQI. Therefore, the overall objective of this study, utilizing 4 experiments, was to examine the relationship of the SQI with the SMI when: 1) active, heat-inactivated, and boiled sperm were incubated and analyzed over 60 min, 2) motile and immotile sperm were combined, 3) dead sperm (boiled or frozen) and live sperm were combined, and 4) sperm were rendered immotile by adding Zn. In experiment 1, the SQI was stable throughout incubation for active sperm and zero for heat-inactivated and boiled sperm. The SMI from active sperm steadily increased over incubation. However, the SMI from heat-inactivated sperm increased drastically resulting in values higher than active sperm after 35 min of incubation. The SMI from active sperm was higher than boiled sperm throughout incubation. For experiment 2, a cubic increase in the SQI occurred as active sperm increased from 0 to 100%. However, there was no difference in SMI readings until samples contained 80% active sperm. In experiment 3, for both boiled and frozen sperm, as the percentage of viable sperm increased, there was a logarithmic increase in the SQI. The SMI values were similar for 0 and 100% viable sperm when using boiled sperm, and all SMI readings were similar to 0% viable for frozen sperm. For experiment 4, both the SQI and SMI values from semen incubated with Zn were lower than that of saline. The SQI from sperm incubated in saline was higher than that of Zn throughout incubation, yet there were no differences in SMI values after 90 min of incubation. In conclusion, both the SQI and SMI of sperm decrease in response to Zn. However, it appears that immotile and dead sperm are capable of increasing SMI values but not SQI values.

  13. Sulfur dioxide inhalation lowers sperm quality and alters testicular histology via increasing expression of CREM and ACT proteins in rat testes.

    PubMed

    Zhang, Jianhai; Zheng, Fei; Liang, Chen; Zhu, Yuchen; Shi, Yan; Han, Yongli; Wang, Jundong

    2016-10-01

    Sulfur dioxide (SO2) is one of the main atmospheric pollutants worldwide, and is reported to be responsible for the formation of severe haze in China. Some studies have demonstrated a potential harmful effect of SO2 on the male reproductive system; however the underlying mechanism is still unknown. The purpose of this study is to investigate the roles of cytochrome P450 (P450), cAMP-responsive element modulator (CREM), and activator of CREM (ACT) in SO2-induced toxicity. Forty-eight male Wistar rats were randomly divided into an experimental and control group. The experiment group was exposed to SO2 in ambient air (10ppm, 4h/day), and the control group was treated with filtered air in the same conditions. After 2 weeks, the results showed a significant decrease in body weight and sperm motility, and an increase in the testis weight-to-body weight ratio as compared to the control group. Histological investigation suggested that SO2 exposure led to loose arrangement of the spermatogenic cells and local structural damage in the seminiferous tubules. Moreover, the expressions of P450, CREM and ACT proteins increased in the testes by 0.22%, 47.26% and 23.38%, respectively. Taken together, SO2 inhalation lowered sperm quality, altered testicular histology, and increased expressions of CREM and ACT proteins in the testes of rats. Overall, these results could contribute to a better understanding of SO2-induced male reproductive toxicity.

  14. Bactericidal/permeability-increasing protein in the reproductive system of male mice may be involved in the sperm-oocyte fusion.

    PubMed

    Li, Kun; Liu, Yue; Xia, Xiaoyu; Wang, Li; Lu, Meige; Hu, Yanqin; Xu, Chen

    2013-08-01

    Bactericidal/permeability-increasing protein (BPI) is a 455-residue (∼55 kDa) protein found mainly in the primary (azurophilic) granules of human neutrophils. BPI is an endogenous antibiotic protein that belongs to the family of mammalian lipopolysaccharide (LPS)-binding and lipid transport proteins. Its major function is to kill Gram-negative bacteria, thereby protecting the host from infection. In addition, BPI can inhibit angiogenesis, suppress LPS-mediated platelet activation, increase DNA synthesis, and activate ERK/Akt signaling. In this study, we found that Bpi was expressed in the testis and epididymis but not in the seminal vesicles, prostate, and solidification glands. BPI expression in the epididymis increased upon upregulation of testosterone, caused by injection of GNRH. In orchidectomized mice, BPI expression was significantly reduced, but its expression was restored to 30% of control levels in orchidectomized mice that received supplementary testosterone. The number of sperm fused per egg significantly decreased after incubation with anti-BPI antiserum. These results suggest that BPI may take part in the process of sperm-oocyte fusion and play a unique and significant role in reproduction.

  15. No evidence for sperm priming responses under varying sperm competition risk or intensity in guppies

    NASA Astrophysics Data System (ADS)

    Evans, Jonathan P.

    2009-07-01

    Sperm competition theory predicts that males should tailor their investment in ejaculates according to the number of rival males competing to fertilize a female’s eggs. Research spanning several taxa supports this prediction by showing that males are often sensitive to the level of sperm competition and adjust their investment in sperm numbers accordingly. More recent work has revealed that males may also tailor the quality of sperm according to the number of males competing for fertilization. Here I test for both effects in guppies ( Poecilia reticulata) in an experiment that simultaneously evaluates the risk and intensity models of sperm competition. The experiment determined whether male guppies adjust the number (stripped ejaculate size) and quality (sperm velocity and viability) of sperm that are primed over a 3-day period according to experimental changes in the perceived level of sperm competition. A total of 136 focal males were initially stripped of all retrievable sperm and assayed for these sperm traits before being allocated at random to one of four treatments simulating different levels of sperm competition risk and intensity. During the 3-day treatment phase, focal males had visual and olfactory access to a sexually receptive (initially virgin) female maintained with different numbers of stimulus males to simulate variation in the risk and intensity of sperm competition. Following this, males were assayed again for the sperm traits. Contrary to predictions, there was no significant change in any of the measured variables among treatments, although qualitatively the patterns for sperm velocity and viability did conform to expectation. The lack of any trend for the number of sperm primed was unequivocal and future work examining the effects of sperm competition on sperm production should focus on whether males differentially allocate sperm numbers among matings that differ in the level of sperm competition.

  16. Effect of dilution in sperm maturation media and time of storage on sperm motility and fertilizing capacity of cryopreserved semen of sex-reversed female rainbow trout.

    PubMed

    Judycka, Sylwia; Ciereszko, Andrzej; Dobosz, Stefan; Zalewski, Tomasz; Dietrich, Grzegorz J

    2017-05-01

    Masculinized females, also called neomales or sex-reversed females have a male phenotype but retain the female genotype (XX). Therefore, all spermatozoa produced in their functional testes carry an X chromosome, which is desired for the production of all-female rainbow trout populations. Semen of sex-reversed female rainbow trout is of low quality and in vitro maturation is required, which includes dilution of sperm suspensions with specially formulated maturation solutions. The aim of this study was to determine the effect of dilution in different maturation media on sperm quality (sperm motility characteristics and fertilizing capacity) of frozen/thawed sperm of sex-reversed female rainbow trout. The effect of time of post-thaw storage (0, 15, 60 and 120min) on semen quality was also tested. Sperm motility parameters and fertilization rate at the eyed and hatching stages were assessed for post-thaw semen diluted in different media. The cryopreservation procedure resulted in high post-thaw sperm motility of about 57% and did not differ from fresh semen. Unexpectedly, maturation media decreased sperm activation capacity immediately after dilution; however, sperm motility increased over time. Fertilization rates of frozen/thawed semen were high (71-87%) and did not differ significantly between experimental variants at any of tested periods of storage. Our results demonstrated that the effect of the maturation media on frozen/thawed sperm is different from that of fresh sperm. The progressive increase in post-thaw sperm motility in maturation media can potentially be applied to routine hatchery practice.

  17. Antioxidant Effects of Brown Algae Sargassum on Sperm Parameters

    PubMed Central

    Sobhani, Alireza; Eftekhaari, Tasnim Eghbal; Shahrzad, Mohammad Esmaeil; Natami, Mohammad; Fallahi, Soghra

    2015-01-01

    Abstract The occurrence of oxidative stress during the sperm freeze-thaw cycles affects the sperm parameters and eventually leads to a decrease in its reproductive potential. Sperm protection against oxidative reactions during freezing is done by antioxidants. Since the selection of a suitable sperm cryopreservation bank is effective in maintaining acceptable reproductive potential and motility of sperm during cryopreservation. This study aimed to evaluate the antioxidant effects of different doses of the extract of brown algae Sargassum on oxidative stress and frozen human sperm parameters. We conducted a randomized controlled trial on the semen samples from 11 healthy men in the age group of 25 to 36 years. The samples were collected by masturbation after 3 to 5 days of abstinence from ejaculation. The specimens were divided into 3 equal parts, including 1 control group and 2 experimental groups. The 2 experimental groups were frozen using the rapid solidification technique with Sargassum extract at doses of 250 and 500 μg/mL. Motility and morphology of sperms were measured using a computer system and CASA software and the amount of reactive oxygen species was determined using Oxisperm kit. Sargassum extract significantly decreased the amount of reactive oxygen species (P < 0.005) and at doses of 250 and 500 μg/mL, significantly increased the overall motility (P < 0.006) and progressive motility (P < 0.007) after solidification, but did not affect the normal morphology of sperms. The addition of ethanol extract of Sargassum prevents reactive oxygen species production during the solidification process and improves sperm motility at doses of 250 and 500 μg/mL. PMID:26717354

  18. Responses of testis, epididymis, and sperm of pubertal rats exposed to functionalized multiwalled carbon nanotubes.

    PubMed

    Farombi, Ebenezer O; Adedara, Isaac A; Forcados, Gilead E; Anao, Osemudiamen O; Agbowo, Agatha; Patlolla, Anita K

    2016-05-01

    The present study investigated the response of testes, epididymides and sperm in pubertal Wistar rats following exposure to 0, 0.25, 0.5, 0.75, and 1.0 mg kg(-1) functionalized multi-walled carbon nanotubes (f-MWCNTs) for 5 days. The results showed that administration of (f-MWCNTs) significantly increased the activities of superoxide dismutase, catalase, and glutathione peroxidase in a dose-dependent manner in both testes and sperm compared with control group. Moreover, the significant decrease in the activity of glutathione-S-transferase and glutathione level was accompanied with significant elevation in the levels of hydrogen peroxide and malondialdehyde in both testes and sperm of (f-MWCNTs)-treated rats. The spermiogram of (f-MWCNTs)-treated rats indicated significant decrease in epididymal sperm number, sperm progressive motility, testicular sperm number and daily sperm production with elevated sperm abnormalities when compared with the control. Exposure to (f-MWCNTs) decreased plasma testosterone level and produced marked morphological changes including decreased geminal epithelium, edema, congestion, reduced spermatogenic cells and focal areas of tubular degeneration in the testes. The lumen of the epididymides contained reduced sperm cells and there was mild to severe hyperplasia epithelial cells lining the duct of the epididymis. Collectively, pubertal exposure of male rats to (f-MWCNTs) elicited oxidative stress response resulting in marked testicular and epididymides dysfunction.

  19. Current status and potential of morphometric sperm analysis

    PubMed Central

    Maroto-Morales, Alejandro; García-Álvarez, Olga; Ramón, Manuel; Martínez-Pastor, Felipe; Fernández-Santos, M Rocío; Soler, A Josefa; Garde, José Julián

    2016-01-01

    The spermatozoon is the most diverse cell type known and this diversity is considered to reflect differences in sperm function. How the diversity in sperm morphology arose during speciation and what role the different specializations play in sperm function, however, remain incompletely characterized. This work reviews the hypotheses proposed to explain sperm morphological evolution, with a focus on some aspects of sperm morphometric evaluation; the ability of morphometrics to predict sperm cryoresistance and male fertility is also discussed. For this, the evaluation of patterns of change of sperm head morphometry throughout a process, instead of the study of the morphometric characteristics of the sperm head at different stages, allows a better identification of the males with different sperm cryoconservation ability. These new approaches, together with more studies employing a greater number of individuals, are needed to obtain novel results concerning the role of sperm morphometry on sperm function. Future studies should aim at understanding the causes of sperm design diversity and the mechanisms that generate them, giving increased attention to other sperm structures besides the sperm head. The implementation of scientific and technological advances could benefit the simultaneous examination of sperm phenotype and sperm function, demonstrating that sperm morphometry could be a useful tool for sperm assessment. PMID:27678465

  20. Decoding mechanisms of loss of fertilization ability of cryopreserved mouse sperm

    NASA Astrophysics Data System (ADS)

    Gray, Jeffrey Earl

    Cryopreservation of mouse sperm is an important technology for management of biomedical research resources. Dramatic progress has been made recently in the development of protocols that combat mouse-strain specific reduction of IVF after cryopreservation. Equal emphasis, however, has not been placed on investigating the biological mechanisms underlying these improvements to IVF. This dissertation broadly investigates the basic question of how mouse-strain specific reduction of IVF occurs after cryopreservation, and how recently developed protocols prevent this process. My research investigated the effects of antioxidants, the cholesterol-acceptor CD, reduced calcium media, and TYH capacitation media on sperm function and oxidative stress after cryopreservation in a variety of mouse strains. I found that reduced IVF was associated with loss of capacitation-dependent sperm function in three strains, B6/J, B6/N, and 129X1, and CD improved sperm function and IVF in all three strains. These findings suggest that cryopreservation inhibits cholesterol efflux resulting in reduced IVF of many mouse strains. I also found that cryopreservation induces uniquely high production of mitochondrial H2O2 by B6/J sperm. H2O2 present in other cellular compartments of B6/J sperm was not elevated compared to other strains. High levels of mitochondrial H2O2 were associated with lipid peroxidation of the sperm head and inability to acrosome react. Antioxidants reduced mitochondrial H2O2 production, decreased sperm head lipid peroxidation, and improved acrosome reaction. The cryopreservation-induced increase in mitochondrial H2O2 production of B6/J and B6129XF1 sperm was associated with elevation of intracellular calcium after cryopreservation and dependent on mitochondrial metabolic substrates. Reducing intracellular calcium levels or removing mitochondrial metabolic substrates decreased mitochondrial H2O2 production and increased IVF rates of cryopreserved B6/J sperm. Many of the strains

  1. Toxicant-induced acceleration of epididymal sperm transit: androgen-dependent proteins may be involved.

    PubMed

    Klinefelter, G R; Suarez, J D

    1997-01-01

    Previously we established that a 4-d exposure to chloroethylmethanesulphonate (CEMS), a chemical that significantly reduces serum testosterone (T) levels, resulted in a significant decrease in cauda epididymal sperm reserves in adult male rats while homogenization-resistant testicular spermatid numbers were unaffected. This epididymis-specific alteration occurred whether or not circulating T levels were maintained using T-filled Silastic implants. To determine whether this epididymis-specific decrease in sperm number was the result of decreased epididymal transit time, the vas deferens was ligated at its midpoint just prior to the first of 4 d of exposure to CEMS with and without T implantation. If epididymal sperm transit was accelerated due to treatment, there would be fewer sperm in the caput/corpus and more sperm in the cauda/vas of the treated animals compared to control. The number of sperm in the caput/corpus decreased significantly (P < 0.05) while the number of sperm in the cauda/vas increased significantly in both the CEMS and CEMS + T animals. Daily sperm production was unaffected, but transit time through the caput/corpus epididymidis was decreased significantly in both treatment groups. To determine if testicular fluid played a role in the epididymis-specific decline in sperm numbers, the efferent ducts were ligated at the same time the vas deferens was ligated. Again, the number of sperm in the caput/corpus decreased significantly with treatment while there was a reciprocal increase in the number of cauda/vas sperm relative to controls. Finally, to determine whether an androgen-mediated process might be involved, the known antiandrogen hydroxyflutamide (HFLUT) was given to castrated, T-implanted animals in which the fertilizing ability of epididymidal sperm is maintained over 4 days. Once again, the number of sperm in the caput/corpus decreased significantly while there was a reciprocal increase in cauda/vas sperm. A quantitative evaluation of the

  2. Fire increases dust production from chaparral soils

    NASA Astrophysics Data System (ADS)

    Gabet, Emmanuel J.

    2014-07-01

    By altering the physical and chemical properties of a landscape, fire may increase its vulnerability to erosive processes. Whereas sediment transport by surface runoff after fires has been often investigated, less is known about the role of wind erosion in burned terrain. To examine how fire might increase a soil's vulnerability to aeolian transport, intact soil samples were collected from a chaparral landscape in southern California and heated with a propane torch with temperatures ranging from 250 to 1025 °C and for durations of 5-60 min to simulate a variety of burn severities. The samples were then subjected to simulated wind and the amounts of eroded sediment were measured. Results indicate a linear increase in the production of wind-erodible sediment with applied heat up to ~ 10 MJ/m2. The increase was not due to a reduction in the threshold shear velocity of the soil surface but, instead, to the role of heat in detaching erodible material. In these soils, organic material may be an important binding agent destroyed at high temperatures. The relationship between fire and erodibility is complex, however, because heating may also help to aggregate soil particles. Experiments performed here also suggest a synergistic effect between fire and rain whereby heated soils are more vulnerable to the erosive power of raindrop impacts. Additionally, the soil heating experiments were used to measure and compare the thermal conductivities of intact and disturbed soils. Finally, it is concluded that soil heating may increase the emission of dust through the detachment of erodible particles, a result that may help in the anticipation of respiratory problems for those living downwind of burned areas.

  3. Why It's Difficult to Increase Productivity.

    ERIC Educational Resources Information Center

    Birnbaum, Robert

    1991-01-01

    Calculating the productivity of a college or university is more complex than determining a machine's productivity. Sixteen rational, cultural, political, and cognitive constraints that influence institutional productivity are outlined and their mediation by institutional culture and history is noted. (MSE)

  4. ESP's placed in horizontal lateral increase production

    SciTech Connect

    Gallup, A.; Wilson, B.L. ); Marshall, R. )

    1990-06-18

    By design, the electric submersible pump (ESP) is an effective method of lifting fluids from horizontal wells. But this ESP application does have unique installation and operating parameters that need to be considered. ESP's have been used for many years in directional wells. This application provides an experience base for understanding deflection limits on the unit. To avoid damaging the ESP, special equipment may be required in some horizontal installations. This paper discusses how several ESP's have been designed specifically for medium-radius wells. In these applications, the deeper pump setting provides for a significant increase in production rate. In general, to realize the full benefit of a horizontal installation, the ESP should be considered when planning, drilling, and completing the well.

  5. Sperm production and mating potential of males after a cold shock on pupae of the parasitoid wasp Dinarmus basalis (Hymenoptera: Pteromalidae).

    PubMed

    Lacoume, Sandrine; Bressac, Christophe; Chevrier, Claude

    2007-10-01

    For ectothermic species, temperature is a key environmental factor influencing several aspects of their physiology and ecology, acting particularly on reproduction. To measure the consequences of a severe thermal stress during development on male reproduction, a cold shock (1h at -18 degrees C) was tested on Dinarmus basalis pupae. D. basalis (Hymenoptera: Pteromalidae) is a parasitoid wasp in which sperm management in both male and female is of prime importance. After a cold shock, developmental success was reduced, with a quarter of cold-shocked males not emerging correctly. The stress effects were estimated at the level of sperm stock in seminal vesicles of males at different ages and on the ability of 2-day-old males to access females in single and multiple mating and in male-male competition. Cold-shocked males had a reduced sperm stock compared to control males and this difference persisted with age. The rate of sperm production was similar in both groups. The consequences of a cold shock on male reproductive ability were perceptible in multiple mating and male-male competition but not in single mating. Cold-shocked males were at a disadvantage, inseminating fewer females and copulating less frequently. Finally, male pupae of D. basalis were able to withstand severe temperature stresses and their reproductive functions were partially preserved.

  6. Differences in ATP Generation Via Glycolysis and Oxidative Phosphorylation and Relationships with Sperm Motility in Mouse Species*

    PubMed Central

    Tourmente, Maximiliano; Villar-Moya, Pilar; Rial, Eduardo; Roldan, Eduardo R. S.

    2015-01-01

    Mouse sperm produce enough ATP to sustain motility by anaerobic glycolysis and respiration. However, previous studies indicated that an active glycolytic pathway is required to achieve normal sperm function and identified glycolysis as the main source of ATP to fuel the motility of mouse sperm. All the available evidence has been gathered from the studies performed using the laboratory mouse. However, comparative studies of closely related mouse species have revealed a wide range of variation in sperm motility and ATP production and that the laboratory mouse has comparatively low values in these traits. In this study, we compared the relative reliance on the usage of glycolysis or oxidative phosphorylation as ATP sources for sperm motility between mouse species that exhibit significantly different sperm performance parameters. We found that the sperm of species with higher oxygen consumption/lactate excretion rate ratios were able to produce higher amounts of ATP, achieving higher swimming velocities. Additionally, we show that the species with higher respiration/glycolysis ratios have a higher degree of dependence upon active oxidative phosphorylation. Moreover, we characterize for the first time two mouse species in which sperm depend on functional oxidative phosphorylation to achieve normal performance. Finally, we discuss that sexual selection could promote adaptations in sperm energetic metabolism tending to increase the usage of a more efficient pathway for the generation of ATP (and faster sperm). PMID:26048989

  7. Differences in ATP Generation Via Glycolysis and Oxidative Phosphorylation and Relationships with Sperm Motility in Mouse Species.

    PubMed

    Tourmente, Maximiliano; Villar-Moya, Pilar; Rial, Eduardo; Roldan, Eduardo R S

    2015-08-14

    Mouse sperm produce enough ATP to sustain motility by anaerobic glycolysis and respiration. However, previous studies indicated that an active glycolytic pathway is required to achieve normal sperm function and identified glycolysis as the main source of ATP to fuel the motility of mouse sperm. All the available evidence has been gathered from the studies performed using the laboratory mouse. However, comparative studies of closely related mouse species have revealed a wide range of variation in sperm motility and ATP production and that the laboratory mouse has comparatively low values in these traits. In this study, we compared the relative reliance on the usage of glycolysis or oxidative phosphorylation as ATP sources for sperm motility between mouse species that exhibit significantly different sperm performance parameters. We found that the sperm of species with higher oxygen consumption/lactate excretion rate ratios were able to produce higher amounts of ATP, achieving higher swimming velocities. Additionally, we show that the species with higher respiration/glycolysis ratios have a higher degree of dependence upon active oxidative phosphorylation. Moreover, we characterize for the first time two mouse species in which sperm depend on functional oxidative phosphorylation to achieve normal performance. Finally, we discuss that sexual selection could promote adaptations in sperm energetic metabolism tending to increase the usage of a more efficient pathway for the generation of ATP (and faster sperm).

  8. A defined medium supports changes consistent with capacitation in stallion sperm, as evidenced by increases in protein tyrosine phosphorylation and high rates of acrosomal exocytosis.

    PubMed

    McPartlin, L A; Littell, J; Mark, E; Nelson, J L; Travis, A J; Bedford-Guaus, S J

    2008-03-15

    Efficient in vitro capacitation of stallion sperm has not yet been achieved, as suggested by low sperm penetration rates reported in in vitro fertilization (IVF) studies. Our objectives were to evaluate defined incubation conditions that would support changes consistent with capacitation in stallion sperm. Protein tyrosine phosphorylation events and the ability of sperm to undergo acrosomal exocytosis under various incubation conditions were used as end points for capacitation. Sperm incubated 4-6h in modified Whitten's (MW) with the addition of 25 mM NaHCO3 and 7 mg/mL BSA (capacitating medium) yielded high rates of protein tyrosine phosphorylation. Either HCO3(-) or BSA was required to support these changes, with the combination of both providing the most intense results. When a membrane-permeable form of cAMP and a phosphodiesterase inhibitor (IBMX) were added to MW in the absence of HCO3(-) and BSA, the tyrosine phosphorylation results obtained in our capacitating conditions could not be replicated, suggesting either effects apart from cAMP were responsible for tyrosine phosphorylation, or that stallion sperm might respond differently to these reagents as compared to sperm from other mammals. Sperm incubation in capacitating conditions was also associated with high percentages (Psperm incubated in medium devoid of BSA and NaHCO3. Our results were novel in that we report protein tyrosine phosphorylation in stallion sperm incubated in defined conditions, coupled with significant percentages of acrosome reacted sperm. The continuation of these studies might help to elucidate the conditions and pathways supporting sperm capacitation in the horse.

  9. Aspermy, Sperm Quality and Radiation in Chernobyl Birds

    PubMed Central

    Møller, Anders Pape; Bonisoli-Alquati, Andrea; Mousseau, Timothy A.; Rudolfsen, Geir

    2014-01-01

    Background Following the Chernobyl nuclear power plant accident, large amounts of radionuclides were emitted and spread in the environment. Animals living in such contaminated areas are predicted to suffer fitness costs including reductions in the quality and quantity of gametes. Methodology/Principal Findings We studied whether aspermy and sperm quality were affected by radioactive contamination by examining ejaculates from wild caught birds breeding in areas varying in background radiation level by more than three orders of magnitude around Chernobyl, Ukraine. The frequency of males with aspermy increased logarithmically with radiation level. While 18.4% of males from contaminated areas had no sperm that was only the case for 3.0% of males from uncontaminated control areas. Furthermore, there were negative relationships between sperm quality as reflected by reduced sperm velocity and motility, respectively, and radiation. Conclusions/Significance Our results suggest that radioactive contamination around Chernobyl affects sperm production and quality. We are the first to report an interspecific difference in sperm quality in relation to radioactive contamination. PMID:24963711

  10. Effect of calcium, bicarbonate, and albumin on capacitation-related events in equine sperm.

    PubMed

    Macías-García, B; González-Fernández, L; Loux, S C; Rocha, A M; Guimarães, T; Peña, F J; Varner, D D; Hinrichs, K

    2015-01-01

    Repeatable methods for IVF have not been established in the horse, reflecting the failure of standard capacitating media to induce changes required for fertilization capacity in equine sperm. One important step in capacitation is membrane cholesterol efflux, which in other species is triggered by cholesterol oxidation and is typically enhanced using albumin as a sterol acceptor. We incubated equine sperm in the presence of calcium, BSA, and bicarbonate, alone or in combination. Bicarbonate induced an increase in reactive oxygen species (ROS) that was abolished by the addition of calcium or BSA. Bicarbonate induced protein tyrosine phosphorylation (PY), even in the presence of calcium or BSA. Incubation at high pH enhanced PY but did not increase ROS production. Notably, no combination of these factors was associated with significant cholesterol efflux, as assessed by fluorescent quantitative cholesterol assay and confirmed by filipin staining. By contrast, sperm treated with methyl-β-cyclodextrin showed a significant reduction in cholesterol levels, but no significant increase in PY or ROS. Presence of BSA increased sperm binding to bovine zonae pellucidae in all three stallions. These results show that presence of serum albumin is not associated with a reduction in membrane cholesterol levels in equine sperm, highlighting the failure of equine sperm to exhibit core capacitation-related changes in a standard capacitating medium. These data indicate an atypical relationship among cholesterol efflux, ROS production, and PY in equine sperm. Our findings may help to elucidate factors affecting failure of equine IVF under standard conditions.

  11. Maturity stage and plasma testosterone levels are related to sperm production in blue catfish Ictalurus furcatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, the channel catfish, Ictalurus puntatus' X blue catfish, I.furcatus ' F1 hybrid has demonstrated good potential for commercial production compared to the commonly raised channel catfish. Efforts by researchers and commercial producers in the last 40 years have improved hybrid fry product...

  12. The effects of male age on sperm DNA damage in healthy non-smokers

    SciTech Connect

    Schmid, T; Eskenazi, B; Baumgartner, A; Marchetti, F; Young, S; Weldon, R; Anderson, D; Wyrobek, A

    2006-03-08

    The trend for men to have children at older ages raises concerns that advancing age may increase the production of genetically defective sperm, increasing the risks of transmitting germ-line mutations. We investigated the associations between male age and sperm DNA damage and the influence of several lifestyle factors in a healthy non-clinical group of 80 non-smokers (age: 22-80) with no known fertility problems using the sperm Comet analyses. The average percent of DNA that migrated out of the sperm nucleus under alkaline electrophoresis increased with age (0.18% per year, p=0.006); but there was no age association for damage measured under neutral conditions (p=0.7). Men who consumed >3 cups coffee per day had {approx}20% higher % tail DNA under neutral but not alkaline conditions compared to men who consumed no caffeine (p=0.005). Our findings indicate that (a) older men have increased sperm DNA damage associated with alkali-labile sites or single-strand DNA breaks, and (b) independent of age, men with substantial daily caffeine consumption have increased sperm DNA damage associated with double-strand DNA breaks. DNA damage in sperm can be converted to chromosomal aberrations and gene mutations after fertilization increasing the risks for developmental defects and genetic diseases among offspring.

  13. Chromosomal abnormalities in human sperm

    SciTech Connect

    Martin, R.H.

    1985-01-01

    The ability to analyze human sperm chromosome complements after penetration of zona pellucida-free hamster eggs provides the first opportunity to study the frequency and type of chromosomal abnormalities in human gametes. Two large-scale studies have provided information on normal men. We have studied 1,426 sperm complements from 45 normal men and found an abnormality rate of 8.9%. Brandriff et al. (5) found 8.1% abnormal complements in 909 sperm from 4 men. The distribution of numerical and structural abnormalities was markedly dissimilar in the 2 studies. The frequency of aneuploidy was 5% in our sample and only 1.6% in Brandriff's, perhaps reflecting individual variability among donors. The frequency of 24,YY sperm was low: 0/1,426 and 1/909. This suggests that the estimates of nondisjunction based on fluorescent Y body data (1% to 5%) are not accurate. We have also studied men at increased risk of sperm chromosomal abnormalities. The frequency of chromosomally unbalanced sperm in 6 men heterozygous for structural abnormalities varied dramatically: 77% for t11;22, 32% for t6;14, 19% for t5;18, 13% for t14;21, and 0% for inv 3 and 7. We have also studied 13 cancer patients before and after radiotherapy and demonstrated a significant dose-dependent increase of sperm chromosome abnormalities (numerical and structural) 36 months after radiation treatment.

  14. Intracytoplasmic Sperm Injection Outcomes with Freshly Ejaculated Sperms and Testicular or Epididymal Sperm Extraction in Patients with Idiopathic Cryptozoospermia

    PubMed Central

    Ketabchi, Ali Asghar

    2016-01-01

    Background Cryptozoospermia (CO) is a situation in which spermatozoa cannot be observed in a fresh semen sample unless an extended centrifugation and microscopic search are performed. CO patients are suggested to use only intracytoplasmic sperm injection (ICSI) as infertility treatment. But still there is debate about the choice of sperm source in cryptozoospermic men candidate for ICSI. Objectives This study was conducted to evaluate fertility outcomes in men with idiopathic cryptozoospermia who were treated using ICSI with freshly ejaculated sperm and testis sperm extraction (TESE) or percutaneous epididymal sperm aspiration (PESA). Methods In this prospective cohort study carried out in an academic institution, 83 out of 92 couples with cryptozoospermia undergoing their first ICSI cycle were recruited. These patients were randomly allocated to two groups: group one (n = 42) who produced freshly ejaculated sperm and, group two (n = 41) who produced a sample by TESE or PESA. The groups were analyzed and compared in terms of fertilization rate, cleavage rate, embryo quality, implantation rate, and clinical pregnancy rate. Results There was a significant difference in fertilization rate, embryo quality, implantation rate, and pregnancy rates between the group of surgically extracted sperm and those of naturally ejaculated sperm using conventional ICSI (P < 0.05). Conclusions Sperm quality extracted by percutaneous PESA and TESE procedures increases fertility outcomes compared to naturally ejaculated sperm in men with idiopathic CO. More specifically, embryo quality, which is most relevant to fertility outcome, improved when surgically extracted sperm was used for ICSI. PMID:27896242

  15. Computer-assisted sperm analysis (CASA): capabilities and potential developments.

    PubMed

    Amann, Rupert P; Waberski, Dagmar

    2014-01-01

    Computer-assisted sperm analysis (CASA) systems have evolved over approximately 40 years, through advances in devices to capture the image from a microscope, huge increases in computational power concurrent with amazing reduction in size of computers, new computer languages, and updated/expanded software algorithms. Remarkably, basic concepts for identifying sperm and their motion patterns are little changed. Older and slower systems remain in use. Most major spermatology laboratories and semen processing facilities have a CASA system, but the extent of reliance thereon ranges widely. This review describes capabilities and limitations of present CASA technology used with boar, bull, and stallion sperm, followed by possible future developments. Each marketed system is different. Modern CASA systems can automatically view multiple fields in a shallow specimen chamber to capture strobe-like images of 500 to >2000 sperm, at 50 or 60 frames per second, in clear or complex extenders, and in <2 minutes, store information for ≥ 30 frames and provide summary data for each spermatozoon and the population. A few systems evaluate sperm morphology concurrent with motion. CASA cannot accurately predict 'fertility' that will be obtained with a semen sample or subject. However, when carefully validated, current CASA systems provide information important for quality assurance of semen planned for marketing, and for the understanding of the diversity of sperm responses to changes in the microenvironment in research. The four take-home messages from this review are: (1) animal species, extender or medium, specimen chamber, intensity of illumination, imaging hardware and software, instrument settings, technician, etc., all affect accuracy and precision of output values; (2) semen production facilities probably do not need a substantially different CASA system whereas biology laboratories would benefit from systems capable of imaging and tracking sperm in deep chambers for a flexible

  16. Ejaculated Mouse Sperm Enter Cumulus-Oocyte Complexes More Efficiently In Vitro than Epididymal Sperm

    PubMed Central

    Suarez, Susan S.

    2015-01-01

    The mouse is an established and popular animal model for studying reproductive biology. Epididymal mouse sperm, which lack exposure to secretions of male accessory glands and do not precisely represent ejaculated sperm for the study of sperm functions, have been almost exclusively used in studies. We compared ejaculated and epididymal sperm in an in vitro fertilization setting to examine whether ejaculated sperm enter cumulus-oocyte complexes more efficiently. In order to prepare sperm for fertilization, they were incubated under capacitating conditions. At the outset of incubation, ejaculated sperm stuck to the glass surfaces of slides and the incidences of sticking decreased with time; whereas, very few epididymal sperm stuck to glass at any time point, indicating differences in surface charge. At the end of the capacitating incubation, when sperm were added to cumulus-oocyte complexes, the form of flagellar movement differed dramatically; specifically, ejaculated sperm predominantly exhibited increased bending on one side of the flagellum (a process termed pro-hook hyperactivation), while epididymal sperm equally exhibited increased bending on one or the other side of the flagellum (pro-hook or anti-hook hyperactivation). This indicates that accessory sex gland secretions might have modified Ca2+ signaling activities in sperm, because the two forms of hyperactivation are reported to be triggered by different Ca2+ signaling patterns. Lastly, over time, more ejaculated than epididymal sperm entered the cumulus oocyte complexes. We concluded that modification of sperm by male accessory gland secretions affects the behavior of ejaculated sperm, possibly providing them with an advantage over epididymal sperm for reaching the eggs in vivo. PMID:25996155

  17. Effect of cinnamon (Cinnamomum zeylanicum) bark oil on heat stress-induced changes in sperm production, testicular lipid peroxidation, testicular apoptosis, and androgenic receptor density in developing Japanese quails.

    PubMed

    Türk, Gaffari; Şimşek, Ülkü G; Çeribaşı, Ali O; Çeribaşı, Songül; Özer Kaya, Şeyma; Güvenç, Mehmet; Çiftçi, Mehmet; Sönmez, Mustafa; Yüce, Abdurrauf; Bayrakdar, Ali; Yaman, Mine; Tonbak, Fadime

    2015-08-01

    The aim of this study was to investigate the effect of cinnamon bark oil (CBO) on heat stress (HS)-induced changes in sperm production, testicular lipid peroxidation, testicular apoptosis, and androgenic receptor (AR) density in developing Japanese quails. Fifteen-day-old 90 male chicks were assigned to two main groups. The first group (45 chicks) was kept in a thermoneutral room at 22 °C for 24 h/day. The second group (45 chicks) was kept in a room with high ambient temperature at 34 °C for 8 h/day (from 9 AM-5 PM) and at 22 °C for 16 h/day. Each of these two main groups was then divided into three subgroups (CBO groups 0, 250, 500 ppm) consisting of 15 chicks (six treatment groups in 2 × 3 factorial order). Each of subgroups was replicated for three times and each replicate included five chicks. Heat stress caused significant decreases in body weight, spermatid and testicular sperm numbers, the density of testicular Bcl-2 (antiapoptotic marker) and AR immunopositivity, and significant increases in testicular lipid peroxidation level, the density of testicular Bax (apoptotic marker) immunopositivity, and a Bax/Bcl-2 ratio along with some histopathologic damages. However, 250 and 500 ppm CBO supplementation provided significant improvements in HS-induced increased level of testicular lipid peroxidation, decreased number of spermatid and testicular sperm, decreased densities of Bcl-2 and AR immunopositivity, and some deteriorated testicular histopathologic lesions. In addition, although HS did not significantly affect the testicular glutathione level, addition of both 250 and 500 ppm CBO to diet of quails reared in both HS and thermoneutral conditions caused a significant increase when compared with quails without any consumption of CBO. In conclusion, HS-induced lipid peroxidation causes testicular damage in developing male Japanese quails and, consumption of CBO, which has antiperoxidative effect, protects their testes against HS.

  18. Depletion of Intracellular Thiols and Increased Production of 4-Hydroxynonenal that Occur During Cryopreservation of Stallion Spermatozoa Lead to Caspase Activation, Loss of Motility, and Cell Death.

    PubMed

    Martin Muñoz, Patricia; Ortega Ferrusola, Cristina; Vizuete, Guillermo; Plaza Dávila, Maria; Rodriguez Martinez, Heriberto; Peña, Fernando J

    2015-12-01

    Oxidative stress has been linked to sperm death and the accelerated senescence of cryopreserved spermatozoa. However, the molecular mechanisms behind this phenomenon remain poorly understood. Reactive oxygen species (ROS) are considered relevant signaling molecules for sperm function, only becoming detrimental when ROS homeostasis is lost. We hereby hypothesize that a major component of the alteration of ROS homeostasis in cryopreserved spermatozoa is the exhaustion of intrinsic antioxidant defense mechanisms. To test this hypothesis, semen from seven stallions was frozen using a standard technique. The parameters of sperm quality (motility, velocity, and membrane integrity) and markers of sperm senescence (caspase 3, 4-hydroxynonenal, and mitochondrial membrane potential) were assessed before and after cryopreservation. Changes in the intracellular thiol content were also monitored. Cryopreservation caused significant increases in senescence markers as well as dramatic depletion of intracellular thiols to less than half of the initial values (P < 0.001) postthaw. Interestingly, very high and positive correlations were observed among thiol levels with sperm functionality postthaw: total motility (r = 0.931, P < 0.001), progressive motility (r = 0.904, P < 0.001), and percentage of live spermatozoa without active caspase 3 (r = 0.996, P < 0.001). In contrast, negative correlations were detected between active caspase 3 and thiol content both in living (r = -0.896) and dead (r = -0.940) spermatozoa; additionally, 4-hydroxynonenal levels were negatively correlated with thiol levels (r = -0.856). In conclusion, sperm functionality postthaw correlates with the maintenance of adequate levels of intracellular thiols. The accelerated senescence of thawed spermatozoa is related to oxidative and electrophilic stress induced by increased production of 4-hydroxynoneal in thawed samples once intracellular thiols are depleted.

  19. Effects of liquid preservation of sperm on their ability to activate oocytes and initiate preimplantational development after intracytoplasmic sperm injection in the pig.

    PubMed

    Binh, N T; Van Thuan, N; Miyake, M

    2009-06-01

    The objective of this study was to clarify the effects of liquid preservation conditions on the ability of pig sperm to activate oocytes, form a male pronucleus, and initiate preimplantational development of embryos after intracytoplasmic sperm injection (ICSI). Porcine ejaculates were preserved at 4, 14, and 24 degrees C for up to 48h, and then damage to the plasma membrane, morphologic changes of the acrosome, and the amount of phospholipase Czeta (PLCzeta) in the sperm were assessed by SYBR-14/propidium iodide staining, fluorescein isothiocyanate-conjugated peanut agglutinin staining, indirect immunofluorescence, and Western blots, respectively. The proportion of sperm with a disintegrated plasma membrane or damaged acrosome increased in all samples as the duration of preservation increased, although the time courses of the increases varied among preservation temperatures. The immunolocalization and immunoreactivity of PLCzeta in the sperm showed its reduction concurrent with disintegration of the plasma membrane and acrosome. Rates of oocyte activation, male-pronuclear formation, and blastocyst formation after ICSI using sperm preserved for 18h at 24 degrees C (78%, 62%, and 35%, respectively) and for 48h at 14 degrees C (63%, 53%, and 28%, respectively) were significantly higher than those of any other sperm sample. We concluded that the damage to the plasma membrane and acrosome, and a sufficient amount of PLCzeta in the sperm head, enhanced successful oocyte activation, fertilization, and early development of the oocytes after ICSI. Moreover, we inferred that appropriate liquid preservation of sperm improved the efficiency of blastocyst production in vitro after ICSI in pigs.

  20. Coal liquefaction to increase jet fuel production

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Processing concept that increases supply of jet fuel has been developed as part of study on methods for converting coal to hydrogen, methane, and jet fuel. Concept takes advantage of high aromatic content of coal-derived liquids to make high-octane gasoline, instead of destroying aromatics to make jet fuel.

  1. Artificial insemination with donor sperm (AID): heterogeneity in sperm banking facilities in a single country (Belgium)

    PubMed Central

    Thijssen, A.; Dhont, N.; Vandormael, E.; Cox, A.; Klerkx, E.; Creemers, E.; Ombelet, W.

    2014-01-01

    Due to the high inflow of foreign patients seeking cross-border reproductive care in Belgium and the increased number of lesbian couples and single women who call for artificial insemination with donor sperm (AID), Belgian sperm banks nowadays face a shortage in donor sperm. However, since there is no central registration system for sperm donors in Belgium, no figures are currently available supporting this statement. Therefore a study was performed to obtain a detailed overview of the sperm banking facilities in Belgium. Questionnaires were sent to all Belgian centres for assisted reproduction with laboratory facilities (n = 18) to report on their sperm banking methods. The results showed that 82% of the centres rely partially or completely on foreign donor sperm. Moreover, four of the thirteen centres that have their own sperm bank use imported donor sperm in > 95% AID cycles. Our results show that in 63% of the Belgian AID cycles imported Danish donor sperm is being used. Donor recruitment is mainly performed through the centre’s website (61%) or by distributing flyers in the centre (46%) and 9 to 180 potential donors have been recruited per centre in 2013. Eventually, 15 to 50% of these candidate donors were accepted. Different criteria for donor acceptance are handled by the centres: donor age limits range from 18-25 to 36-46 years old, and thresholds for sperm normality differ considerably. We can conclude that a wide variation in methods associated with sperm banking is observed in Belgian centres. PMID:25009728

  2. On-site evaluation of commercial-scale hybrid catfish production using cryopreserved blue catfish sperm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cryopreservation is an effective tool for conservation of genetic resources and is becoming increasingly used worldwide with aquatic species. Broadening the application of this technology to a commercial scale through high-throughput approaches has become essential for use with aquatic species. This...

  3. Sensors Increase Productivity in Harsh Environments

    NASA Technical Reports Server (NTRS)

    2008-01-01

    California's San Juan Capistrano-based Endevco Corporation licensed three patents covering high-temperature, harsh-environment silicon carbide (Si-C) pressure sensors from Glenn Research Center. The company is exploring their use in government markets, as well as in commercial markets, including commercial jet testing, deep well drilling applications where pressure and temperature increase with drilling depth, and in automobile combustion chambers.

  4. Tactic-specific differences in seminal fluid influence sperm performance.

    PubMed

    Locatello, Lisa; Poli, Federica; Rasotto, Maria B

    2013-03-22

    Seminal fluid often makes up a large part of an ejaculate, yet most empirical and theoretical studies on sperm competition have focused on how sperm characteristics (number and quality) affect fertilization success. However, seminal fluid influences own sperm performance and may potentially influence the outcome of sperm competition, by also affecting that of rivals. As a consequence males may be expected to allocate their investment in both sperm and seminal fluid in relation to the potential level of competition. Grass goby (Zosterisessor ophiocephalus) is an external fertilizer with guard-sneaker mating tactics, where sperm competition risk varies according to the tactic adopted. Here, we experimentally manipulated grass goby ejaculates by separately combining sperm and seminal fluid from territorial and sneaker males. While sperm of sneaker and territorial males did not differ in their performance when they interacted with their own seminal fluid only, sperm of sneakers increased their velocity and fertilization rate in the presence of territorial males' seminal fluid. By contrast, sneaker males' seminal fluid had a detrimental effect on the performance of territorial males' sperm. Sperm velocity was unaffected by the seminal fluid of males employing the same tactic, suggesting that seminal fluid's effect on rival-tactic sperm is not based on a self/non-self recognition mechanism. Our findings show that cross interactions of sperm and seminal fluid may influence the fertilization success of competing ejaculates with males investing in both sperm and seminal fluid in response to sperm competition risk.

  5. Sperm competition differentially affects swimming velocity and size of spermatozoa from closely related muroid rodents: head first.

    PubMed

    Gómez Montoto, Laura; Varea Sánchez, María; Tourmente, Maximiliano; Martín-Coello, Juan; Luque-Larena, Juan José; Gomendio, Montserrat; Roldan, Eduardo R S

    2011-12-01

    Sperm competition favours an increase in sperm swimming velocity that maximises the chances that sperm will reach the ova before rival sperm and fertilise. Comparative studies have shown that the increase in sperm swimming speed is associated with an increase in total sperm size. However, it is not known which are the first evolutionary steps that lead to increases in sperm swimming velocity. Using a group of closely related muroid rodents that differ in levels of sperm competition, we here test the hypothesis that subtle changes in sperm design may represent early evolutionary changes that could make sperm swim faster. Our findings show that as sperm competition increases so does sperm swimming speed. Sperm swimming velocity is associated with the size of all sperm components. However, levels of sperm competition are only related to an increase in sperm head area. Such increase is a consequence of an increase in the length of the sperm head, and also of the presence of an apical hook in some of the species studied. These findings suggest that the presence of a hook may modify the sperm head in such a way that would help sperm swim faster and may also be advantageous if sperm with larger heads are better able to attach to the epithelial cells lining the lower isthmus of the oviduct where sperm remain quiescent before the final race to reach the site of fertilisation.

  6. Pregnancy rates in cattle with cryopreserved sexed sperm: effects of sperm numbers per inseminate and site of sperm deposition.

    PubMed

    Seidel, G E; Schenk, J L

    2008-04-01

    In six field trials, doses between 1.0 and 6.0 x 10(6) total sexed, frozen-thawed sperm were inseminated into the uterine body or bilaterally into the uterine horns of heifers and nursing Angus cows 12 or 24h after observed estrus. Except for one comparison in one trial in which uterine body insemination was slightly superior (P<0.05) to uterine horn insemination, there was no significant (P>0.1) difference between sites of semen deposition. Additionally, except for one small study with limited numbers, there was essentially no difference in pregnancy rates in the range between 1.5 and 6 x 10(6) sexed, frozen-thawed sperm per inseminate. Pregnancy rates with smaller doses of sexed sperm averaged about 75% of controls of 20 x 10(6) total frozen-thawed, unsexed sperm. While 1.0 x 10(6) sexed, frozen-thawed sperm per insemination dose resulted in decreased pregnancy rates compared to larger doses, the lesser fertility with sexed sperm could not be compensated by increasing sperm numbers in the range of 1.5-6 x 10(6) sperm per dose. Pregnancy rates with 2 x 10(6) sexed, frozen-thawed sperm per dose were not markedly less than control pregnancy rates with 20 x 10(6) frozen-thawed unsexed sperm/dose in well-managed herds.

  7. Exposure to bisphenol A (BPA) in Wistar rats reduces sperm quality with disruption of ERK signal pathway.

    PubMed

    Li, Juan; Mao, Rui; Zhou, Qin; Ding, Ling; Tao, Jin; Ran, Mao-Mei; Gao, Er-Sheng; Yuan, Wei; Wang, Jin-Tao; Hou, Li-Fang

    2016-01-01

    Bisphenol A (BPA) is an estrogenic environmental toxin widely used in the production of plastics and ubiquitous human exposure to this chemical has been proposed to be a potential risk to human health. Exposure to BPA can negatively impact sperm quality. However, the mechanism remains largely unknown. The objectives of this study were to assess the role of BPA on sperm quality and explore the possible mechanisms. The Wistar male rats (aged 28 days) were administered BPA by oral gavage for 28 days at dose of 50, 100 and 200 mg/kg/day; meanwhile, the negative control with corn oil (0 mg/kg/day BPA) and positive control with E2 at the dose of 100 μg/kg/day. The sperm density, sperm activity and sperm survival rate were analyzed byCASA system, and the sperm abnormality rate was analyzed by improved Papanicolaou stained. The protein expression levels of Src/p-Src, ERK1/2, p-ERK1/2 and CREB/p-CREB were detected by Western bolt. The results showed that the body weight gain, testes weight, testis coefficient, sperm density, sperm activity, sperm survival rate and protein expression levels of p-ERK1, p-ERK2 and p-CREB decreased, but the sperm abnormality rate increased with increasing BPA concentrations. There were positive correlations between sperm density, sperm activity and sperm survival rate with protein expression levels of p-ERK1, p-ERK2 and p-CREB, and negative correlations between sperm abnormality rate with the protein expression levels of p-ERK1, p-ERK2 and p-CREB. Results from the structural equation model demonstrated that BPA retained a significant negative effect to p-ERK, whereas p-ERK retained a significant positive effect to sperm quality and acted as the mediate variable. This study provides a novel insight regarding the potential role of p-ERK1 and p-ERK2 protein kinase on reproductive toxicity of BPA. The adverse effects of BPA on adult male sperm quality may be through the induction of the disruption of ERK signal pathway. However, additional

  8. Sperm antioxidant defences decrease during epididymal transit from caput to cauda in parallel with increases in epididymal fluid in the goat (Capra hircus).

    PubMed

    Rana, Mashidur; Roy, Sudhir C; Divyashree, Bannur C

    2016-09-28

    The status of antioxidant defences of both spermatozoa and their associated fluids during epididymal transit from the caput to cauda have not been studied so far in any species. Herein we report for the first time that sperm antioxidant defences, namely Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and catalase activity, decrease significantly (P<0.05) from the caput to cauda during epididymal transit in parallel with increases in Cu,Zn-SOD, total SOD and total glutathione peroxidase (GPx) activity in the luminal fluid of the respective segments. However, levels of GPX1 and GPX3 in epididymal fluid did not change significantly from the caput to cauda. Catalase was detected for the first time in goat spermatozoa. A significantly higher total antioxidant capacity of caudal fluid than of the caput suggests a requirement for a rich antioxidant environment for the storage of spermatozoa. The retention of cytoplasmic droplets in most of the caudal spermatozoa confirmed that these droplets do not contribute to the increased antioxidant defences of cauda epididymidal fluid. Thus, the antioxidant defences of the spermatozoa and their associated epididymal fluid are modulated from the caput to cauda in a region-specific manner. This may be one of the compensatory mechanisms of epididymal fluid to scavenge any excess reactive oxygen species produced in the microenvironment of spermatozoa.

  9. Early Eocene climate warming increased petroleum production

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-04-01

    From the late Paleocene, about 58 million years ago, to the early Eocene, about 51 million years ago, Earth's surface temperatures warmed by about 5°-10°C. Also in the early Eocene, there was an increase of carbon-13-depleted carbon in the oceans that cannot be accounted for by changes in carbon cycling at the surface. To better understand the source of that carbon, Kroeger and Funnell modeled the thermal evolution of four sedimentary basins in the southwestern Pacific Ocean. The authors show that the rising surface temperatures of the early Eocene eventually led to warming of the sedimentary beds deep beneath the surface. Petroleum can be produced at only a certain range of temperatures; rising temperatures at greater depths would bring more potential source rocks into temperature conditions under which oil and gas can be produced and released.

  10. Yankee links computing needs, increases productivity

    SciTech Connect

    1994-10-01

    Yankee Atomic Electric Company provides design and consultation services to electric utility companies that operate nuclear power plants. This means bringing together the skills and talents of more than 500 people in many disciplines, including computer-aided design, human resources, financial services, and nuclear engineering. The company was facing a problem familiar to many companies in the nuclear industry.Key corporate data and applications resided on UNIX or other types of computer systems, but most users at Yankee had personal computers on their desks. How could Yankee enable the PC users to share the data, applications, and resources of the larger computing environment such as UNIX, while ensuring they could still use their favorite PC applications? The solution was PC-NFS from Sunsoft, of Chelmsford, Mass., which links PCs to UNIX and other systems. The Yankee computing story is an example of computer downsizing-the trend of moving away from mainframe computers in favor of lower-cost, more flexible client/server computing. Today, Yankee Atomic has more than 350 PCs on desktops throughout the company, using PC-NFS, which enables them t;o use the data, applications, disks, and printers of the FUNIX server systems. This new client/server environment has reduced Yankee`s computing costs while increasing its computing power and its ability to respond to customers.

  11. Increasing Labour Productivity in Agriculture and Its Implications

    ERIC Educational Resources Information Center

    van den Ban, Anne

    2011-01-01

    In order to profit from the economic growth in their society farmers can (1) increase the yields of their crops and animals, (2) switch to the production of high value products for which there is an increasing demand in the market, (3) increase the labour productivity on their farm, (4) find non-farm sources of income for some or all of their…

  12. Cofilin is correlated with sperm quality and influences sperm fertilizing capacity in humans.

    PubMed

    Chen, S M; Chen, X M; Lu, Y L; Liu, B; Jiang, M; Ma, Y X

    2016-11-01

    Spermatozoa should undergo a series of biochemical modifications in female reproduction tract, which is collectively called sperm capacitation. The capacitated spermatozoa can bind to the egg zona pellucida, resulting in the occurrence of acrosome reaction which enabled spermatozoa penetrate into the egg. The formation of actin plays an important role in these processes. Actin polymerized during sperm capacitation, but the polymers dispersed before acrosome reaction. In this study, we take our focus on actin-binding protein, cofilin. Our results showed that the % and intensity of sperm expressing cofilin in normal sperm were significantly higher than in abnormal sperm, and the sperm expressing cofilin was correlated with sperm quality. Furthermore, treatment with anti-cofilin antibody increased the percentage of sperm capacitation and inhibited progesterone- or A23187- induced acrosome reaction in a dose-dependent manner. The presence of 100 ng/mL anti-cofilin antibodies markedly blocked the sperm penetration of zona-free hamster eggs. Besides, immunofluorescence results revealed that cofilin was colocalized with F-actin in the midpiece of spermatozoa; however, phospho-cofilin was expressed in the tail rather than in the midpiece of spermatozoa, which was not colocalized with F-actin in spermatozoa. Moreover, western blot revealed that phospho-cofilin increased in sperm capacitation, and the total cofilin and cofilin in insoluble fraction increased in acrosome reaction; immunofluorescence results showed that the amount of cofilin in acrosome increased in sperm capacitation. In conclusion, our study revealed that cofilin expression in human sperm is correlated with sperm quality and the alterations of cofilin and phospho-cofilin in fertilization affects sperm capacitation, acrosome reaction, and spermatozoa-oocyte fusion.

  13. Effect of manganese supplementation on the membrane integrity and the mitochondrial potential of the sperm of grazing Nelore bulls.

    PubMed

    Reis, L S L S; Ramos, A A; Camargos, A S; Oba, E

    2014-11-10

    The effect of dietary manganese (Mn(2+)) supplementation on the reproductive performance of Nelore bulls was evaluated by assessment of sperm membrane integrity. Sixty Nelore bulls (Bos taurus indicus) aged 18-20 mo were randomly divided into four groups (n=15) receiving dietary Mn(2+) supplementation at 540, 1300, 3800 and 6300mg/kg (treatments TC, T1300, T3800 and T6300, respectively). The diets were changed for the groups every 70d. Semen samples were obtained 15 and 56d after the diet change, which corresponded to the period of adjustment to the new diet and the time required for a complete spermatogenesis cycle, respectively. Sperm integrity was assessed by detection of: intact (IMe) or damaged (DMe) membranes, intact (IA) or damaged (DA) acrosomes, and high (HM) or low (LM) mitochondrial membrane potentials. Only bulls from the TC treatment showed a significant increase in the production of intact sperm [IMe/IA/LM] and decrease in the production of sperm with damaged acrosome [IMe/DA/LM] or completely damaged sperm [DMe/DA/LM] (P<0.05). The Mn(2+) concentrations in the semen were positively correlated with the incidence of sperm with IMe, DA, and LM and negatively correlated with number of sperm with DMe, IA, and LM. Therefore, dietary Mn(2+) supplementation for Nelore bulls must be limited to 540mg of Mn(2+)/kg given that higher doses are detrimental to the integrity of the plasma and acrosomal sperm membranes.

  14. Sperm motility of externally fertilizing fish and amphibians.

    PubMed

    Browne, R K; Kaurova, S A; Uteshev, V K; Shishova, N V; McGinnity, D; Figiel, C R; Mansour, N; Agney, D; Wu, M; Gakhova, E N; Dzyuba, B; Cosson, J

    2015-01-01

    We review the phylogeny, sperm competition, morphology, physiology, and fertilization environments of the sperm of externally fertilizing fish and amphibians. Increased sperm competition in both fish and anurans generally increases sperm numbers, sperm length, and energy reserves. The difference between the internal osmolarity and iconicity of sperm cells and those of the aquatic medium control the activation, longevity, and velocity of sperm motility. Hypo-osmolarity of the aquatic medium activates the motility of freshwater fish and amphibian sperm and hyperosmolarity activates the motility of marine fish sperm. The average longevity of the motility of marine fish sperm (~550 seconds) was significantly (P < 0.05) greater than that of freshwater fish sperm (~150 seconds), with the longevities of both marine and freshwater fish being significantly (P < 0.05) lower than that of anuran sperm (~4100 seconds). The average velocity of anuran sperm (25 μm/s) was significantly (P < 0.05) lower than that of marine fish (140 μm/s) or freshwater fish (135 μm/s) sperm. The longevity of the sperm of giant salamanders (Cryptobranchoidea) of approximately 600 seconds was greater than that of freshwater fish sperm but much lower than anuran sperm. Our research and information from the literature showed that higher osmolarities promote greater longevity in anuran sperm, and some freshwater fish sperm, and that anuran and cryptobranchid sperm maintained membrane integrity long after the cessation of motility, demonstrating a preferential sharing of energy reserves toward the maintenance of membrane integrity. The maintenance of the membrane integrity of anuran sperm in fresh water for up to 6 hours showed an extremely high osmotic tolerance relative to fish sperm. The very high longevity and osmotic tolerance of anuran sperm and high longevity of cryptobranchid sperm, relative to those of freshwater fish, may reflect the complex fertilization history of amphibian sperm in

  15. Production of lion (Panthera leo) blastocysts after in vitro maturation of oocytes and intracytoplasmic sperm injection.

    PubMed

    Fernandez-Gonzalez, Lorena; Hribal, Romy; Stagegaard, Julia; Zahmel, Jennifer; Jewgenow, Katarina

    2015-04-01

    Assisted reproductive techniques are becoming widely applied to the breeding of endangered species, but establishing reliable protocols for the production of embryos in vitro is challenging because of the scarcity of sample material. In our study, we applied an assisted reproductive technique protocol for IVM and intracytoplasmic sperm injection (ICSI), developed in the domestic cat, to oocytes retrieved from ovaries of four 2-year-old lionesses (Panthera leo) eight hours postmortem. In total, 68 cumulus-oocyte complexes of good quality were randomly distributed and cultured for 32 to 34 hours in two different maturation culture media, consisting of Medium 199 with Earle's salts, 3 mg/mL BSA, 0.1 mg/mL cysteine, 1.4 mg/mL sodium pyruvate, 0.6 mg/mL sodium lactate, 0.15 mg/mL l-glutamine, and 0.055 mg/mL gentamicin. Hormonal supplementation of IVM_1 was 0.02 IU/mL FSH and 0.05 IU/mL LH; IVM_2 consisted of 1.64 IU/mL FSH, 1.06 IU/mL LH, and 1 μg/mL 17ß-estradiol. Differences in hormonal supplementation did not produce significant differences in oocyte maturation rates, which were 39.4% in IVM_1 and 34.3% in IVM_2. Matured oocytes were microinjected with homologous frozen-thawed spermatozoa, and subsequent cleavage rates were 30.8% and 58.3%, respectively. Half of the embryos derived from oocytes matured in IVM_1 developed into blastocysts, whereas only 28.6% of embryos from oocytes matured in IVM_2 reached the blastocyst stage. Morula stages were present from Day 6 onward, and blastocyst stages from Day 9 on, indicating a slower developmental speed in comparison with domestic cats. This is the first report of in vitro-produced blastocysts using ICSI in the lion, and the results report that IVM and ICSI can be successfully performed with cumulus-oocyte complexes retrieved from ovaries after eight hours of shipping, obtaining competent embryos in culture.

  16. Hypercholesterolemia Impaired Sperm Functionality in Rabbits

    PubMed Central

    Monclus, Maria A.; Cabrillana, Maria E.; Clementi, Marisa A.; Espínola, Leandro S.; Cid Barría, Jose L.; Vincenti, Amanda E.; Santi, Analia G.; Fornés, Miguel W.

    2010-01-01

    Hypercholesterolemia represents a high risk factor for frequent diseases and it has also been associated with poor semen quality that may lead to male infertility. The aim of this study was to analyze semen and sperm function in diet-induced hypercholesterolemic rabbits. Twelve adult White New Zealand male rabbits were fed ad libitum a control diet or a diet supplemented with 0.05% cholesterol. Rabbits under cholesterol-enriched diet significantly increased total cholesterol level in the serum. Semen examination revealed a significant reduction in semen volume and sperm motility in hypercholesterolemic rabbits (HCR). Sperm cell morphology was seriously affected, displaying primarily a “folded head”-head fold along the major axe-, and the presence of cytoplasmic droplet on sperm flagellum. Cholesterol was particularly increased in acrosomal region when detected by filipin probe. The rise in cholesterol concentration in sperm cells was determined quantitatively by Gas chromatographic-mass spectrometric analyses. We also found a reduction of protein tyrosine phosphorylation in sperm incubated under capacitating conditions from HCR. Interestingly, the addition of Protein Kinase A pathway activators -dibutyryl-cyclic AMP and iso-butylmethylxanthine- to the medium restored sperm capacitation. Finally, it was also reported a significant decrease in the percentage of reacted sperm in the presence of progesterone. In conclusion, our data showed that diet-induced hypercholesterolemia adversely affects semen quality and sperm motility, capacitation and acrosomal reaction in rabbits; probably due to an increase in cellular cholesterol content that alters membrane related events. PMID:20976152

  17. Induced lipid peroxidation in ram sperm: semen profile, DNA fragmentation and antioxidant status.

    PubMed

    Hamilton, Thais Rose dos Santos; de Castro, Letícia Signori; Delgado, Juliana de Carvalho; de Assis, Patrícia Monken; Siqueira, Adriano Felipe Perez; Mendes, Camilla Mota; Goissis, Marcelo Demarchi; Muiño-Blanco, Teresa; Cebrián-Pérez, José Álvaro; Nichi, Marcílio; Visintin, José Antonio; D'Ávila Assumpção, Mayra Elena Ortiz

    2016-04-01

    Action of reactive oxygen species, protamination failures and apoptosis are considered the most important etiologies of sperm DNA fragmentation. This study evaluated the effects of induced lipid peroxidation susceptibility on native semen profile and identified the mechanisms involved in sperm DNA fragmentation and testicular antioxidant defense on Santa Ines ram sperm samples. Semen was collected from 12 adult rams (Ovis aries) performed weekly over a 9-week period. Sperm analysis (motility, mass motility, abnormalities, membrane and acrosome status, mitochondrial potential, DNA fragmentation, lipid peroxidation and intracellular free radicals production); protamine deficiency; PRM1, TNP1 and TNP2 gene expression; and determination of glutathione peroxidase (GPx), glutathione reductase, catalase (CAT) and superoxide dismutase activity and immunodetection in seminal plasma were performed. Samples were distributed into four groups according to the sperm susceptibility to lipid peroxidation after induction with ascorbate and ferrous sulfate (low, medium, high and very high). The results were analyzed by GLM test and post hoc least significant difference. We observed an increase in native GPx activity and CAT immunodetection in groups with high susceptibility to induced lipid peroxidation. We also found an increase in total sperm defects, acrosome and membrane damages in the group with the highest susceptibility to induced lipid peroxidation. Additionally, the low mitochondrial membrane potential, susceptible to chromatin fragmentation and the PRM1 mRNA were increased in the group showing higher susceptibility to lipid peroxidation. Ram sperm susceptibility to lipid peroxidation may compromise sperm quality and interfere with the oxidative homeostasis by oxidative stress, which may be the main cause of chromatin damage in ram sperm.

  18. Protein and carbohydrate intake influence sperm number and fertility in male cockroaches, but not sperm viability

    PubMed Central

    Bunning, Harriet; Rapkin, James; Belcher, Laurence; Archer, C. Ruth; Jensen, Kim; Hunt, John

    2015-01-01

    It is commonly assumed that because males produce many, tiny sperm, they are cheap to produce. Recent work, however, suggests that sperm production is not cost-free. If sperm are costly to produce, sperm number and/or viability should be influenced by diet, and this has been documented in numerous species. Yet few studies have examined the exact nutrients responsible for mediating these effects. Here, we quantify the effects of protein (P) and carbohydrate (C) intake on sperm number and viability in the cockroach Nauphoeta cinerea, as well as the consequences for male fertility. We found the intake of P and C influenced sperm number, being maximized at a high intake of diets with a P : C ratio of 1 : 2, but not sperm viability. The nutritional landscapes for male fertility and sperm number were closely aligned, suggesting that sperm number is the major determinant of male fertility in N. cinerea. Under dietary choice, males regulate nutrient intake at a P : C ratio of 1 : 4.95, which is midway between the ratios needed to maximize sperm production and pre-copulatory attractiveness in this species. This raises the possibility that males regulate nutrient intake to balance the trade-off between pre- and post-copulatory traits in this species. PMID:25608881

  19. Cytometry of mammalian sperm

    SciTech Connect

    Gledhill, B.L.

    1983-10-11

    Male germ cells respond dramatically to a variety of insults and are important reproductive dosimeters. Semen analyses are very useful in studies on the effects of drugs, chemicals, and environmental hazards on testicular function, male fertility and heritable germinal mutations. The accessibility of male cells makes them well suited for analytical cytology. We might automate the process of determining sperm morphology but should not do so solely for increased speed. Rather, richer tangible benefits will derive from cytometric evaluation through increased sensitivity, reduced subjectivity, standardization between investigators and laboratories, enhanced archival systems, and the benefits of easily exchanged standardized data. Inroads on the standardization of assays for motility and functional integrity are being made. Flow cytometric analysis of total DNA content of individual sperm is an insensitive means to detect exposure to reproductive toxins because of the small size and low frequency of the DNA content errors. Flow cytometry can be applied to determine the proportions of X- and Y-sperm in semen samples.

  20. Reducing endogenous estrogen during prepuberal life does not affect boar libido or sperm fertilizing potential.

    PubMed

    Berger, Trish; Conley, Alan J

    2014-09-01

    Increasing sperm production per breeding male has economic significance with increasing use of artificial insemination. Manipulations to increase sperm production in livestock will only be useful if libido and sperm fertilizing capacity are not adversely affected. Reducing endogenous estrogens in the postnatal interval increases the number of Sertoli cells and hence testicular sperm production capacity. These experiments were designed to evaluate the effects of reducing endogenous estrogens on libido and sperm fertilizing capacity. Boars were treated with an aromatase inhibitor, letrozole, to reduce testicular estrogen production between 1 and 6 weeks of age or between 11 and 16 weeks of age, and the littermates to these boars were treated with the canola oil vehicle. Letrozole treatment did not affect time to first mount at 22 weeks of age, regardless of whether the treatment occurred from 1 to 6 weeks of age (118 seconds vs. 233 seconds, SEM = 161 for letrozole-treated and vehicle-treated boars, respectively) or from 11 to 16 weeks of age (107 seconds vs. 67 seconds, SEM = 63 for letrozole-treated and vehicle-treated boars, respectively). Similarly, sperm fertilizing ability and in vivo fertility were equivalent in letrozole-treated boars and their vehicle-treated littermates. Surprisingly, the increase in Sertoli cell numbers observed in the letrozole-treated boars at 20 weeks of age (5.8 vs. 4.3 billion, SEM = 0.5; P < 0.05) was not maintained to 40 weeks of age in their letrozole-treated littermates. Reducing endogenous estrogen production neonatally or prepuberally had no detectable adverse effect on libido or sperm fertilizing capacity.

  1. Mass-Specific Metabolic Rate and Sperm Competition Determine Sperm Size in Marsupial Mammals

    PubMed Central

    Tourmente, Maximiliano; Gomendio, Montserrat; Roldan, Eduardo R. S.

    2011-01-01

    Two complementary hypotheses have been proposed to explain variation in sperm size. The first proposes that post-copulatory sexual selection favors an increase in sperm size because it enhances sperm swimming speed, which is an important determinant of fertilization success in competitive contexts. The second hypothesis proposes that mass-specific metabolic rate acts as a constraint, because large animals with low mass-specific metabolic rates will not be able to process resources at the rates needed to produce large sperm. This constraint is expected to be particularly pronounced among mammals, given that this group contains some of the largest species on Earth. We tested these hypotheses among marsupials, a group in which mass-specific metabolic rates are roughly 30% lower than those of eutherian mammals of similar size, leading to the expectation that metabolic rate should be a major constraint. Our findings support both hypotheses because levels of sperm competition are associated with increases in sperm size, but low mass-specific metabolic rate constrains sperm size among large species. We also found that the relationship between sperm size and mass-specific metabolic rate is steeper among marsupials and shallower among eutherian mammals. This finding has two implications: marsupials respond to changes in mass-specific metabolic rate by modifying sperm length to a greater extent, suggesting that they are more constrained by metabolic rate. In addition, for any given mass-specific metabolic rate, marsupials produce longer sperm. We suggest that this is the consequence of marsupials diverting resources away from sperm numbers and into sperm size, due to their efficient sperm transport along the female tract and the existence of mechanisms to protect sperm. PMID:21731682

  2. Seasonal occurrence of sperm whales (Physeter macrocephalus) around Kelvin Seamount in the Sargasso Sea in relation to oceanographic processes

    NASA Astrophysics Data System (ADS)

    Wong, Sarah N. P.; Whitehead, Hal

    2014-09-01

    Sperm whales (Physeter macrocephalus) are widely distributed in all oceans, but they are clumped geographically, generally in areas associated with high primary and secondary productivity. The warm, clear waters of the Sargasso Sea are traditionally thought to be low in productivity, however recent surveys have found large numbers of sperm whales there. The New England Seamount Chain bisects the north-western portion of the Sargasso Sea, and might influence the mesoscale eddies associated with the Gulf Stream; creating areas of higher productivity within the Sargasso Sea. We investigated the seasonal occurrence of sperm whales over Kelvin Seamount (part of the New England Seamount Chain) and how it is influenced by oceanographic variables. An autonomous recording device was deployed over Kelvin Seamount from May to June 2006 and November 2006 to June 2007. A total of 6505 hourly two-minute recordings were examined for the presence of sperm whale echolocation clicks. Sperm whales were more prevalent around Kelvin in the spring (April to June: mean=51% of recordings contained clicks) compared to the winter (November to March: mean=16% of recordings contained clicks). Sperm whale prevalence at Kelvin was related to chlorophyll-a concentration four weeks previous, eddy kinetic energy and month. The mesoscale activity associated with the Gulf Stream and the Gulf Stream's interaction with the New England Seamount Chain likely play an important role in sperm whale occurrence in this area, by increasing productivity and perhaps concentration of cephalopod species.

  3. Accurate sperm morphology assessment predicts sperm function.

    PubMed

    Abu Hassan Abu, D; Franken, D R; Hoffman, B; Henkel, R

    2012-05-01

    Sperm morphology has been associated with in vitro as well as in vivo fertilisation. The study aimed to evaluate the possible relation between the percentage of spermatozoa with normal morphology and the following sperm functional assays: (i) zona-induced acrosome reaction (ZIAR); (ii) DNA integrity; (iii) chromatin condensation; (iv) sperm apoptosis; and (v) fertilisation rates. Regression analysis was employed to calculate the association between morphology and different functional tests. Normal sperm morphology correlated significantly with the percentages of live acrosome-reacted spermatozoa in the ZIAR (r = 0.518; P < 0.0001; n = 92), DNA integrity (r = -0.515; P = 0.0018; n = 34), CMA(3) -positive spermatozoa (r = -0.745; P < 0.0001; n = 92), sperm apoptosis (r = -0.395; P = 0.0206; n = 34) and necrosis (r = -0.545; P = 0.0009; n = 34). Negative correlations existed between for the acrosome reaction, and DNA integrity, while negative associations were recorded with the percentages of CMA(3) -positive spermatozoa, apoptotic and necrotic spermatozoa. Sperm morphology is related to sperm dysfunction such as poor chromatin condensation, acrosome reaction and DNA integrity. Negative and significant correlations existed between normal sperm morphology and chromatin condensation, the percentage of spermatozoa with abnormal DNA and spermatozoa with apoptotic activity. The authors do not regard sperm morphology as the only test for the diagnosis of male fertility, but sperm morphology can serve as a valuable indicator of underlying dysfunction.

  4. Prudent sperm use by leaf-cutter ant queens

    PubMed Central

    den Boer, Susanne P. A.; Baer, Boris; Dreier, Stephanie; Aron, Serge; Nash, David R.; Boomsma, Jacobus J.

    2009-01-01

    In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps), reproduction is usually monopolized by one or relatively few queens, who mate only during a brief period early in life and store sperm for later use. The queens of some ants are particularly long-lived and have the potential to produce millions of offspring during their life. To do so, queens store many sperm cells, and this sperm must remain viable throughout the years of storage. Queens should also be under strong selection to use stored sperm prudently when fertilizing eggs. We used the leaf-cutter ant Atta colombica to investigate the dynamics of sperm use during egg fertilization. We show that queens are able to fertilize close to 100 per cent of the eggs and that the average sperm use per egg is very low, but increases with queen age. The robustness of stored sperm was found to decrease with years of storage, signifying that senescence affects sperm either directly or indirectly via the declining glandular secretions or deteriorating sperm-storage organs. We evaluate our findings with a heuristic model, which suggests that the average queen has sperm for almost 9 years of normal colony development. We discuss the extent to which leaf-cutter ant queens have been able to optimize their sperm expenditure and infer that our observed averages of sperm number, sperm robustness and sperm use are consistent with sperm depletion being a significant cause of mortality of mature colonies of Atta leaf-cutter ants. PMID:19710057

  5. Prudent sperm use by leaf-cutter ant queens.

    PubMed

    den Boer, Susanne P A; Baer, Boris; Dreier, Stephanie; Aron, Serge; Nash, David R; Boomsma, Jacobus J

    2009-11-22

    In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps), reproduction is usually monopolized by one or relatively few queens, who mate only during a brief period early in life and store sperm for later use. The queens of some ants are particularly long-lived and have the potential to produce millions of offspring during their life. To do so, queens store many sperm cells, and this sperm must remain viable throughout the years of storage. Queens should also be under strong selection to use stored sperm prudently when fertilizing eggs. We used the leaf-cutter ant Atta colombica to investigate the dynamics of sperm use during egg fertilization. We show that queens are able to fertilize close to 100 per cent of the eggs and that the average sperm use per egg is very low, but increases with queen age. The robustness of stored sperm was found to decrease with years of storage, signifying that senescence affects sperm either directly or indirectly via the declining glandular secretions or deteriorating sperm-storage organs. We evaluate our findings with a heuristic model, which suggests that the average queen has sperm for almost 9 years of normal colony development. We discuss the extent to which leaf-cutter ant queens have been able to optimize their sperm expenditure and infer that our observed averages of sperm number, sperm robustness and sperm use are consistent with sperm depletion being a significant cause of mortality of mature colonies of Atta leaf-cutter ants.

  6. The sperm chromatin dispersion test: a simple method for the determination of sperm DNA fragmentation.

    PubMed

    Fernández, Jose Luis; Muriel, Lourdes; Rivero, Maria Teresa; Goyanes, Vicente; Vazquez, Rosana; Alvarez, Juan G

    2003-01-01

    Sperm DNA fragmentation is being increasingly recognized as an important cause of infertility. We herein describe the Sperm Chromatin Dispersion (SCD) test, a novel assay for sperm DNA fragmentation in semen. The SCD test is based on the principle that sperm with fragmented DNA fail to produce the characteristic halo of dispersed DNA loops that is observed in sperm with non-fragmented DNA, following acid denaturation and removal of nuclear proteins. This was confirmed by the analysis of DNA fragmentation using the specific DNA Breakage Detection-Fluorescence In Situ Hybridization (DBD-FISH) assay, which allows the detection of DNA breaks in lysed sperm nuclei. Sperm suspensions either prepared from semen or isolated from semen by gradient centrifugation were embedded in an agarose microgel on slides and treated with 0.08 N HCl and lysing solutions containing 0.8 M dithiothreitol (DTT), 1% sodium dodecyl sulfate (SDS), and 2 M NaCl. Then, the slides were sequentially stained with DAPI (4',6-diamidino-2-phenylindole) and/or the Diff-Quik reagent, and the percentages of sperm with nondispersed and dispersed chromatin loops were monitored by fluorescence and brightfield microscopy, respectively. The results indicate that all sperm with nondispersed chromatin displayed DNA fragmentation, as measured by DBD-FISH. Conversely, all sperm with dispersed chromatin had very low to undetectable DBD-FISH labeling. SCD test values were significantly higher in patients being screened for infertility than in normozoospermic sperm donors who had participated in a donor insemination program. The coefficient of variation obtained using 2 different observers, either by digital image analysis (DIA) or by brightfield microscopy scoring, was less than 3%. In conclusion, the SCD test is a simple, accurate, highly reproducible, and inexpensive method for the analysis of sperm DNA fragmentation in semen and processed sperm. Therefore, the SCD test could potentially be used as a routine test

  7. Sperm of patients with severe asthenozoospermia show biochemical, molecular and genomic alterations.

    PubMed

    Bonanno, Oriana; Romeo, Giulietta; Asero, Paola; Pezzino, Franca Maria; Castiglione, Roberto; Burrello, Nunziatina; Sidoti, Giuseppe; Frajese, Giovanni Vanni; Vicari, Enzo; D'Agata, Rosario

    2016-12-01

    The multifactorial pathological condition, that is, severe low sperm motility is a frequent cause of infertility. However, mechanisms underlying the development of this condition are not completely understood. Single abnormalities have been reported in sperm of patients with asthenozoospermia. In this study, we characterized, in 22 normozoospermic men and in 37 patients with asthenozoospermia, biochemical, molecular and genomic abnormalities that frequently occur in sperm of patients with asthenozoospermia. We evaluated a panel of sperm biomarkers that may affect the motility and fertilizing ability of sperm of patients with severe asthenozoospermia. Since reactive oxygen species (ROS) production is involved in the pathogenesis of such sperm abnormalities, we determined the association between ROS production and sperm abnormalities. High percentage of patients with severe asthenozoospermia showed increased basal and stimulated ROS production. Moreover, these patients showed increased mitochondrial DNA (mtDNA) copy number but decreased mtDNA integrity and they were associated with elevated ROS levels. Furthermore, mitochondrial membrane potential was also significantly decreased and again associated with high ROS production in these patients. However, the rate of nuclear DNA fragmentation was increased only in less than one-fifth of these patients. An important cohort of these patients showed multiple identical biochemical, molecular and genomic abnormalities, which are typical manifestations of oxidative stress. The most frequent association was found in patients with high ROS levels, increased mtDNA copy number and decreased integrity, and low MMP. A smaller cohort of the aforementioned patients also showed nDNA fragmentation. Therefore, patients with asthezoospermia likely present reduced fertilizing potential because of such composed abnormalities.

  8. Experimental evolution of sperm competitiveness in a mammal

    PubMed Central

    2011-01-01

    Background When females mate with multiple partners, sperm from rival males compete to fertilise the ova. Studies of experimental evolution have proven the selective action of sperm competition on male reproductive traits. However, while reproductive traits may evolve in response to sperm competition, this does not necessarily provide evidence that sperm competitive ability responds to selection. Indeed, a study of Drosophila failed to observe divergence in sperm competitive ability of males in lines selected for enhanced sperm offence and defence. Results Adopting the naturally polygamous house mouse (Mus domesticus) as our vertebrate model, we performed an experimental evolution study and observed genetic divergence in sperm quality; males from the polygamous selection lines produced ejaculates with increased sperm numbers and greater sperm motility compared to males from the monogamous lines. Here, after 12 generations of experimental evolution, we conducted competitive matings between males from lineages evolving under sperm competition and males from lineages subject to relaxed selection. We reduced variation in paternity arising from embryo mortality by genotyping embryos in utero at 14 days gestation. Our microsatellite data revealed a significant paternity bias toward males that evolved under the selective regime of sperm competition. Conclusion We provide evidence that the sperm competitiveness phenotype can respond to selection, and show that improved sperm quality translates to greater competitive fertilisation success in house mice. PMID:21251249

  9. Female choice of young sperm in a genetically monogamous bird.

    PubMed Central

    Wagner, Richard H; Helfenstein, Fabrice; Danchin, Etienne

    2004-01-01

    When females copulate with multiple males the potential exists for female sperm choice. Females may increase the probability of being fertilized by preferred males by selectively retaining their sperm while ejecting the sperm of unfavoured males. An alternative criterion to male quality for female sperm choice may be sperm age because old sperm degrade and can lead to zygote death or unhealthy offspring. Here, we report that in a genetically monogamous bird, the black-legged kittiwake Rissa tridactyla, females eject their mates' sperm according to when the copulations were performed. Following copulations that were performed approximately two weeks before egg laying, females ejected inseminations at high frequencies while retaining inseminations that occurred soon before laying. Females that suffered hatching failure had ejected sperm from early copulations less than half as frequently as females whose entire clutches hatched. Furthermore, chicks that hatched from eggs fertilized by old sperm were in poor condition relative to those fertilized by young sperm. These findings support the 'young sperm' hypothesis, which predicts that females choose fresh sperm to avoid reproductive failure and are the first to show intra-male sperm choice by females. PMID:15252964

  10. In vitro embryo production in buffalo (Bubalus bubalis) using sexed sperm and oocytes from ovum pick up.

    PubMed

    Liang, X W; Lu, Y Q; Chen, M T; Zhang, X F; Lu, S S; Zhang, M; Pang, C Y; Huang, F X; Lu, K H

    2008-04-15

    The objective was to explore the use of sexed sperm and OPU-derived oocytes in an IVP system to produce sex-preselected bubaline embryos. Oocytes were recovered from 20 fertile Murrah and Nili-Ravi buffalo cows by repeated (twice weekly) ultrasound-guided transvaginal ovum pick up (OPU), or by aspiration of abbatoir-derived bubaline ovaries, and subjected to IVF, using frozen-thawed sexed or unsexed bubaline semen. On average, 4.6 oocytes were retrieved per buffalo per session (70.9% were Grades A or B). Following IVF with sexed sperm, oocytes derived from OPU had similar developmental competence as those from abattoir-derived ovaries, in terms of cleavage rate (57.6 vs. 50.4%, P=0.357) and blastocyst development rate (16.0 vs. 23.9%, P=0.237). Furthermore, using frozen-thawed sexed versus unsexed semen did not affect rates of cleavage (50.5 vs. 50.9%, P=0.978) or blastocyst development (15.3 vs. 19.1%, P=0.291) after IVF using OPU-derived oocytes. Of the embryos produced in an OPU-IVP system, 9 of 34 sexed fresh embryos (26.5%) and 5 of 43 sexed frozen embryos (11.6%) transferred to recipients established pregnancies, whereas 7 of 26 unsexed fresh embryos (26.9%) and 6 out of 39 unsexed frozen embryos (15.4%) transferred to recipients established pregnancies. Eleven sex-preselected buffalo calves (10 females and one male) and 10 sexed buffalo calves (six females and four males) were born following embryo transfer. In the present study, OPU, sperm sexing technology, IVP, and embryo transfer, were used to produce sex-preselected buffalo calves. This study provided proof of concept for further research and wider field application of these technologies in buffalo.

  11. Region-wide impairment of Atlantic croaker testicular development and sperm production in the northern Gulf of Mexico hypoxic dead zone.

    PubMed

    Thomas, Peter; Rahman, Md Saydur

    2010-01-01

    Recently evidence has been obtained for reproductive impairment in estuarine populations of Atlantic croaker exposed to seasonal hypoxia. However, it is not known whether a similar disruption of reproductive function occurs in croaker inhabiting a much larger hypoxic area, the extensive dead zone in coastal regions of the northern Gulf of Mexico extending from the Mississippi Delta to East Texas. Gonadal development in male Atlantic croaker collected in September 2008 at six sites in the dead zone was compared to that in male fish sampled from three reference sites east of the Mississippi Delta which do not experience persistent hypoxia. Croaker testes collected from the dead zone were at an earlier stage of spermatogenesis than those from the reference sites. Histological examination of the testes collected from the dead zone showed that their tubules had small lumens that contained very little sperm compared to the lumens of the reference fish. Overall, sperm production was 26.2% that of the control fish at the reference sites. This decrease in spermatogenesis at the dead zone sites was accompanied by an approximately 50% decrease in testicular growth compared to that in the reference fish. The results suggest that reproductive impairment can occur over regional scales in marine fish populations exposed to extensive seasonal hypoxia in dead zones with potential long-term impacts on population abundance.

  12. Genome-wide Loci linked to non-obstructive azoospermia susceptibility may be independent of reduced sperm production in males with normozoospermia.

    PubMed

    Tu, Wenling; Liu, Yunqiang; Shen, Ying; Yan, Yuanlong; Wang, Xianding; Yang, Dong; Li, Lei; Ma, Yongxin; Tao, Dachang; Zhang, Sizhong; Yang, Yuan

    2015-02-01

    Non-obstructive azoospermia (NOA) is a complex, multifactorial disease. Recent genome-wide association studies (GWAS) have identified eight NOA susceptibility loci at genome-wide significance of P < 5.0 × 10(-8) in Han Chinese from southeastern, northern, and central China. To better understand the role of the variants in conferring NOA risk, we selected four GWAS loci (HLA-DRA rs3129878, PRMT6 rs12097821, SOX5 rs10842262, and PEX10 rs2477686) that were reported before 2014 to investigate their association with NOA and their potential effects on sperm production in 1177 Han males from southwest China, including 545 patients with idiopathic NOA and 632 controls with normozoospermia. The results confirmed that the HLA-DRA rs3129878 was an NOA susceptibility locus in the present population. Along with our data, meta-analyses supported the association of the four GWAS-linked loci with NOA, whereas an additive effect of the four loci on NOA susceptibility was not found. Interestingly, the normozoospermic males with the risk genotypes of rs12097821 and rs3129878 + rs10842262 + rs12097821 were observed to have higher total sperm counts relative to non-risk genotypes, suggesting that the risk alleles of the genetic loci may not be via impairing spermatogenic ability to express susceptibility to NOA. These findings may advance our understanding of the role of the NOA susceptibility loci, although the results need to be confirmed in larger samples.

  13. Impact of increasing milk production on whole farm environmental management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing herd milk production can provide both economic benefit to the producer and environmental benefit to society. Simulated dairy farms with average annual herd productions from 16,000 to 30,000 lb/cow illustrate that increasing milk yield per cow improves feed efficiency, reduces feed costs a...

  14. Improving the Potential for Increased World Food Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A stable world food production is completely dependent on the ability of people to grow, harvest, and utilize plants as a source of food. The United Nations estimates that in order to feed the world’s increasing population that by the year 2040 agriculture will have to increase food production by a...

  15. Targets to increase food production: One Health implications.

    PubMed

    McMahon, Barry J; Wall, Patrick G; Fanning, Séamus; Fahey, Alan G

    2015-01-01

    The increasing world population means that there is a requirement to expand global food production. Looking at the Republic of Ireland as an example, the risks and opportunities associated with the expansion of food production are outlined, particularly in relation to zoonoses transmission. A One Health approach to sustainable food production is required to avert a potential public health problem associated with increased agricultural expansion.

  16. Recovery and cryopreservation of epididymal sperm of plains bison (Bison bison bison) as a model for salvaging the genetics of wood bison (Bison bison athabascae).

    PubMed

    Aurini, L C; Whiteside, D P; Elkin, B T; Thundathil, J C

    2009-10-01

    The objective of this study was to optimize recovery and cryopreservation of epididymal sperm from plains bison, as a model for wood bison. In Phase 1, cauda epididymides were recovered from bison (n = 14) immediately after slaughter, minced and incubated in Sp-TALPH buffer for 3 h at 36 degrees C. The resulting sperm suspensions were cryopreserved in Triladyl, using a protocol for bovine semen. In Phase 2, epididymal sperm were cryopreserved in either Triladyl or Andromed. The mean (+/-SD) estimated number of sperm recovered was 468 +/- 207 x 10(6). There was an increase (p < 0.05) in the proportion of sperm with normal morphology between initial recovery and after extension (52.4 +/- 4.6 vs 69.7 +/- 2.4%), with a concurrent decrease (p < 0.05) in the proportion of sperm with distal droplets. Median values for progressively motile sperm in post-thaw samples (60%) were lower (p < 0.05) than that after extension or after chilling (70% for both). The mean percentages of viable sperm and of sperm with an intact acrosome were lower (p < 0.05) for frozen-thawed samples (38.7 +/- 2.8 and 85.2 +/- 1.1) compared with extended (66.2 +/- 2.2 and 92.4 +/- 0.9) or chilled (63.7 +/- 2.5 and 90.0 +/- 1.0) samples. Rates of cleavage, morulae and blastocyst production were not significantly different for chilled (70.9, 38.7 and 8.0%) vs post-thaw sperm (73.0, 46.0 and 6.3%). There was no significant difference between extenders for most sperm characteristics. In conclusion, we developed a functional protocol for the recovery and cryopreservation of epididymal sperm from plains bison, which may have implications for the genetic preservation of wood bison.

  17. Effects of the Czech Propolis on Sperm Mitochondrial Function

    PubMed Central

    Cedikova, Miroslava; Miklikova, Michaela; Stachova, Lenka; Grundmanova, Martina; Tuma, Zdenek; Vetvicka, Vaclav; Zech, Nicolas; Kralickova, Milena; Kuncova, Jitka

    2014-01-01

    Propolis is a natural product that honeybees collect from various plants. It is known for its beneficial pharmacological effects. The aim of our study was to evaluate the impact of propolis on human sperm motility, mitochondrial respiratory activity, and membrane potential. Semen samples from 10 normozoospermic donors were processed according to the World Health Organization criteria. Propolis effects on the sperm motility and mitochondrial activity parameters were tested in the fresh ejaculate and purified spermatozoa. Propolis preserved progressive motility of spermatozoa in the native semen samples. Oxygen consumption determined in purified permeabilized spermatozoa by high-resolution respirometry in the presence of adenosine diphosphate and substrates of complex I and complex II (state OXPHOSI+II) was significantly increased in the propolis-treated samples. Propolis also increased uncoupled respiration in the presence of rotenone (state ETSII) and complex IV activity, but it did not influence state LEAK induced by oligomycin. Mitochondrial membrane potential was not affected by propolis. This study demonstrates that propolis maintains sperm motility in the native ejaculates and increases activities of mitochondrial respiratory complexes II and IV without affecting mitochondrial membrane potential. The data suggest that propolis improves the total mitochondrial respiratory efficiency in the human spermatozoa in vitro thereby having potential to improve sperm motility. PMID:25104965

  18. Detection of structural and numerical chomosomal abnormalities by ACM-FISH analysis in sperm of oligozoospermic infertility patients

    SciTech Connect

    Schmid, T E; Brinkworth, M H; Hill, F; Sloter, E; Kamischke, A; Marchetti, F; Nieschlag, E; Wyrobek, A J

    2003-11-10

    Modern reproductive technologies are enabling the treatment of infertile men with severe disturbances of spermatogenesis. The possibility of elevated frequencies of genetically and chromosomally defective sperm has become an issue of concern with the increased usage of intracytoplasmic sperm injection (ICSI), which can enable men with severely impaired sperm production to father children. Several papers have been published about aneuploidy in oligozoospermic patients, but relatively little is known about chromosome structural aberrations in the sperm of these patients. We examined sperm from infertile, oligozoospermic individuals for structural and numerical chromosomal abnormalities using a multicolor ACM FISH assay that utilizes DNA probes specific for three regions of chromosome 1 to detect human sperm that carry numerical chromosomal abnormalities plus two categories of structural aberrations: duplications and deletions of 1pter and 1cen, and chromosomal breaks within the 1cen-1q12 region. There was a significant increase in the average frequencies of sperm with duplications and deletions in the infertility patients compared with the healthy concurrent controls. There was also a significantly elevated level of breaks within the 1cen-1q12 region. There was no evidence for an increase in chromosome-1 disomy, or in diploidy. Our data reveal that oligozoospermia is associated with chromosomal structural abnormalities suggesting that, oligozoospermic men carry a higher burden of transmissible, chromosome damage. The findings raise the possibility of elevated levels of transmissible chromosomal defects following ICSI treatment.

  19. Effects of photobiomodulation therapy (PBMT) on bovine sperm function.

    PubMed

    Siqueira, Adriano F P; Maria, Fernanda S; Mendes, Camilla M; Hamilton, Thais R S; Dalmazzo, Andressa; Dreyer, Thiago R; da Silva, Herculano M; Nichi, Marcilio; Milazzotto, Marcella P; Visintin, José A; Assumpção, Mayra E O A

    2016-08-01

    Fertilization rates and subsequent embryo development rely on sperm factors related to semen quality and viability. Photobiomodulation therapy (PBMT) is based on emission of electromagnetic waves of a laser optical system that interact with cells and tissues resulting in biological effects. This interaction is mediated by photoacceptors that absorb the electromagnetic energy. Effects are dependent of irradiation parameters, target cell type, and species. In sperm, PBMT improves several features like motility and viability, affecting sperm aerobic metabolism and energy production. The aim of this study was to investigate, under same conditions, how different output powers (5, 7.5, and 10 mW) and time of irradiation (5 and 10 min) of laser (He-Ne laser, 633 nm) may affect frozen/thawed bovine sperm functions. Results showed significant effects depending on power while using 10 min of irradiation on motility parameters and mitochondrial potential. However, no effect was observed using 5 min of irradiation, regardless of power applied. In conclusion, PBMT is effective to modulate bovine sperm function. The effectiveness is dependent on the interaction between power applied and duration of irradiation, showing that these two parameters simultaneously influence sperm function. In this context, when using the same fluency and energy with different combinations of power and time of exposure, we observed distinct effects, revealing that biological effects should be also based on simple parameters rather than only composite parameters such as fluency, irradiance and energy. Laser irradiation of frozen/thawed bovine semen led to an increase on mitochondrial function and motility parameters that could potentially improve fertility rates.

  20. Flow cytometry of sperm

    SciTech Connect

    Gledhill, B.L.

    1987-09-21

    This brief paper summarizes automated flow cytometric determination of sperm morphology and flow cytometry/sorting of sperm with application to sex preselection. In the latter context, mention is made of results of karyotypic determination of sex chromosome ratios in albumin-processed human sperm. 23 refs., 1 fig., 1 tab.

  1. China's success in increasing per capita food production.

    PubMed

    Zhang, Jianhua

    2011-07-01

    China has to feed 20% of the global population with only about 5% of the planet's water resources and 7% of its arable land. With such limited natural conditions, however, China's grain production has increased from about 200 kg per capita in 1949 to about 400 kg in the early 1990s. Hunger as a social problem has largely disappeared after being prevalent in China for several thousand years with the rise and decline of dynasties. This achievement has been accompanied by a 2.5-fold increase in the population and a 4.5-fold increase in total grain production. Although total cropped land has increased slightly in some areas, land used for cropping has decreased from 0.18 hectare per capita in the 1950s to less than 0.1 hectare per capita today. Apparently, yield increase or improved land productivity is the major contributor to the increase of food production per capita. What are the major reasons for the unprecedented achievement in China's food production? Political decisions, good or bad, on land distribution and ownership changes, have caused unusual fluctuation in grain production. Technical progress, however, has maintained a long-term increasing trend. The semi-dwarf cultivars of rice and wheat, the use of heterosis in rice and maize, and the alleviation of salinized soil stress in the major grain-producing areas have all played significant roles in increasing China's food production capability.

  2. Factors associated with increased milk production for automatic milking systems.

    PubMed

    Tremblay, Marlène; Hess, Justin P; Christenson, Brock M; McIntyre, Kolby K; Smink, Ben; van der Kamp, Arjen J; de Jong, Lisanne G; Döpfer, Dörte

    2016-05-01

    Automatic milking systems (AMS) are increasingly popular throughout the world. Our objective was to analyze 635 North American dairy farms with AMS for (risk) factors associated with increased milk production per cow per day and milk production per robot per day. We used multivariable generalized mixed linear regressions, which identified several significant risk factors and interactions of risk factors associated with milk production. Free traffic was associated with increased production per cow and per robot per day compared with forced systems, and the presence of a single robot per pen was associated with decreased production per robot per day compared with pens using 2 robots. Retrofitted farms had significantly less production in the first 4 yr since installation compared with production after 4 yr of installation. In contrast, newly built farms did not see a significant change in production over time since installation. Overall, retrofitted farms did not produce significantly more or less milk than newly constructed farms. Detailed knowledge of factors associated with increased production of AMS will help guide future recommendations to producers looking to transition to an AMS and maximize their production.

  3. Turbidity as a method of preparing sperm dilutions in the echinoid sperm/egg bioassay

    SciTech Connect

    Hall, T.J.; Haley, R.K.; Battan, K.J. )

    1993-11-01

    The use of turbidimeter for preparing sperm dilutions used in the echinoid sperm/egg bioassay was evaluated. Regression analyses of the relationship between sperm density and turbidity for the sea urchins Strongylocentrotus purpuratus and Strongylocentrotus droebachiensis and the sand dollar Dendraster excentricus indicated that although there were slope differences for each species, each coefficient of determination was highly significant. For Dendraster excentricus, triplicate hemacytometer counts over a range of turbidities as well as repeated preparations of a single sperm turbidity indicated similar variability for each. The use of the turbidimeter has time-saving advantages over conventional hemacytometer methods without sacrificing precision. Sperm dilutions can be prepared rapidly, minimizing seawater sperm preactivation before test initiation, and may therefore contribute to increased test precision.

  4. Sperm chromatin structure assay (SCSA®).

    PubMed

    Evenson, Donald P

    2013-01-01

    The SCSA(®) is the pioneering assay for the detection of damaged sperm DNA and altered proteins in sperm nuclei via flow cytometry of acridine orange (AO) stained sperm. The SCSA(®) is considered to be the most precise and repeatable test providing very unique, dual parameter data (red vs. green fluorescence) on a 1,024 × 1,024 channel scale, not only on DNA fragmentation but also on abnormal sperm characterized by lack of normal exchange of histones to protamines. Raw semen/sperm aliquots or purified sperm can be flash frozen, placed in a box with dry ice and shipped by overnight courier to an experienced SCSA(®) lab. The samples are individually thawed, prepared, and analyzed in ∼10 min. Of significance, data on 5,000 individual sperm are recorded on a 1,024 × 1,024 dot plot of green (native DNA) and red (broken DNA) fluorescence. Repeat measurements have virtually identical dot plot patterns demonstrating that the low pH treatment that opens up the DNA strands at the sites of breaks and staining by acridine orange (AO) are highly precise and repeatable (CVs of 1-3%) and the same between fresh and frozen samples. SCSAsoft(®) software transforms the X-Y data to total DNA stainability versus red/red + green fluoresence (DFI) providing a more accurate determination of % DFI as well as the more sensitive value of standard deviation of DFI (SD DFI) as demonstrated by animal fertility and dose-response toxicology studies. The current established clinical threshold is 25% DFI for placing a man into a statistical probability of the following: (a) longer time to natural pregnancy, (b) low odds of IUI pregnancy, (c) more miscarriages, or (d) no pregnancy. Changes in lifestyle as well as medical intervention can lower the %DFI to increase the probability of natural pregnancy. Couples of men with >25% DFI are counseled to try ICSI and when in the >50% range may consider TESE/ICSI. The SCSA(®) simultaneously determines the % of sperm with high DNA stainability (%HDS

  5. Female sperm use and storage between fertilization events drive sperm competition and male ejaculate allocation.

    PubMed

    Requena, Gustavo S; Alonzo, Suzanne H

    2014-12-01

    Sperm competition theory has traditionally focused on how male allocation responds to female promiscuity, when males compete to fertilize a single clutch of eggs. Here, we develop a model to ask how female sperm use and storage across consecutive reproductive events affect male ejaculate allocation and patterns of mating and paternity. In our model, sperm use (a single parameter under female control) is the main determinant of sperm competition, which alters the effect of female promiscuity on male success and, ultimately, male reproductive allocation. Our theory reproduces the general pattern predicted by existing theory that increased sperm competition favors increased allocation to ejaculates. However, our model predicts a negative correlation between male ejaculate allocation and female promiscuity, challenging the generality of a prevailing expectation of sperm competition theory. Early models assumed that the energetic costs of precopulatory competition and the level of sperm competition are both determined by female promiscuity, which leads to an assumed covariation between these two processes. By modeling precopulatory costs and sperm competition independently, our theoretical framework allows us to examine how male allocation should respond independently to variation in sperm competition and energetic trade-offs in mating systems that have been overlooked in the past.

  6. Predominance of sperm motion in corners

    PubMed Central

    Nosrati, Reza; Graham, Percival J.; Liu, Qiaozhi; Sinton, David

    2016-01-01

    Sperm migration through the female tract is crucial to fertilization, but the role of the complex and confined structure of the fallopian tube in sperm guidance remains unknown. Here, by confocal imaging microchannels head-on, we distinguish corner- vs. wall- vs. bulk-swimming bull sperm in confined geometries. Corner-swimming dominates with local areal concentrations as high as 200-fold that of the bulk. The relative degree of corner-swimming is strongest in small channels, decreases with increasing channel size, and plateaus for channels above 200 μm. Corner-swimming remains predominant across the physiologically-relevant range of viscosity and pH. Together, boundary-following sperm account for over 95% of the sperm distribution in small rectangular channels, which is similar to the percentage of wall swimmers in circular channels of similar size. We also demonstrate that wall-swimming sperm travel closer to walls in smaller channels (~100 μm), where the opposite wall is within the hydrodynamic interaction length-scale. The corner accumulation effect is more than the superposition of the influence of two walls, and over 5-fold stronger than that of a single wall. These findings suggest that folds and corners are dominant in sperm migration in the narrow (sub-mm) lumen of the fallopian tube and microchannel-based sperm selection devices. PMID:27211846

  7. Predominance of sperm motion in corners

    NASA Astrophysics Data System (ADS)

    Nosrati, Reza; Graham, Percival J.; Liu, Qiaozhi; Sinton, David

    2016-05-01

    Sperm migration through the female tract is crucial to fertilization, but the role of the complex and confined structure of the fallopian tube in sperm guidance remains unknown. Here, by confocal imaging microchannels head-on, we distinguish corner- vs. wall- vs. bulk-swimming bull sperm in confined geometries. Corner-swimming dominates with local areal concentrations as high as 200-fold that of the bulk. The relative degree of corner-swimming is strongest in small channels, decreases with increasing channel size, and plateaus for channels above 200 μm. Corner-swimming remains predominant across the physiologically-relevant range of viscosity and pH. Together, boundary-following sperm account for over 95% of the sperm distribution in small rectangular channels, which is similar to the percentage of wall swimmers in circular channels of similar size. We also demonstrate that wall-swimming sperm travel closer to walls in smaller channels (~100 μm), where the opposite wall is within the hydrodynamic interaction length-scale. The corner accumulation effect is more than the superposition of the influence of two walls, and over 5-fold stronger than that of a single wall. These findings suggest that folds and corners are dominant in sperm migration in the narrow (sub-mm) lumen of the fallopian tube and microchannel-based sperm selection devices.

  8. Sperm macromolecules associated with bull fertility.

    PubMed

    Kaya, Abdullah; Memili, Erdoğan

    2016-06-01

    Bull fertility, ability of the sperm to fertilize and activate the egg that sustain embryo development, is vitally important for effective and efficient production of cattle. Fertility is a complex trait with low heritability. Despite recent advances in genomic selection and possibility of enormous paternal benefits to profitable cattle production, there exist no reliable tests for evaluating semen quality and predicting bull fertility. This review focuses on sperm macromolecules such as transcripts, proteins and the epigenome, i.e., the functional genome that are associated with bull fertility. Generating new information in these systems is important beyond agriculture because such progress advances the fundamental science of the mammalian male gamete while at the same time introduces biotechnology into livestock production. Sperm macromolecules and epigenome markers associated with bull fertility can be used alone or in combination with the current SNP microarrays to determine sperm quality and to indicate bull fertility.

  9. Efficient production by sperm-mediated gene transfer of human decay accelerating factor (hDAF) transgenic pigs for xenotransplantation

    PubMed Central

    Lavitrano, Marialuisa; Bacci, Maria Laura; Forni, Monica; Lazzereschi, Davide; Di Stefano, Carla; Fioretti, Daniela; Giancotti, Paola; Marfé, Gabriella; Pucci, Loredana; Renzi, Luigina; Wang, Hongjun; Stoppacciaro, Antonella; Stassi, Giorgio; Sargiacomo, Massimo; Sinibaldi, Paola; Turchi, Valeria; Giovannoni, Roberto; Della Casa, Giacinto; Seren, Eraldo; Rossi, Giancarlo

    2002-01-01

    A large number of hDAF transgenic pigs to be used for xenotransplantation research were generated by using sperm-mediated gene transfer (SMGT). The efficiency of transgenesis obtained with SMGT was much greater than with any other method. In the experiments reported, up to 80% of pigs had the transgene integrated into the genome. Most of the pigs carrying the hDAF gene transcribed it in a stable manner (64%). The great majority of pigs that transcribed the gene expressed the protein (83%). The hDAF gene was transmitted to progeny. Expression was stable and found in caveolae as it is in human cells. The expressed gene was functional based on in vitro experiments performed on peripheral blood mononuclear cells. These results show that our SMGT approach to transgenesis provides an efficient procedure for studies involving large animal models. PMID:12393815

  10. Laboratory studies of cryopreservation of sperm and trochophore larvae of the eastern oyster.

    PubMed

    Paniagua-Chavez, C G; Tiersch, T R

    2001-11-01

    The eastern oyster, Crassostrea virginica, is the most important cultured oyster species of the Atlantic and Gulf coasts of the United States. Cryopreservation of gametes and larvae of aquatic organisms has increased in importance in recent years. However, studies on the cryopreservation of sperm and larvae of mollusks have focused on the Pacific oyster, Crassostrea gigas. The present study was conducted to improve cryopreservation of sperm and trochophore larvae and to assess fertilizing ability and male-to-male variation of thawed sperm of the eastern oyster. Sperm were diluted in 12 cryoprotectant solutions composed of Hanks' balanced salt solution without calcium and 0, 5, 10, 15, 20, and 25% (v/v) propylene glycol with or without 0.25 M sucrose. Trochophore larvae were suspended in artificial seawater and 10 or 15% propylene glycol (v/v). Sperm or trochophore larvae were placed in 5-mL macrotubes and allowed to equilibrate for 15 min. The macrotubes were cooled in a controlled-rate freezer at a rate of 2.5 degrees C per min until reaching a final temperature of -30 degrees C and were plunged into liquid nitrogen. After storage for 2 weeks, the samples were thawed in a water bath at 70 degrees C for 15 s. Overall, for cryopreservation of sperm and larvae, best results were obtained using 10 or 15% propylene glycol. Thawed sperm presented significant male-to-male variation in fertilizing ability. Survival of thawed larvae decreased as the concentration of larvae per macrotube increased. The procedures developed in this study for sperm and larvae are suitable for production of seedstock in commercial oyster hatcheries.

  11. Drosophila Sperm Motility in the Reproductive Tract1

    PubMed Central

    Yang, Yong; Lu, Xiangyi

    2011-01-01

    Motile cilia and flagella exhibit many waveforms as outputs of dynein activation sequences on the highly conserved axoneme. Motility change of sperm in the reproductive tract is difficult to study and remains an important area of investigation. Sperm typically execute a sinusoidal waveform. Increased viscosity in the medium induces somewhat unusual arc-line and helical waveforms in some sperm. However, whether the latter two waveforms occur in vivo is not known. Using green fluorescence protein imaging, we show that Drosophila sperm in the uterus move in circular foci via arc-line waves, predominantly in a tail-leading orientation. From the uterus, a small fraction of the sperm enters the seminal receptacle (SR) in parallel formations. After sperm storage and coincident with fertilization of the egg, the sperm exit the SR via head-leading helical waves. Consistent with the observed bidirectional movements, the sperm show the ability to propagate both base-to-tip and tip-to-base flagellar waves. Numerous studies have shown that sperm motility is regulated by intraflagellar calcium concentrations; in particular, the Pkd2 calcium channel has been shown to affect sperm storage. Our analyses here suggest that Pkd2 is required for the sperm to adopt the correct waveform and movement orientation during SR entry. A working model for the sperm's SR entry movement is proposed. PMID:21293028

  12. Biodiversity increases the resistance of ecosystem productivity to climate extremes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It remains unclear whether biodiversity buffers ecosystems against extreme climate events, which are becoming increasingly frequent worldwide. Although early results suggested that biodiversity might provide both resistance and resilience (sensu rapid recovery) of ecosystem productivity to drought, ...

  13. Increasing Productivity in Education: A Few Seminal Ideas.

    ERIC Educational Resources Information Center

    Lessinger, Leon M.

    As the element of government closest to direct taxpayer control, education is in deep crisis. Education must become more productive if only to maintain its present level of operation. Increasing productivity means getting the same results for less cost, getting better results for the same cost, or getting significantly better results for…

  14. Enhanced precipitation variability decreases grass- and increases shrub-productivity.

    PubMed

    Gherardi, Laureano A; Sala, Osvaldo E

    2015-10-13

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present results from a 6-y field experiment, where we applied sequences of wet and dry years, increasing interannual precipitation coefficient of variation while maintaining a precipitation amount constant. Increased precipitation variability significantly reduced ecosystem primary production. Dominant plant-functional types showed opposite responses: perennial-grass productivity decreased by 81%, whereas shrub productivity increased by 67%. This pattern was explained by different nonlinear responses to precipitation. Grass productivity presented a saturating response to precipitation where dry years had a larger negative effect than the positive effects of wet years. In contrast, shrubs showed an increasing response to precipitation that resulted in an increase in average productivity with increasing precipitation variability. In addition, the effects of precipitation variation increased through time. We argue that the differential responses of grasses and shrubs to precipitation variability and the amplification of this phenomenon through time result from contrasting root distributions of grasses and shrubs and competitive interactions among plant types, confirmed by structural equation analysis. Under drought conditions, grasses reduce their abundance and their ability to absorb water that then is transferred to deep soil layers that are exclusively explored by shrubs. Our work addresses an understudied dimension of climate change that might lead to widespread shrub encroachment reducing the provisioning of ecosystem services to society.

  15. Enhanced precipitation variability decreases grass- and increases shrub-productivity

    PubMed Central

    Gherardi, Laureano A.; Sala, Osvaldo E.

    2015-01-01

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present results from a 6-y field experiment, where we applied sequences of wet and dry years, increasing interannual precipitation coefficient of variation while maintaining a precipitation amount constant. Increased precipitation variability significantly reduced ecosystem primary production. Dominant plant-functional types showed opposite responses: perennial-grass productivity decreased by 81%, whereas shrub productivity increased by 67%. This pattern was explained by different nonlinear responses to precipitation. Grass productivity presented a saturating response to precipitation where dry years had a larger negative effect than the positive effects of wet years. In contrast, shrubs showed an increasing response to precipitation that resulted in an increase in average productivity with increasing precipitation variability. In addition, the effects of precipitation variation increased through time. We argue that the differential responses of grasses and shrubs to precipitation variability and the amplification of this phenomenon through time result from contrasting root distributions of grasses and shrubs and competitive interactions among plant types, confirmed by structural equation analysis. Under drought conditions, grasses reduce their abundance and their ability to absorb water that then is transferred to deep soil layers that are exclusively explored by shrubs. Our work addresses an understudied dimension of climate change that might lead to widespread shrub encroachment reducing the provisioning of ecosystem services to society. PMID:26417095

  16. Melatonin intake since weaning ameliorates steroidogenic function and sperm motility of streptozotocin-induced diabetic rats.

    PubMed

    da Costa, C F P; Gobbo, M G; Taboga, S R; Pinto-Fochi, M E; Góes, R M

    2016-05-01

    Melatonin may be used as an antioxidant in therapy against systemic sequelae caused by oxidative stress in diabetes. However, as melatonin has a major role in regulating reproductive activity, its consequence on reproductive parameters under diabetes needs to be better clarified. We have studied whether prior and concomitant treatment of juvenile Wistar rats with low doses of melatonin interferes in reproductive damage induced by experimental diabetes after 1 and 8 weeks. The consequences of melatonin administration since weaning on reproductive parameters of healthy rats at adulthood were also evaluated. Melatonin was provided in drinking water (10 μg/kg b.w./day) after weaning (5-week-old). Diabetes was induced by streptozotocin injection (4.5 mg/100 g b.w.) at 13-week-old rats, and rats were euthanized 1 and 8 weeks after disease onset. Diabetes decreased circulating testosterone levels (~35% to 1 week; ~62% to 2 months; p < 0.01) but did not affect testes sperm counts. Two months of diabetes reduced the sperm reserve and led to atrophy of epididymal cauda. Both 1-week and 2-month diabetes impaired sperm motility, decreased the number of spermatozoa with progressive movement, and increased the number of immotile sperm. Melatonin intake reduced serum testosterone levels ~29% in healthy 14-week-old and ~23% in 21-week-old rats and reduced daily testicular sperm production ~26% in the latter disease stage, but did not interfere in sperm reserves and transit time for both experimental periods. Exogenous melatonin prevented the serum testosterone decrease and damage to sperm motility in diabetic rats and attenuated reduction in sperm counts and transit time induced by 1-week diabetes but did not avoid this decrease at 2-month diabetes. Low doses of melatonin administered prior to and during experimental diabetes attenuated damage to testicular steroidogenic activity and preserved sperm motility, but not sperm reserves in the rat. Our data indicated a

  17. Semiautomatic cold wire feeder systems increase GTA productivity

    SciTech Connect

    Richardson, M. )

    1995-01-01

    Often, the focus of attempts to increase GTA welding productivity is on studies to determine if justification exists for additional workstations, or for the investment in new fully automated dedicated welding fixtures. Often less costly and simpler solutions can bring about the necessary means to increase production rates and reduce operating costs. For short-run production applications, it is almost impossible to justify the substantial investment in a dedicated automatic fixture. Now, low cost GTA cold wire feeder systems are within the reach of even small shops. The paper views how cold wire equipment has been applied in several GTAW applications to improve results.

  18. Sperm competition affects male behaviour and sperm output in the rainbow darter

    PubMed Central

    Fuller, R. C.

    1998-01-01

    Rainbow darters, Etheostoma caeruleum, are promiscuous fish with moderate rates of group spawning (between one and five males may simultaneously mate with one female). In this study, I examined male sperm output and male willingness to spawn under different levels of sperm competition intensity. One male and one female were allowed to spawn in an aquarium where they had visual and olfactory access to one of four treatments: four males, one male, zero males, or one female. Theory predicts that males should reduce sperm output when there are more than the average number of males at a group spawning (four-male treatment) and should increase sperm output when there are fewer than average males at a group spawning (one-male treatment). Mean sperm output did not differ among treatments. However, males released more sperm when spawning in the presence of competing males (four-male and one-male treatments pooled) than when spawning in the absence of competing males (zero-male and one-female treatments pooled). Males were also most likely to forego spawning opportunities when sperm competition intensity was high. Furthermore, male willingness to spawn was size dependent. Large males were more likely to forego spawning opportunities under high sperm competition intensity. Large males may be better off waiting for future spawning opportunities when there is a lower potential for sperm competition intensity.

  19. Boar seminal plasma exosomes maintain sperm function by infiltrating into the sperm membrane

    PubMed Central

    Du, Jian; Shen, Jian; Wang, Yuanxian; Pan, Chuanying; Pang, Weijun; Diao, Hua; Dong, Wuzi

    2016-01-01

    Seminal plasma ingredients are important for maintenance of sperm viability. This study focuses on the effect of boar seminal plasma exosomes on sperm function during long-term liquid storage. Boar seminal plasma exosomes had typical nano-structure morphology as measured by scanning electron microscopy (SEM) and molecular markers such as AWN, CD9 and CD63 by western blot analysis. The effect on sperm parameters of adding different ratio of boar seminal plasma exosomes to boar sperm preparations was analyzed. Compared to the diluent without exosomes, the diluent with four times or sixteen times exosomes compared to original semen had higher sperm motility, prolonged effective survival time, improved sperm plasma membrane integrity (p < 0.05), increased total antioxidant capacity (T-AOC) activity and decreased malondialdehyde (MDA) content. The diluent containing four times concentration of exosomes compared to original semen was determined to inhibit premature capacitation, but not to influence capacitation induced in vitro. Inhibition of premature capacitation is likely related to the concentration of exosomes which had been demonstrated to transfer proteins including AWN and PSP-1 into sperm. In addition, using fluorescence microscopy and scanning electron microscopy analysis, it was demonstrated that exosomes in diluent were directly binding to the membrane of sperm head which could improve sperm plasma membrane integrity. PMID:27542209

  20. Sperm competition in a fish with external fertilization: the contribution of sperm number, speed and length.

    PubMed

    Stoltz, J A; Neff, B D

    2006-11-01

    The role of sperm number and quality in male competitiveness was investigated using in vitro fertilization experiments with bluegill (Lepomis macrochirus). Bluegill males use one of three mating tactics: 'sneakers', which streak spawn; 'satellites', which mimic females; and 'parentals', which are territorial. The in vitro experiments mimicked natural spawning by incorporating these males' mean proximity to eggs and timing of sperm release. Using a maximum-likelihood algorithm, raffle equations were fit to paternity data, which revealed a strong effect of sperm number on male competitiveness. There was no difference in sperm flagellum length, curvilinear swim speed or path linearity among the three male mating types, and these traits did not explain any additional variation in male competitiveness. It was estimated that, given closer proximity to eggs, satellites need release only 0.34 times as many sperm as parentals to obtain equal paternity. Despite being farther from the eggs and releasing sperm about half a second after parentals, sneakers need only release 0.58 times as many sperm as parentals to obtain equal paternity. Thus, the increased competitiveness of sneakers' sperm must come from a component of sperm quality other than speed or length.

  1. Biodiversity increases the resistance of ecosystem productivity to climate extremes.

    PubMed

    Isbell, Forest; Craven, Dylan; Connolly, John; Loreau, Michel; Schmid, Bernhard; Beierkuhnlein, Carl; Bezemer, T Martijn; Bonin, Catherine; Bruelheide, Helge; de Luca, Enrica; Ebeling, Anne; Griffin, John N; Guo, Qinfeng; Hautier, Yann; Hector, Andy; Jentsch, Anke; Kreyling, Jürgen; Lanta, Vojtěch; Manning, Pete; Meyer, Sebastian T; Mori, Akira S; Naeem, Shahid; Niklaus, Pascal A; Polley, H Wayne; Reich, Peter B; Roscher, Christiane; Seabloom, Eric W; Smith, Melinda D; Thakur, Madhav P; Tilman, David; Tracy, Benjamin F; van der Putten, Wim H; van Ruijven, Jasper; Weigelt, Alexandra; Weisser, Wolfgang W; Wilsey, Brian; Eisenhauer, Nico

    2015-10-22

    It remains unclear whether biodiversity buffers ecosystems against climate extremes, which are becoming increasingly frequent worldwide. Early results suggested that the ecosystem productivity of diverse grassland plant communities was more resistant, changing less during drought, and more resilient, recovering more quickly after drought, than that of depauperate communities. However, subsequent experimental tests produced mixed results. Here we use data from 46 experiments that manipulated grassland plant diversity to test whether biodiversity provides resistance during and resilience after climate events. We show that biodiversity increased ecosystem resistance for a broad range of climate events, including wet or dry, moderate or extreme, and brief or prolonged events. Across all studies and climate events, the productivity of low-diversity communities with one or two species changed by approximately 50% during climate events, whereas that of high-diversity communities with 16-32 species was more resistant, changing by only approximately 25%. By a year after each climate event, ecosystem productivity had often fully recovered, or overshot, normal levels of productivity in both high- and low-diversity communities, leading to no detectable dependence of ecosystem resilience on biodiversity. Our results suggest that biodiversity mainly stabilizes ecosystem productivity, and productivity-dependent ecosystem services, by increasing resistance to climate events. Anthropogenic environmental changes that drive biodiversity loss thus seem likely to decrease ecosystem stability, and restoration of biodiversity to increase it, mainly by changing the resistance of ecosystem productivity to climate events.

  2. Atropine-induced inhibition of sperm and semen transport impairs fertility in male rats.

    PubMed

    Sato, Takahiro; Ban, Yoshiki; Uchida, Miki; Gondo, Eri; Yamamoto, Masakatsu; Sekiguchi, Yoshiko; Sakaue, Akiko; Kemi, Masayuki; Nakatsuka, Toshio

    2005-08-01

    Previous studies revealed that atropine reduced male fertility in rats without any effects on mating performance, sperm production and motility, and testicular morphology. The present study was conducted to investigate whether the impairment of male fertility induced by atropine was related to the inhibition of sperm and semen transports from the vas deferens and seminal vesicle to the urethra during the process of emission. Male rats were treated with atropine at 125 mg/kg/day for 10-17 days prior to mating with untreated females. After confirmation of mating, male rats were euthanized and sperm number in the vas deferens and weights of the seminal vesicle and copulatory plug were determined as indicators of inhibition of sperm and semen transports, respectively. Reproductive status of mated females was determined on gestation days 15-17. A low pregnancy rate associated with a decreased number of implants was observed in females that mated with the atropine-treated males. The average number of sperm in the vas deferens was increased in the atropine-treated males. The average seminal vesicle weight in the atropine-treated males was greater than that of controls. The copulatory plug weights were decreased in the atropine-treated males. These results suggest that inhibitions of sperm and semen transports from the vas deferens and seminal vesicle to the urethra during the process of emission result in reduced male fertility in rats.

  3. Assessment of DNA integrity (COMET assay) in sperm cells of boron-exposed workers.

    PubMed

    Duydu, Yalçin; Başaran, Nurşen; Ustündağ, Aylin; Aydin, Sevtap; Undeğer, Ulkü; Ataman, Osman Yavuz; Aydos, Kaan; Düker, Yalçin; Ickstadt, Katja; Waltrup, Britta Schulze; Golka, Klaus; Bolt, Hermann M

    2012-01-01

    An extension of a male reproductive study conducted in a boric acid/borate production zone at Bandırma, Turkey, is presented. The relation between DNA-strand breaks (COMET assay, neutral and alkaline version) in sperm cells and previously described sperm quality parameters was investigated in boron-exposed males. A correlation between blood boron levels and mean DNA-strand breaks in sperm was weak, and DNA-strand breaks in sperm were statistically not different between control and exposed groups. Therefore, increasing boron exposures had no additional contribution in addition to already pre-existing DNA-strand breaks in the sperm cells. Weak but statistically significant correlations between DNA-strand breaks and motility/morphology parameters of sperm samples were observed in the neutral version of the COMET assay, while correlations between the same variables were statistically not significant in the alkaline version. A likely reason for these negative results, even in highly exposed humans, is that experimental exposures that had led to reproductive toxicity in animals were significantly higher than any boron exposures, which may be reached under realistic human conditions.

  4. Sperm morphology, adenosine triphosphate (ATP) concentration and swimming velocity: unexpected relationships in a passerine bird

    PubMed Central

    Bennison, Clair; Brookes, Lola; Slate, Jon; Birkhead, Tim

    2016-01-01

    The relationship between sperm energetics and sperm function is poorly known, but is central to our understanding of the evolution of sperm traits. The aim of this study was to examine how sperm morphology and ATP content affect sperm swimming velocity in the zebra finch Taeniopygia guttata. We exploited the high inter-male variation in this species and created extra experimental power by increasing the number of individuals with very long or short sperm through artificial selection. We found a pronounced quadratic relationship between total sperm length and swimming velocity, with velocity increasing with length up to a point, but declining in the very longest sperm. We also found an unexpected negative association between midpiece length and ATP content: sperm with a short midpiece generally contained the highest concentration of ATP. Low intracellular ATP is therefore unlikely to explain reduced swimming velocity among the very longest sperm (which tend to have a shorter midpiece). PMID:27559067

  5. Is sperm motility maturation affected by static magnetic fields?

    PubMed Central

    Tablado, L; Pérez-Sánchez, F; Soler, C

    1996-01-01

    Kinematic parameters were evaluated in mouse epididymal extracts to monitor maturation of sperm movement in animals exposed to static magnetic fields using the Sperm-Class Analyzer computerized image analysis system. For this purpose, animals were exposed to a field of 0.7 T generated by a permanent magnet over 10 or 35 days for either 1 or 24 hr/day. The values of the motion endpoints were similar in animals used as controls and in those exposed to the nonionizing radiation, whatever the period of exposure or daily dosage. Changes in motility were observed in all groups: the percentage of total motile and progressive motile spermatozoa increased during passage through the epididymis, with major changes between the caput and corpus epididymides, and the pattern of swimming changed clearly towards more rapid and straighter trajectories. The processes of initiation of sperm motility and maturation of displacement patterns were not then affected by magnetic treatment. Moreover, it appears that sperm production is unaffected because no changes were observed in testicular or epididymal weights after exposure to static magnetic fields. Images Figure 1. Figure 2. Figure 3. PMID:8959411

  6. Morphometric analysis of llama (Lama glama) sperm head.

    PubMed

    Casaretto, C; Lombardo, D M; Giuliano, S; Gambarotta, M; Carretero, M I; Miragaya, M H

    2012-05-01

    Llama production in Argentina has increased, as the international interest in breeding this type of animals has grown in the last years. Considering the great polymorphism that llama spermatozoa present at evaluation using light microscopy, the aim of this study was to objectively evaluate llama sperm head morphometry using digital morphometric analysis. Five ejaculates from each of eight males were obtained to evaluate morphometric parameters of 8000 sperm heads stained with Tinción 15(®). The following average results were obtained for each parameter: size parameters: area 20.09 μm(2), length 6.60 μm, width 4.14 μm, equivalent circle diameter 5.06 μm, curve length 5.79 μm and curve width 3.48 μm; boundary parameters: perimeter 18.54 μm and convex perimeter 17.34 μm; and shape parameters: roundness 1.28 and elongation 1.59. Morphometric parameters of sperm head were compared between ejaculates of the same male and between males. Significant differences between ejaculates of the same male were found for all parameters evaluated (P < 0.01). Significant differences between males were found for all morphometric parameters (P < 0.01) except for curve length, curve width and perimeter. The differences detected would indicate that there is not a single morphometric pattern for Lama glama sperm head, because parameter values cannot be standardised.

  7. Mammalian sperm morphometry.

    PubMed Central

    Gage, M J

    1998-01-01

    Understanding the adaptive significance of sperm form and function has been a challenge to biologists because sperm are highly specialized cells operating at a microscopic level in a complex environment. A fruitful course of investigation has been to use the comparative approach. This comparative study attempts to address some fundamental questions of the evolution of mammalian sperm morphometry. Data on sperm morphometry for 445 mammalian species were collated from published sources. I use contemporary phylogenetic analysis to control for the inherent non-independence of species and explore relationships between the morphometric dimensions of the three essential spermatozoal components: head, mid-piece and flagellum. Energy for flagellar action is metabolized by the mitochondrial-dense mid-piece and these combine to propel the sperm head, carrying the male haplotype, to the ovum. I therefore search for evolutionary associations between sperm morphometry and body mass, karyotype and the duration of oestrus. In contrast to previous findings, there is no inverse correlation between body weight and sperm length. Sperm mid-piece and flagellum lengths are positively associated with both head length and area, and the slopes of these relationships are discussed. Flagellum length is positively associated with mid-piece length but, in contrast to previous research and after phylogenetic control, I find no relationship between flagellum length and the volume of the mitochondrial sheath. Sperm head dimensions are not related to either genome mass or chromosome number, and there are no relationships between sperm morphometry and the duration of oestrus. PMID:9474794

  8. Long-term effects of triethylenemelamine exposure on mouse testis cells and sperm chromatin structure assayed by flow cytometry

    SciTech Connect

    Evenson, D.P.; Baer, R.K.; Jost, L.K. )

    1989-01-01

    The toxic and potentially mutagenic actions of triethylenemelamine (TEM) on mouse body and testis weights, testicular cell kinetics, sperm production, sperm head morphology, and sperm chromatin structure were assessed in two experiments. The first experiment examined effects of four dose levels of TEM, assayed 1, 4, or 10 wk after toxic exposure. In the second study, effects from five dosage levels were measured at 1, 4, and 10 wk, and the highest dosage level was evaluated over 44 wk. TEM produced an expected dose related loss of spermatogenic activity and subsequent recovery as determined by dual-parameter (DNA, RNA) flow cytometry (FCM) measurements of testicular cells. Both testicular weights and caudal sperm reserves remained generally below controls after 44 wk recovery following exposure to the highest dosage. Chromatin structure alterations, defined as increased susceptibility to DNA denaturation in situ, and sperm head morphology were highly correlated with dose and with each other. Sperm head morphology and sperm chromatic structure remained abnormal at 44 wk for the 1.0 mg/kg TEM dosage, suggesting that the abnormalities, present long after the initial toxic response, may be a result of mutation. This study demonstrates that flow cytometry provides a unique, rapid, and efficient means to measure effects of reproductive toxins and potential mutagens.

  9. Elevated frequencies of hyperhaploid sperm were detected in a man with a history of multiple aneuploid pregnancies

    SciTech Connect

    Chuu, Y.J.; Wyrobek, A.J.; Kidd, S.

    1997-10-01

    The goal of this research is to determine the heritable risk associated with elevations in the proportion of hyperhaploid human sperm. A case family presented with a history of four aneuploid pregnancies: two with autosomal trisomies (47,+ 22 and 47, +15) which were non-viable and two children with sex chromosomal aneuploidies (47, XYY and Klinefelter syndrome, 47, XXY). The father consumed {approximately}{1/2} pack of cigarettes and 1 alcoholic drink per day. He had no notable occupational or environmental exposures. Paternal origin of extra X chromosomes in the boy with Klinefelter syndrome was confirmed by DNA analyses of blood using polymorphic X-linked microsatellite markers. The inheritance pattern was established by {ge}2 informative loci using PCR products analyzed on an automatic DNA sequencer. Multi-probe sperm FISH was employed to determine the proportion of sperm with aneuploidies involving chromosome 21, X, and Y. Sperm aneuploidy frequencies of hyper-haploid sperm; XY ({approximately}6 fold, p < 0.001), 21-21 ({approximately}6 fold, p< 0.001), XX and YY ({approximately}2 fold, p<0.02). These findings suggest that elevated proportions of aneuploid sperm may be associated with an increased risk of fathering an aneuploid offspring. These findings are also relevant for future studies of heritable risk for men with elevations in sperm aneuploidy after exposures to therapeutic or environmental agents.

  10. The dynamics of sperm cooperation in a competitive environment

    PubMed Central

    Fisher, Heidi S.; Giomi, Luca; Hoekstra, Hopi E.; Mahadevan, L.

    2014-01-01

    Sperm cooperation has evolved in a variety of taxa and is often considered a response to sperm competition, yet the benefit of this form of collective movement remains unclear. Here, we use fine-scale imaging and a minimal mathematical model to study sperm aggregation in the rodent genus Peromyscus. We demonstrate that as the number of sperm cells in an aggregate increase, the group moves with more persistent linearity but without increasing speed. This benefit, however, is offset in larger aggregates as the geometry of the group forces sperm to swim against one another. The result is a non-monotonic relationship between aggregate size and average velocity with both a theoretically predicted and empirically observed optimum of six to seven sperm per aggregate. To understand the role of sexual selection in driving these sperm group dynamics, we compared two sister-species with divergent mating systems. We find that sperm of Peromyscus maniculatus (highly promiscuous), which have evolved under intense competition, form optimal-sized aggregates more often than sperm of Peromyscus polionotus (strictly monogamous), which lack competition. Our combined mathematical and experimental study of coordinated sperm movement reveals the importance of geometry, motion and group size on sperm velocity and suggests how these physical variables interact with evolutionary selective pressures to regulate cooperation in competitive environments. PMID:25056618

  11. [Impacts of ultraviolet irradiation on the sperm motility and longevity of Acipenser baerii].

    PubMed

    Zhang, Tao; Yan, Shi-wei; Zhang, Long-zhen; Zhuang, Ping; Tian, Mei-ping; Yan, Wen-gang; Jiang, Qi; Yao, Zhi-feng

    2011-08-01

    This paper studied the impacts of different dose ultraviolet irradiation (254 nm, UVC) on the sperm motility and longevity of Acipenser baerii. Ultraviolet irradiation had significant impacts on the sperm motility, its fast motion time, and longevity. With the increasing dose of ultraviolet irradiation, the sperm motility decreased rapidly first, increased rapidly then, and decreased rapidly again. The sperm fast motion time had the similar variation trend as the sperm motility, but the sperm longevity kept decreasing with increasing dose of ultraviolet irradiation. When the ultraviolet irradiation dose increased to 288 mJ x cm(-2), the sperm fast motion disappeared; when the ultraviolet irradiation dose increased up to 324 mJ x cm(-2), the sperm had no motility and died. According to the "Hertwig effect", the optimum ultraviolet irradiation dose for inactivating A. baerii sperm was 216 mJ x cm(-2).

  12. Increasing productivity during grinding of high-alumina ceramics

    SciTech Connect

    Belous, K.P.; Leptukha, V.P.

    1984-01-01

    The grinding of high-alumina ceramics involves specific problems as the effectiveness of the grinding is affected by the rate of material removal to ensure high productivity, the surface roughness, and the wear of the diamond tool. This study of the cutting processes in cylindrical and internal grinding was done to determine the optimum cutting parameters and specifications of the diamond grinding wheels, and the results helped increase productivity and reduce wheel consumption.

  13. Calorie increase and water savings of redistributing global crop production

    NASA Astrophysics Data System (ADS)

    Davis, K. F.; Seveso, A.; Rulli, M. C.; D'Odorico, P.

    2015-12-01

    Human demand for crop production is expected to increase substantially in the coming decades as a result of population growth, richer diets and biofuel use. In order for food production to keep pace, unprecedented amounts of resources - water, fertilizers, energy - will be required. This has led to calls for 'sustainable intensification' in which yields are increased on existing croplands while seeking to minimize impacts on water and other agricultural resources. Recent studies have quantified aspects of this, showing that there is a large potential to improve crop yields and increase harvest frequencies to better meet human demand. Though promising, both solutions would necessitate large additional inputs of water and fertilizer in order to be achieved under current technologies. However, the question of whether the current distribution of crops is, in fact, the best for realizing maximized production has not been considered to date. To this end, we ask: Is it possible to increase calorie production and minimize water demand by simply growing crops where soil and climate conditions are best suited? Here we use maps of agro-ecological suitability - a measure of physical and chemical soil fertility - for 15 major food crops to identify differences between current crop distributions and where they can most suitably be planted. By redistributing crops across currently cultivated lands, we determine the potential improvement in calorie production as well as the associated change in water demand. We also consider what distribution of crops would maintain current calorie production while minimizing crop water demand. In doing all of this, our study provides a novel tool for improving crop calorie production without necessarily increasing resource demands.

  14. Queen reproductive tract secretions enhance sperm motility in ants

    PubMed Central

    Baer, Boris; Boomsma, Jacobus J.

    2016-01-01

    Queens of Acromyrmex leaf-cutting ants store sperm of multiple males after a single mating flight, and never remate even though they may live for decades and lay tens of thousands of eggs. Sperm of different males are initially transferred to the bursa copulatrix and compete for access to the long-term storage organ of queens, but the factors determining storage success or failure have never been studied. We used in vitro experiments to show that reproductive tract secretions of Acromyrmex echinatior queens increase sperm swimming performance by at least 50% without discriminating between sperm of brothers and unrelated males. Indiscriminate female-induced sperm chemokinesis makes the likelihood of storage directly dependent on initial sperm viability and thus provides a simple mechanism to secure maximal possible reproductive success of queens, provided that initial sperm motility is an accurate predictor of viability during later egg fertilization. PMID:27807252

  15. Enhancing biomass and ethanol production by increasing NADPH production in Synechocystis sp. PCC 6803.

    PubMed

    Choi, Yun-Nam; Park, Jong Moon

    2016-08-01

    This study demonstrates that increased NADPH production can improve biomass and ethanol production in cyanobacteria. We over-expressed the endogenous zwf gene, which encodes glucose-6-phosphate dehydrogenase of pentose phosphate pathway, in the model cyanobacterium Synechocystis sp. PCC 6803. zwf over-expression resulted in increased NADPH production, and promoted biomass production compared to the wild type in both autotrophic and mixotrophic conditions. Ethanol production pathway including NADPH-dependent alcohol dehydrogenase was also integrated with and without zwf over-expression. Excessive NADPH production by zwf over-expression could improve both biomass and ethanol production in the autotrophic conditions.

  16. Sexing mammalian sperm--intertwining of commerce, technology, and biology.

    PubMed

    Seidel, George E

    2003-12-15

    Sperm from many mammalian species can be sexed by flow cytometry/cell sorting at about 90% accuracy without damaging them unduly. However, because sperm are evaluated one at a time, in series, the number of sexed sperm produced per unit time is limited. Furthermore, the equipment required currently is expensive, in the order of 300,000 US dollars per machine. Despite these limitations, commercialization of this technology has begun with bovine semen, in part by inseminating cattle with relatively low number of sperms. No other approach to sexing sperm in any practical way is likely to be available within the next few years. The constraints for commercial application of sexed sperm in cattle can be somewhat lowered fertility, the high costs of equipment and skilled personnel, and costs of intellectual property such as licensing fees and royalty payments. Most economic analyses indicate that farmers can afford to pay 10-20 US dollars more per dose of sexed sperm than unsexed sperm if costs must be recouped by selling milk or meat. When the product is breeding stock or for certain niche applications, a higher price for sexed semen may be justified. Sexed sperm will be used more broadly in cattle only when improved production and/or efficiency can compensate for the extra costs of purchasing sexed sperm.

  17. Cryopreservation of Sperm from the Endangered Colorado Pikeminnow

    USGS Publications Warehouse

    Tiersch, T.R.; Figiel, C.R.; Wayman, W.R.; Williamson, J.H.; Gorman, O.T.; Carmichael, G.J.

    2004-01-01

    We developed methods for the cryopreservation of sperm of the endangered Colorado pikeminnow Ptychocheilus lucius. Sperm were collected from a captive broodstock population of Colorado pikeminnow reared and maintained at the Dexter National Fish Hatchery and Technology Center. Our objectives were to (1) evaluate the effects on sperm motility of 24-h storage in Hanks' balanced salt solution (HBSS); (2) characterize sperm motility and duration; (3) examine the relationship between sperm motility and osmotic pressure; (4) examine the effect of four cryoprotectants (dimethyl sulfoxide [DMSO], dimethyl acetamide [DMA], glycerol, and methanol [MeOH] at two concentrations [5% and 10%]) on postthaw motility; and (5) compare the effect of two cooling rates (40??C/ min and 4??C/min) on postthaw motility. The sperm samples diluted with HBSS retained higher motility (mean ??SD, 77 ?? 22%; n = 9) than did undiluted samples (12 ?? 30%; n = 9) after 24 h of storage. When exposed to HBSS at 274 mosmols/kg or more, few sperm became motile (???1%). Exposure to HBSS at 265 mosmols/kg elicited threshold activation (defined as 10% motility), and maximum motility (>95%) was observed at 93 mosmols/ kg. The maximum motility of sperm was observed within 10 s after activation with deionized water, and sperm remained motile for 57 s. The sperm that were cooled at a rate of 40??C/min and cryopreserved with 5% MeOH retained higher postthaw motility (56 ?? 13%) than did sperm cryopreserved with DMSO, DMA, or glycerol (at 5% and 10%). When the sperm samples were cooled at a rate of 4??C/min, sperm cryopreserved with MeOH (5% or 10%) or DMSO (5% or 10%) retained the highest postthaw motilities (???14%). The use of cryopreserved sperm can assist hatchery managers in the production of fish, provide for the long-term conservation of genetic resources, and assist in the recovery of endangered species such as the Colorado pikeminnow.

  18. Sodium affects the sperm motility in the European eel.

    PubMed

    Vílchez, M Carmen; Morini, Marina; Peñaranda, David S; Gallego, Víctor; Asturiano, Juan F; Pérez, Luz

    2016-08-01

    The role of seminal plasma sodium and activation media sodium on sperm motility was examined by selectively removing the element from these two media, in European eel sperm. Sperm size (sperm head area) was also measured using an ASMA (Automated Sperm Morphometry Analyses) system, in the different conditions. Intracellular sodium [Na(+)]i was quantitatively analyzed by first time in the spermatozoa from a marine fish species. Measurement of [Na(+)]i was done before and after motility activation, by Flow Cytometry, using CoroNa Green AM as a dye. Sperm motility activation induced an increase in [Na(+)]i, from 96.72mM in quiescent stage to 152.21mM post-activation in seawater. A significant decrease in sperm head area was observed post-activation in seawater. There was a notable reduction in sperm motility when sodium was removed from the seminal plasma, but not when it was removed from the activation media. Sodium removal was also linked to a significant reduction in sperm head area in comparison to the controls. Our results indicate that the presence of the ion Na(+) in the seminal plasma (or in the extender medium) is necessary for the preservation of sperm motility in European eel, probably because it plays a role in maintaining an appropriate sperm cell volume in the quiescent stage of the spermatozoa.

  19. Microscopic analysis of MTT stained boar sperm cells.

    PubMed

    van den Berg, B M

    2015-01-01

    The ability of sperm cells to develop colored formazan by reduction of MTT was used earlier to develop a spectrophotometric assay to determine the viability of sperm cells for several mammalian species. It was the objective of the present study to visualize microscopically the location of the formazan in boar sperm cells. The MTT staining process of boar sperm cells can be divided into a series of morphological events. Incubation of the sperm cells in the presence of MTT resulted after a few min in a diffuse staining of the midpiece of the sperm cells. Upon further incubation the staining of the midpiece became more intense, and gradually the formation of packed formazan granules became more visible. At the same time, a small formazan stained granule appeared medially on the sperm head, which increased in size during further incubation. After incubation for about 1 h the midpiece granules were intensely stained and more clearly distinct as granules, while aggregation of sperm cells occurred. Around 90% of the sperm cells showed these staining events. At the end of the staining the formazan granules have disappeared from both the sperm cells and medium, whereas formazan crystals appeared as thin crystal threads, that became heavily aggregated in the incubation medium. It was concluded that formazan is taken up by lipid droplets in the cytoplasm. Further, the use of the MTT assay to test for sperm viability should be regarded as a qualitative assay, whereas its practical use at artificial insemination (AI) Stations is limited.

  20. Influence of staining and sampling procedures on goat sperm morphometry using the Sperm Class Analyzer.

    PubMed

    Hidalgo, Manuel; Rodríguez, Inmaculada; Dorado, Jesús

    2006-09-01

    Computer-assisted sperm morphometry analysis (ASMA) has improved the assessment of sperm morphology, but the results depend on the use of adequate sampling and staining procedures of spermatozoa from individual species. In this study, the Sperm Class Analyzer ASMA system was used for the morphometric analysis of goat sperm heads. Semen samples, obtained from four bucks, were used to evaluate the influence of three staining procedures (Diff-Quik, Hemacolor and Harris' Haematoxylin) on the accuracy of image processing and sperm morphometry, the effect of the number of cells analysed and the repeatability of the method. These experiments were performed to obtain objective, accurate and reliable sperm morphometric measurements of goat spermatozoa. Diff-Quik and Harris' Haematoxylin were significantly (p<0.05) more accurate than Hemacolor. However, Diff-Quik obtained the highest proportion of correctly analysed sperm heads (86.06%) and the lowest coefficients of variation on the image processing and morphometric measurements. The staining methods affected significantly the sperm dimensions (p<0.001) with increased values from Diff-Quik than Hemacolor and Harris' Haematoxylin, respectively (Diff-Quik>Hemacolor>Harris' Haematoxylin). No differences in morphometric parameters were found when 100, 150, 175 or 200 spermatozoa were analysed. The repeatability of results obtained was very high since no differences were found when measuring the same sperm on multiple attempts. In conclusion, to obtain objective, accurate and repeatable sperm morphometric measurements by the Sperm Class Analyzer system in goats, the analysis of 100 spermatozoa from slides which have been previously stained with Diff-Quik is recommended.

  1. Oxidative stress in zebrafish (Danio rerio) sperm.

    PubMed

    Hagedorn, Mary; McCarthy, Megan; Carter, Virginia L; Meyers, Stuart A

    2012-01-01

    Laboratories around the world have produced tens of thousands of mutant and transgenic zebrafish lines. As with mice, maintaining all of these valuable zebrafish genotypes is expensive, risky, and beyond the capacity of even the largest stock centers. Because reducing oxidative stress has become an important aspect of reducing the variability in mouse sperm cryopreservation, we examined whether antioxidants might improve cryopreservation of zebrafish sperm. Four experiments were conducted in this study. First, we used the xanthine-xanthine oxidase (X-XO) system to generate reactive oxygen species (ROS). The X-XO system was capable of producing a stress reaction in zebrafish sperm reducing its sperm motility in a concentration dependent manner (P<0.05). Second, we examined X-XO and the impact of antioxidants on sperm viability, ROS and motility. Catalase (CAT) mitigated stress and maintained viability and sperm motility (P>0.05), whereas superoxide dismutase (SOD) and vitamin E did not (P<0.05). Third, we evaluated ROS in zebrafish spermatozoa during cryopreservation and its effect on viability and motility. Methanol (8%) reduced viability and sperm motility (P<0.05), but the addition of CAT mitigated these effects (P>0.05), producing a mean 2.0 to 2.9-fold increase in post-thaw motility. Fourth, we examined the effect of additional cryoprotectants and CAT on fresh sperm motility. Cryoprotectants, 8% methanol and 10% dimethylacetamide (DMA), reduced the motility over the control value (P<0.5), whereas 10% dimethylformamide (DMF) with or without CAT did not (P>0.05). Zebrafish sperm protocols should be modified to improve the reliability of the cryopreservation process, perhaps using a different cryoprotectant. Regardless, the simple addition of CAT to present-day procedures will significantly improve this process, assuring increased and less variable fertilization success and allowing resource managers to dependably plan how many straws are needed to safely

  2. Egg jelly proteins stimulate directed motility in Xenopus laevis sperm.

    PubMed

    Burnett, Lindsey A; Sugiyama, Hitoshi; Bieber, Allan L; Chandler, Douglas E

    2011-06-01

    Previously we have shown that extracts from Xenopus egg jelly (egg water) increase the passage of sperm through a porous membrane in a dose-dependent manner. Although this assay has shown that sperm accumulation occurs only in the presence of an egg water gradient, it has not revealed the dynamic features of how Xenopus sperm swim in such gradients. Here, we use video microscopic observations to trace sperm trajectories in a Zigmond chamber. Our results show that Xenopus sperm swim in linear and gently curving paths and only infrequently perform turns. In the presence of an egg water gradient, however, the percent of sperm swimming up the gradient axis and the net distance traveled by each sperm along this axis was increased significantly. There was no change in curvilinear velocity. Rather, the orientation of sperm travel was shifted to more closely match that of the gradient axis. In addition, using a porous filter assay, we demonstrate that the egg water protein allurin, in both purified and recombinant forms, stimulates directed motility of sperm. Finally, we use Oregon Green 488-conjugated allurin to show that this protein binds primarily to the sperm midpiece; binding of allurin to the entire head was observed in a minor subpopulation of sperm. Dose dependence of allurin binding occurred over the 0-1 µg/ml range and correlated well with previously published dose-dependent sperm attraction data. Binding was rapid with a half-time of about 10 sec. These data suggest that egg water proteins bind to sperm and modify sperm-orienting behavior.

  3. Evaluation of Lasting Effects of Heat Stress on Sperm Profile and Oxidative Status of Ram Semen and Epididymal Sperm

    PubMed Central

    Hamilton, Thais Rose dos Santos; Mendes, Camilla Mota; de Castro, Letícia Signori; de Assis, Patrícia Monken; Siqueira, Adriano Felipe Perez; Delgado, Juliana de Carvalho; Goissis, Marcelo Demarchi; Muiño-Blanco, Teresa; Cebrián-Pérez, José Álvaro; Nichi, Marcílio; Visintin, José Antonio; Assumpção, Mayra Elena Ortiz D'Ávila

    2016-01-01

    Higher temperatures lead to an increase of testicular metabolism that results in spermatic damage. Oxidative stress is the main factor responsible for testicular damage caused by heat stress. The aim of this study was to evaluate lasting effects of heat stress on ejaculated sperm and immediate or long-term effects of heat stress on epididymal sperm. We observed decrease in motility and mass motility of ejaculated sperm, as well as an increase in the percentages of sperm showing major and minor defects, damaged plasma and acrosome membranes, and a decrease in the percentage of sperm with high mitochondrial membrane potential in the treated group until one spermatic cycle. An increased enzymatic activity of glutathione peroxidase and an increase of stressed cells were observed in ejaculated sperm of the treated group. A decrease in the percentage of epididymal sperm with high mitochondrial membrane potential was observed in the treated group. However, when comparing immediate and long-term effects, we observed an increase in the percentage of sperm with low mitochondrial membrane potential. In conclusion, testicular heat stress induced oxidative stress that led to rescuable alterations after one spermatic cycle in ejaculated sperm and also after 30 days in epididymal sperm. PMID:26881013

  4. Etiologies of sperm oxidative stress

    PubMed Central

    Sabeti, Parvin; Pourmasumi, Soheila; Rahiminia, Tahereh; Akyash, Fatemeh; Talebi, Ali Reza

    2016-01-01

    Sperm is particularly susceptible to reactive oxygen species (ROS) during critical phases of spermiogenesis. However, the level of seminal ROS is restricted by seminal antioxidants which have beneficial effects on sperm parameters and developmental potentials. Mitochondria and sperm plasma membrane are two major sites of ROS generation in sperm cells. Besides, leukocytes including polymer phonuclear (PMN) leukocytes and macrophages produce broad category of molecules including oxygen free radicals, non-radical species and reactive nitrogen species. Physiological role of ROS increase the intracellular cAMP which then activate protein kinase in male reproductive system. This indicates that spermatozoa need small amounts of ROS to acquire the ability of nuclear maturation regulation and condensation to fertilize the oocyte. There is a long list of intrinsic and extrinsic factors which can induce oxidative stress to interact with lipids, proteins and DNA molecules. As a result, we have lipid peroxidation, DNA fragmentation, axonemal damage, denaturation of the enzymes, over generation of superoxide in the mitochondria, lower antioxidant activity and finally abnormal spermatogenesis. If oxidative stress is considered as one of the main cause of DNA damage in the germ cells, then there should be good reason for antioxidant therapy in these conditions. PMID:27351024

  5. Warming increases methylmercury production in an Arctic soil.

    PubMed

    Yang, Ziming; Fang, Wei; Lu, Xia; Sheng, Guo-Ping; Graham, David E; Liang, Liyuan; Wullschleger, Stan D; Gu, Baohua

    2016-07-01

    Rapid temperature rise in Arctic permafrost impacts not only the degradation of stored soil organic carbon (SOC) and climate feedback, but also the production and bioaccumulation of methylmercury (MeHg) toxin that can endanger humans, as well as wildlife in terrestrial and aquatic ecosystems. Currently little is known concerning the effects of rapid permafrost thaw on microbial methylation and how SOC degradation is coupled to MeHg biosynthesis. Here we describe the effects of warming on MeHg production in an Arctic soil during an 8-month anoxic incubation experiment. Net MeHg production increased >10 fold in both organic- and mineral-rich soil layers at warmer (8 °C) than colder (-2 °C) temperatures. The type and availability of labile SOC, such as reducing sugars and ethanol, were particularly important in fueling the rapid initial biosynthesis of MeHg. Freshly amended mercury was more readily methylated than preexisting mercury in the soil. Additionally, positive correlations between mercury methylation and methane and ferrous ion production indicate linkages between SOC degradation and MeHg production. These results show that climate warming and permafrost thaw could potentially enhance MeHg production by an order of magnitude, impacting Arctic terrestrial and aquatic ecosystems by increased exposure to mercury through bioaccumulation and biomagnification in the food web.

  6. Diversity increases biomass production for trematode parasites in snails

    USGS Publications Warehouse

    Hechinger, Ryan F.; Lafferty, Kevin D.; Kuris, Armand M.

    2008-01-01

    Increasing species diversity typically increases biomass in experimental assemblages. But there is uncertainty concerning the mechanisms of diversity effects and whether experimental findings are relevant to ecological process in nature. Hosts for parasites provide natural, discrete replicates of parasite assemblages. We considered how diversity affects standing-stock biomass for a highly interactive parasite guild: trematode parasitic castrators in snails. In 185 naturally occurring habitat replicates (individual hosts), diverse parasite assemblages had greater biomass than single-species assemblages, including those of their most productive species. Additionally, positive diversity effects strengthened as species segregated along a secondary niche axis (space). The most subordinate species—also the most productive when alone—altered the general positive effect, and was associated with negative diversity effects on biomass. These findings, on a previously unstudied consumer class, extend previous research to illustrate that functional diversity and species identity may generally both explain how diversity influences biomass production in natural assemblages of competing species.

  7. Campus Improvement Committee Working to Increase Morale, Productivity | Poster

    Cancer.gov

    The Campus Improvement Committee (CIC) has recently been re-established, with Mike Addington, manager, Operations and Maintenance, as chair. Addington is excited to be involved in a committee that’s so near and dear to his heart, and he’s a big believer in the value of increasing morale and productivity through an appealing and pleasant work environment.

  8. A vernonia diacylglycerol acyltransferase can increase renewable oil production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing the production of plant oils such as soybean oil, a critical renewable resource for food and fuel, will be highly valuable. Successful breeding for higher oil levels in soybean, however, usually results in reduced protein, a second valuable seed component. We show that by manipulating a h...

  9. Organophosphorous pesticide exposures and sperm quality

    PubMed Central

    Perry, Melissa J.; Venners, Scott A.; Chen, Xing; Liu, Xue; Tang, Genfu; Xing, Houxun; Barr, Dana Boyd; Xu, Xiping

    2010-01-01

    Many Americans are exposed to low levels of organophosphorous (OP) pesticides. In is unclear whether these exposures impact sperm production. We investigated whether there was an association between urinary OP insecticide metabolites and sperm concentration and motility in newly married men from a rural area of eastern People’s Republic of China. Ninety-four cases and 95 controls were included based on their median residual value of sperm concentration and motility after adjusting for relevant covariates. Their urine was analyzed for six dialkylphosphate (DAP) compounds. After adjustment for demographic and exposure variables, the odds of being a case were greater (Odds Ratio=1.30, 95% Confidence Interval 1.02-1.65) in men with higher urinary concentrations of dimethylphosphate (DMP) compared to men with lower levels. No significant differences between cases and controls were found among the other DAP concentrations. DMP exposure and sperm concentration and motility should be explored further in environmental exposure studies. PMID:20850521

  10. Effect of organic selenium in the diet on sperm quality of boars.

    PubMed

    López, A; Rijsselaere, T; Van Soom, A; Leroy, J L M R; De Clercq, J B P; Bols, P E J; Maes, D

    2010-12-01

    The effect of a diet supplemented with organic selenium (Se) on sperm production and quality of boars was investigated. Sixty mature boars from a commercial artificial insemination centre were randomly allocated at Day (D) 0 into Group A and B. Group A received the regular ration supplemented with inorganic Se (0.4 mg/kg feed as Na(2) SeO(3)) whereas Group B was switched to the same diet but with organic Se (0.4 mg/kg fed as Se-yeast). The sperm was investigated during 4 months (D0, D30, D60, D75, D90, D105 and D120). Sperm concentration and motility were objectively measured using a photometer and Computer Assisted Semen Analysis (CASA) respectively. Morphology of the sperm was assessed using eosin-nigrosin staining and the resistance to induction of oxidative stress (production of malonaldehyde, MDA) through thiobarbituric acid reagent species analysis. Additionally, the Se concentration in sperm and blood plasma were measured. Repeated measures analysis of variance (anova) from D60 to 120 (spermatogenesis of approximately 2 months) or anova at D120 (Se concentrations) were used for statistical analysis. The total number of ejaculated sperm was not significantly different between both groups, but boars of Group B had a significantly higher sperm concentration (434.6 vs 514.1 × 10(6) sperm/ml; p < 0.05). Small differences (p < 0.05) were observed between both groups for some CASA parameters, namely straight line velocity (μm/s) (Group A: 48.3, Group B: 45.1), straightness (%) (Group A: 65.6, Group B: 62.2) and linearity (%) (Group A: 32.2, Group B: 29.3). The sperm of Group B showed more oxidative stress (4.1 vs 4.9 μmol MDA/l; p < 0.05) compared with those of Group A. No significant differences (p > 0.05) were observed for the other parameters. Under the present study conditions, changing from inorganic Se to organic Se in the diet of boars increased sperm concentration but reduced some motility parameters and resistance to

  11. Male mammals respond to a risk of sperm competition conveyed by odours of conspecific males

    NASA Astrophysics Data System (ADS)

    delBarco-Trillo, Javier; Ferkin, Michael H.

    2004-09-01

    Sperm competition occurs when a female copulates with two or more males and the sperm of those males compete within the female's reproductive tract to fertilize her eggs. The frequent occurrence of sperm competition has forced males of many species to develop different strategies to overcome the sperm of competing males. A prevalent strategy is for males to increase their sperm investment (total number of sperm allocated by a male to a particular female) after detecting a risk of sperm competition. It has been shown that the proportion of sperm that one male contributes to the sperm pool of a female is correlated with the proportion of offspring sired by that male. Therefore, by increasing his sperm investment a male may bias a potential sperm competition in his favour. Here we show that male meadow voles, Microtus pennsylvanicus, increase their sperm investment when they mate in the presence of another male's odours. Such an increase in sperm investment does not occur by augmenting the frequency of ejaculations, but by increasing the amount of sperm in a similar number of ejaculations.

  12. Sperm motility-initiating substance in newt egg-jelly induces differential initiation of sperm motility based on sperm intracellular calcium levels.

    PubMed

    Watanabe, Akihiko; Takayama-Watanabe, Eriko; Vines, Carol A; Cherr, Gary N

    2011-01-01

    Sperm motility-initiating substance (SMIS), a novel motility inducer from newt egg-jelly, is activated by the release from associated jelly substances at the beginning of internal fertilization and affects female-stored sperm. We examined motility initiation kinetics of newt sperm in response to SMIS by monitoring the changes of sperm intracellular calcium ([Ca²(+)](i)). In quiescent non-motile sperm loaded with the Ca²(+) indicator Fluo-4, intracellular free Ca²(+) was observed around mitochondria using confocal scanning laser microscopy. A slight increase in [Ca²(+)](i) occurred simultaneously and transiently at motility initiation in sperm treated with either heated jelly extract (hJE) containing activated SMIS, or a low osmotic solution, which naturally initiates motility in externally-fertilizing amphibians and can initiate motility in urodele sperm. When the increase of [Ca²(+)](i) at motility-initiation was monitored using spectrofluorometry, large increases in [Ca²(+)](i) occurred immediately in the low osmotic solution and within 1.5 min in the hJE. In the intact jelly extract (no heating), small increases of [Ca²(+)](i) irregularly occurred from around 1 min and for about 4 min, during which motility was differentially initiated among sperm. These results indicate that the SMIS induces differential initiation of sperm motility depending on the activational states of the SMIS and its overall activity. The motility initiation in the jelly extract was delayed in sperm whose intracellular Ca²(+) had been chelated with BAPTA-AM. The relative levels of [Ca²(+)](i) were variable with a mean of 414 ± 256 nmol/L among resting sperm, suggesting that the level of [Ca²(+)](i) in the resting sperm modulates the responsiveness to the SMIS.

  13. Ocean acidification impacts on sperm mitochondrial membrane potential bring sperm swimming behaviour near its tipping point.

    PubMed

    Schlegel, Peter; Binet, Monique T; Havenhand, Jonathan N; Doyle, Christopher J; Williamson, Jane E

    2015-04-01

    Broadcast spawning marine invertebrates are susceptible to environmental stressors such as climate change, as their reproduction depends on the successful meeting and fertilization of gametes in the water column. Under near-future scenarios of ocean acidification, the swimming behaviour of marine invertebrate sperm is altered. We tested whether this was due to changes in sperm mitochondrial activity by investigating the effects of ocean acidification on sperm metabolism and swimming behaviour in the sea urchin Centrostephanus rodgersii. We used a fluorescent molecular probe (JC-1) and flow cytometry to visualize mitochondrial activity (measured as change in mitochondrial membrane potential, MMP). Sperm MMP was significantly reduced in ΔpH -0.3 (35% reduction) and ΔpH -0.5 (48% reduction) treatments, whereas sperm swimming behaviour was less sensitive with only slight changes (up to 11% decrease) observed overall. There was significant inter-individual variability in responses of sperm swimming behaviour and MMP to acidified seawater. We suggest it is likely that sperm exposed to these changes in pH are close to their tipping point in terms of physiological tolerance to acidity. Importantly, substantial inter-individual variation in responses of sperm swimming to ocean acidification may increase the scope for selection of resilient phenotypes, which, if heritable, could provide a basis for adaptation to future ocean acidification.

  14. Human sperm chromosome analysis after subzonal sperm insemination of hamster oocytes

    SciTech Connect

    Cozzi, J.

    1994-09-01

    Sperm microinjection techniques, subzonal sperm insemination (SUZI) and intracytoplasmic sperm injection (ICSI), have achieved a wide spread clinical application for the treatment of male infertility. To date, only one study has focused on sperm karyotypes after microinjection. Martin et al. reported a very high incidence of abnormal human sperm complements after ICSI into hamster oocytes. In the present study, are reported the first human sperm karyotypes after SUZI of hamster oocytes. Spermatozoa from two control donors were treated by calcium ionophore A23187 and injected under the zona of hamster eggs. The microinjected eggs were then cultured for cytogenetic analysis of the pronuclei. Out of 47 analyzed sperm chromosome metaphases, 5 (10.6%) were abnormal, 4 (8.5%) were hypohaploid and 1 (2.1%) had a structural abnormality. The sex ratio was not significantly different from the expected 1:1 ratio. Rates of chromosomal abnormalities in microinjected spermatozoa were similar to those observed in spermatozoa inseminated with zona free eggs, suggesting that SUZI procedure per se does not increase sperm chromosomal abnormalities.

  15. Differences in the fatty-acid composition of rodent spermatozoa are associated to levels of sperm competition.

    PubMed

    delBarco-Trillo, Javier; Mateo, Rafael; Roldan, Eduardo R S

    2015-03-20

    Sperm competition is a prevalent phenomenon that drives the evolution of sperm function. High levels of sperm competition lead to increased metabolism to fuel higher sperm velocities. This enhanced metabolism can result in oxidative damage (including lipid peroxidation) and damage to the membrane. We hypothesized that in those species experiencing high levels of sperm competition there are changes in the fatty-acid composition of the sperm membrane that makes the membrane more resistant to oxidative damage. Given that polyunsaturated fatty acids (PUFAs) are the most prone to lipid peroxidation, we predicted that higher sperm competition leads to a reduction in the proportion of sperm PUFAs. In contrast, we predicted that levels of sperm competition should not affect the proportion of PUFAs in somatic cells. To test these predictions, we quantified the fatty-acid composition of sperm, testis and liver cells in four mouse species (genus Mus) that differ in their levels of sperm competition. Fatty-acid composition in testis and liver cells was not associated to sperm competition levels. However, in sperm cells, as predicted, an increase in sperm competition levels was associated with an increase in the proportion of saturated fatty-acids (the most resistant to lipid peroxidation) and by a concomitant decrease in the proportion of PUFAs. Two particular fatty acids were most responsible for this pattern (arachidonic acid and palmitic acid). Our findings thus indicate that sperm competition has a pervasive influence in the composition of sperm cells that ultimately may have important effects in sperm function.

  16. Increasing loyalty to breastfeeding: investigating a product development strategy.

    PubMed

    Parkinson, Joy; Russell-Bennett, Rebekah; Previte, Josephine

    2012-01-01

    This article demonstrates how social marketing insights were used to influence women's loyalty to breastfeeding. The article reports on a social marketing campaign undertaken by the Australian Breastfeeding Association and a government health department, which used a product development strategy in order to increase breastfeeding loyalty. Seeking new approaches to support breastfeeding behaviors is critical and timely, because while initiation rates of breastfeeding are high in developed countries such as the United Kingdom, Australia, Canada, and the United States, duration rates are significantly lower. Results indicate that a product- focused strategy influences pregnant women's loyalty to exclusively breastfeeding.

  17. Current status of freeze-drying technology to preserve domestic animals sperm.

    PubMed

    Gil, L; Olaciregui, M; Luño, V; Malo, C; González, N; Martínez, F

    2014-10-01

    In recent years, there has been an increased interest in new preservation techniques that facilitate sperm storage and distribution, with freeze-drying (FD) having been proposed as an alternative method for sperm preservation and maintenance of genetic resources in different animal species. FD is a method in which frozen material is dried by sublimation of ice, thereby involving a direct transition from a solid (ice) to a vapour (gas) phase. One of the main advantages of FD is that nitrogen and dry ice are no longer required for the storage and shipment of frozen sperm, which can be stored at room temperature or 4°C, thereby resulting in enormous reductions in storage and shipping costs. Unlike sperm cryopreserved after gradual freezing, the sperm membrane may be further damaged by both snap-freezing and drying stresses during the FD procedure. As mammalian spermatozoa lose their motility, viability and, at least partially, their DNA integrity when freeze-dried, they must be microinjected into an oocyte by intracytoplasmic sperm injection (ICSI). Although the efficiency of ICSI is limited when freeze-dried spermatozoa are used, embryos and live offspring can be produced. DNA fragmentation in freeze-dried spermatozoa is one of the main causes of failure of embryonic development and successful pregnancy. In this regard, it has been suggested that endonucleases are among the leading causes of DNA fragmentation in spermatozoa along with oxidative stress caused by the release of reactive oxygen species (ROS). Many factors influence the FD process, and it is not clear how FD affects specific components of sperm from different animal species. As such, a sound understanding of the FD process would result in increased production of embryos and/or live offspring. The aim of this review was to study the various stages and techniques used in the FD process and to further evaluate the results obtained.

  18. Sperm Patch-Clamp

    PubMed Central

    Lishko, Polina; Clapham, David E.; Navarro, Betsy; Kirichok, Yuriy

    2014-01-01

    Sperm intracellular pH and calcium concentration ([Ca2+]i) are two central factors that control sperm activity within the female reproductive tract. As such, the ion channels of the sperm plasma membrane that alter intracellular sperm [Ca2+] and pH play important roles in sperm physiology and the process of fertilization. Indeed, sperm ion channels regulate sperm motility, control sperm chemotaxis toward the egg in some species, and may trigger the acrosome reaction. Until recently, our understanding of these important molecules was rudimentary due to the inability to patch-clamp spermatozoa and directly record the activity of these ion channels under voltage clamp. Recently, we overcame this technical barrier and developed a method for reproducible application of the patch-clamp technique to mouse and human spermatozoa. This chapter covers important aspects of application of the patch-clamp technique to spermatozoa, such as selection of the electrophysiological equipment, isolation of spermatozoa for patch-clamp experiments, formation of the gigaohm seal with spermatozoa, and transition into the whole-cell mode of recording. We also discuss potential pitfalls in application of the patch-clamp technique to flagellar ion channels. PMID:23522465

  19. Sperm competition risk generates phenotypic plasticity in ovum fertilizability

    PubMed Central

    Firman, Renée C.; Simmons, Leigh W.

    2013-01-01

    Theory predicts that sperm competition will generate sexual conflict that favours increased ovum defences against polyspermy. A recent study on house mice has shown that ovum resistance to fertilization coevolves in response to increased sperm fertilizing capacity. However, the capacity for the female gamete to adjust its fertilizability as a strategic response to sperm competition risk has never, to our knowledge, been studied. We sourced house mice (Mus domesticus) from natural populations that differ in the level of sperm competition and sperm fertilizing capacity, and manipulated the social experience of females during their sexual development to simulate conditions of either a future ‘risk’ or ‘no risk’ of sperm competition. Consistent with coevolutionary predictions, we found lower fertilization rates in ova produced by females from a high sperm competition population compared with ova from a low sperm competition population, indicating that these populations are divergent in the fertilizability of their ova. More importantly, females exposed to a ‘risk’ of sperm competition produced ova that had greater resistance to fertilization than ova produced by females reared in an environment with ‘no risk’. Consequently, we show that variation in sperm competition risk during development generates phenotypic plasticity in ova fertilizability, which allows females to prepare for prevailing conditions during their reproductive life. PMID:24132308

  20. Sperm competition risk generates phenotypic plasticity in ovum fertilizability.

    PubMed

    Firman, Renée C; Simmons, Leigh W

    2013-12-07

    Theory predicts that sperm competition will generate sexual conflict that favours increased ovum defences against polyspermy. A recent study on house mice has shown that ovum resistance to fertilization coevolves in response to increased sperm fertilizing capacity. However, the capacity for the female gamete to adjust its fertilizability as a strategic response to sperm competition risk has never, to our knowledge, been studied. We sourced house mice (Mus domesticus) from natural populations that differ in the level of sperm competition and sperm fertilizing capacity, and manipulated the social experience of females during their sexual development to simulate conditions of either a future 'risk' or 'no risk' of sperm competition. Consistent with coevolutionary predictions, we found lower fertilization rates in ova produced by females from a high sperm competition population compared with ova from a low sperm competition population, indicating that these populations are divergent in the fertilizability of their ova. More importantly, females exposed to a 'risk' of sperm competition produced ova that had greater resistance to fertilization than ova produced by females reared in an environment with 'no risk'. Consequently, we show that variation in sperm competition risk during development generates phenotypic plasticity in ova fertilizability, which allows females to prepare for prevailing conditions during their reproductive life.

  1. Prospects for increasing starch and sucrose yields for bioethanol production.

    PubMed

    Smith, Alison M

    2008-05-01

    In the short term, the production of bioethanol as a liquid transport fuel is almost entirely dependent on starch and sugars from existing food crops. The sustainability of this industry would be enhanced by increases in the yield of starch/sugar per hectare without further inputs into the crops concerned. Efforts to achieve increased yields of starch over the last three decades, in particular via manipulation of the enzyme ADPglucose pyrophosphorylase, have met with limited success. Other approaches have included manipulation of carbon partitioning within storage organs in favour of starch synthesis, and attempts to manipulate source-sink relationships. Some of the most promising results so far have come from manipulations that increase the availability of ATP for starch synthesis. Future options for achieving increased starch contents could include manipulation of starch degradation in organs in which starch turnover is occurring, and introduction of starch synthesis into the cytosol. Sucrose accumulation is much less well understood than starch synthesis, but recent results from research on sugar cane suggest that total sugar content can be greatly increased by conversion of sucrose into a non-metabolizable isomer. A better understanding of carbohydrate storage and turnover in relation to carbon assimilation and plant growth is required, both for improvement of starch and sugar crops and for attempts to increase biomass production in second-generation biofuel crops.

  2. The increasing divergence of raw agricultural production from edible calories

    NASA Astrophysics Data System (ADS)

    Johnston, M.; Cassidy, E. S.; Ray, D. K.; Mueller, N. D.; Foley, J. A.

    2012-12-01

    As we look forward to 2050 and the need to dramatically increase agricultural production, we must first look to our recent past to see how changes in yields and area have helped to grow agricultural resources. However, those changes must not be viewed in a vacuum -- it is insufficient to assess advancements in agricultural productivity without converting resources to usable calories by humans and to put the supply in context of population changes. This study looks at major countries and growing regions to determine the availability of usable calories from agriculture from 1965 to 2005. We examine how rapid increases in agricultural supplies in the past have freed up resources for a growing number of non-food uses. We look at how this new competition and pressures from a changing climate might impact the resiliency of our agricultural system.

  3. Warming increases methylmercury production in an Arctic soil

    DOE PAGES

    Yang, Ziming; Fang, Wei; Lu, Xia; ...

    2016-04-29

    The rapid temperature rise in Arctic permafrost concerns not only the degradation of stored soil organic carbon (SOC) and climate feedback, but also the production and bioaccumulation of methylmercury (MeHg) that may endanger humans, as well as wildlife in terrestrial, aquatic, and marine ecosystems. Decomposition of SOC provides an energy source for microbial methylation, although little is known how rapid permafrost thaw affects Hg methylation and how SOC degradation is coupled to MeHg biosynthesis. We describe rates of MeHg production in Arctic soils from an 8-month warming microcosm experiment under anoxic conditions. MeHg production increased >10 fold in both organic-more » and the mineral-rich soil layers at a warmer temperature (8 C) compared to a sub-zero temperature ( 2 C). MeHg production was positively correlated to methane and ferrous ion concentrations, suggesting that Hg methylation is coupled with methanogenesis and iron reduction. Labile SOC, such as reducing sugars and alcohol, were particularly effective in fueling the initial rapid biosynthesis of MeHg. In freshly amended Hg we found that there was more bioavailable than existing Hg in the mineral soil. Finally, the data indicate that climate warming and permafrost thaw could greatly enhance MeHg production, thereby impacting Arctic aquatic and marine ecosystems through biomagnification in the food web.« less

  4. Warming increases methylmercury production in an Arctic soil

    SciTech Connect

    Yang, Ziming; Fang, Wei; Lu, Xia; Sheng, Guo-Ping; Graham, David E.; Liang, Liyuan; Wullschleger, Stan D.; Gu, Baohua

    2016-04-29

    The rapid temperature rise in Arctic permafrost concerns not only the degradation of stored soil organic carbon (SOC) and climate feedback, but also the production and bioaccumulation of methylmercury (MeHg) that may endanger humans, as well as wildlife in terrestrial, aquatic, and marine ecosystems. Decomposition of SOC provides an energy source for microbial methylation, although little is known how rapid permafrost thaw affects Hg methylation and how SOC degradation is coupled to MeHg biosynthesis. We describe rates of MeHg production in Arctic soils from an 8-month warming microcosm experiment under anoxic conditions. MeHg production increased >10 fold in both organic- and the mineral-rich soil layers at a warmer temperature (8 C) compared to a sub-zero temperature ( 2 C). MeHg production was positively correlated to methane and ferrous ion concentrations, suggesting that Hg methylation is coupled with methanogenesis and iron reduction. Labile SOC, such as reducing sugars and alcohol, were particularly effective in fueling the initial rapid biosynthesis of MeHg. In freshly amended Hg we found that there was more bioavailable than existing Hg in the mineral soil. Finally, the data indicate that climate warming and permafrost thaw could greatly enhance MeHg production, thereby impacting Arctic aquatic and marine ecosystems through biomagnification in the food web.

  5. Zymomonas mobilis mutants with an increased rate of alcohol production

    SciTech Connect

    Osman, Y.A.; Ingram, L.O.

    1987-07-01

    Two new derivatives of Zymomonas mobilis CP4 were isolated from enrichment cultures after 18 months of serial transfer. These new strains were selected for the ability to grow and produce ethanol rapidly on transfer into fresh broth containing ethanol and allyl alcohol. Ethanol production by these strains was examined in batch fermentations under three sets of conditions. Both new derivatives were found to be superior to the parent strain CP4 with respect to the speed and completeness of glucose conversion to ethanol. The best of these, strain YO2, produced 9.5% ethanol (by weight; 11.9% by volume) after 17.4 h compared with 31.8 h for the parent strain CP4. The addition of 1 mM magnesium sulfate improved ethanol production in all three strains. Two factors contributed to the decrease in fermentation time required by the mutants: more rapid growth with minimal lag on subculturing and the retention of higher rates of ethanol production as fermentation proceeded. Alcohol dehydrogenase isozymes were altered in both new strains and no longer catalyzed the oxidation of allyl alcohol into the toxic product acrolein. This loss of allyl alcohol-oxidizing capacity is proposed as a primary factor contributing to increased allyl alcohol resistance, although it is likely that other mutations affecting glycolysis also contribute to the improvement in ethanol production.

  6. Disturbance Increases Microbial Community Diversity and Production in Marine Sediments

    PubMed Central

    Galand, Pierre E.; Lucas, Sabrina; Fagervold, Sonja K.; Peru, Erwan; Pruski, Audrey M.; Vétion, Gilles; Dupuy, Christine; Guizien, Katell

    2016-01-01

    Disturbance strongly impacts patterns of community diversity, yet the shape of the diversity-disturbance relationship remains a matter of debate. The topic has been of interest in theoretical ecology for decades as it has practical implications for the understanding of ecosystem services in nature. One of these processes is the remineralization of organic matter by microorganisms in coastal marine sediments, which are periodically impacted by disturbances across the sediment-water interface. Here we set up an experiment to test the hypothesis that disturbance impacts microbial diversity and function during the anaerobic degradation of organic matter in coastal sediments. We show that during the first 3 weeks of the experiment, disturbance increased both microbial production, derived from the increase in microbial abundance, and diversity of the active fraction of the community. Both community diversity and phylogenetic diversity increased, which suggests that disturbance promoted the cohabitation of ecologically different microorganisms. Metagenome analysis also showed that disturbance increased the relative abundance of genes diagnostic of metabolism associated with the sequential anaerobic degradation of organic matter. However, community composition was not impacted in a systematic way and changed over time. In nature, we can hypothesize that moderate storm disturbances, which impact coastal sediments, promote diverse, and productive communities. These events, rather than altering the decomposition of organic matter, may increase the substrate turnover and, ultimately, remineralization rates. PMID:27994581

  7. Sperm motility under conditions of weightlessness.

    PubMed

    Engelmann, U; Krassnigg, F; Schill, W B

    1992-01-01

    The aim of this study was to determine the differences in motility of frozen and thawed bull spermatozoa under conditions of weightlessness compared with ground conditions. The tests were performed within a series of scientific and technologic experiments under microgravity using sounding rockets in the Technologische Experimente unter Schwerelosigkeit (TEXUS) program launched in Kiruna, North Sweden. Using a computerized sperm motility analyzer, significant differences were found in sperm motility under microgravity compared with sperm under gravitational conditions on earth. Computer analysis showed alterations in straight line and curvilinear velocity, as well as in linearity values. The amount of progressively motile spermatozoa, including all spermatozoa with a velocity > 20 microns/second, increased significantly from 24% +/- 9.5% in the reference test to 49% +/- 7.6% in the microgravity test. In conclusion, there is strong evidence that gravity influences sperm motility.

  8. Mammalian Sperm Motility: Observation and Theory

    NASA Astrophysics Data System (ADS)

    Gaffney, E. A.; Gadêlha, H.; Smith, D. J.; Blake, J. R.; Kirkman-Brown, J. C.

    2011-01-01

    Mammalian spermatozoa motility is a subject of growing importance because of rising human infertility and the possibility of improving animal breeding. We highlight opportunities for fluid and continuum dynamics to provide novel insights concerning the mechanics of these specialized cells, especially during their remarkable journey to the egg. The biological structure of the motile sperm appendage, the flagellum, is described and placed in the context of the mechanics underlying the migration of mammalian sperm through the numerous environments of the female reproductive tract. This process demands certain specific changes to flagellar movement and motility for which further mechanical insight would be valuable, although this requires improved modeling capabilities, particularly to increase our understanding of sperm progression in vivo. We summarize current theoretical studies, highlighting the synergistic combination of imaging and theory in exploring sperm motility, and discuss the challenges for future observational and theoretical studies in understanding the underlying mechanics.

  9. Examining the impacts of increased corn production on ...

    EPA Pesticide Factsheets

    This study demonstrates the value of a coupled chemical transport modeling system for investigating groundwater nitrate contamination responses associated with nitrogen (N) fertilizer application and increased corn production. The coupled Community Multiscale Air Quality Bidirectional and Environmental Policy Integrated Climate modeling system incorporates agricultural management practices and N exchange processes between the soil and atmosphere to estimate levels of N that may volatilize into the atmosphere, re-deposit, and seep or flow into surface and groundwater. Simulated values from this modeling system were used in a land-use regression model to examine associations between groundwater nitrate-N measurements and a suite of factors related to N fertilizer and groundwater nitrate contamination. Multi-variable modeling analysis revealed that the N-fertilizer rate (versus total) applied to irrigated (versus rainfed) grain corn (versus other crops) was the strongest N-related predictor variable of groundwater nitrate-N concentrations. Application of this multi-variable model considered groundwater nitrate-N concentration responses under two corn production scenarios. Findings suggest that increased corn production between 2002 and 2022 could result in 56% to 79% increase in areas vulnerable to groundwater nitrate-N concentrations ≥ 5 mg/L. These above-threshold areas occur on soils with a hydraulic conductivity 13% higher than the rest of the domain. Additio

  10. Insulin affects sperm capacity in pig through nitric oxide.

    PubMed

    Aquila, Saveria; Giordano, Francesca; Guido, Carmela; Rago, Vittoria; Carpino, Amalia

    2013-11-01

    Insulin (Ins) has recently been demonstrated to have the ability to induce the capacitation process in pig spermatozoa. In various mammalian species, capacitation has been linked to the nitric oxide (NO) signalling; therefore, this study investigated NO production in Ins-treated pig spermatozoa by fluorescence-activated cell sorting. For the same samples, sperm capacitation was evaluated by chlortetracycline staining, protein tyrosine phosphorylation pattern and acrosomal status. A significant increase of the intrasperm NO level and the activation of three capacitation indices were detected in response to Ins treatment. Conversely, sperm preincubation with an NO synthase inhibitor (N-nitro-L-arginine methyl ester) or with the anti-Ins receptor β (IRβ) antibody reversed all of the Ins-related effects. These results suggest that Ins has the capacity to enhance intracellular NO concentrations in pig spermatozoa and indicate a possible NO implication upon Ins promotion of capacitation.

  11. Speract, a sea urchin egg peptide that regulates sperm motility, also stimulates sperm mitochondrial metabolism.

    PubMed

    García-Rincón, Juan; Darszon, Alberto; Beltrán, Carmen

    2016-04-01

    Sea urchin sperm have only one mitochondrion, that in addition to being the main source of energy, may modulate intracellular Ca(2+) concentration ([Ca(2+)]i) to regulate their motility and possibly the acrosome reaction. Speract is a decapeptide from the outer jelly layer of the Strongylocentrotus purpuratus egg that upon binding to its receptor in the sperm, stimulates sperm motility, respiration and ion fluxes, among other physiological events. Altering the sea urchin sperm mitochondrial function with specific inhibitors of this organelle, increases [Ca(2+)]i in an external Ca(2+) concentration ([Ca(2+)]ext)-dependent manner (Ardón, et al., 2009. BBActa 1787: 15), suggesting that the mitochondrion is involved in sperm [Ca(2+)]i homeostasis. To further understand the interrelationship between the mitochondrion and the speract responses, we measured mitochondrial membrane potential (ΔΨ) and NADH levels. We found that the stimulation of sperm with speract depolarizes the mitochondrion and increases the levels of NADH. Surprisingly, these responses are independent of external Ca(2+) and are due to the increase in intracellular pH (pHi) induced by speract. Our findings indicate that speract, by regulating pHi, in addition to [Ca(2+)]i, may finely modulate mitochondrial metabolism to control motility and ensure that sperm reach the egg and fertilize it.

  12. Assay of sperm motility to study the effects of metal ions

    SciTech Connect

    Timourian, H.; Watchmaker, G.

    1984-01-01

    A method for quantitating sperm motility is applied here to study the effects of metal ions on animal cells. The quantitative technique is based on orienting sperm by subjecting them to flow and then measuring their capacity for returning to randomness when the orienting force is discontinued. The optical anisotropy of sperm permits determination of orientation with a spectrophotometer equipped with a flow cell. A wide range of concentrations of zinc, copper, and nickel ions were tested to determine their effects on the motility of sea-urchin sperm. Sea urchins are a ready and convenient source of sperm. Since energy production in sperm depends on their limited supply of endogenous substrate, this test system gives us a simple screening procedure for comparing the effects of various agents on the cell's capacity for utilizing energy. Nickel at concentrations higher than 10..pi../sup 5/M had an initial depressing effect on motility; however, this effect was eventually overcome, and in some cases overcompensation resulted in an increase motility. Zinc had either an enhancing or a depressing effect, depending not only on its concentration but on the time of exposure. At 10/sup -5/M it enhanced motility if present at the time the sperm were first shed in seawater, the time of high respiration. At 10..pi../sup 4/M it depressed motility only if present during the period of decreasing respiration, 1 to 2 hr after being shed into seawater. Copper depressed activity at 10..pi../sup 4/M to 10..pi../sup 6/M at all times tested.

  13. Elemental composition of human semen is associated with motility and genomic sperm defects among older men

    PubMed Central

    Schmid, Thomas E.; Grant, Patrick G.; Marchetti, Francesco; Weldon, Rosana H.; Eskenazi, Brenda; Wyrobek, Andrew J.

    2013-01-01

    BACKGROUND Older men tend to have poorer semen quality and are generally at higher risks for infertility and abnormal reproductive outcomes. METHODS We employed proton-induced X-ray emission (PIXE, 3 MeV proton beam) to investigate the concentrations of zinc, copper, calcium, sulfur, chlorine, potassium, titanium, iron and nickel in washed sperm and seminal plasma from non-smoking groups of 10 older men (65–80 years old) and 10 younger men (22–28 years old) who were concurrently assayed for sperm function and genomicly defective sperm. RESULTS The older group showed elevated zinc, copper and calcium in sperm and elevated sulfur in seminal plasma compared with the younger men. The older group also showed reduced motility as well as increased sperm DNA fragmentation, achondroplasia mutations, DNA strand breaks and chromosomal aberrations. Sperm calcium and copper were positively associated with sperm DNA fragmentation (P < 0.03). Seminal sulfur was positively associated with sperm DNA fragmentation and chromosomal aberrations (P < 0.04), and negatively associated with sperm motility (P < 0.05). Sperm calcium was negatively associated with sperm motility, independent of male age (P = 0.01). CONCLUSIONS We identified major differences in elemental concentrations between sperm and seminal plasma and that higher sperm copper, sulfur and calcium are quantitatively associated with poorer semen quality and increased frequencies of genomic sperm defects. PMID:23042799

  14. Increasing native, but not exotic, biodiversity increases aboveground productivity in ungrazed and intensely grazed grasslands.

    PubMed

    Isbell, Forest I; Wilsey, Brian J

    2011-03-01

    Species-rich native grasslands are frequently converted to species-poor exotic grasslands or pastures; however, the consequences of these changes for ecosystem functioning remain unclear. Cattle grazing (ungrazed or intensely grazed once), plant species origin (native or exotic), and species richness (4-species mixture or monoculture) treatments were fully crossed and randomly assigned to plots of grassland plants. We tested whether (1) native and exotic plots exhibited different responses to grazing for six ecosystem functions (i.e., aboveground productivity, light interception, fine root biomass, tracer nitrogen uptake, biomass consumption, and aboveground biomass recovery), and (2) biodiversity-ecosystem functioning relationships depended on grazing or species origin. We found that native and exotic species exhibited different responses to grazing for three of the ecosystem functions we considered. Intense grazing decreased fine root biomass by 53% in exotic plots, but had no effect on fine root biomass in native plots. The proportion of standing biomass consumed by cattle was 16% less in exotic than in native grazed plots. Aboveground biomass recovery was 30% less in native than in exotic plots. Intense grazing decreased aboveground productivity by 25%, light interception by 14%, and tracer nitrogen uptake by 54%, and these effects were similar in native and exotic plots. Increasing species richness from one to four species increased aboveground productivity by 42%, and light interception by 44%, in both ungrazed and intensely grazed native plots. In contrast, increasing species richness did not influence biomass production or resource uptake in ungrazed or intensely grazed exotic plots. These results suggest that converting native grasslands to exotic grasslands or pastures changes ecosystem structure and processes, and the relationship between biodiversity and ecosystem functioning.

  15. Breeding technologies to increase crop production in a changing world.

    PubMed

    Tester, Mark; Langridge, Peter

    2010-02-12

    To feed the several billion people living on this planet, the production of high-quality food must increase with reduced inputs, but this accomplishment will be particularly challenging in the face of global environmental change. Plant breeders need to focus on traits with the greatest potential to increase yield. Hence, new technologies must be developed to accelerate breeding through improving genotyping and phenotyping methods and by increasing the available genetic diversity in breeding germplasm. The most gain will come from delivering these technologies in developing countries, but the technologies will have to be economically accessible and readily disseminated. Crop improvement through breeding brings immense value relative to investment and offers an effective approach to improving food security.

  16. Novel Flow Cytometry Analyses of Boar Sperm Viability: Can the Addition of Whole Sperm-Rich Fraction Seminal Plasma to Frozen-Thawed Boar Sperm Affect It?

    PubMed Central

    Díaz, Rommy; Boguen, Rodrigo; Martins, Simone Maria Massami Kitamura; Ravagnani, Gisele Mouro; Leal, Diego Feitosa; Oliveira, Melissa de Lima; Muro, Bruno Bracco Donatelli; Parra, Beatriz Martins; Meirelles, Flávio Vieira; Papa, Frederico Ozanan; Dell’Aqua, José Antônio; Alvarenga, Marco Antônio; Moretti, Aníbal de Sant’Anna; Sepúlveda, Néstor

    2016-01-01

    Boar semen cryopreservation remains a challenge due to the extension of cold shock damage. Thus, many alternatives have emerged to improve the quality of frozen-thawed boar sperm. Although the use of seminal plasma arising from boar sperm-rich fraction (SP-SRF) has shown good efficacy; however, the majority of actual sperm evaluation techniques include a single or dual sperm parameter analysis, which overrates the real sperm viability. Within this context, this work was performed to introduce a sperm flow cytometry fourfold stain technique for simultaneous evaluation of plasma and acrosomal membrane integrity and mitochondrial membrane potential. We then used the sperm flow cytometry fourfold stain technique to study the effect of SP-SRF on frozen-thawed boar sperm and further evaluated the effect of this treatment on sperm movement, tyrosine phosphorylation and fertility rate (FR). The sperm fourfold stain technique is accurate (R2 = 0.9356, p > 0.01) for simultaneous evaluation of plasma and acrosomal membrane integrity and mitochondrial membrane potential (IPIAH cells). Centrifugation pre-cryopreservation was not deleterious (p > 0.05) for any analyzed variables. Addition of SP-SRF after cryopreservation was able to improve total and progressive motility (p < 0.05) when boar semen was cryopreserved without SP-SRF; however, it was not able to decrease tyrosine phosphorylation (p > 0.05) or improve IPIAH cells (p > 0.05). FR was not (p > 0.05) statistically increased by the addition of seminal plasma, though females inseminated with frozen-thawed boar semen plus SP-SRF did perform better than those inseminated with sperm lacking seminal plasma. Thus, we conclude that sperm fourfold stain can be used to simultaneously evaluate plasma and acrosomal membrane integrity and mitochondrial membrane potential, and the addition of SP-SRF at thawed boar semen cryopreserved in absence of SP-SRF improve its total and progressive motility. PMID:27529819

  17. Engineering electron metabolism to increase ethanol production in Clostridium thermocellum

    DOE PAGES

    Lo, Jonathan; Olson, Daniel G.; Murphy, Sean Jean-Loup; ...

    2016-10-28

    Here, the NfnAB (NADH-dependent reduced ferredoxin:NADP+ oxidoreductase) and Rnf (Rhodobacter nitrogen fixation) complexes are thought to catalyze electron transfer between reduced ferredoxin and NAD(P)+. Efficient electron flux is critical for engineering fuel production pathways, but little is known about the relative importance of these enzymes in vivo. In this study we investigate the importance of the NfnAB and Rnf complexes in Clostridium thermocellum for growth on cellobiose and Avicel using gene deletion, enzyme assays, and fermentation product analysis. The NfnAB complex does not seem to play a major role in metabolism, since deletion of nfnAB genes had little effect onmore » the distribution of fermentation products. By contrast, the Rnf complex appears to play an important role in ethanol formation. Deletion of rnf genes resulted in a decrease in ethanol formation. Overexpression of rnf genes resulted in an increase in ethanol production of about 30%, but only in strains where the hydG hydrogenase maturation gene was also deleted.« less

  18. Engineering electron metabolism to increase ethanol production in Clostridium thermocellum

    SciTech Connect

    Lo, Jonathan; Olson, Daniel G.; Murphy, Sean Jean-Loup; Tian, Liang; Hon, Shuen; Lanahan, Anthony; Guss, Adam M.; Lynd, Lee R.

    2016-10-28

    Here, the NfnAB (NADH-dependent reduced ferredoxin:NADP+ oxidoreductase) and Rnf (Rhodobacter nitrogen fixation) complexes are thought to catalyze electron transfer between reduced ferredoxin and NAD(P)+. Efficient electron flux is critical for engineering fuel production pathways, but little is known about the relative importance of these enzymes in vivo. In this study we investigate the importance of the NfnAB and Rnf complexes in Clostridium thermocellum for growth on cellobiose and Avicel using gene deletion, enzyme assays, and fermentation product analysis. The NfnAB complex does not seem to play a major role in metabolism, since deletion of nfnAB genes had little effect on the distribution of fermentation products. By contrast, the Rnf complex appears to play an important role in ethanol formation. Deletion of rnf genes resulted in a decrease in ethanol formation. Overexpression of rnf genes resulted in an increase in ethanol production of about 30%, but only in strains where the hydG hydrogenase maturation gene was also deleted.

  19. How nematode sperm crawl.

    PubMed

    Bottino, Dean; Mogilner, Alexander; Roberts, Tom; Stewart, Murray; Oster, George

    2002-01-15

    Sperm of the nematode, Ascaris suum, crawl using lamellipodial protrusion, adhesion and retraction, a process analogous to the amoeboid motility of other eukaryotic cells. However, rather than employing an actin cytoskeleton to generate locomotion, nematode sperm use the major sperm protein (MSP). Moreover, nematode sperm lack detectable molecular motors or the battery of actin-binding proteins that characterize actin-based motility. The Ascaris system provides a simple 'stripped down' version of a crawling cell in which to examine the basic mechanism of cell locomotion independently of other cellular functions that involve the cytoskeleton. Here we present a mechanochemical analysis of crawling in Ascaris sperm. We construct a finite element model wherein (a) localized filament polymerization and bundling generate the force for lamellipodial extension and (b) energy stored in the gel formed from the filament bundles at the leading edge is subsequently used to produce the contraction that pulls the rear of the cell forward. The model reproduces the major features of crawling sperm and provides a framework in which amoeboid cell motility can be analyzed. Although the model refers primarily to the locomotion of nematode sperm, it has important implications for the mechanics of actin-based cell motility.

  20. Industrial Assessment Centers - Small Manufacturers Reduce Energy & Increase Productivity

    SciTech Connect

    2015-11-06

    Since 1976, the Industrial Assessment Centers (IACs), administered by the US Department of Energy, have supported small and medium-sized American manufacturers to reduce energy use and increase their productivity and competitiveness. The 24 IACs, located at premier engineering universities around the country (see below), send faculty and engineering students to local small and medium-sized manufacturers to provide no-cost assessments of energy use, process performance and waste and water flows. Under the direction of experienced professors, IAC engineering students analyze the manufacturer’s facilities, energy bills and energy, waste and water systems, including compressed air, motors/pumps, lighting, process heat and steam. The IACs then follow up with written energy-saving and productivity improvement recommendations, with estimates of related costs and payback periods.

  1. Wind Power Ramping Product for Increasing Power System Flexibility

    SciTech Connect

    Cui, Mingjian; Zhang, Jie; Wu, Hongyu; Hodge, Bri-Mathias; Ke, Deping; Sun, Yuanzhang

    2016-05-05

    With increasing penetrations of wind power, system operators are concerned about a potential lack of system flexibility and ramping capacity in real-time dispatch stages. In this paper, a modified dispatch formulation is proposed considering the wind power ramping product (WPRP). A swinging door algorithm (SDA) and dynamic programming are combined and used to detect WPRPs in the next scheduling periods. The detected WPRPs are included in the unit commitment (UC) formulation considering ramping capacity limits, active power limits, and flexible ramping requirements. The modified formulation is solved by mixed integer linear programming. Numerical simulations on a modified PJM 5-bus System show the effectiveness of the model considering WPRP, which not only reduces the production cost but also does not affect the generation schedules of thermal units.

  2. Arctic foxes as ecosystem engineers: increased soil nutrients lead to increased plant productivity on fox dens.

    PubMed

    Gharajehdaghipour, Tazarve; Roth, James D; Fafard, Paul M; Markham, John H

    2016-04-05

    Top predators can provide fundamental ecosystem services such as nutrient cycling, and their impact can be even greater in environments with low nutrients and productivity, such as Arctic tundra. We estimated the effects of Arctic fox (Vulpes lagopus) denning on soil nutrient dynamics and vegetation production near Churchill, Manitoba in June and August 2014. Soils from fox dens contained higher nutrient levels in June (71% more inorganic nitrogen, 1195% more extractable phosphorous) and in August (242% more inorganic nitrogen, 191% more extractable phosphorous) than adjacent control sites. Inorganic nitrogen levels decreased from June to August on both dens and controls, whereas extractable phosphorous increased. Pup production the previous year, which should enhance nutrient deposition (from urine, feces, and decomposing prey), did not affect soil nutrient concentrations, suggesting the impact of Arctic foxes persists >1 year. Dens supported 2.8 times greater vegetation biomass in August, but δ(15)N values in sea lyme grass (Leymus mollis) were unaffected by denning. By concentrating nutrients on dens Arctic foxes enhance nutrient cycling as an ecosystem service and thus engineer Arctic ecosystems on local scales. The enhanced productivity in patches on the landscape could subsequently affect plant diversity and the dispersion of herbivores on the tundra.

  3. Arctic foxes as ecosystem engineers: increased soil nutrients lead to increased plant productivity on fox dens

    NASA Astrophysics Data System (ADS)

    Gharajehdaghipour, Tazarve; Roth, James D.; Fafard, Paul M.; Markham, John H.

    2016-04-01

    Top predators can provide fundamental ecosystem services such as nutrient cycling, and their impact can be even greater in environments with low nutrients and productivity, such as Arctic tundra. We estimated the effects of Arctic fox (Vulpes lagopus) denning on soil nutrient dynamics and vegetation production near Churchill, Manitoba in June and August 2014. Soils from fox dens contained higher nutrient levels in June (71% more inorganic nitrogen, 1195% more extractable phosphorous) and in August (242% more inorganic nitrogen, 191% more extractable phosphorous) than adjacent control sites. Inorganic nitrogen levels decreased from June to August on both dens and controls, whereas extractable phosphorous increased. Pup production the previous year, which should enhance nutrient deposition (from urine, feces, and decomposing prey), did not affect soil nutrient concentrations, suggesting the impact of Arctic foxes persists >1 year. Dens supported 2.8 times greater vegetation biomass in August, but δ15N values in sea lyme grass (Leymus mollis) were unaffected by denning. By concentrating nutrients on dens Arctic foxes enhance nutrient cycling as an ecosystem service and thus engineer Arctic ecosystems on local scales. The enhanced productivity in patches on the landscape could subsequently affect plant diversity and the dispersion of herbivores on the tundra.

  4. Arctic foxes as ecosystem engineers: increased soil nutrients lead to increased plant productivity on fox dens

    PubMed Central

    Gharajehdaghipour, Tazarve; Roth, James D.; Fafard, Paul M.; Markham, John H.

    2016-01-01

    Top predators can provide fundamental ecosystem services such as nutrient cycling, and their impact can be even greater in environments with low nutrients and productivity, such as Arctic tundra. We estimated the effects of Arctic fox (Vulpes lagopus) denning on soil nutrient dynamics and vegetation production near Churchill, Manitoba in June and August 2014. Soils from fox dens contained higher nutrient levels in June (71% more inorganic nitrogen, 1195% more extractable phosphorous) and in August (242% more inorganic nitrogen, 191% more extractable phosphorous) than adjacent control sites. Inorganic nitrogen levels decreased from June to August on both dens and controls, whereas extractable phosphorous increased. Pup production the previous year, which should enhance nutrient deposition (from urine, feces, and decomposing prey), did not affect soil nutrient concentrations, suggesting the impact of Arctic foxes persists >1 year. Dens supported 2.8 times greater vegetation biomass in August, but δ15N values in sea lyme grass (Leymus mollis) were unaffected by denning. By concentrating nutrients on dens Arctic foxes enhance nutrient cycling as an ecosystem service and thus engineer Arctic ecosystems on local scales. The enhanced productivity in patches on the landscape could subsequently affect plant diversity and the dispersion of herbivores on the tundra. PMID:27045973

  5. Improvements of soil quality for increased food production in Norway

    NASA Astrophysics Data System (ADS)

    Øygarden, Lillian; Klakegg, Ove; Børresen, Trond; Krogstad, Tore; Kjersti Uhlen, Anne

    2016-04-01

    Since the 1990ties, agricultural land in use in Norway has diminished and yields per hectare for cereals and forages have stagnated. An expert panel appointed to advice on how to increase Norwegian grain production emphasizes low profitability and poor soil quality as limiting factors. A White Paper from the Norwegian Government, Report No.9 (2011-2012), stated that the main goal for the agricultural sector is to increase food production proportional to the expected increase in population (20 % by 2030) in order to maintain self-sufficiency at the present level. This is the background for the interdisciplinary project AGROPRO "Agronomy for increased food production - Challenges and solutions" (2013 - 2017)" financed by the Norwegian research council. A mail goal is seeking possibilities for improvements in agronomic practices for increased and sustainable food production and to identify drivers and challenges for their implementation. Are the key to higher yields hidden in the soil? The paper present an overview of the research activities in the project and some results of the improvements of soil quality to minimize yield gap in cereal and forage production. Detailed new soil maps provide soil information on field scale of soil quality and the suitability for growing different crops like cereal production or vegetables. The detailed soil information is also beeing used for development and adaptation of the planning tool «Terranimo» to reduce risk of soil compaction.The farmer get available soil information for each field, provide information about the maschinery in use- tractors and equipment, tyres, pressure. The decision tool evaluate when the soil is suitable for tillage, calculate the risk of compaction for dry, moist and wet soil. New research data for compaction on Norwegian clay and silt soil are included. Climate change with wetter conditions gives challenges for growing cereals. The project is testing genetic variation in cereals for tolerance to water

  6. Sperm cryopreservation of a live-bearing fish, Xiphophorus couchianus: male-to-male variation in post-thaw motility and production of F(1) hybrid offspring.

    PubMed

    Yang, Huiping; Hazlewood, Leona; Walter, Ronald B; Tiersch, Terrence R

    2009-03-01

    Fishes of the genus Xiphophorus are well-studied biomedical research models, and some species, such as X. couchianus, are currently listed as endangered in the wild. Sperm cryopreservation in these live-bearing fishes has begun recently. Thus far, live young have been produced with cryopreserved sperm only in one species (Xiphophorus helleri). In this study, the goal was to develop a practical protocol for sperm cryopreservation of Xiphophorus couchianus, and to produce live young with cryopreserved sperm. Sperm were collected by crushing of testis in Hanks' balanced salt solution at an osmolality of 500 mOsmol/kg (HBSS500), and were cryopreserved with 14% glycerol (v/v) as cryoprotectant at a cooling rate of 20 degrees C/min from 5 to -80 degrees C in 250-microL French straws. For artificial insemination, samples were thawed at 40 degrees C for 5 s in a water bath, washed once using fresh HBSS500 by centrifuging at 1000 g for 5 min at 4 degrees C, concentrated into approximately 5 microL, and injected into virgin females of Xiphophorus maculatus. The inseminated females were monitored for 90 days for subsequent discharge of live young. Results from 2006 and 2007 showed considerable male-to-male variation in post-thaw motility (from 1 to 70%). Offspring were produced by cryopreserved sperm in two tanks (of three) at 36 and 66 days after insemination in 2007. Paternity was confirmed via phenotypes (body color) and genotypes (microsatellite genetic marker) of the hybrid offspring. Overall, a practical protocol for sperm cryopreservation and artificial insemination is provided to preserve X. couchianus, which is an important biomedical research model, and also currently listed as an endangered species in the International Union for Conservation of Nature (IUCN) red list.

  7. Membrane hyperpolarization during human sperm capacitation

    PubMed Central

    López-González, I.; Torres-Rodríguez, P.; Sánchez-Carranza, O.; Solís-López, A.; Santi, C.M.; Darszon, A.; Treviño, C.L.

    2014-01-01

    Sperm capacitation is a complex and indispensable physiological process that spermatozoa must undergo in order to acquire fertilization capability. Spermatozoa from several mammalian species, including mice, exhibit a capacitation-associated plasma membrane hyperpolarization, which is necessary for the acrosome reaction to occur. Despite its importance, this hyperpolarization event has not been adequately examined in human sperm. In this report we used flow cytometry to show that a subpopulation of human sperm indeed undergo a plasma membrane hyperpolarization upon in vitro capacitation. This hyperpolarization correlated with two other well-characterized capacitation parameters, namely an increase in intracellular pH and Ca2+ concentration, measured also by flow cytometry. We found that sperm membrane hyperpolarization was completely abolished in the presence of a high external K+ concentration (60 mM), indicating the participation of K+ channels. In order to identify, which of the potential K+ channels were involved in this hyperpolarization, we used different K+ channel inhibitors including charybdotoxin, slotoxin and iberiotoxin (which target Slo1) and clofilium (a more specific blocker for Slo3). All these K+ channel antagonists inhibited membrane hyperpolarization to a similar extent, suggesting that both members of the Slo family may potentially participate. Two very recent papers recorded K+ currents in human sperm electrophysiologically, with some contradictory results. In the present work, we show through immunoblotting that Slo3 channels are present in the human sperm membrane. In addition, we found that human Slo3 channels expressed in CHO cells were sensitive to clofilium (50 μM). Considered altogether, our data indicate that Slo1 and Slo3 could share the preponderant role in the capacitation-associated hyperpolarization of human sperm in contrast to what has been previously reported for mouse sperm, where Slo3 channels are the main contributors to the

  8. Sperm DNA oxidative damage and DNA adducts

    PubMed Central

    Jeng, Hueiwang Anna; Pan, Chih-Hong; Chao, Mu-Rong; Lin, Wen-Yi

    2015-01-01

    The objective of this study was to investigate DNA damage and adducts in sperm from coke oven workers who have been exposed to polycyclic aromatic hydrocarbons. A longitudinal study was conducted with repeated measurements during spermatogenesis. Coke-oven workers (n=112) from a coke-oven plant served the PAH-exposed group, while administrators and security personnel (n=67) served the control. Routine semen parameters (concentration, motility, vitality, and morphology) were analyzed simultaneously; the assessment of sperm DNA integrity endpoints included DNA fragmentation, bulky DNA adducts, and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxo-dGuo). The degree of sperm DNA fragmentation was measured using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and sperm chromatin structure assay (SCSA). The PAH-exposed group had a significant increase in bulky DNA adducts and 8-oxo-dGuo compared to the control subjects (Ps = 0.002 and 0.045, respectively). Coke oven workers' percentages of DNA fragmentation and denaturation from the PAH-exposed group were not significantly different from those of the control subjects (Ps = 0.232 and 0.245, respectively). Routine semen parameters and DNA integrity endpoints were not correlated. Concentrations of 8-oxo-dGuo were positively correlated with percentages of DNA fragmentation measured by both TUNEL and SCSA (Ps = 0.045 and 0.034, respectively). However, the concentrations of 8-oxo-dGuo and percentages of DNA fragmentation did not correlate with concentrations of bulky DNA adducts. In summary, coke oven workers with chronic exposure to PAHs experienced decreased sperm DNA integrity. Oxidative stress could contribute to the degree of DNA fragmentation. Bulky DNA adducts may be independent of the formation of DNA fragmentation and oxidative adducts in sperm. Monitoring sperm DNA integrity is recommended as a part of the process of assessing the impact of occupational and environmental toxins on

  9. Sperm navigation in complex environments

    NASA Astrophysics Data System (ADS)

    Olson, Sarah

    2016-11-01

    Sperm can swim in a variety of environments, interacting with chemicals and other proteins in the fluid. Some of these extra proteins or cells may act as friction, possibly preventing or enhancing forward progression of swimmers. The homogenized fluid flow is assumed to be governed by the incompressible Brinkman equation, where a friction term with a resistance parameter represents a sparse array of obstacles. Representing the swimmers with a centerline approximation, we employ regularized fundamental solutions to investigate swimming speeds, trajectories, and interactions of swimmers. Asymmetric waveforms due to an increase in flagellar calcium is known to be important for sperm to reach and fertilize the egg. The trajectories of hyperactivated swimmers are found to have a decreased path curvature. Although attraction of two swimmers is more efficient in the Stokes regime, we find that attraction does not occur for larger resistance. Additionally, we study interactions of swimmers in a channel. NSF DMS 1413110.

  10. Protein kinase C activity in boar sperm.

    PubMed

    Teijeiro, J M; Marini, P E; Bragado, M J; Garcia-Marin, L J

    2017-03-01

    Male germ cells undergo different processes within the female reproductive tract to successfully fertilize the oocyte. These processes are triggered by different extracellular stimuli leading to activation of protein phosphorylation. Protein kinase C (PKC) is a key regulatory enzyme in signal transduction mechanisms involved in many cellular processes. Studies in boar sperm demonstrated a role for PKC in the intracellular signaling involved in motility and cellular volume regulation. Experiments using phorbol 12-myristate 13-acetate (PMA) showed increases in the Serine/Threonine phosphorylation of substrates downstream of PKC in boar sperm. In order to gain knowledge about those cellular processes regulated by PKC, we evaluate the effects of PMA on boar sperm motility, lipid organization of plasma membrane, integrity of acrosome membrane and sperm agglutination. Also, we investigate the crosstalk between PKA and PKC intracellular pathways in spermatozoa from this species. The results presented here reveal a participation of PKC in sperm motility regulation and membrane fluidity changes, which is probably associated to acrosome reaction and to agglutination. Also, we show the existence of a hierarchy in the kinases pathway. Previous works on boar sperm suggest a pathway in which PKA is positioned upstream to PKC and this new results support such model.

  11. Essential Role of CFTR in PKA-Dependent Phosphorylation, Alkalinization, and Hyperpolarization During Human Sperm Capacitation.

    PubMed

    Puga Molina, Lis C; Pinto, Nicolás A; Torres Rodríguez, Paulina; Romarowski, Ana; Vicens Sanchez, Alberto; Visconti, Pablo E; Darszon, Alberto; Treviño, Claudia L; Buffone, Mariano G

    2017-06-01

    Mammalian sperm require to spend a limited period of time in the female reproductive tract to become competent to fertilize in a process called capacitation. It is well established that HCO3(-) is essential for capacitation because it activates the atypical soluble adenylate cyclase ADCY10 leading to cAMP production, and promotes alkalinization of cytoplasm, and membrane hyperpolarization. However, how HCO3(-) is transported into the sperm is not well understood. There is evidence that CFTR activity is involved in the human sperm capacitation but how this channel is integrated in the complex signaling cascades associated with this process remains largely unknown. In the present work, we have analyzed the extent to which CFTR regulates different events in human sperm capacitation. We observed that inhibition of CFTR affects HCO3(-) -entrance dependent events resulting in lower PKA activity. CFTR inhibition also affected cAMP/PKA-downstream events such as the increase in tyrosine phosphorylation, hyperactivated motility, and acrosome reaction. In addition, we demonstrated for the first time, that CFTR and PKA activity are essential for the regulation of intracellular pH, and membrane potential in human sperm. Addition of permeable cAMP partially recovered all the PKA-dependent events altered in the presence of inh-172 which is consistent with a role of CFTR upstream of PKA activation. J. Cell. Physiol. 232: 1404-1414, 2017. © 2016 Wiley Periodicals, Inc.

  12. Increased production of nutriments by genetically engineered crops.

    PubMed

    Sévenier, Robert; van der Meer, Ingrid M; Bino, Raoul; Koops, Andries J

    2002-06-01

    Plants are the basis of human nutrition and have been selected and improved to assure this purpose. Nowadays, new technologies such as genetic engineering and genomics approaches allow further improvement of plants. We describe here three examples for which these techniques have been employed. We introduced the first enzyme involved in fructan synthesis, the sucrose sucrose fructosyltransferase (isolated from Jerusalem artichoke), into sugar beet. The transgenic sugar beet showed a dramatic change in the nature of the accumulated sugar, 90% of the sucrose being converted into fructan. The use of transgenic sugar beet for the production and isolation of fructans will result in a more efficient plant production system of fructans and should promote their use in human food. The second example shows how the over-expression of the key enzyme of flavonoid biosynthesis could increase anti-oxidant levels in tomato. Introduction of a highly expressed chalcone isomerase led to a seventyfold increase of the amount of quercetin glucoside, which is a strong anti-oxidant in tomato. We were also able to modify the essential amino acid content of potato in order to increase its nutritional value. The introduction of a feedback insensitive bacterial gene involved in biosynthesis of aspartate family amino acids led to a sixfold increase of the lysine content. Because the use of a bacterial gene could appear to be controversial, we also introduced a mutated form of the plant key enzyme of lysine biosynthesis (dihydrodipicolinate synthase) in potato. This modification led to a 15 times increase of the lysine content of potato. This increase of the essential amino acid lysine influences the nutritional value of potato, which normally has low levels of several essential amino acids. These three examples show how the metabolism of primary constituents of the plant cell such as sugar or amino acids, but also of secondary metabolites such as flavonoids, can be modified by genetic

  13. Direct visualization of sperm competition and sperm storage in Drosophila.

    PubMed

    Civetta, A

    Drosophila females engage in multiple matings [1] [2] [3] [4] even though they can store sperm in specialized organs for most of their life [5]. The existence of sperm competition in Drosophila has been inferred from the proportion of progeny sired by the second male in double-mating experiments [6] [7] [8]. Investigators have used this approach to quantify genetic variation underlying sperm competition [8] [9] [10], to elucidate its genetic basis [11], to identify the dependence of different male competitive ability on the genotype of the females with which they mate [12] and to discern the potential role of sperm competition in species isolation [13] [14]. This approach assumes that the sperm from two males stored in a female compete to fertilize the eggs. The mechanism by which sperm competition is accomplished is still unknown, however. Here, fluorescence microscopy, cytometry, and differently labeled sperm were used to analyze the fate of sperm inside the female's sperm storage organs, to quantify sperm competition, and to assess how closely paternity success corresponds to the appearance and location of the sperm. The results show that the first male's sperm is retained for a shortened period if the female remates, and that the second males that sire more progeny either induce females to store and use more of their sperm or strongly displace resident sperm.

  14. One-sided ejaculation of echidna sperm bundles.

    PubMed

    Johnston, S D; Smith, B; Pyne, M; Stenzel, D; Holt, W V

    2007-12-01

    We report for the first time an unusual ejaculatory mechanism in the short-beaked echidna in which each side of the bilaterally symmetrical, rosettelike glans penis is used alternately, with the other being shut down. This is unparalleled in mammals but is reminiscent of the use of hemipenes in squamate reptiles, providing further reproductive evidence of a sauropsidian lineage in the Monotremata. Further, we describe the occurrence of motile sperm bundles in ejaculated echidna semen and provide scanning electron micrographs of their morphology. Sperm bundling appears to confer increased sperm motility, which may provide the potential for sperm competition between males.

  15. Fenitrothion induced oxidative stress and morphological alterations of sperm and testes in male sprague-dawley rats

    PubMed Central

    Taib, Izatus Shima; Budin, Siti Balkis; Ghazali, Ahmad Rohi; Jayusman, Putri Ayu; Louis, Santhana Raj; Mohamed, Jamaludin

    2013-01-01

    OBJECTIVE: Fenitrothion residue is found primarily in soil, water and food products and can lead to a variety of toxic effects on the immune, hepatobiliary and hematological systems. However, the effects of fenitrothion on the male reproductive system remain unclear. This study aimed to evaluate the effects of fenitrothion on the sperm and testes of male Sprague-Dawley rats. METHODS: A 20 mg/kg dose of fenitrothion was administered orally by gavages for 28 consecutive days. Blood sample was obtained by cardiac puncture and dissection of the testes and cauda epididymis was performed to obtain sperm. The effects of fenitrothion on the body and organ weight, biochemical and oxidative stress, sperm characteristics, histology and ultrastructural changes in the testes were evaluated. RESULTS: Fenitrothion significantly decreased the body weight gain and weight of the epididymis compared with the control group. Fenitrothion also decreased plasma cholinesterase activity compared with the control group. Fenitrothion altered the sperm characteristics, such as sperm concentration, sperm viability and normal sperm morphology, compared with the control group. Oxidative stress markers, such as malondialdehyde, protein carbonyl, total glutathione and glutathione S-transferase, were significantly increased and superoxide dismutase activity was significantly decreased in the fenitrothion-treated group compared with the control group. The histopathological and ultrastructural examination of the testes of the fenitrothion-treated group revealed alterations corresponding with the biochemical changes compared with the control group. CONCLUSION: A 20 mg/kg dose of fenitrothion caused deleterious effects on the sperm and testes of Sprague-Dawley rats. PMID:23420164

  16. The healthy men study: an evaluation of exposure to disinfection by-products in tap water and sperm quality

    EPA Science Inventory

    BACKGROUND: Chlorination of drinking water generates disinfection by-products (DBPs), which have been shown to disrupt spermatogenesis in rodents at high doses, suggesting that DBPs could pose a reproductive risk to men. In this study we assessed DBP exposure and testicular toxic...

  17. Intracytoplasmic Sperm Injection (ICSI)

    MedlinePlus

    ... to the inside of the egg (cytoplasm), where fertilization takes place. Sometimes the sperm cannot penetrate the ... ICSI) can be done along with in vitro fertilization (IVF) to help fertilize the egg. During ICSI, ...

  18. Exposure to endosulfan influences sperm competition in Drosophila melanogaster

    PubMed Central

    Misra, Snigdha; Kumar, Ajay; Ratnasekhar, Ch.; Sharma, Vandana; Mudiam, Mohana Krishna Reddy; Ram, Kristipati Ravi

    2014-01-01

    Dwindling male fertility due to xenobiotics is of global concern. Accordingly, male reproductive toxicity assessment of xenobiotics through semen quality analysis in exposed males, and examining progeny production of their mates is critical. These assays, in part, are biased towards monogamy. Females soliciting multiple male partners (polyandry) is the norm in many species. Polyandry incites sperm competition and allows females to bias sperm use. However, consequences of xenobiotic exposure to the sperm in the light of sperm competition remain to be understood. Therefore, we exposed Drosophila melanogaster males to endosulfan, and evaluated their progeny production as well as the ability of their sperm to counter rival control sperm in the storage organs of females sequentially mated to control/exposed males. Endosulfan (2 μg/ml) had no significant effect on progeny production and on the expression of certain genes associated with reproduction. However, exposed males performed worse in sperm competition, both as 1st and 2nd male competitors. These findings indicate that simple non-competitive measures of reproductive ability may fail to demonstrate the harmful effects of low-level exposure to xenobiotics on reproduction and advocate consideration of sperm competition, as a parameter, in the reproductive toxicity assessment of xenobiotics to mimic situations prevailing in the nature. PMID:25503806

  19. Nutrient cycling by fish supports relatively more primary production as lake productivity increases.

    PubMed

    Vanni, Michael J; Bowling, Anna M; Dickman, Elizabeth M; Hale, R Scott; Higgins, Karen A; Horgan, Martin J; Knoll, Lesley B; Renwick, William H; Stein, Roy A

    2006-07-01

    Animals can be important in nutrient cycling in particular ecosystems, but few studies have examined how this importance varies along environmental gradients. In this study we quantified the nutrient cycling role of an abundant detritivorous fish species, the gizzard shad (Dorosoma cepedianum), in reservoir ecosystems along a gradient of ecosystem productivity. Gizzard shad feed mostly on sediment detritus and excrete sediment-derived nutrients into the water column, thereby mediating a cross-habitat translocation of nutrients to phytoplankton. We quantified nitrogen and phosphorus cycling (excretion) rates of gizzard shad, as well as nutrient demand by phytoplankton, in seven lakes over a four-year period (16 lake-years). The lakes span a gradient of watershed land use (the relative amounts of land used for agriculture vs. forest) and productivity. As the watersheds of these lakes became increasingly dominated by agricultural land, primary production rates, lake trophic state indicators (total phosphorus and chlorophyll concentrations), and nutrient flux through gizzard shad populations all increased. Nutrient cycling by gizzard shad supported a substantial proportion of primary production in these ecosystems, and this proportion increased as watershed agriculture (and ecosystem productivity) increased. In the four productive lakes with agricultural watersheds (>78% agricultural land), gizzard shad supported on average 51% of phytoplankton primary production (range 27-67%). In contrast, in the three relatively unproductive lakes in forested or mixed-land-use watersheds (>47% forest, <52% agricultural land), gizzard shad supported 18% of primary production (range 14-23%). Thus, along a gradient of forested to agricultural landscapes, both watershed nutrient inputs and nutrient translocation by gizzard shad increase, but our data indicate that the importance of nutrient translocation by gizzard shad increases more rapidly. Our results therefore support the

  20. Pregnancy rates in heifers and cows with cryopreserved sexed sperm: effects of sperm numbers per inseminate, sorting pressure and sperm storage before sorting.

    PubMed

    Schenk, J L; Cran, D G; Everett, R W; Seidel, G E

    2009-03-15

    Field trials were conducted to increase fertility with AI of flow-sorted, sexed bovine sperm. In the first trial, a novel competitive fertilization approach was used to compare pressures (30psi vs 50psi) for sorting sperm. Both X- and Y-sperm were sorted to approximately 95% purity at 30 and at 50psi; X-50+Y-30 (and the converse) were mixed in equal numbers for AI of heifers. Fetal sex divulged which treatment produced the pregnancy; 82% of pregnancies resulted from the 30psi treatment (P<0.05). Based on a similar approach, a new-pulsed laser did not damage sperm any more than the previous standard continuous wave laser. In a large field trial, sorting sperm at 40psi increased pregnancy rates in heifers relative to 50psi (42.3% vs 34.1%, n=367/group, P<0.05). Storing sperm for 20h before sorting at 40psi decreased pregnancy rates from 42.3% (n=367) to 36.8% (n=368; P<0.05). Breeding heifers with sexed sperm 55-56h after CIDR removal and PGF(2alpha) resulted in 34% (n=32) pregnant, compared to 49% (n=35) with fixed-time insemination 67-68h after CIDR removal (P>0.1). Lactating dairy cows pre-screened for normal reproductive tracts when OvSynch injections (GnRH, prostaglandin, GnRH) were initiated, had similar (P>0.1) pregnancy rates to timed AI, with 10x10(6) sexed sperm (43.9%, n=57), 2x10(6) sexed sperm (40.5%, n=57) and 10x10(6) unsexed control sperm (55.6%, n=58). A final field trial with unselected, lactating dairy cows resulted in similar pregnancy rates for 2x10(6) sexed sperm in 0.25mL straws (25.0%, n=708) and 0.5mL straws (24.4%, n=776), but lower (P<0.05) than unsexed control sperm (37.7%, n=713). Younger cows and those >84 days in milk had the highest pregnancy rates for both sexed and unsexed sperm. These studies improved sperm sexing procedures, and provided insight into appropriate commercial use of sexed sperm.

  1. Mouse Sperm Membrane Potential Hyperpolarization Is Necessary and Sufficient to Prepare Sperm for the Acrosome Reaction*

    PubMed Central

    De La Vega-Beltran, Jose Luis; Sánchez-Cárdenas, Claudia; Krapf, Darío; Hernandez-González, Enrique O.; Wertheimer, Eva; Treviño, Claudia L.; Visconti, Pablo E.; Darszon, Alberto

    2012-01-01

    Mammalian sperm are unable to fertilize the egg immediately after ejaculation; they acquire this capacity during migration in the female reproductive tract. This maturational process is called capacitation and in mouse sperm it involves a plasma membrane reorganization, extensive changes in the state of protein phosphorylation, increases in intracellular pH (pHi) and Ca2+ ([Ca2+]i), and the appearance of hyperactivated motility. In addition, mouse sperm capacitation is associated with the hyperpolarization of the cell membrane potential. However, the functional role of this process is not known. In this work, to dissect the role of this membrane potential change, hyperpolarization was induced in noncapacitated sperm using either the ENaC inhibitor amiloride, the CFTR agonist genistein or the K+ ionophore valinomycin. In this experimental setting, other capacitation-associated processes such as activation of a cAMP-dependent pathway and the consequent increase in protein tyrosine phosphorylation were not observed. However, hyperpolarization was sufficient to prepare sperm for the acrosome reaction induced either by depolarization with high K+ or by addition of solubilized zona pellucida (sZP). Moreover, K+ and sZP were also able to increase [Ca2+]i in non-capacitated sperm treated with these hyperpolarizing agents but not in untreated cells. On the other hand, in conditions that support capacitation-associated processes blocking hyperpolarization by adding valinomycin and increasing K+ concentrations inhibited the agonist-induced acrosome reaction as well as the increase in [Ca2+]i. Altogether, these results suggest that sperm hyperpolarization by itself is key to enabling mice sperm to undergo the acrosome reaction. PMID:23095755

  2. Influence of bovine sperm DNA fragmentation and oxidative stress on early embryo in vitro development outcome.

    PubMed

    Simões, Renata; Feitosa, Weber Beringui; Siqueira, Adriano Felipe Perez; Nichi, Marcilio; Paula-Lopes, Fabíola Freitas; Marques, Mariana Groke; Peres, Maria Angélica; Barnabe, Valquíria Hyppolito; Visintin, José Antônio; Assumpção, Mayra Elena Ortiz

    2013-01-01

    Sperm chromatin fragmentation may be caused by a number of factors, the most significant of which is reactive oxygen species. However, little is known about the effect of sperm oxidative stress (OS) on DNA integrity, fertilization, and embryonic development in cattle. Therefore, the goal of this study was to evaluate the influence of sperm OS susceptibility on the DNA fragmentation rate and in vitro embryo production (IVP) in a population of bulls. Groups of cryopreserved sperm samples were divided into four groups, based on their susceptibility to OS (G1, low OS; G2, average OS; G3, high OS; and G4, highest OS). Our results demonstrated that the sperm DNA integrity was compromised in response to increased OS susceptibility. Furthermore, semen samples with lower susceptibility to OS were also less susceptible to DNA damage (G1, 4.06%; G2, 6.09%; G3, 6.19%; and G4, 6.20%). In addition, embryo IVP provided evidence that the embryo cleavage rate decreased as the OS increased (G1, 70.18%; G2, 62.24%; G3, 55.85%; and G4, 50.93%), but no significant difference in the blastocyst rate or the number of blastomeres was observed among the groups. The groups with greater sensitivity to OS were also associated with a greater percentage of apoptotic cells (G1, 2.6%; G2, 2.76%; G3, 5.59%; and G4, 4.49%). In conclusion, we demonstrated that an increased susceptibility to OS compromises sperm DNA integrity and consequently reduces embryo quality.

  3. Detection of nerve growth factor (NGF) and its specific receptor (TrkA) in ejaculated bovine sperm, and the effects of NGF on sperm function.

    PubMed

    Li, C; Sun, Y; Yi, K; Ma, Y; Sun, Y; Zhang, W; Zhou, X

    2010-12-01

    The objective was to confirm the presence of nerve growth factor (NGF) and its specific receptor, TrkA, in ejaculated bovine sperm, and to investigate the effects of NGF on specific aspects of bovine sperm function. Both TrkA transcripts and immunoreactivity typical of the translated protein were detected by RT-PCR and western blotting. However, only the NGF protein was detected in bovine sperm using western blotting, and there was no RT-PCR evidence for NGF transcripts in sperm. Using an immunofluorescent technique, NGF-immunoreactivity was localized to the sperm head and tail, whereas that of TrkA was detected in the acrosomal cap, nucleus, and tail regions When sperm were treated with exogenous NGF, both leptin secretion and sperm viability were increased (P < 0.05); moreover, the percentages of late apoptotic and dead sperm were increased (P < 0.05). However, NGF had no effects on insulin secretion, mitochondrial activity, intracellular calcium levels, or the acrosome reaction of sperm (P > 0.05). In conclusion, the presence of TrkA transcript, as well as NGF and TrkA immunoreactivity were confirmed in bovine sperm. Furthermore, exogenous NGF had significant effects on the secretion of leptin, cell viability, and sperm apoptosis. This study provided strong evidence that NGF/TrkA may have roles in regulation of sperm physiology and perhaps male fertility and infertility.

  4. Separation of sperm through a 12-layer percoll column decreases the percentage of sperm staining with quinacrine.

    PubMed

    Check, M L; Bollendorf, A; Check, J H; Hourani, W; Long, R; McMonagle, K

    2000-01-01

    Previous methods of enriching sperm with a higher percentage of Y-bearing sperm have been questioned because the claims that Y enrichment was present were based on quinacrine staining of the Y chromosome, and the enrichment was not confirmed by polymerase chain reaction (PCR) or fluorescent in situ hybridization (FISH) techniques. A technique was evaluated that theoretically could increase the percentage of X-bearing sperm by isolating a fraction of the "heaviest" sperm by passing them through 12 layers of discontinuous Percoll gradient. Initially 12 specimens were checked both before and then after separation with 12 layers of Percoll for percentage of Y sperm. The median for baseline Y percentage was 49% and after processing the percentage of Y dropped to 10%. An additional 19 specimens were checked after separation only. The median was 19%. The sample with the lowest preseparation % of quinacrine staining sperm was 45% and the highest was 54%. After 12-layer Percoll, the lowest percentage was 3% and the highest was 24%. There have been claims that quinacrine staining can falsely increase apparent Y-bearing sperm enrichment following certain separation procedures, e.g.. albumin separation, by nonspecific staining of autosomal chromosomes. If anything, then, it should falsely decrease X-bearing sperm enrichment. Thus, 12-layer Percoll separation may actually enrich for X-bearing sperm or possibly this procedure somehow nonspecifically inhibits the ability of quinacrine to stain the Y chromosome.

  5. Oxidative phosphorylation is essential for felid sperm function, but is substantially lower in cheetah (Acinonyx jubatus) compared to domestic cat (Felis catus) ejaculate.

    PubMed

    Terrell, Kimberly A; Wildt, David E; Anthony, Nicola M; Bavister, Barry D; Leibo, S P; Penfold, Linda M; Marker, Laurie L; Crosier, Adrienne E

    2011-09-01

    Compared with the normospermic domestic cat, sperm metabolic function is compromised in the teratospermic cat and cheetah, but the pathway(s) involved in this deficiency are unknown. Glycolysis is essential for sperm motility, yet it appears to function normally in spermatozoa of either species regardless of structural morphology. We conducted a comparative study to further understand the mechanisms of energy production in felid spermatozoa, with the hypothesis that oxidative phosphorylation is required for normal sperm function and is impaired in teratospermic ejaculates. Electroejaculates from both species were stained with MitoTracker to quantify mitochondrial membrane potential (MMP) or were incubated to assess changes in sperm function (motility, acrosomal integrity, and lactate production) after mitochondrial inhibition with myxothiazol. Sperm midpiece dimensions also were quantified. Sperm mitochondrial fluorescence (directly proportional to MMP) was ~95% lower in the cheetah compared with the normospermic and teratospermic cat, despite the cheetah having a 10% longer midpiece. In both species, MMP was increased 5-fold in spermatozoa with retained cytoplasm compared with structurally normal cells. Inhibition of oxidative phosphorylation impaired sperm function in both species, but a 100-fold higher inhibitor concentration was required in the cat compared with the cheetah. Collectively, findings revealed that oxidative phosphorylation was required for sperm function in the domestic cat and cheetah. This pathway of energy production appeared markedly less active in the cheetah, indicating a species-specific vulnerability to mitochondrial dysfunction. The unexpected, cross-species linkage between retained cytoplasmic droplets and elevated MMP may reflect increased concentrations of metabolic enzymes or substrates in these structures.

  6. Coevolutionary Feedbacks between Female Mating Interval and Male Allocation to Competing Sperm Traits Can Drive Evolution of Costly Polyandry.

    PubMed

    Bocedi, Greta; Reid, Jane M

    2016-03-01

    Complex coevolutionary feedbacks between female mating interval and male sperm traits have been hypothesized to explain the evolution and persistence of costly polyandry. Such feedbacks could potentially arise because polyandry creates sperm competition and consequent selection on male allocation to sperm traits, while the emerging sperm traits could create female sperm limitation and, hence, impose selection for increased polyandry. However, the hypothesis that costly polyandry could coevolve with male sperm dynamics has not been tested. We built a genetically explicit individual-based model to simulate simultaneous evolution of female mating interval and male allocation to sperm number versus longevity, where these two sperm traits trade off. We show that evolution of competing sperm traits under polyandry can indeed cause female sperm limitation and, hence, promote further evolution and persistence of costly polyandry, particularly when sperm are costly relative to the degree of female sperm limitation. These feedbacks were stronger, and greater polyandry evolved, when postcopulatory competition for paternity followed a loaded rather than fair raffle and when sperm traits had realistically low heritability. We therefore demonstrate that the evolution of allocation to sperm traits driven by sperm competition can prevent males from overcoming female sperm limitation, thereby driving ongoing evolution of costly polyandry.

  7. Female promiscuity promotes the evolution of faster sperm in cichlid fishes.

    PubMed

    Fitzpatrick, John L; Montgomerie, Robert; Desjardins, Julie K; Stiver, Kelly A; Kolm, Niclas; Balshine, Sigal

    2009-01-27

    Sperm competition, the contest among ejaculates from rival males to fertilize ova of a female, is a common and powerful evolutionary force influencing ejaculate traits. During competitive interactions between ejaculates, longer and faster spermatozoa are expected to have an edge; however, to date, there has been mixed support for this key prediction from sperm competition theory. Here, we use the spectacular radiation of cichlid fishes from Lake Tanganyika to examine sperm characteristics in 29 closely related species. We provide phylogenetically robust evidence that species experiencing greater levels of sperm competition have faster-swimming sperm. We also show that sperm competition selects for increases in the number, size, and longevity of spermatozoa in the ejaculate of a male, and, contrary to expectations from theory, we find no evidence of trade-offs among sperm traits in an interspecific analysis. Also, sperm swimming speed is positively correlated with sperm length among, but not within, species. These different responses to sperm competition at intra- and interspecific levels provide a simple, powerful explanation for equivocal results from previous studies. Using phylogenetic analyses, we also reconstructed the probable evolutionary route of trait evolution in this taxon, and show that, in response to increases in the magnitude of sperm competition, the evolution of sperm traits in this clade began with the evolution of faster (thus, more competitive) sperm.

  8. Flow Cytometry Analysis Reveals That Only a Subpopulation of Mouse Sperm Undergoes Hyperpolarization During Capacitation1

    PubMed Central

    Escoffier, Jessica; Navarrete, Felipe; Haddad, Doug; Santi, Celia M.; Darszon, Alberto; Visconti, Pablo E.

    2015-01-01

    To gain fertilizing capacity, mammalian sperm should reside in the female tract for a period of time. The physiological changes that render the sperm able to fertilize are known as capacitation. Capacitation is associated with an increase in intracellular pH, an increase in intracellular calcium, and phosphorylation of different proteins. This process is also accompanied by the hyperpolarization of the sperm plasma membrane potential (Em). In the present work, we used flow cytometry to analyze changes in sperm Em during capacitation in individual cells. Our results indicate that a subpopulation of hyperpolarized mouse sperm can be clearly distinguished by sperm flow cytometry analysis. Using sperm bearing green fluorescent protein in their acrosomes, we found that this hyperpolarized subpopulation is composed of sperm with intact acrosomes. In addition, we show that the capacitation-associated hyperpolarization is blocked by high extracellular K+, by PKA inhibitors, and by SLO3 inhibitors in CD1 mouse sperm, and undetectable in Slo3 knockout mouse sperm. On the other hand, in sperm incubated in conditions that do not support capacitation, sperm membrane hyperpolarization can be induced by amiloride, high extracellular NaHCO3, and cAMP agonists. Altogether, our observations are consistent with a model in which sperm Em hyperpolarization is downstream of a cAMP-dependent pathway and is mediated by the activation of SLO3 K+ channels. PMID:25855261

  9. Effect of semen preparation technique and its incubation on sperm quality in the Moroccan population.

    PubMed

    Aboulmaouahib, S; Madkour, A; Kaarouch, I; Saadani, B; Sefrioui, O; Louanjli, N; Copin, H; Cadi, R; Benkhalifa, M

    2016-09-05

    In in vitro fertilisation (IVF), sperm preparation as critical part and influencing the sperm quality is especially dependent on the chosen technique itself and incubation parameters including temperature and CO2. In this study, we compared firstly density-gradient centrifugation technique (DGC) to the adapted DGC using the sperm pellet of 80% fraction (DGC/80P) in order to improve the sperm yield. Secondly, this study led to evaluate different sperm incubation conditions based on temperature effect (room temperature (RT = 23°C) versus 35°C) and in the other hand, with or without 5% CO2 during 24 hrs. Based on evaluating sperm conventional parameters and the DNA damage using TUNEL assay, our result showed that DGC/80P increased sperm quality compared to DGC with 25% of improvement. For temperature incubation effect after 24 hrs, 35°C increased the DNA damage and decreased the sperm quality while RT could improve sperm motility by 38%. Moreover, the sperm incubation with 5% CO2 after 24 hrs realised a negative impact on sperm parameters and its DNA damage. Indeed, for current IVF practice, a good sperm quality can be maintained for several hours at room temperature, while the sperm preparation is processed using the DGC/80P without CO2.

  10. Immune Activation Reduces Sperm Quality in the Great Tit

    PubMed Central

    Losdat, Sylvain; Richner, Heinz; Blount, Jonathan D.; Helfenstein, Fabrice

    2011-01-01

    Mounting an immune response against pathogens incurs costs to organisms by its effects on important life-history traits, such as reproductive investment and survival. As shown recently, immune activation produces large amounts of reactive species and is suggested to induce oxidative stress. Sperm are highly susceptible to oxidative stress, which can negatively impact sperm function and ultimately male fertilizing efficiency. Here we address the question as to whether mounting an immune response affects sperm quality through the damaging effects of oxidative stress. It has been demonstrated recently in birds that carotenoid-based ornaments can be reliable signals of a male's ability to protect sperm from oxidative damage. In a full-factorial design, we immune-challenged great tit males while simultaneously increasing their vitamin E availability, and assessed the effect on sperm quality and oxidative damage. We conducted this experiment in a natural population and tested the males' response to the experimental treatment in relation to their carotenoid-based breast coloration, a condition-dependent trait. Immune activation induced a steeper decline in sperm swimming velocity, thus highlighting the potential costs of an induced immune response on sperm competitive ability and fertilizing efficiency. We found sperm oxidative damage to be negatively correlated with sperm swimming velocity. However, blood resistance to a free-radical attack (a measure of somatic antioxidant capacity) as well as plasma and sperm levels of oxidative damage (lipid peroxidation) remained unaffected, thus suggesting that the observed effect did not arise through oxidative stress. Towards the end of their breeding cycle, swimming velocity of sperm of more intensely colored males was higher, which has important implications for the evolution of mate choice and multiple mating in females because females may accrue both direct and indirect benefits by mating with males having better quality sperm

  11. Triennial Reproduction Symposium: sperm characteristics that limit success of fertilization.

    PubMed

    Flowers, W L

    2013-07-01

    Current industry estimates of reproductive performance for cattle, sheep, and swine operations indicate that males contribute significantly to fertility failures. This appears to be due to the use of subfertile individuals and emphasizes the need for additional research in identifying characteristics of sperm that compromise fertilization. In theory, sperm characteristics, such as motility or the percentage of normal sperm, form a positive relationship with fertility that reaches a certain maximal fertility (i.e., an asymptotic relationship). It is clear that variation exists among males in terms of how fertility responds to increasing sperm dosage or numbers of normal sperm, both in the slope of the curve and the point at which the fertility reaches a maximum. Variations along the linear portion of fertility curves are due to compensable traits that are involved with the ability of sperm to penetrate the zona pellucida. It appears that most fertility curves reach their plateau when 70% of sperm possess a given compensable trait. The level of fertility at which the plateau occurs is determined by noncompensable traits that are associated with binding of sperm to the oolemma, syngamy, and subsequent development of the zygote. Several studies have shown differences in fertility among males that have similar levels of compensable traits but differed in their noncompensable characteristics. Compensable and noncompensable traits can estimate either individual or functional characteristics of sperm. Intuitively, functional traits such as in vitro penetration should provide a better indication of fertilization than individual ones such as motility. However, correlations of both types with fertility are very similar. Reasons for this may be related to how characteristics of sperm cells are influenced by the female reproductive tract after insemination. Sperm capacitation is a functional trait in boars that is quite different in vitro versus in vivo. If this relationship

  12. Pentoxifylline effects on capacitation and fertility of stallion epididymal sperm.

    PubMed

    Guasti, P N; Monteiro, G A; Maziero, R R D; Carmo, M T; Dell'Aqua, J A; Crespilho, A M; Rifai, E A; Papa, F O

    2017-04-01

    The aims of this study were to determinate whether pentoxifylline (PTX) increases the motion parameters of fresh and frozen-thawed equine epididymal spermatozoa, to evaluate the tyrosine phosphorylation of frozen-thawed epididymal sperm in the presence of PTX and to determine whether the PTX-treatment of stallion epididymal sperm prior to freezing improves the fertility response of mares to a reduced number of spermatozoa per insemination dose. Fifty epididymis were flushed with a skim milk based extender with or without PTX. The pre-treatment with PTX enhanced the sperm motility after being harvested (P<0.05); however the freeze-thaw process did not alter the sperm kinematics between control and treated samples (P>0.05). Plasma membrane integrity did not differ between control and PTX group after recovery and after thawing (P>0.05), as observed in tyrosine phosphorylation, which the PTX treatment did not alter the percentage of tail-associated immunofluorescence of cryopreserved epididymal sperm (P>0.05). For the fertility trial, different insemination groups were tested: 800×10(6) epididymal sperm (C800); 100×10(6) epididymal sperm (C100); 100×10(6) epididymal sperm recovered in an extender containing PTX (PTX100). The conception rates for C800; C100 and PTX100 were 68.7% (11/16); 31.5% (5/16) and 50% (8/16), respectively. The conception rate did not differ among groups (P>0.05), however, a low number of animals was used in this study. A trend toward significance (P=0.07) was observed between C800 and C100 groups. In conclusion, PTX has no deleterious effect on sperm motility, viability and capacitation of cryopreserved stallion epididymal sperm. The conventional artificial insemination with 100×10(6) sperm recovered with PTX ensures acceptable conception rates and maximize the limited number of doses of cryopreserved stallion epididymal sperm.

  13. Administration of flutamide alters sperm ultrastructure, sperm plasma membrane integrity and its stability, and sperm mitochondrial oxidative capability in the boar: in vivo and in vitro approach.

    PubMed

    Lydka, M; Piasecka, M; Gaczarzewicz, D; Koziorowski, M; Bilinska, B

    2012-08-01

    Our previous work has shown that an anti-androgen flutamide administered pre- and post-natally induced adverse effects on the epididymal morphology and function of adult boars. The present investigation is aimed to understand the effect of flutamide and its metabolite on changes in sperm plasma membrane integrity and its stability, changes in mitochondrial oxidative capability and frequency of abnormal sperm. In vivo effects of flutamide (50 mg/kg b.w.) on sperm ultrastructure were examined by electron microscopic observations. In vitro effects of 5, 50 and 100 μg/ml hydroxyflutamide, administered for 2 and 24 h, on sperm plasma membrane integrity were measured by LIVE/DEAD Sperm Vitality kit, while those on sperm membrane stability and mitochondrial oxidoreductive activity were investigated using Merocyanine 540 and NADH tests, respectively. The incidence of abnormal spermatozoa increased significantly (p < 0.05) in flutamide-treated boars compared with controls. In an in vitro approach, low dose of hydroxyflutamide in 2-h incubations appeared less effective in altering the sperm plasma membrane integrity and its stability than two higher doses used (p < 0.05). No further decrease in the membrane integrity was found when the effect of anti-androgen lasted for 24 h. On the other hand, a decrease in sperm membrane destabilization and mitochondrial oxidoreductive activity was strengthened after 24 h of hydroxyflutamide administration (p < 0.05). Characterization of sperm parameters with regard to oxidative capability of mitochondria, plasma membrane changes and sperm ultrastructure provides novel data on the boar sperm sensitivity to anti-androgen action. Results indicate high sensitivity of boar spermatozoa to androgen withdrawal.

  14. Methods for increasing the production of ethanol from microbial fermentation

    DOEpatents

    Gaddy, James L.; Arora, Dinesh K.; Ko, Ching-Whan; Phillips, John Randall; Basu, Rahul; Wikstrom, Carl V.; Clausen, Edgar C.

    2007-10-23

    A stable continuous method for producing ethanol from the anaerobic bacterial fermentation of a gaseous substrate containing at least one reducing gas involves culturing a fermentation bioreactor anaerobic, acetogenic bacteria in a liquid nutrient medium; supplying the gaseous substrate to the bioreactor; and manipulating the bacteria in the bioreactor by reducing the redox potential, or increasing the NAD(P)H TO NAD(P) ratio, in the fermentation broth after the bacteria achieves a steady state and stable cell concentration in the bioreactor. The free acetic acid concentration in the bioreactor is maintained at less than 5 g/L free acid. This method allows ethanol to be produced in the fermentation broth in the bioreactor at a productivity greater than 10 g/L per day. Both ethanol and acetate are produced in a ratio of ethanol to acetate ranging from 1:1 to 20:1.

  15. Potentials of engineered nanoparticles as fertilizers for increasing agronomic productions.

    PubMed

    Liu, Ruiqiang; Lal, Rattan

    2015-05-01

    Development and application of new types of fertilizers using innovative nanotechnology are one of the potentially effective options of significantly enhancing the global agricultural productions needed to meet the future demands of the growing population. Indeed, the review of available literature indicates that some engineered nanomaterials can enhance plant-growth in certain concentration ranges and could be used as nanofertilizers in agriculture to increase agronomic yields of crops and/or minimize environmental pollution. This article summarizes this type of nanomaterials under four categories: macronutrient nanofertilizers, micronutrient nanofertilizers, nutrient-loaded nanofertilizers, and plant-growth-enhancing nanomaterials. Each category is discussed respectively with reference to nanomaterials' chemical composition, particle size, concentrations applied, benefited plant species, plant incubation methods, and plant-growth enhancement aspects and the rates. The importance, research directions, and research requirements of each nanofertilizer category for achieving sustainable agriculture are also specifically examined. Finally, this review suggests that development of N and P macronutrient nanofertilizers is a high research and development priority both for food production and environmental protection.

  16. Thyroxin Is Useful to Improve Sperm Motility

    PubMed Central

    Mendeluk, Gabriela Ruth; Rosales, Mónica

    2016-01-01

    Background The aim of this study was to evaluate the non-genomic action of thyroxin on sperm kinetic and its probable use to improve sperm recovery after applying an en- richment method like “swim-up” in comparison with the available one, pentoxifylline. Materials and Methods This is an experimental study. A total of 50 patients were re- cruited, followed by infertility consultation. Conventional sperm assays were performed according to World Health Organization criteria-2010 (WHO-2010). A Computer Aided Semen Analysis System was employed to assess kinetic parameters and concentrations. Number of the motile sperm recovered after preparation technique was calculated. Results Addition of T4 (0.002 µg/ml) to semen samples increased hypermotility at 20 minutes (control: 14.18 ± 5.1% vs. 17.66 ± 8.88%, P<0.03, data expressed as mean ± SD) and remained unchanged after 40 minutes. Significant differences were found in the motile sperm recovered after swim-up (control: 8.93×106 ± 9.52× 06vs. 17.20×106 ± 21.16×106, P<0.03), achieving all of the tested samples a desirable threshold value for artificial insemination outcome, while adding pentoxifylline increased the number of recovered sperm after swim-up in 60% of the studied cases. No synergism between two treatments could be determined. Conclusion We propose a new physiological tool to artificially improve insemination. The discussion opens windows to investigate unknown pathways involved in sperm ca- pacitation and gives innovative arguments to better understand infertility mechanisms. PMID:27441054

  17. Increased production of beta2-microglobulin after heart transplantation.

    PubMed

    Erez, E; Aravot, D; Erman, A; Sharoni, E; van Oyk, D J; Raanani, E; Abramov, D; Sulkes, J; Vidne, B A

    1998-05-01

    Serum beta2-microglobulin (beta2m) levels were measured to evaluate the state of immunoactivation in stable heart transplant recipients. Serum beta2m and renal function of 29 heart transplant recipients were compared with 16 control subjects, who were age and sex matched, and 11 patients with chronic kidney failure. Serum creatinine and 24-hour urine collection for albuminuria were used as markers of renal impairment. Heart transplant recipients with normal renal function (n = 7) had significantly elevated beta2m levels compared with control subjects: 2.6 +/- 0.9 vs 1.66 +/- 0.32 microg/ml, p < or = 0.05. Heart transplant recipients with impaired renal function (n = 22) had significantly elevated beta2m compared with the chronic kidney failure group: 4.42 +/- 1.3 vs 3.49 +/- 0.66 microg/ml (p < or = 0.05); although there was no significant difference in serum creatinine levels. Albuminuria excretion was significantly elevated in the chronic kidney failure group compared with the heart transplant recipients with impaired renal function (p < or = 0.05). Elevated serum beta2m in heart transplant recipients suggests increased beta2m production, reflecting increased immunoactivation. This observation could be useful in monitoring long-term immunosuppressive therapy.

  18. Hyaluronan production increases the malignant properties of mesothelioma cells

    PubMed Central

    Li, Y; Heldin, P

    2001-01-01

    Malignant pleural mesotheliomas is in most cases associated with elevated amounts of hyaluronan. To investigate the importance of hyaluronan for the malignant properties of mesotheliomas, we have expressed murine hyaluronan synthase 2 (HAS2) in the non-hyaluronan producing mesothelioma cell line, Mero-25. We found that upon hyaluronan overproduction the mesothelioma cells changed their epitheloid character to a fibroblastic phenotype and were surrounded by pericellular matrices, the size of which correlated to the amount of synthesized hyaluronan. HAS2-transfected cells with the ability to synthesize about 520 ng hyaluronan/5 × 104cells/24 h exhibited about a 2-fold increase in the expression of the cell surface hyaluronan receptor CD44 and their locomotion increased compared to that of mock-transfected Mero-25 cells. Furthermore, the malignant properties of mesothelioma cell clones as determined by the ability to grow in a soft agar assay correlated to their hyaluronan production. These results provide evidence for an important role of hyaluronan in the aggressive spread of mesotheliomas in adjacent non-cancerous stromal tissues. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11506502

  19. Earthworms increase plant production: a meta-analysis

    PubMed Central

    van Groenigen, Jan Willem; Lubbers, Ingrid M.; Vos, Hannah M. J.; Brown, George G.; De Deyn, Gerlinde B.; van Groenigen, Kees Jan

    2014-01-01

    To meet the challenge of feeding a growing world population with minimal environmental impact, we need comprehensive and quantitative knowledge of ecological factors affecting crop production. Earthworms are among the most important soil dwelling invertebrates. Their activity affects both biotic and abiotic soil properties, in turn affecting plant growth. Yet, studies on the effect of earthworm presence on crop yields have not been quantitatively synthesized. Here we show, using meta-analysis, that on average earthworm presence in agroecosystems leads to a 25% increase in crop yield and a 23% increase in aboveground biomass. The magnitude of these effects depends on presence of crop residue, earthworm density and type and rate of fertilization. The positive effects of earthworms become larger when more residue is returned to the soil, but disappear when soil nitrogen availability is high. This suggests that earthworms stimulate plant growth predominantly through releasing nitrogen locked away in residue and soil organic matter. Our results therefore imply that earthworms are of crucial importance to decrease the yield gap of farmers who can't -or won't- use nitrogen fertilizer. PMID:25219785

  20. Earthworms increase plant production: a meta-analysis.

    PubMed

    van Groenigen, Jan Willem; Lubbers, Ingrid M; Vos, Hannah M J; Brown, George G; De Deyn, Gerlinde B; van Groenigen, Kees Jan

    2014-09-15

    To meet the challenge of feeding a growing world population with minimal environmental impact, we need comprehensive and quantitative knowledge of ecological factors affecting crop production. Earthworms are among the most important soil dwelling invertebrates. Their activity affects both biotic and abiotic soil properties, in turn affecting plant growth. Yet, studies on the effect of earthworm presence on crop yields have not been quantitatively synthesized. Here we show, using meta-analysis, that on average earthworm presence in agroecosystems leads to a 25% increase in crop yield and a 23% increase in aboveground biomass. The magnitude of these effects depends on presence of crop residue, earthworm density and type and rate of fertilization. The positive effects of earthworms become larger when more residue is returned to the soil, but disappear when soil nitrogen availability is high. This suggests that earthworms stimulate plant growth predominantly through releasing nitrogen locked away in residue and soil organic matter. Our results therefore imply that earthworms are of crucial importance to decrease the yield gap of farmers who can't -or won't- use nitrogen fertilizer.

  1. Profiling of sperm gene transcripts in crossbred (Bos taurus x Bos indicus) bulls.

    PubMed

    H M, Yathish; Kumar, Subodh; Dubey, Prem P; Modi, Rajendra P; Chaudhary, Rajni; A, Siva Kumar; Ghosh, Subrata K; Sarkar, Mihir; B, Sivamani

    2017-02-01

    Crossbred cattle in some sectors of the world have a significant role in enhancing milk production thereby enhancing the per capita milk availability as a human food source. However, there are certain constraints associated with crossbred animals, such as disease susceptibility, increased reproductive problems, repeat breeding and poor seminal quality. The semen of crossbred bulls has a poor freezing capacity, increased cryo-damage, poor mass cell motility, greater percentages of dead/abnormal sperm and poor initial and post-freeze cell motility. The rejection rate of crossbred bulls for cryostorage of semen has been reported to be as great as 50% as a result of unacceptable semen quality. The identification of superior bulls using molecular technologies is needed which necessitates identification of the genes having a role in sperm function. The present study was, therefore, conducted to gain information on identification and expression of genes having a role in sperm motility in crossbred bulls. The gene transcripts in bulls with sperm of superior and inferior quality were profiled in Vrindavani crossbred cattle by microarray analyses and the results were verified by real time-quantitative PCR. Microarray analyses revealed 19,454 genes which were differentially expressed. At a two-fold cut off, 305 genes were differentially (P<0.01) expressed with 160 genes upregulated and 145 genes down regulated. Some of the upregulated candidate genes were further validated by RT-qPCR. These genes had a four to 16 fold upregulation in sperm with inferior motility as compared to sperm of crossbred bulls with superior motility.

  2. Gadolinium, a mechano-sensitive channel blocker, inhibits osmosis-initiated motility of sea- and freshwater fish sperm, but does not affect human or ascidian sperm motility.

    PubMed

    Krasznai, Zoltán; Morisawa, Masaaki; Krasznai, Zoárd Tibor; Morisawa, Sachiko; Inaba, Kazuo; Bazsáné, Zsuzsa Kassai; Rubovszky, Bálint; Bodnár, Béla; Borsos, Antal; Márián, Teréz

    2003-08-01

    Exposure to hypo-osmotic or hyperosmotic environment triggers the initiation of fish sperm motility. In this article, we report that calcium and potassium channel blockers do not influence motility of puffer fish sperm but calmodulin antagonists reversibly decrease it, suggesting that calmodulin-Ca(2+) interactions are prerequisite for the initiation of sperm motility in this species. Gadolinium (a stretch activated ion channel blocker) decreased the motility of puffer fish sperm from 92 +/- 3% to 6 +/- 3% and that of carp sperm from 91 +/- 7% to 3.5 +/- 4.3% in a dose-dependent manner (10-40 micro M). The effect of gadolinium was reversible, suggesting that stretch activated ion channels participate in the initiation of sperm motility of the two species. Gadolinium inhibits changes in the isoelectric point of certain proteins of puffer fish sperm, which occur when sperm motility is initiated in a hypertonic solution. Anisotropy measurements showed that hypo-osmotic treatment, which initiates carp sperm motility, increased membrane fluidity. When hypo-osmotic treatment was given in the presence of gadolinium, the sperm membrane remained as rigid as in quiescent cells, while motility was blocked. By contrast, gadolinium did not influence the motility parameters of Ciona or human sperm. Based on these lines of evidence, we suggest that conformational changes of mechanosensitive membrane proteins are involved in osmolality-dependent but not osmolality-independent sperm.

  3. Hepatosteatosis and estrogen increase apolipoprotein O production in the chicken.

    PubMed

    Schmidinger, Barbara; Weijler, Anna M; Schneider, Wolfgang J; Hermann, Marcela

    2016-08-01

    Apolipoprotein O (ApoO) is a recently discovered plasma apolipoprotein that may also play a role in the mitochondrial inner membrane. Possibly due to this complexity, its physiological functions have not been elucidated yet. To gain insight from a non-mammalian experimental system, we have investigated the regulation of ApoO levels in an alternative, well-suited model for studies on lipid metabolism, the chicken. qPCR using specific primer pairs and Western blot analysis with our rabbit anti-chicken ApoO antiserum demonstrated ApoO in the liver of chickens fed a control or a fat-enriched diet, as well as in 2 chicken hepatoma cell lines, LMH cells and the estrogen-responsive LMH-2A cells, under conditions of lipid loading by incubation with BSA-complexed oleic acid. Induced triglyceride accumulation in both the liver and the hepatic cells was associated with significantly increased levels of ApoO mRNA and protein. Furthermore, upon treatment for 24 h with estrogen of the estrogen receptor-expressing LMH-2A cells, quantitative analysis of ApoO transcripts and Western blotting revealed increases of ApoO expression. Finally, upon a single administration of estrogen to roosters that leads to hyperlipidemia, higher hepatic levels of both ApoO transcript and protein were observed within 24 h. Based on these data, we propose that hepatic expression of ApoO is tightly linked not only to diet-induced hepatosteatosis, but also to increased lipoprotein-production induced by, e.g., hormones. The findings support a role of ApoO as an effector of compromised mitochondrial function that likely accompanies the onset of non-alcoholic fatty liver disease.

  4. Methamphetamine induces abnormal sperm morphology, low sperm concentration and apoptosis in the testis of male rats.

    PubMed

    Nudmamud-Thanoi, S; Thanoi, S

    2011-08-01

    Methamphetamine has been reported to be an important drug in the field of reproductive toxicology. The aim of this study was to investigate the effects of methamphetamine administrations on sperm morphology, sperm concentration and apoptotic activity inside seminiferous tubule in male rats. Rats were administered a dose of 8 mg kg(-1) , intraperitoneally (IP), for acute group and a dose of 4 mg kg(-1) , IP, once daily for 14 days for sub-acute group. Percentage of normal sperm morphology was decreased in acute group when compared with control. Total numbers of sperm count were significantly decreased in acute and sub-acute groups. Apoptotic activities were most abundant in the seminiferous tubules of acute treated animals with a highly significant increase in the number of apoptotic cells per tubule. Those effects of methamphetamine seem to be dose-dependent. The results suggest that methamphetamine not only works as drug of abuse in central nervous system, but also in gametogenesis of males.

  5. Royal Jelly Increases Collagen Production in Rat Skin After Ovariectomy

    PubMed Central

    Park, Hye Min; Cho, Min Hyoung; Cho, Yunhi

    2012-01-01

    Abstract Royal jelly (RJ) is a honeybee product that contains proteins, carbohydrates, fats, free amino acids, vitamins, and minerals. RJ has been reported to have antitumor, antibacterial, and wound-healing activities. We previously reported that RJ enhanced the migration of human dermal fibroblasts and altered the levels of cholesterol and sphinganine in an in vitro wound-healing model in addition to regulating skin photoaging following exposure to ultraviolet-B radiation. We established an animal model of skin aging in the context of estrogen deficiency and assessed the antiaging effects of RJ on skin. To establish an in vivo model of skin aging, bilateral ovariectomies were performed in 12-week-old virgin female Sprague-Dawley rats. Induction of osteoporosis was confirmed through two-dimensional images of the trabecular bone in the left femoral necks using microcomputed tomography. The protective effects of RJ ovariectomy-induced skin aging were examined by determining the protein expression of type I procollagen and matrix metalloproteinase (MMP)-1. The collagen content and epidermal thickness of skin tissue were measured by staining techniques. There was a significant difference in weight between sham-operated and ovariectomized groups. Food efficiency ratio did not differ significantly among the groups. The level of procollagen type I protein was increased in the dorsal skin of ovariectomized rats fed with a dietary supplement containing 1% RJ extract, but the level of MMP-1 was not altered. In particular, the amount of collagen recovered was close to the normal level. RJ may protect against skin aging by enhancing collagen production in rats with ovariectomy-induced estrogen deficiency. PMID:22468645

  6. Hyperoxia increases hepatic arginase expression and ornithine production in mice

    SciTech Connect

    Malleske, Daniel T.; Rogers, Lynette K.; Velluci, Sean M.; Young, Tamara L.; Park, Min S.; Long, Donald W.; Welty, Stephen E.; Smith, Charles V.; Nelin, Leif D. . E-mail: NelinL@pediatrics.ohio-state.edu

    2006-08-15

    Hyperoxic exposure affects the levels and activities of some hepatic proteins. We tested the hypothesis that hyperoxic exposure would result in greater hepatic .NO concentrations. C3H/HeN mice were exposed to >95% O{sub 2} for 72 or 96 h and compared to room air-breathing controls. In contrast to our working hypothesis, exposure to >95% O{sub 2} for 96 h decreased hepatic nitrite/nitrate NO {sub X} concentrations (10.9 {+-} 2.2 nmol/g liver versus 19.3 {+-} 2.4 nmol/g liver in room air, P < 0.05). The hepatic levels of endothelial NO synthase (eNOS) and inducible NOS (iNOS) proteins were not different among the groups. The arginases, which convert L-arginine to urea and L-ornithine, may affect hepatic NOS activities by decreasing L-arginine bioavailability. Hepatic ornithine concentrations were greater in hyperoxic animals than in controls (318 {+-} 18 nmol/g liver in room air, and 539 {+-} 64, and 475 {+-} 40 at 72 and 96 h of hyperoxia, respectively, P < 0.01). Hepatic arginase I protein levels were greater in hyperoxic animals than in controls. Hepatic carbamoyl phosphate synthetase (CPS) protein levels and activities were not different among groups. These results indicate that increases in hepatic levels of arginase I in mice exposed to hyperoxia may diminish .NO production, as reflected by lower liver levels of NO {sub X}. The resultant greater hepatic ornithine concentrations may represent a mechanism to facilitate tissue repair, by favoring the production of polyamines and/or proline.

  7. Enhanced membrane protein expression by engineering increased intracellular membrane production

    PubMed Central

    2013-01-01

    Background Membrane protein research is frequently hampered by the low natural abundance of these proteins in cells and typically relies on recombinant gene expression. Different expression systems, like mammalian cells, insect cells, bacteria and yeast are being used, but very few research efforts have been directed towards specific host cell customization for enhanced expression of membrane proteins. Here we show that by increasing the intracellular membrane production by interfering with a key enzymatic step of lipid synthesis, enhanced expression of membrane proteins in yeast is achieved. Results We engineered the oleotrophic yeast, Yarrowia lipolytica, by deleting the phosphatidic acid phosphatase, PAH1, which led to massive proliferation of endoplasmic reticulum (ER) membranes. For all eight tested representatives of different integral membrane protein families, we obtained enhanced protein accumulation levels and in some cases enhanced proteolytic integrity in the ∆pah1 strain. We analysed the adenosine A2AR G-protein coupled receptor case in more detail and found that concomitant induction of the unfolded protein response in the ∆pah1 strain enhanced the specific ligand binding activity of the receptor. These data indicate an improved quality control mechanism for membrane proteins accumulating in yeast cells with proliferated ER. Conclusions We conclude that redirecting the metabolic flux of fatty acids away from triacylglycerol- and sterylester-storage towards membrane phospholipid synthesis by PAH1 gene inactivation, provides a valuable approach to enhance eukaryotic membrane protein production. Complementary to this improvement in membrane protein quantity, UPR co-induction further enhances the quality of the membrane protein in terms of its proper folding and biological activity. Importantly, since these pathways are conserved in all eukaryotes, it will be of interest to investigate similar engineering approaches in other cell types of

  8. Quantification of mammalian sperm morphology by slit-scan flow cytometry

    SciTech Connect

    Benaron, D.A.; Gray, J.W.; Gledhill, B.L.; Lake, S.; Wyrobek, A.J.; Young, I.T.

    1982-03-01

    The head shapes of mammalian sperm have been measured by slit-scan flow cytometry (SSFCM). In this approach, the distribution of fluorescence along acriflavine stained mammalian sperm is recorded and used as a measure of head shape. Fluorescence profiles were measured for sperm from mice, rabbits, hamsters, and bulls, and for sperm from mice exposed to testicular x-irradiation from 0 to 900 rads. The profiles for sperm from nonirradiated animals were characteristic of each species and were reproducible from sperm to sperm. Some of the fluorescence profiles for sperm from the irradiated mice differed significantly from the profiles usually measured for sperm from exposed mice. An algorithm was developed to determine the frequency of these sperm. The estimated frequencies of atypical profiles correlated well (r . 0.99) with the frequencies of abnormally shaped sperm determined by microscopic scoring. The maximum SSFCM sensitivity (minimum detectable dose . 199 rad) was not as high as that for the visual assay (minimum detectable dose . 116 rad). However, only 100 profiles were measured by SSFCM at each dose while at least 500 sperm were scored visually at each dose. The sensitivity of the SSFCM assay should be increased substantially by measuring more profiles. The objective nature of SSFCM couple with the high correlation with results from the visually based assay of morphology suggests the use of SSFCM to measure frequencies of misshapen sperm when testing for mutagens or monitoring for effects of environmental contaminants.

  9. Potency of blue catfish, Ictalurus furcatus (individual vs pooled) sperm to fertilize stripped channel catfish, I. punctatus eggs on the production and performance of progeny

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel x blue hybrid catfish is the desired genotype for US farm-raised catfish industry. Induced spawning of gravid channel catfish, followed by fertilization of stripped eggs with blue catfish sperm is the only reliable means to produce hybrid catfish embryos in hatcheries. Hybrid catfish fry p...

  10. Sperm-egg interaction is mediated by a sperm-associated body in quail.

    PubMed

    Rabbani, M Golam; Sasanami, Tomohiro; Mori, Makoto; Yoshizaki, Norio

    2006-01-01

    The present study describes the holes in the inner vitelline membrane of fertile eggs of the quail Coturnix japonica, which remain after the spermatozoa pass through. It was shown that the light-microscopically observable 'holes' correspond mostly to electron-microscopically defined 'disks', and, to a lesser extent (about 5%), real holes. Immunofluorescent staining of the vitelline membranes with an antiquail ZPC antiserum was used to discriminate the holes from the disks light-microscopically. Over 96% of holes were accompanied by calcium-coated sperm-associated bodies, indicating a close relationship between the two. There was no preferential localization of the disks, holes or sperm-associated bodies in the vitelline membrane around the egg. The sperm-associated bodies bound with the spermatozoa at the posterior end of sperm flagella. Incubation of the inner vitelline membranes, isolated from the largest follicles, with spermatozoa resulted in production only of the disks, whereas the holes (about 9%) were produced when the sperm-associated bodies were added to the system. It was suggested that the sperm-associated bodies assist fertile spermatozoa in binding to the inner vitelline membrane, making holes in the membrane and passing through them in fertile eggs.

  11. Organic fertilization leads to increased peach root production and lifespan.

    PubMed

    Baldi, E; Toselli, M; Eissenstat, D M; Marangoni, B

    2010-11-01

    We evaluated the effects of mineral and organic fertilizers on peach root dynamics in the growing season from 2003 to 2006 in a nectarine (Prunus persica L.) orchard, planted in 2001 and located in the Po valley, northeastern Italy. Very few studies have conducted long-term investigations of root dynamics of fruit crops. Our main objective was to determine whether organic fertilizers affect root dynamics differently than mineral fertilizers. The experiment was a completely randomized block design with four replicates of three treatments: unfertilized, mineral fertilized and composted with municipal waste. Mineral fertilizers included P (100 kg ha(-1) year(-1)) and K (200 kg ha(-1) year(-1)) applied only at planting and N (70-130 kg ha(-1) year(-1)) split into two applications, one at 40 days after full bloom (60%) and the other in September (40%) each year. The compost fertilization represented a yearly rate of 10 metric tons (t) dry weight ha(-1), which approximates (in kg ha(-1) year(-1)) 240 N, 100 P and 200 K, split similarly to that described for the mineral fertilization of N. Both root growth and survival were evaluated at 20-day intervals during the growing season by the minirhizotron technique. Compost increased the production of new roots compared with the other treatments (P < 0.01). Roots were mainly produced at a depth of 41-80 cm and from March to May and in late summer. An analysis of covariance indicated no significant effect of soil nitrate on root production (P = 0.47). The root lifespan was longer in compost-treated trees than in mineral-fertilized or unfertilized trees (P < 0.01) and it was strongly affected by time of birth; roots born later in the summer lived longer than those born in the spring. Across years and treatments, the average root lifespan was positively correlated with soil nitrate (r = 0.60; P < 0.001). Variation in root lifespan with method of fertilization could be accounted for by variation in soil

  12. Speract induces calcium oscillations in the sperm tail.

    PubMed

    Wood, Chris D; Darszon, Alberto; Whitaker, Michael

    2003-04-14

    Sea urchin sperm motility is modulated by sperm-activating peptides. One such peptide, speract, induces changes in intracellular free calcium concentration ([Ca2+]i). High resolution imaging of single sperm reveals that speract-induced changes in [Ca2+]i have a complex spatiotemporal structure. [Ca2+]i increases arise in the tail as periodic oscillations; [Ca2+]i increases in the sperm head lag those in the tail and appear to result from the summation of the tail signal transduction events. The period depends on speract concentration. Infrequent spontaneous [Ca2+]i transients were also seen in the tail of unstimulated sperm, again with the head lagging the tail. Speract-induced fluctuations were sensitive to membrane potential and calcium channel blockers, and were potentiated by niflumic acid, an anion channel blocker. 3-isobutyl-1-methylxanthine, which potentiates the cGMP/cAMP-signaling pathways, abolished the [Ca2+]i fluctuations in the tail, leading to a very delayed and sustained [Ca2+]i increase in the head. These data point to a model in which a messenger generated periodically in the tail diffuses to the head. Sperm are highly polarized cells. Our results indicate that a clear understanding of the link between [Ca2+]i and sperm motility will only be gained by analysis of [Ca2+]i signals at the level of the single sperm.

  13. Egg Activation at Fertilization by a Soluble Sperm Protein.

    PubMed

    Swann, Karl; Lai, F Anthony

    2016-01-01

    The most fundamental unresolved issue of fertilization is to define how the sperm activates the egg to begin embryo development. Egg activation at fertilization in all species thus far examined is caused by some form of transient increase in the cytoplasmic free Ca(2+) concentration. What has not been clear, however, is precisely how the sperm triggers the large changes in Ca(2+) observed within the egg cytoplasm. Here, we review the studies indicating that the fertilizing sperm stimulates a cytosolic Ca(2+) increase in the egg specifically by delivering a soluble factor that diffuses into the cytosolic space of the egg upon gamete membrane fusion. Evidence is primarily considered in species of eggs where the sperm has been shown to elicit a cytosolic Ca(2+) increase by initiating Ca(2+) release from intracellular Ca(2+) stores. We suggest that our best understanding of these signaling events is in mammals, where the sperm triggers a prolonged series of intracellular Ca(2+) oscillations. The strongest empirical studies to date suggest that mammalian sperm-triggered Ca(2+) oscillations are caused by the introduction of a sperm-specific protein, called phospholipase C-zeta (PLCζ) that generates inositol trisphosphate within the egg. We will discuss the role and mechanism of action of PLCζ in detail at a molecular and cellular level. We will also consider some of the evidence that a soluble sperm protein might be involved in egg activation in nonmammalian species.

  14. Sperm Motility in Flow

    NASA Astrophysics Data System (ADS)

    Guasto, Jeffrey; Juarez, Gabriel; Stocker, Roman

    2012-11-01

    A wide variety of plants and animals reproduce sexually by releasing motile sperm that seek out a conspecific egg, for example in the reproductive tract for mammals or in the water column for externally fertilizing organisms. Sperm are aided in their quest by chemical cues, but must also contend with hydrodynamic forces, resulting from laminar flows in reproductive tracts or turbulence in aquatic habitats. To understand how velocity gradients affect motility, we subjected swimming sperm to a range of highly-controlled straining flows using a cross-flow microfluidic device. The motion of the cell body and flagellum were captured through high-speed video microscopy. The effects of flow on swimming are twofold. For moderate velocity gradients, flow simply advects and reorients cells, quenching their ability to cross streamlines. For high velocity gradients, fluid stresses hinder the internal bending of the flagellum, directly inhibiting motility. The transition between the two regimes is governed by the Sperm number, which compares the external viscous stresses with the internal elastic stresses. Ultimately, unraveling the role of flow in sperm motility will lead to a better understanding of population dynamics among aquatic organisms and infertility problems in humans.

  15. Sperm-egg interaction.

    PubMed

    Evans, Janice P

    2012-01-01

    A crucial step of fertilization is the sperm-egg interaction that allows the two gametes to fuse and create the zygote. In the mouse, CD9 on the egg and IZUMO1 on the sperm stand out as critical players, as Cd9(-/-) and Izumo1(-/-) mice are healthy but infertile or severely subfertile due to defective sperm-egg interaction. Moreover, work on several nonmammalian organisms has identified some of the most intriguing candidates implicated in sperm-egg interaction. Understanding of gamete membrane interactions is advancing through characterization of in vivo and in vitro fertilization phenotypes, including insights from less robust phenotypes that highlight potential supporting (albeit not absolutely essential) players. An emerging theme is that there are varied roles for gamete molecules that participate in sperm-egg interactions. Such roles include not only functioning as fusogens, or as adhesion molecules for the opposite gamete, but also functioning through interactions in cis with other proteins to regulate membrane order and functionality.

  16. Healthy Sperm: Improving Your Fertility

    MedlinePlus

    Healthy Lifestyle Getting pregnant Healthy sperm aren't always a given. Understand how lifestyle factors can affect your ... as a laptop, might enhance sperm quality. Adopting healthy lifestyle practices to promote your fertility — and avoiding things ...

  17. Increased production of inflammatory cytokines in mild cognitive impairment.

    PubMed

    Magaki, Shino; Mueller, Claudius; Dickson, Cindy; Kirsch, Wolff

    2007-03-01

    Recent studies indicate that chronic inflammation plays a pathogenic role in both the central nervous system (CNS) and periphery in Alzheimer's disease (AD). We have screened for cytokines differentially produced by peripheral blood mononuclear cells (PBMCs) isolated from subjects with mild cognitive impairment (MCI) and mild AD subjects who had progressed from MCI using a commercially available cytokine array. Following determination of expressed cytokines, we quantified levels of the proinflammatory cytokines TNF-alpha, IL-6, and IL-8, and the anti-inflammatory cytokine IL-10 using flow cytometry. We have found a significant increase in the levels of IL-6, IL-8, and IL-10 produced by PBMCs stimulated for 24 h with phytohemagglutinin (PHA) in MCI subjects compared to healthy elderly controls. However, in PBMCs stimulated for 48 h with lipopolysaccharide (LPS), lower TNF-alpha/IL-10, IL-6/IL-10, and IL-8/IL-10 ratios were seen in MCI subjects. There were no differences in plasma levels of IL-8 between aged controls, MCI, and mild AD, and the levels of circulating IL-6 and IL-10 were below detection limits. Our data indicate that changes in cytokine production by PBMCs may be detected early in MCI, and an alteration of the immune response may precede clinical AD.

  18. Sorting of Sperm by Morphology

    NASA Astrophysics Data System (ADS)

    Koh, James; Marcos, Marcos

    2016-11-01

    Many studies have proven that the percentage of morphologically normal sperm is a significant factor in determining the success of assisted reproduction. The velocity of sperm in a microchannel with shear flow subjected to an external field will be explored theoretically. The difference in response between morphologically normal and abnormal sperm will be computed from a statistical approach, to study the feasibility and effectiveness of sorting by an external field to remove abnormal sperm. The full name of this author is Marcos.

  19. Mobilisation of Ca2+ stores and flagellar regulation in human sperm by S-nitrosylation: a role for NO synthesised in the female tract

    PubMed Central

    Machado-Oliveira, Gisela; Lefièvre, Linda; Ford, Christopher; Herrero, M Belen; Barratt, Christopher; Connolly, Thomas J; Nash, Katherine; Morales-Garcia, Aduen; Kirkman-Brown, Jackson; Publicover, Steve

    2009-01-01

    Summary Generation of NO by nitric oxide synthase (NOS) is implicated in gamete interaction and fertilisation. Exposure of human spermatozoa to NO donors caused mobilisation of stored Ca2+ by a mechanism that did not require activation of guanylate cyclase but was mimicked by S-nitroso-glutathione (GSNO; an S-nitrosylating agent). Application of dithiothreitol, to reduce protein –SNO groups, rapidly reversed the actions of NO and GSNO on [Ca2+]i. The effects of NO, GSNO and dithiothreitol on sperm protein S-nitrosylation, assessed using the biotin switch method, closely paralleled their actions on [Ca2+]i. Immunofluorescent staining revealed constitutive and inducible NOS in human oviduct and cumulus (the cellular layer investing the oocyte). 4,5-diaminofluorescein (DAF) staining demonstrated production of NO by these tissues. Incubation of human sperm with oviduct explants induced sperm protein S-nitrosylation resembling that induced by NO donors and GSNO. Progesterone (a product of cumulus cells) also mobilises stored Ca2+ in human sperm. Pre-treatment of sperm with NO greatly enhanced the effect of progesterone on [Ca2+]i, resulting in a prolonged increase in flagellar excursion. We conclude that NO regulates mobilisation of stored Ca2+ in human sperm by protein S-nitrosylation, that this action is synergistic with progesterone and that this synergism is potentially highly significant in gamete interactions leading to fertilisation. PMID:18842814

  20. Chemotactic behavior of the sperm of chitons (Mollusca: Polyplacophora).

    PubMed

    Miller, R L

    1977-11-01

    Observations of sperm behavior in the vicinity of gradients of egg-water or alcohol extracts of whole freshly-spawned eggs of several chitons reveal what appear to be directed movements of sperm up the gradient, resulting in the aggregation of motile sperm at the gradient source. Plots of the tracks of the sperm approaching the gradient source show that the cells increase the time during which they move toward the source and decrease the time spent moving away. Although this resembles the kinesis behavior shown by bacteria in a gradient, the path directions are markedly non-random. The reorientation behavior of thigmotactic sperm involves enlargement of the normal circular path diameter in the direction of the source and an alternation of tight loops and wide circular arcs, with the latter made in the direction of the source. The form of the path of attracted chiton sperm is like that observed during chemotaxis of the sperm of the hydroid Tubularia and the tunicate Ciona and resembles the behavior of Ciona sperm in that there is no increase in velocity as the cells move up the gradient. However, unlike the cnidarian and urochordate cases, the attracting substances extracted from chiton eggs do not act species-specifically.

  1. Conspecific sperm precedence in Callosobruchus subinnotatus (Coleoptera: Bruchidae): mechanisms and consequences

    PubMed Central

    Rugman-Jones, Paul F; Eady, Paul E

    2007-01-01

    Conspecific sperm precedence (CSP) has been identified as an important post-copulatory, pre-zygotic mechanism that can act to reduce gene flow between populations. The evolution of CSP is thought to have arisen as a by-product of male and female coevolution in response to intraspecific post-copulatory sexual selection. However, little is known about the mechanisms that generate CSP. When Callosobruchus subinnotatus females copulate with both C. subinnotatus and Callosobruchus maculatus males, regardless of mating order, the majority of eggs are fertilized by conspecific sperm. The low number of heterospecific fertilizations does not result from general differences in the viability of sperm in the female reproductive tract, as heterospecific sperm fertilized equivalent numbers of eggs as conspecific sperm in the absence of sperm competition. Instead, CSP results from disadvantages to heterospecific sperm that are manifest only when in competition with conspecific sperm. CSP in C. subinnotatus appears to result from two, not mutually exclusive, mechanisms. First, conspecific sperm are better able to displace heterospecific sperm from female storage. Second, conspecific sperm achieve disproportionately higher numbers of fertilizations relative to their proportional representation in the fertilization set. Thus, we provide evidence of differential sperm use from the female spermatheca. PMID:17251102

  2. Conspecific sperm precedence in Callosobruchus subinnotatus (Coleoptera: Bruchidae): mechanisms and consequences.

    PubMed

    Rugman-Jones, Paul F; Eady, Paul E

    2007-04-07

    Conspecific sperm precedence (CSP) has been identified as an important post-copulatory, pre-zygotic mechanism that can act to reduce gene flow between populations. The evolution of CSP is thought to have arisen as a by-product of male and female coevolution in response to intraspecific post-copulatory sexual selection. However, little is known about the mechanisms that generate CSP. When Callosobruchus subinnotatus females copulate with both C. subinnotatus and Callosobruchus maculatus males, regardless of mating order, the majority of eggs are fertilized by conspecific sperm. The low number of heterospecific fertilizations does not result from general differences in the viability of sperm in the female reproductive tract, as heterospecific sperm fertilized equivalent numbers of eggs as conspecific sperm in the absence of sperm competition. Instead, CSP results from disadvantages to heterospecific sperm that are manifest only when in competition with conspecific sperm. CSP in C. subinnotatus appears to result from two, not mutually exclusive, mechanisms. First, conspecific sperm are better able to displace heterospecific sperm from female storage. Second, conspecific sperm achieve disproportionately higher numbers of fertilizations relative to their proportional representation in the fertilization set. Thus, we provide evidence of differential sperm use from the female spermatheca.

  3. Effect of sorafenib on sperm count and sperm motility in male Swiss albino mice

    PubMed Central

    Shetty, Surekha Devadasa; Bairy, Laxminarayana Kurady

    2015-01-01

    The issue of male germ line mutagenesis and the effects on developmental defects in the next generation has become increasingly high profile over recent years. Mutagenic substance affects germinal cells in the testis. Since the cells are undergoing different phases of cell division and maturation, it is an ideal system to study the effect of chemotherapeutic agents. There are lacunae in the literature on the effect of sorafenib on gonadal function. With background, a study was planned to evaluate the effects of sorafenib on sperm count and sperm motility in male Swiss albino mice. Male Swiss albino mice were used for the study. The animals were segregated into control, positive control (PC) and three treatment groups. PC received oral imatinib (100 mg/kg body weight) and treatment groups received 25, 50, and 100 mg/kg body weight of sorafenib orally for 7 consecutive days at intervals of 24 h between two administrations. The control group remained in the home cage for an equal duration of time to match their corresponding treatment groups. The animals were sacrificed at the end of 1st, 2nd, 4th, 5th, 7th, and 10th weeks after the last exposure to drug, respectively. Sperm suspensions were prepared and introduced into a counting chamber. Total sperm count and motility were recorded. There was a significant decrease in sperm count and sperm motility by sorafenib which was comparable with the effect of PC imatinib. Sorafenib adversely affects sperm count and sperm motility which are reversible after discontinuation of treatment. PMID:26605157

  4. Comparison of methods for assessing integrity of equine sperm membranes.

    PubMed

    Foster, M L; Love, C C; Varner, D D; Brinsko, S P; Hinrichs, K; Teague, S; Lacaze, K; Blanchard, T L

    2011-07-15

    Sperm membrane integrity (SMI) is thought to be an important measure of stallion sperm quality. The objective was to compare three methods for evaluating SMI: flow cytometry using SYBR-14/propidium iodide (PI) stain; an automated cell counting device using PI stain; and eosin-nigrosin stain. Raw equine semen was subjected to various treatments containing 20 to 80% seminal plasma in extender, with differing sperm concentrations, to simulate spontaneous loss of SMI. The SMI was assessed immediately, and after 1 and 2 d of cooled storage. Agreement between methods was determined according to Bland-Altman methodology. Eosin-nigrosin staining yielded higher (2%) overall mean values for SMI than did flow cytometry. Flow cytometry yielded higher (6%) overall mean values for SMI than did the automated cell counter. As percentage of membrane-damaged sperm increased, agreement of SMI measurement between methods decreased. When semen contained 50-79% membrane-intact sperm, the 95% limits of agreement between SMI determined by flow cytometry and eosin-nigrosin staining were greater (range = -26.9 to 24.3%; i.e., a 51.2% span) than for SMI determined by flow cytometry and the automated cell counter (range = -3.1 to 17.0%; 20.1% span). When sperm populations contained <50% membrane-intact sperm, the 95% limits of agreement between SMI determined by flow cytometry and eosin-nigrosin staining were greater (range = -35.9 to 19.0%; 54.9% span) than for SMI determined by flow cytometry and the automated cell counter (range = -11.6 to 28.7%; 40.3% span). We concluded that eosin-nigrosin staining assessments of percent membrane-intact sperm agreed less with flow cytometry when <80% of sperm had intact membranes, whereas automated cell counter assessments of percent membrane-intact sperm agreed less with flow cytometry when <30% of sperm had intact membranes.

  5. Sperm proteasomes degrade sperm receptor on the egg zona pellucida during mammalian fertilization.

    PubMed

    Zimmerman, Shawn W; Manandhar, Gaurishankar; Yi, Young-Joo; Gupta, Satish K; Sutovsky, Miriam; Odhiambo, John F; Powell, Michael D; Miller, David J; Sutovsky, Peter

    2011-02-23

    Despite decades of research, the mechanism by which the fertilizing spermatozoon penetrates the mammalian vitelline membrane, the zona pellucida (ZP) remains one of the unexplained fundamental events of human/mammalian development. Evidence has been accumulating in support of the 26S proteasome as a candidate for echinoderm, ascidian and mammalian egg coat lysin. Monitoring ZP protein degradation by sperm during fertilization is nearly impossible because those few spermatozoa that penetrate the ZP leave behind a virtually untraceable residue of degraded proteins. We have overcome this hurdle by designing an experimentally consistent in vitro system in which live boar spermatozoa are co-incubated with ZP-proteins (ZPP) solubilized from porcine oocytes. Using this assay, mimicking sperm-egg interactions, we demonstrate that the sperm-borne proteasomes can degrade the sperm receptor protein ZPC. Upon coincubation with motile spermatozoa, the solubilized ZPP, which appear to be ubiquitinated, adhered to sperm acrosomal caps and induced acrosomal exocytosis/formation of the acrosomal shroud. The degradation of the sperm receptor protein ZPC was assessed by Western blotting band-densitometry and proteomics. A nearly identical pattern of sperm receptor degradation, evident already within the first 5 min of coincubation, was observed when the spermatozoa were replaced with the isolated, enzymatically active, sperm-derived proteasomes. ZPC degradation was blocked by proteasomal inhibitors and accelerated by ubiquitin-aldehyde(UBAL), a modified ubiquitin protein that stimulates proteasomal proteolysis. Such a degradation pattern of ZPC is consistent with in vitro fertilization studies, in which proteasomal inhibitors completely blocked fertilization, and UBAL increased fertilization and polyspermy rates. Preincubation of intact zona-enclosed ova with isolated active sperm proteasomes caused digestion, abrasions and loosening of the exposed zonae, and significantly reduced

  6. Microfluidic assessment of swimming media for motility-based sperm selection

    PubMed Central

    Eamer, Lise; Nosrati, Reza; Vollmer, Marion; Zini, Armand; Sinton, David

    2015-01-01

    Selection medium is important in sperm isolation for assisted reproductive technologies. Contrary to the naturally occurring human cervical mucus which has a high viscosity, most current practices for motility based sperm selection use a low viscosity medium. In this study, we used a microfluidic device to assess the effects of high viscosity media made with hyaluronic acid (HA) and methyl cellulose (MC) on bovine and human sperm motility and viability (sperm transferred directly from cryoprotectant). The microfluidic penetration test, viability, and motility were compared for sperm swimming in both HA and MC media with about 20cp viscosity (measured at 20 °C). Our resulted indicate that MC medium resulted in a significantly higher number of viable bovine sperm penetrating the medium as compared to HA. Furthermore, MC resulted in the selection of a sperm subpopulation with a 274% increase in sperm viability in comparison to the raw semen, while HA increased viability by only 133%. In addition to viability, bovine sperm motility parameters were significantly higher in the MC medium as compared with HA. Experiments with human sperm swimming in MC indicate that sperm swim slower and straighter at higher viscosities. In conclusion, the results indicate that in a micro-confined environment representative of the in vivo environment, MC is a preferred high viscosity medium to ensure the highest concentration of motile and viable sperm. PMID:26339314

  7. Sperm count and sperm motility decrease in old rats.

    PubMed

    Lucio, Rosa Angélica; Tlachi-López, José L; Eguibar, Jose R; Ågmo, Anders

    2013-02-17

    Sexual behavior declines with age in male rats. The rate and magnitude of this decline may depend on the amount of prior sexual experience and a number of other, unidentified factors. Age-dependent changes in the characteristics of ejaculate quality in rats have not been described earlier, and the relationship between such changes and modifications of sexual behavior is likewise unknown. We have recently developed a technique for the detailed analysis of parameters of ejaculate in rats, and this technique was used for the determination of semen and seminal plug characteristics in rats of different ages. Sexually experienced Wistar rats were tested for sex behavior at the ages of 3, 12 and 24 months. Semen was obtained from the female partner immediately after ejaculation at these tests. Between tests, the males were offered the opportunity to copulate once every 3-4 weeks. The behavioral data showed that the latency to ejaculation was increased only at 24 months. Concerning the characteristics of semen, there was a substantial increase in the proportion of immobile spermatozoa and motility of those moving was much reduced, both at 12 and 24 months of age. There was no relationship between parameters of sexual behavior and those of the ejaculate. Likewise, the size of the seminal plug did not affect the amount of intrauterine spermatozoa. The reduced sperm number together with the increased sperm immobility diminishes the ejaculate quality of old males, which could influence fertility.

  8. Increasing Children's ASL Classifier Production: A Multicomponent Intervention

    ERIC Educational Resources Information Center

    Beal-Alvarez, Jennifer S.; Easterbrooks, Susan R.

    2013-01-01

    The Authors examined classifier production during narrative retells by 10 deaf and hard of hearing students in grades 2-4 at a day school for the deaf following a 6-week intervention of repeated viewings of stories in American Sign Language (ASL) paired with scripted teacher mediation. Classifier production, documented through a…

  9. Increasing Military Physician Productivity in a Managed Care Environment

    DTIC Science & Technology

    1992-07-13

    allows us to obtain to a common denominator, or one single rating even though the services are dissimilar and the input units are not "weighted." Serway ...Productivity 34 Riley, J. (1992, May). Quality Improvement Means Better Productivity. Health care Executive. 7, 19-22. Serway , G. (1987). Alternative

  10. Productivity Continued to Increase in Many Industries during 1984.

    ERIC Educational Resources Information Center

    Herman, Arthur S.

    1986-01-01

    Productivity, as measured by output per employee hour, grew in 1984 in about three quarters of the industries for which the Bureau of Labor Statistics regularly publishes data. (A table shows productivity trends in industries measured by the Bureau, including mining, transportation and utilities, and trade and services.) (CT)

  11. Increasing cropping system diversity balances productivity, profitability and environmental health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and can have large negative im...

  12. Ram seminal plasma proteins contribute to sperm capacitation and modulate sperm-zona pellucida interaction.

    PubMed

    Luna, C; Colás, C; Casao, A; Serrano, E; Domingo, J; Pérez-Pé, R; Cebrián-Pérez, J A; Muiño-Blanco, T

    2015-03-01

    Incubation of ram spermatozoa in capacitating conditions with cAMP-elevating agents promotes a progressive time-dependent increase in the capacitated sperm subpopulation. In this study, the fertilizing capacity of ram spermatozoa (ability to bind to the zona pellucida, ZBA rate) capacitated in these conditions was determined. The results showed an increase (P < 0.001) in ZBA rate related to control samples in basal medium that contained BSA, calcium, and bicarbonate (1.97 ± 0.19 vs. 1.31 ± 0.09 sperm bound/oocyte, respectively). A significant correlation between protein tyrosine phosphorylation and ZBA rate (P < 0.05, r = 0.501) corroborated that incubation in a "high-cAMP" environment improves the fertilizing ability of ram spermatozoa. Likewise, the presence of two seminal plasma (SP) proteins able to protect sperm against cold shock (RSVP14 and RSVP20) was evidenced in both SP and the ram sperm surface, and their influence in the fertilizing ability of spermatozoa capacitated in basal medium or with cAMP-elevating agents was determined. The results verified that RSVP14 and RSVP20 act as decapacitating factors given that their addition to SP-free sperm samples previously to capacitation maintained high proportions of the noncapacitated sperm pattern with no increase in protein tyrosine phosphorylation. However, the obtained ZBA rate in the high-cAMP-containing samples was increased in the presence of RSVP20 (P < 0.05). These findings would indicate that the stimulating effect exerted by this protein on the sperm-oocyte binding occurs downstream from the cAMP generation and that the mechanisms by which RSVP20 promotes the zona pellucida binding might be independent of protein tyrosine phosphorylation.

  13. Sperm-macrophage interaction in the mouse: a quantitative assay in vitro using 111indium oxine-labeled sperm

    SciTech Connect

    Olive, D.L.; Weinberg, J.B.; Haney, A.F.

    1987-12-01

    The role of reproductive tract macrophages in contraception and reproductive failure has become widely recognized. However, in vitro analysis of sperm phagocytosis by macrophages has relied upon a semi-quantitative method of sperm counting that is of limited accuracy and reproducibility. We have developed an assay using murine sperm labeled with /sup 111/indium oxine, and results indicate the labeling to be rapid and efficient. Incorporation of /sup 111/indium into sperm increased the dose and sperm concentration and reached 90% maximal uptake after 15 min incubation, with maximal uptake occurring at 30 min. No decrease in sperm motility was noted with levels of oxine in excess of those required for significant labeling. Maximal labeling efficiency occurred in phosphate-buffered saline (PBS), with Dulbecco's modified Eagle's medium (DMEM) + 10% adult bovine serum (ABS) producing significantly less uptake. Label dissociation was detectable in PBS at room temperature, but at 37 degrees C in DMEM + 10% ABS, loss of label occurred at a rate of 23.5%/h. Addition of labeled sperm to murine macrophage monolayers under optimal conditions resulted in uptake of /sup 111/indium by macrophages, while free label was unincorporated. Results indicated assay specificity for macrophage-limited uptake, with insignificant label uptake by nonphagocytic murine fibroblasts and better sensitivity than sperm counting. Macrophages from Bacillus Calmette-Guerin (BCG)-infected mice resulted in a decrease in sperm uptake. Female macrophages showed greater capacity for sperm uptake than those of the male mouse. These initial studies demonstrated the utility of this model system in enhancing the understanding of sperm-macrophage interaction in the female reproductive tract.

  14. Role of calcium on the initiation of sperm motility in the European eel.

    PubMed

    Pérez, Luz; Vílchez, M Carmen; Gallego, Víctor; Morini, Marina; Peñaranda, David S; Asturiano, Juan F

    2016-01-01

    Sperm from European eel males treated with hCGrec was washed in a calcium free extender, and sperm motility was activated both in the presence (seawater, SW) and in the absence of calcium (NaCl+EDTA), and treated with calcium inhibitors or modulators. The sperm motility parameters were evaluated by a computer-assisted sperm analysis (CASA) system, and changes in the [Ca(2+)]i fluorescence (and in [Na(+)]i in some cases) were evaluated by flow cytometry. After sperm motility was activated in a medium containing Ca(2+) (seawater, SW) the intracellular fluorescence emitted by Ca(2+) increased 4-6-fold compared to the levels in quiescent sperm. However, while sperm activation in a Ca-free media (NaCl+EDTA) resulted in a percentage of motility similar to seawater, the [Ca(2+)]i levels did not increase at all. This result strongly suggests that increasing [Ca(2+)]i is not a pre-requisite for the induction of sperm motility in European eel sperm. Several sperm velocities (VCL, VSL, VAP) decreased when sperm was activated in the Ca-free activator, thus supporting the theory that Ca(2+) has a modulatory effect on sperm motility. The results indicate that a calcium/sodium exchanger (NCX) which is inhibited by bepridil and a calcium calmodulin kinase (inhibited by W-7), are involved in the sperm motility of the European eel. Our results indicate that the increase in [Ca(2+)]i concentrations during sperm activation is due to an influx from the external medium, but, unlike in most other species, it does not appear to be necessary for the activation of motility in European eel sperm.

  15. Biodiversity increases the productivity and stability of phytoplankton communities.

    PubMed

    Corcoran, Alina A; Boeing, Wiebke J

    2012-01-01

    Global biodiversity losses provide an immediate impetus to elucidate the relationships between biodiversity, productivity and stability. In this study, we quantified the effects of species richness and species combination on the productivity and stability of phytoplankton communities subject to predation by a single rotifer species. We also tested one mechanism of the insurance hypothesis: whether large, slow-growing, potentially-defended cells would compensate for the loss of small, fast-growing, poorly-defended cells after predation. There were significant effects of species richness and species combination on the productivity, relative yield, and stability of phytoplankton cultures, but the relative importance of species richness and combination varied with the response variables. Species combination drove patterns of productivity, whereas species richness was more important for stability. Polycultures containing the most productive single species, Dunaliella, were consistently the most productive. Yet, the most species rich cultures were the most stable, having low temporal variability in measures of biomass. Polycultures recovered from short-term negative grazing effects, but this recovery was not due to the compensation of large, slow-growing cells for the loss of small, fast-growing cells. Instead, polyculture recovery was the result of reduced rotifer grazing rates and persisting small species within the polycultures. Therefore, although an insurance effect in polycultures was found, this effect was indirect and unrelated to grazing tolerance. We hypothesize that diverse phytoplankton assemblages interfered with efficient rotifer grazing and that this "interference effect" facilitated the recovery of the most productive species, Dunaliella. In summary, we demonstrate that both species composition and species richness are important in driving patterns of productivity and stability, respectively, and that stability in biodiverse communities can result from an

  16. Reliable single sperm cryopreservation in Cell Sleepers for azoospermia management.

    PubMed

    Coetzee, K; Ozgur, K; Berkkanoglu, M; Bulut, H; Isikli, A

    2016-03-01

    Conventional sperm freezing methods perform best when freezing sperm samples containing at least hundreds of spermatozoa. In this severe male factor infertility case series, we examined the reproductive outcomes in 12 intracytoplasmic sperm injection cases where spermatozoa used were frozen in Cell Sleepers. Cell Sleepers are novel devices in which individual spermatozoa can be frozen in microdroplets. The case series included five men with obstructive azoospermia, six with nonobstructive azoospermia and one with cryptozoospermia, in whom microscopic sperm retrievals from testicular sperm extraction (TESE), micro-TESE extracts and a centrifugation procedure resulted in less than 50 spermatozoa. A total of 304 microscopically retrieved spermatozoa were frozen in 20 Cell Sleepers using a rapid manual cryopreservation method. A total of 179 mature oocytes were injected with recovered thawed spermatozoa, resulting in a fertilisation rate of 65.9% (118 of 179), with no total fertilisation failures. In 10 cases, an embryo transfer was performed, three on day 3 and seven on day 5, resulting in a per cycle pregnancy rate of 58.3% (seven of 12). Four of the pregnancies have progressed past 20 gestation weeks. The recovery and use of spermatozoa that were frozen in Cell Sleepers was uncomplicated and effective and eliminated the need to perform any microscopic sperm retrieval procedures on the day of oocyte collection. Modification of the routine sperm cryopreservation methodology to include the use of Cell Sleepers increases the range of sperm samples that can be effectively cryopreserved, to include men with severe male factor fertility.

  17. Response of boar sperm to the treatment with cholesterol-loaded cyclodextrins added prior to cryopreservation.

    PubMed

    Blanch, E; Tomás, C; Graham, J K; Mocé, E

    2012-12-01

    Cryopreserved boar sperm is not used extensively for artificial insemination, owing to the poor fertility rates of the sperm after freezing and thawing. The sperm membrane is damaged as the cells are cooled from body temperature to 5°C (cold shock), as well as during the freeze-thaw process. Increasing the cholesterol content of boar sperm membranes could help them survive cryopreservation, similar to sperm from other species that are cold shock sensitive. The aim of this study was to determine the optimal cholesterol-loaded cyclodextrin (CLC) concentration to use for boar sperm cryopreservation, and the influence of CLCs on the cryosurvival of sperm from boars classified as good or poor freezers. Treating boar sperm with 1 mg of CLC/120 × 10(6) sperm slightly improved (p < 0.05) the percentage of viable sperm after freezing-thawing. On the other hand, sperm, from both good and poor freezers, responded similarly to CLC treatment. Nevertheless, additional studies will be needed to study the effect of this treatment on other parameters of sperm quality.

  18. Trade-off between carotenoid-based sexual ornamentation and sperm resistance to oxidative challenge.

    PubMed

    Tomášek, Oldřich; Albrechtová, Jana; Němcová, Martina; Opatová, Pavlína; Albrecht, Tomáš

    2017-01-25

    It has been hypothesized that carotenoid-based sexual ornamentation signals male fertility and sperm competitive ability as both ornamentation and sperm traits may be co-affected by oxidative stress, resulting in positive covariation (the 'redox-based phenotype-linked fertility hypothesis'; redox-based PLFH). On the other hand, the 'sperm competition theory' (SCT) predicts a trade-off between precopulatory and postcopulatory traits. Here, we manipulate oxidative status (using diquat dibromide) and carotenoid availability in adult zebra finch (Taeniopygia guttata) males in order to test whether carotenoid-based beak ornamentation signals, or is traded off against, sperm resistance to oxidative challenge. Initial beak colouration, but not its change during the experiment, was associated with effect of oxidative challenge on sperm velocity, such that more intense colouration predicted an increase in sperm velocity under control conditions but a decline under oxidative challenge. This suggests a long-term trade-off between ornament expression and sperm resistance to oxidative challenge. Shortening of the sperm midpiece following oxidative challenge further suggests that redox homeostasis may constrain sperm morphometry. Carotenoid supplementation resulted in fewer sperm abnormalities but had no effect on other sperm traits. Overall, our data challenge the redox-based PLFH, partially support the SCT and highlight the importance of carotenoids for normal sperm morphology.

  19. Raman spectroscopy of DNA packaging in individual human sperm cells distinguishes normal from abnormal cells.

    PubMed

    Huser, Thomas; Orme, Christine A; Hollars, Christopher W; Corzett, Michele H; Balhorn, Rod

    2009-05-01

    Healthy human males produce sperm cells of which about 25-40% have abnormal head shapes. Increases in the percentage of sperm exhibiting aberrant sperm head morphologies have been correlated with male infertility, and biochemical studies of pooled sperm have suggested that sperm with abnormal shape may contain DNA that has not been properly repackaged by protamine during spermatid development. We have used micro-Raman spectroscopy to obtain Raman spectra from individual human sperm cells and examined how differences in the Raman spectra of sperm chromatin correlate with cell shape. We show that Raman spectra of individual sperm cells contain vibrational marker modes that can be used to assess the efficiency of DNA-packaging for each cell. Raman spectra obtained from sperm cells with normal shape provide evidence that DNA in these sperm is very efficiently packaged. We find, however, that the relative protein content per cell and DNA packaging efficiencies are distributed over a relatively wide range for sperm cells with both normal and abnormal shape. These findings indicate that single cell Raman spectroscopy should be a valuable tool in assessing the quality of sperm cells for in-vitro fertilization.

  20. Raman Spectroscopy of DNA Packaging in Individual Human Sperm Cells distinguishes Normal from Abnormal Cells

    SciTech Connect

    Huser, T; Orme, C; Hollars, C; Corzett, M; Balhorn, R

    2009-03-09

    Healthy human males produce sperm cells of which about 25-40% have abnormal head shapes. Increases in the percentage of sperm exhibiting aberrant sperm head morphologies have been correlated with male infertility, and biochemical studies of pooled sperm have suggested that sperm with abnormal shape may contain DNA that has not been properly repackaged by protamine during spermatid development. We have used micro-Raman spectroscopy to obtain Raman spectra from individual human sperm cells and examined how differences in the Raman spectra of sperm chromatin correlate with cell shape. We show that Raman spectra of individual sperm cells contain vibrational marker modes that can be used to assess the efficiency of DNA-packaging for each cell. Raman spectra obtained from sperm cells with normal shape provide evidence that DNA in these sperm is very efficiently packaged. We find, however, that the relative protein content per cell and DNA packaging efficiencies are distributed over a relatively wide range for sperm cells with both normal and abnormal shape. These findings indicate that single cell Raman spectroscopy should be a valuable tool in assessing the quality of sperm cells for in-vitro fertilization.

  1. Polyandry in the medfly - shifts in paternity mediated by sperm stratification and mixing

    PubMed Central

    2014-01-01

    Background In the Mediterranean fruit fly (medfly), Ceratitis capitata, a highly invasive agricultural pest species, polyandry, associated with sperm precedence, is a recurrent behaviour in the wild. The absence of tools for the unambiguous discrimination between competing sperm from different males in the complex female reproductive tract has strongly limited the understanding of mechanisms controlling sperm dynamics and use. Results Here we use transgenic medfly lines expressing green or red fluorescent proteins in the spermatozoa, which can be easily observed and unambiguously differentiated within the female fertilization chamber. In twice-mated females, one day after the second mating, sperm from the first male appeared to be homogenously distributed all over the distal portion of each alveolus within the fertilization chamber, whereas sperm from the second male were clearly concentrated in the central portion of each alveolus. This distinct stratified sperm distribution was not maintained over time, as green and red sperm appeared homogeneously mixed seven days after the second mating. This dynamic sperm storage pattern is mirrored by the paternal contribution in the progeny of twice-mated females. Conclusions Polyandrous medfly females, unlike Drosophila, conserve sperm from two different mates to fertilize their eggs. From an evolutionary point of view, the storage of sperm in a stratified pattern by medfly females may initially favour the fresher ejaculate from the second male. However, as the second male's sperm gradually becomes depleted, the sperm from the first male becomes increasingly available for fertilization. The accumulation of sperm from different males will increase the overall genetic variability of the offspring and will ultimately affect the effective population size. From an applicative point of view, the dynamics of sperm storage and their temporal use by a polyandrous female may have an impact on the Sterile Insect Technique (SIT

  2. Removing seminal plasma improves bovine sperm sex-sorting.

    PubMed

    Steinhauser, C B; Graham, J K; Lenz, R W; Seidel, G E

    2016-11-01

    Bull ejaculates with sperm concentrations of less than 1 billion sperm sort poorly for sex chromosomes, but whether this is because of the sperm concentration or the concomitant seminal plasma content has not been elucidated. Experiments were conducted to determine why ejaculates with lower sperm concentrations sort poorly and develop a protocol to increase sorting efficiency. In Experiment I, spermatozoa at 160 or 240 × 10(6) sperm/mL were stained at 49, 65 or 81 μm Hoechst 33342 with 0 or 10% seminal plasma and then sex-sorted. In Experiment II, seminal plasma was adjusted to create samples with sperm concentrations of 0.7, 1.4 and 2.1 × 10(9) sperm/mL, prior to sex-sorting. In Experiment III, spermatozoa were diluted to 0.7, 1.4 and 2.1 × 10(9) sperm/mL using TALP containing 0 or 10% seminal plasma prior to sex-sorting and cryopreservation. In Experiment I, the optimal staining combination was 160 × 10(6) sperm/mL stained with 65 μm Hoechst 33342 and no seminal plasma. In Experiment II, the percentages of membrane-impaired sperm were lower for sample concentrations of 2.1 × 10(9) sperm/mL (15%) than for samples at 1.4 × 10(9) (17%) or 0.7 × 10(9) sperm/mL (18%; p < 0.01). The X sort rate was slower for samples stored at 0.7 × 10(9) sperm/mL (3.45 × 10(3) sperm/sec) than for samples stored at 1.4 × 10(9) and 2.1 × 10(9) sperm/mL (3.85 and 3.94 × 10(3) sperm/sec, respectively; p < 0.05). In Experiment III, samples containing 0% seminal plasma had higher percentages of live-oriented cells (54 vs. 50%; p < 0.05), fewer dead sperm (19 vs. 22%; p < 0.01) and higher post-thaw motility (41 vs. 35%; p < 0.05) than samples containing 10% seminal plasma. Ejaculates with high sperm concentrations result in superior sorting because these samples have less seminal plasma during staining than ejaculates with lower initial sperm concentrations as all samples are diluted to 160 × 10(6) sperm/mL for staining. Therefore, sorting

  3. Effect of various commercial buffers on sperm viability and capacitation.

    PubMed

    Andrisani, Alessandra; Donà, Gabriella; Ambrosini, Guido; Bonanni, Guglielmo; Bragadin, Marcantonio; Cosmi, Erich; Clari, Giulio; Armanini, Decio; Bordin, Luciana

    2014-08-01

    A wide variety of sperm preparation protocols are currently available for assisted conception. They include density gradient separation and washing methods. Both aim at isolating and capacitating as much motile sperm as possible for subsequent oocyte fertilization. The aim of this study was to examine the effects of four commercial sperm washing buffers on sperm viability and capacitation. Semen samples from 48 healthy donors (normal values of sperm count, motility, morphology, and volume) were analyzed. After separation (density gradient 40/80%), sperm were incubated in various buffers then analysed for reactive oxygen species (ROS) production, viability, tyrosine phosphorylation (Tyr-P), cholera toxin B subunit (CTB) labeling, and the acrosome reaction (AR). The buffers affected ROS generation in various ways resulting either in rapid cell degeneration (when the amount of ROS was too high for cell survival) or the inability of the cells to maintain correct functioning (when ROS were too few). Only when the correct ROS generation curve was maintained, suitable membrane reorganization, evidenced by CTB labeling was achieved, leading to the highest percentages of both Tyr-P- and acrosome-reacted-cells. Distinguishing each particular pathological state of the sperm sample would be helpful to select the preferred buffer treatment since both ROS production and membrane reorganization can be significantly altered by commercial buffers.

  4. Effects of chloroformic extracts from washed and unwashed papaya seeds (Carica papaya) on the sperm concentration of dogs.

    PubMed

    Ortega-Pacheco, A; Jiménez-Coello, M; Gutiérrez-Blanco, E; Acosta-Viana, K Y; Guzmán-Marín, E; Zavala-Sánchez, M A; Montalvo-Beltrán, N E; Pérez-Gutiérrez, M S

    2010-12-01

    Papaya seeds (Carica papaya Linn) have been found to have a significant effect on sperm characteristics in some mammals, including humans, but no studies have investigated the effects on dogs. In the present study, a significant decrease in sperm concentration was observed in a group of dogs treated with extracts from washed papaya seeds, but no decrease was observed in the group of dogs treated with non-washed seeds. An important effect of extract components from washed seeds such as fatty acids is probably involved in the reduction of sperm production because of Sertoli cell damage, as has been suggested for langur monkeys. Dilution of the active components in the non-washed papaya seeds or interference with some of the components may reduce the expected effect on spermatogenesis. This first report on the effects of a chloroformic extract of papaya seeds in dogs suggests that an increased dose is necessary to achieve azoospermia.

  5. Drill-in fluid reduces formation damage, increases production rates

    SciTech Connect

    Hands, N.; Kowbel, K.; Nouris, R.

    1998-07-13

    A sodium formate drill-in fluid system reduced formation damage, resulting in better-than-expected production rates for an off-shore Dutch development well. Programmed to optimize production capacity and reservoir drainage from a Rotliegend sandstone gas discovery, the 5-7/8-in. subhorizontal production interval was drilled and completed barefoot with a unique, rheologically engineered sodium formate drill-in fluid system. The new system, consisting of a sodium formate (NaCOOH) brine as the base fluid and properly sized calcium carbonate as the formation-bridging agent, was selected on the basis of its well-documented record in reducing solids impairment and formation damage in similar sandstone structures in Germany. The system was engineered around the low-shear-rate viscosity (LSRV) concept, designed to provide exceptional rheological properties. After describing the drilling program, the paper gives results on the drilling and completion.

  6. An effective increase in milk production through triticale feeding.

    PubMed

    Derbal, Nora; Benbelkacem, A; Dib, Y

    2014-01-01

    Since the first studies in Algeria in 1999, 2002 and 2005, triticale has been used in arid and semi-arid areas mainly for livestock production. Efforts have been done for the utilization of triticale as hay, silage and hole grain to feed dairy cattle and small ruminants (sheep). Studies have shown that triticale could be easily integrated in the existing crop-livestock system of northern Algeria. In spite of the good results in the yield performance and adaptation to diverse environments, decision makers are not giving the necessary attention to triticale. Dairy cattle holders that tested the crop have adopted it quickly and developed it in an informal way. Now, more than 90% of the triticale seed business is in the hands of private farmers without any help or subsidies nor a good price policy to develop strongly this crop. The utilization of triticale in Algeria is roughly as follow: human consumption 5%, forage crop (hay or silage) 60% and 30% as feed grain, the remaining 5% are kept for sowing seed. In our studies we have compared different feed sources (barley, triticale, concentrate diet and mixtures) to dairy cattle and sheep. Triticale showed highly significantly better results for meat production and gave also an amazing response for dairy and sheep milk production in Algeria. Milk production of animals fed with triticale over exceeded the other feed sources by 26% to 53%; mean weight gain exhibited the same rates.

  7. Disrupting Faculty Service: Using Technology to Increase Academic Service Productivity

    ERIC Educational Resources Information Center

    Burnett, Perry; Shemroske, Kenneth; Khayum, Mohammed

    2014-01-01

    Scholarly attention regarding faculty involvement has primarily focused on faculty opinions of shared governance and faculty influence on institutional decision-making. There has been limited attention given to academic service productivity and the effectiveness of traditional approaches toward the accomplishment of faculty service requirements.…

  8. Effect of staining and sorting on boar sperm membrane integrity, mitochondrial activity and in vitro blastocyst development.

    PubMed

    Spinaci, M; De Ambrogi, M; Volpe, S; Galeati, G; Tamanini, C; Seren, E

    2005-07-01

    The objective of this study was to determine the effects of staining with Hoechst 33342 and of the entire sorting procedure on boar sperm membrane integrity (using Annexin-V/PI), mitochondrial activity (using JC-1/SYBR/PI) and blastocyst development in vitro; the effect of storage at 17 degrees C for 24h prior to Hoechst staining and sorting was also investigated. The Hoechst staining and the whole sorting procedure reduced the percent of live spermatozoa in both fresh (day 0) and stored (day 1) semen, as determined by both assays; nevertheless, there was no increase in live sperm cells showing signs of early damage (Annexin-V positive, propidium negative), whose percentages remained nearly zero. The majority of Annexin-V positive cells were propidium positive, therefore dead. JC-1 staining evidenced a correlation between mitochondrial activity and viability. However, a significant difference between viable sperm cells and sperm cells with active mitochondria was detected in control and stained sperm, whereas almost all viable sorted spermatozoa had active mitochondria. No significant differences in the in vitro produced blastocysts both on day 0 and 1 were observed. In conclusion, despite the damages induced by sorting procedures, semen sorted as fresh or after storage at 17 degrees C can be successfully used for in vitro production of pig embryos.

  9. Morphological study of boar sperm during their passage through the female genital tract

    PubMed Central

    GARCÍA-VÁZQUEZ, Francisco Alberto; HERNÁNDEZ-CARAVACA, Iván; MATÁS, Carmen; SORIANO-ÚBEDA, Cristina; ABRIL-SÁNCHEZ, Silvia; IZQUIERDO-RICO, María José

    2015-01-01

    Once deposited in the female tract, sperm face a series of challenges that must be overcome to ensure the presence of an adequate normal sperm population close to the site of fertilization. Our aim was to evaluate the influence of the uterine milieu on boar sperm morphology. In experiment 1, sperm morphology was evaluated in the backflow (60 min after insemination) and within the uterotubal junction (UTJ) (collected ~24 h after insemination) following intrauterine sperm deposition (n = 6) and compared with the morphology of the sperm in the insemination dose. In experiment 2, the influence of the uterine fluid (UF) on sperm morphological modifications was evaluated. For this purpose, ejaculated (n = 4) and epididymal (n = 4) sperm were in vitro incubated with or without UF for 2 and 24 h. In both experiments, sperm were classified as normal, having a cytoplasmic droplet (proximal or distal) or having tail defects. The results of experiment 1 pointed to an increase in morphologically abnormal sperm collected in the backflow (27.70%) and a reduction of the same in the UTJ (2.12%) compared with the insemination dose (17.75%) (P < 0.05). In experiment 2, incubation of ejaculated sperm with UF did not provoke any morphological modifications; however, when epididymal sperm were incubated with UF, a pronounced increase in the percentage of normal sperm was evident after 24 h compared with the initial dose (from 25.77% to 53.58%, P < 0.05), mainly due to distal cytoplasmatic droplet shedding (53.22 vs. 20.20%). In conclusion, almost all the sperm that colonize the UTJ had a normal morphology, with part of the abnormal sperm having been discarded in the backflow and part selected/modified on their way to the oviduct. UF seems to influence cytoplasmic distal droplet removal, as demonstrated previously in seminal plasma. PMID:26119829

  10. Protective effect of royal jelly on the sperm parameters and testosterone level and lipid peroxidation in adult mice treated with oxymetholone

    PubMed Central

    Zahmatkesh, Ensieh; Najafi, Gholamreza; Nejati, Vahid; Heidari, Reza

    2014-01-01

    Objectives : The aim of the present study was to evaluate protective effect of royal jelly on sperm parameters, testosterone level, and malondialdehyde (MDA) production in mice. Materials and Methods: Thirty-two adult male NMRI mice weighing 30±2 g were used. All the animals were divided into 4 groups. Control group: received saline 0.1 ml/mouse/day orally for 30 days. Royal jelly group (RJ): received royal jelly at dose of 100 mg/kg daily for 30 days orally. Oxymetholone group: the received Oxymetholone (OX) at dose of 5 mg/kg daily for 30 days orally. Royal jelly+Oxymetholone group: received royal jelly at dose of 100 mg/kg/day orally concomitant with OX administration. Sperm count, sperm motility, viability, maturity, and DNA integrity were analyzed. Furthermore, serum testosterone and MDA concentrations were determined. Results: In Oxymetholone group, sperm count, motility as well as testosterone concentration reduced significantly (p<0.05), while significant (p<0.05) increases in immature sperm, sperm with DNA damaged, and MDA concentration were announced in Oxymetholone group in comparison with control group and Royal jelly+Oxymetholone group. RJ caused partially amelioration in all of the above- mentioned parameters in Royal Jelly+Oxymetholone group. Conclusion: In conclusion, RJ may be used in combination with OX to improve OX-induced oxidative stress and male infertility. PMID:25050300

  11. Viewing death on television increases the appeal of advertised products.

    PubMed

    Dar-Nimrod, Ilan

    2012-01-01

    References to death abound in many television programs accessible to most people. Terror Management Theory postulates that existential anxiety, which death reminders activate, may reinforce materialistic tendencies. The current article explores the effect of a death reminder in television shows on the desirability of advertised products. Consistent with Terror Management Theory's predictions, in two studies participants show greater desire for products, which were advertised immediately following clips from programs that featured a death scene, compared with programs that did not. Cognitive accessibility of death predicted the appeal difference while changes in affect or interest in the show did not. The findings are discussed in light on affective and existential theories which make opposite predictions. Implications and future directions are considered.

  12. Potential strategies for increasing drug-discovery productivity.

    PubMed

    Cumming, John G; Finlay, M Raymond V; Giordanetto, Fabrizio; Hemmerling, Martin; Lister, Troy; Sanganee, Hitesh; Waring, Michael J

    2014-04-01

    The productivity challenge facing the pharmaceutical industry is well documented. Strategies to improve productivity have mainly focused on enhancing efficiency, such as the application of Lean Six Sigma process improvement methods and the introduction of modeling and simulation in place of 'wet' experiments. While these strategies have their benefits, the real challenge is to improve effectiveness by reducing clinical failure rates. We advocate redesigning the screening cascade to identify and optimize novel compounds with improved efficacy against disease, not just with improved potency against the target. There should be greater use of disease-relevant phenotypic screens in conjunction with target-based assays to drive medicinal chemistry optimization. An opportunistic approach to polypharmacology is recommended. There should also be more emphasis on optimization of the molecular mechanism of action incorporating understanding of binding kinetics, consideration of covalent drug strategies and targeting allosteric modulators.

  13. Viewing Death on Television Increases the Appeal of Advertised Products

    PubMed Central

    DAR-NIMROD, ILAN

    2012-01-01

    References to death abound in many television programs accessible to most people. Terror Management Theory (TMT) postulates that existential anxiety, which death reminders activate, may reinforce materialistic tendencies. The current paper explores the effect of a death reminder in television shows on the desirability of advertised products. Consistent with TMT's predictions, in two studies participants show greater desire for products, which were advertised immediately following clips from programs that featured a death scene, compared with programs that did not. Cognitive accessibility of death predicted the appeal difference while changes in affect or interest in the show did not. The findings are discussed in light on affective and existential theories which make opposite predictions. Implications and future directions are considered. PMID:22468421

  14. Increasing Cropping System Diversity Balances Productivity, Profitability and Environmental Health

    PubMed Central

    Davis, Adam S.; Hill, Jason D.; Chase, Craig A.; Johanns, Ann M.; Liebman, Matt

    2012-01-01

    Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and large negative impacts on the environment. We hypothesized that cropping system diversification would promote ecosystem services that would supplement, and eventually displace, synthetic external inputs used to maintain crop productivity. To test this, we conducted a field study from 2003–2011 in Iowa that included three contrasting systems varying in length of crop sequence and inputs. We compared a conventionally managed 2-yr rotation (maize-soybean) that received fertilizers and herbicides at rates comparable to those used on nearby farms with two more diverse cropping systems: a 3-yr rotation (maize-soybean-small grain + red clover) and a 4-yr rotation (maize-soybean-small grain + alfalfa-alfalfa) managed with lower synthetic N fertilizer and herbicide inputs and periodic applications of cattle manure. Grain yields, mass of harvested products, and profit in the more diverse systems were similar to, or greater than, those in the conventional system, despite reductions of agrichemical inputs. Weeds were suppressed effectively in all systems, but freshwater toxicity of the more diverse systems was two orders of magnitude lower than in the conventional system. Results of our study indicate that more diverse cropping systems can use small amounts of synthetic agrichemical inputs as powerful tools with which to tune, rather than drive, agroecosystem performance, while meeting or exceeding the performance of less diverse systems. PMID:23071739

  15. Increasing cropping system diversity balances productivity, profitability and environmental health.

    PubMed

    Davis, Adam S; Hill, Jason D; Chase, Craig A; Johanns, Ann M; Liebman, Matt

    2012-01-01

    Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and large negative impacts on the environment. We hypothesized that cropping system diversification would promote ecosystem services that would supplement, and eventually displace, synthetic external inputs used to maintain crop productivity. To test this, we conducted a field study from 2003-2011 in Iowa that included three contrasting systems varying in length of crop sequence and inputs. We compared a conventionally managed 2-yr rotation (maize-soybean) that received fertilizers and herbicides at rates comparable to those used on nearby farms with two more diverse cropping systems: a 3-yr rotation (maize-soybean-small grain + red clover) and a 4-yr rotation (maize-soybean-small grain + alfalfa-alfalfa) managed with lower synthetic N fertilizer and herbicide inputs and periodic applications of cattle manure. Grain yields, mass of harvested products, and profit in the more diverse systems were similar to, or greater than, those in the conventional system, despite reductions of agrichemical inputs. Weeds were suppressed effectively in all systems, but freshwater toxicity of the more diverse systems was two orders of magnitude lower than in the conventional system. Results of our study indicate that more diverse cropping systems can use small amounts of synthetic agrichemical inputs as powerful tools with which to tune, rather than drive, agroecosystem performance, while meeting or exceeding the performance of less diverse systems.

  16. Physiological hypercortisolemia increases proteolysis, glutamine, and alanine production

    SciTech Connect

    Darmaun, D.; Matthews, D.E.; Bier, D.M. Cornell Univ. Medical College, New York, NY )

    1988-09-01

    Physiological elevations of plasma cortisol levels, as are encountered in stress and severe trauma, were produced in six normal subjects by infusing them with hydrocortisone for 64 h. Amino acid kinetics were measured in the postabsorptive state using three 4-h infusions of L-(1-{sup 13}C)leucine, L-phenyl({sup 2}H{sub 5})phenylalanine, L-(2-{sup 15}N)glutamine, and L-(1-{sup 13}C)alanine tracers (1) before, (2) at 12 h, and (3) at 60 h of cortisol infusion. Before and throughout the study, the subjects ate a normal diet of adequate protein and energy intake. The cortisol infusion raised plasma cortisol levels significantly from 10 {plus minus} 1 to 32 {plus minus} 4 {mu}g/dl, leucine flux from 83 {plus minus} 3 to 97 {plus minus} 3 {mu}mol{center dot}kg{sup {minus}1}{center dot}h{sup {minus}1}, and phenylalanine flux from 34 {plus minus} 1 to 39 {plus minus} 1 (SE) {mu}mol{center dot}kg{sup {minus}1}{center dot}h{sup {minus}1} after 12 h of cortisol infusion. These increases were maintained until the cortisol infusion was terminated. These nearly identical 15% increases in two different essential amino acid appearance rates are reflective of increased whole body protein breakdown. Glutamine flux rose by 12 h of cortisol infusion and remained elevated at the same level at 64 h. The increase in flux was primarily due to a 55% increase in glutamine de novo synthesis. Alanine flux increased with acute hypercortisolemia and increased further at 60 h of cortisol infusion, a result primarily of increased alanine de novo synthesis. Insulin, alanine, and lactate plasma levels responded similarly with significant rises between the acute and chronic periods of cortisol infusion. Thus hypercortisolemia increases both protein breakdown and the turnover of important nonessential amino acids for periods of up to 64 h.

  17. Shedding light on the controversy surrounding the temporal decline in human sperm counts: a systematic review.

    PubMed

    Cocuzza, Marcello; Esteves, Sandro C

    2014-01-01

    We systematically examined the evidence of declining sperm counts and the hypothesis that an increased exposure to environmental pollutants is responsible for such decline. Search engines, including PUBMED, MEDLINE, EMBASE, BIOSIS, and Cochrane library, were used to identify epidemiologic studies published from 1985 to 2013. We concluded that there is no enough evidence to confirm a worldwide decline in sperm counts. Also, there seems to be no scientific truth of a causative role for endocrine disruptors in the temporal decline of sperm production. Such assumptions are based on few meta-analyses and retrospective studies, while other well-conducted researches could not confirm these findings. We acknowledge that difficult-to-control confounding factors in the highly variable nature of semen, selection criteria, and comparability of populations from different time periods in secular-trend studies, the quality of laboratory methods for counting sperm, and apparently geographic variations in semen quality are the main issues that complicate the interpretation of the available evidence. Owing to the importance of this subject and the uncertainties still prevailing, there is a need not only for continuing monitoring of semen quality, reproductive hormones, and xenobiotics, but also for a better definition of fecundity.

  18. Enhanced precipitation variability decreases grass- and increases shrub-productivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present resul...

  19. Sperm transport after insemination in the Alpine newt (Triturus alpestris, Caudata, Salamandridae).

    PubMed

    Osikowski, Artur

    2007-01-01

    The goal of this study was to test if sperm transport to the spermathecae in the Alpine newt (Triturus alpestris) requires active co-operation of the female. Artificial insemination of anaesthetised female newts was conducted using spermatophores collected from courting males and with sperm duct contents collected from sacrificed males. Sperm was present in the spermathecae of 9 out of 10 females inseminated with the spermatophores but in only 1 out of 8 females inseminated with sperm duct contents. The females of both groups laid some eggs after insemination, and a portion of these eggs in group of females inseminated with spermatophores were fertilized. However, the number of eggs produced by the females was much lower than typical egg-production in newts. The presence of sperm in the spermathecae of females inseminated with spermatophores and lack of sperm in the spermathecae of females inseminated with sperm duct contents suggests that sperm transport is either induced by the substances present in spermatophores and/or that sperm from the sperm duct is not fully mobile in comparison with sperm from the spermatophores.

  20. Hyaluronic acid delays boar sperm capacitation after 3 days of storage at 15 degrees C.

    PubMed

    Yeste, M; Briz, M; Pinart, E; Sancho, S; Garcia-Gil, N; Badia, E; Bassols, J; Pruneda, A; Bussalleu, E; Casas, I; Bonet, S

    2008-12-01

    The present study was undertaken to determine the effects of the addition of hyaluronic acid (HA), ranged from 12.5 to 200 microg/ml, on boar sperm capacitation status during a storage time (up to 3 days) at 15 degrees C in Beltsville thawing solution (BTS). The raw extender was the negative control whereas different concentrations of caffeine (CAF), ranged from 0.25 to 8mM, served as positive controls. Sperm viability, motility, morphology, and osmotic resistance were also determined before and after assessing the treatments. Samples were obtained from 28 healthy and post-pubertal Piétrain boars and sperm parameters were tested immediately after the addition of treatments and after 1, 2 and 3 days of refrigeration at 15 degrees C. Sperm capacitation status was determined by chlortetracycline (CTC) staining and sperm viability by means of a multiple fluorochrome-staining test. Sperm motility and morphology were assessed using phase-contrast microscopy accompanied by a computer assisted sperm analysis system (CASA). Whereas HA delayed sperm capacitation, CAF increased the frequency of capacitated spermatozoa after 2 days of cooling. Moreover, HA did not modify other sperm parameters, such as sperm velocity, whereas CAF increased progressive motility during the first 2 days of cooling and then decreased. It can be concluded that the addition of HA at 50 and 100 microg/ml to the BTS extender may delay sperm capacitation after 3 days of cooling.

  1. In vitro effects of nicotine on sperm motility and bio-functional flow cytometry sperm parameters.

    PubMed

    Condorelli, R A; La Vignera, S; Giacone, F; Iacoviello, L; Vicari, E; Mongioi', L; Calogero, A E

    2013-01-01

    The aim of this experimental study was to evaluate the effects of nicotine on sperm motility and on non-conventional sperm parameters in vitro. Capacitated spermatozoa isolated from 10 normozoospermic, healthy, non-smoker men were evaluated. Spermatozoa were exposed to increasing concentrations of nicotine (0, 1, 10, and 100 ng/ml) for 3 and 24 hours. Progressive motility and the following non-conventional sperm parameters, evaluated by flow cytometry, were assessed: mitochondrial membrane potential, viability, phosphatidylserine externalization, late apoptosis, degree of chromatin compactness, and DNA fragmentation. Nicotine suppressed, in a concentration-dependent manner, sperm progressive motility starting from the lowest concentration used (1 ng/ml). Similarly, it reduced the percentage of viable spermatozoa and increased the number of spermatozoa in late apoptosis, with altered chromatin compactness, or DNA fragmentation already after 3 hours of incubation. These effects were observed at a concentration similar (100 ng/ml) to that found in the seminal plasma of smokers (70 ng/ml), with the exception of the effects on sperm DNA fragmentation whose significant effect was detected also at a lower concentration (10 ng/ml). Nicotine may be regarded as a noxious component of cigarette smoke on the male reproductive function.

  2. Golbal Economic and Environmental Impacts of Increased Bioenergy Production

    SciTech Connect

    Wallace Tyner

    2012-05-30

    The project had three main objectives: to build and incorporate an explicit biomass energy sector within the GTAP analytical framework and data base; to provide an analysis of the impact of renewable fuel standards and other policies in the U.S. and E.U, as well as alternative biofuel policies in other parts of the world, on changes in production, prices, consumption, trade and poverty; and to evaluate environmental impacts of alternative policies for bioenergy development. Progress and outputs related to each objective are reported.

  3. Sperm Binding to Oviduct Epithelial Cells Enhances TGFB1 and IL10 Expressions in Epithelial Cells as Well as Neutrophils In Vitro: Prostaglandin E2 As a Main Regulator of Anti-Inflammatory Response in the Bovine Oviduct

    PubMed Central

    Yousef, Mohamed Samy; Marey, Mohamed Ali; Hambruch, Nina; Hayakawa, Hiroyuki; Shimizu, Takashi; Hussien, Hassan Ali; Abdel-Razek, Abdel-Razek Khalifa; Pfarrer, Christiane; Miyamoto, Akio

    2016-01-01

    Sperm are allogenic to the female genital tract; however, oviducts provide optimal conditions for survival and capacitation of these non-self cells until fertilization. Recently, we showed that oviduct-conditioned media and prostaglandin E2 (PGE2) suppress sperm phagocytosis by polymorphonuclear neutrophils (PMNs) under physiological conditions. We hypothesized that sperm binding to bovine oviduct epithelial cells (BOECs) could change the local innate immunity via PGE2. As the first step to obtain basic information, sub-confluent BOEC monolayers were co-cultured with swim-up sperm for 2 h. BOECs with viable bound sperm were cultured for an additional 3, 6, 12, or 24 h. Then, we confirmed the impact of the sperm-BOEC binding on both BOECs and PMN gene expression. Immunohistochemistry revealed that BOECs strongly express TGFB1 and IL10 in the oviduct. Sperm binding to BOECs in culture induced the anti-inflammatory cytokines (TGFB1 and IL10) and PGE2 production by BOECs. Exogenous PGE2 in vitro suppressed pro-inflammatory cytokine expression (TNF and IL1B) in BOECs. Moreover, pre-exposure of PMNs to BOEC-conditioned media suppressed the TNF expression, but the BOEC media co-cultured with sperm stimulated PMNs to express TGFB1 and IL10, with increasing PGE2 secretion. Of note, exogenous PGE2 led PMNs in vitro to decrease their TNF expression and increase anti-inflammatory cytokines expression. Our findings strongly suggest that BOECs provide an anti-inflammatory environment under physiological conditions and the sperm-BOEC binding further strengthens this milieu thus suppresses PMNs in the bovine oviduct. PGE2 is likely to drive this stable anti-inflammatory environment in the oviduct. PMID:27662642

  4. Methamidophos alters sperm function and DNA at different stages of spermatogenesis in mice

    SciTech Connect

    Urióstegui-Acosta, Mayrut; Hernández-Ochoa, Isabel; Sánchez-Gutiérrez, Manuel; Piña-Guzmán, Belem; Rafael-Vázquez, Leticia; Solís-Heredia, M.J.; Martínez-Aguilar, Gerardo; Quintanilla-Vega, Betzabet

    2014-09-15

    Methamidophos (MET) is a highly toxic organophosphate (OP) pesticide that is widely used in developing countries. MET has male reproductive effects, including decreased fertility. We evaluated MET effects on sperm quality, fertilization and DNA integrity, exploring the sensitivity of different stages of spermatogenesis. Adult male mice received MET (3.75 or 5 mg/kg-bw/ip/day/4 days) and were euthanized 1, 28 or 45 days post-treatment (dpt) to evaluate MET's effects on epididymal maturation, meiosis or mitosis, respectively. Spermatozoa were obtained from the cauda epididymis–vas deferens and were evaluated for sperm quality, acrosome reaction (AR; Coomassie staining), mitochondrial membrane potential (by JC-1), DNA damage (comet assay), oxidative damage (malondialdehyde (MDA) production), in vitro fertilization and protein phosphorylation (immunodetection), and erythrocyte acetylcholinesterase (AChE) activity. At 1-dpt, MET inhibited AChE (43–57%) and increased abnormal cells (6%). While at 28- and 45-dpt, sperm motility and viability were significantly reduced with an increasing MET dose, and abnormal morphology increased at 5 mg/kg/day/4 days. MDA and mitochondrial activity were not affected at any dose or time. DNA damage (OTM and %DNA) was observed at 5 mg/kg/day/4 days in a time-dependent manner, whereas both parameters were altered in cells from mice exposed to 3.75 mg/kg/day/4 days only at 28-dpt. Depending on the time of collection, initial-, spontaneous- and induced-AR were altered at 5 mg/kg/day/4 days, and the fertilization capacity also decreased. Sperm phosphorylation (at serine and tyrosine residues) was observed at all time points. Data suggest that meiosis and mitosis are the more sensitive stages of spermatogenesis for MET reproductive toxicity compared to epididymal maturation. - Highlights: • Methamidophos alters sperm cell function at different stages of spermatogenesis. • Testicular stages of spermatogenesis are more sensitive to

  5. Sperm storage mediated by cryptic female choice for nuptial gifts.

    PubMed

    Albo, Maria J; Bilde, Trine; Uhl, Gabriele

    2013-12-07

    Polyandrous females are expected to discriminate among males through postcopulatory cryptic mate choice. Yet, there is surprisingly little unequivocal evidence for female-mediated cryptic sperm choice. In species in which nuptial gifts facilitate mating, females may gain indirect benefits through preferential storage of sperm from gift-giving males if the gift signals male quality. We tested this hypothesis in the spider Pisaura mirabilis by quantifying the number of sperm stored in response to copulation with males with or without a nuptial gift, while experimentally controlling copulation duration. We further assessed the effect of gift presence and copulation duration on egg-hatching success in matings with uninterrupted copulations with gift-giving males. We show that females mated to gift-giving males stored more sperm and experienced 17% higher egg-hatching success, compared with those mated to no-gift males, despite matched copulation durations. Uninterrupted copulations resulted in both increased sperm storage and egg-hatching success. Our study confirms the prediction that the nuptial gift as a male signal is under positive sexual selection by females through cryptic sperm storage. In addition, the gift facilitates longer copulations and increased sperm transfer providing two different types of advantage to gift-giving in males.

  6. Role of prostatic fluid in cooled canine epididymal sperm.

    PubMed

    Hori, T; Masuda, T; Kobayashi, M; Kawakami, E

    2017-03-29

    In this study, sperms collected from the right and left cauda epididymis were grouped into having canine prostatic fluid (PF) sensitization or not diluted with egg yolk Tris-fructose citrate extender, and stored at 4°C. The necessity of canine PF in cooled preservation was determined by elucidating the sperm quality after the storage. As a result, while there was no difference among all groups up to 48 hr of storage, after storage for 96 hr and more, a significantly lower sperm motility was observed in the group without being sensitized to PF than the groups with being sensitized to PF (p < .05, p < .01). Although sperm abnormality increased in all groups with increased storage time, the group without being sensitized to PF showed significantly higher sperm abnormality than did the groups with being sensitized to PF after storage for 24 hr and more (p < .01). From these findings, we concluded that PF was necessary for the cooled preservation of the canine sperm because these sperms were protected from any effects of low temperatures by being sensitized to PF.

  7. The increasing importance of herbicides in worldwide crop production.

    PubMed

    Gianessi, Leonard P

    2013-10-01

    Herbicide use is increasingly being adopted around the world. Many developing countries (India, China, Bangladesh) are facing shortages of workers to hand weed fields as millions of people move from rural to urban areas. In these countries, herbicides are far cheaper and more readily available than labor for hand weeding. History shows that in industrializing countries in the past, including the United States, Germany, Japan and South Korea, the same phenomenon has occurred-as workers have left agriculture, herbicides have been adopted. It is inevitable that herbicide use will increase in sub-Saharan Africa, not only because millions of people are leaving rural areas, creating shortages of hand weeders, but also because of the need to increase crop yields. Hand weeding has never been a very efficient method of weed control-often performed too late and not frequently enough. Uncontrolled weeds have been a major cause of low crop yields in sub-Saharan Africa for a long time. In many parts of the world, herbicides are being increasingly used to replace tillage in order to improve environmental conditions. In comparison with tillage, herbicide use reduces erosion, fuel use, greenhouse gas emissions and nutrient run-off and conserves water.

  8. Increasing Your Productivity with Web-Based Surveys

    ERIC Educational Resources Information Center

    Wissmann, Mary; Stone, Brittney; Schuster, Ellen

    2012-01-01

    Web-based survey tools such as Survey Monkey can be used in many ways to increase the efficiency and effectiveness of Extension professionals. This article describes how Survey Monkey has been used at the state and county levels to collect community and internal staff information for the purposes of program planning, administration, evaluation and…

  9. Increased calf production in cattle selected for twin ovulations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of increasing fetal numbers and their distribution between the left and right uterine horns on calf survival, calf BW at birth and weaning, gestation length, dystocia, and calf sex ratio were evaluated for single (n = 1,587), twin (n = 2,440), and triplet calves (n = 147) born to primipa...

  10. Writing Retreat Increases Productivity And Community For Women Geoscientists

    NASA Astrophysics Data System (ADS)

    O'Connell, S.; Holmes, M.

    2011-12-01

    Five, weeklong geoscientist writing retreats have been completed with an NSF ADANCE PAID grant. During the five nights and four and a half days, eight to twenty-four academics have gathered in a rural setting outside of Boston to get to focus on writing papers and proposals while getting to know each other. Participants range in age and experience from graduate students to emeritus professors. Over twenty papers and proposals acknowledge their production, in part to this writing retreat. Impact extends beyond papers as informal mentoring and discussions at meals and in the evenings centers on succeeding in academia. Research and teaching are foremost in the conversation. Post-docs learn strategies for applying for jobs and grants, and senior professors discuss strategies for working with academic administrations, running departments and mentoring students. They also learn new technologies and perspectives from younger participants. Particularly helpful are discussions on work-life balance. Networking opportunities extend beyond the retreat as participants join each other at their home institutions to give seminars, develop research projects and mentor each other's students. All weeks follow the same format. Participants arrive Sunday and meet during an evening welcome reception. Monday is devoted to writing. Tuesday a writing coach is available. In the morning, using examples from the scientific literature, she discusses strategies and techniques for writing clearly at a group session. During the afternoon, participants work with the coach individually or in small groups to improve their own writing projects. Wednesday evening a skill session is offered on a topic of interest. These have included undergraduate research, NSF funding, productive techniques for dealing with conflict, and generational characteristics and attitudes, which can hamper communication. A Thursday evening wrap-up session prepares participants for Friday's departure. We believe that this model

  11. Science Video Journals to Increase Productivity in Research and Education

    NASA Astrophysics Data System (ADS)

    Henderson, K. M.

    2013-12-01

    Research in both the physical and biological sciences chronically suffers from the low productivity and reproducibility of experimental studies. This is due in part because the traditional text-based format of science journals cannot provide an adequate description of complex research procedures. This creates a critical 'bottleneck' problem of knowledge transfer for research and education. Addressing this challenge, a new generation of science journals employs online video to provide a systematic visualized publication of experimental studies. This presentation will provide an overview of the growing field of video publication and discuss its technical challenges, implications for scholarly communication and acceptance in the academic and library community. Results and recently conducted case studies will be shown in support of video publications as a valid communication venue in scientific publishing.

  12. Increase Productivity and Cost Optimization in CNC Manufacturing

    NASA Astrophysics Data System (ADS)

    Musca, Gavril; Mihalache, Andrei; Tabacaru, Lucian

    2016-11-01

    The advantage of the technological assisted design consists in easy modification of the machining technologies for obtaining machine alternation, tool changing, working parameters variation or the modification of loads to which the tools are subjected. By determining tool movement inside machining and by using tool related moving speeds needed for both positioning and manufacturing we are able to compute the required machining time for each component of the machining operation in progress. The present study describes a cost optimization model for machining operations which uses the following components: machine and its operator related cost, set-up and adjustment, unproductive costs (idle state), direct and indirect costs. By using manufacturing technologies assisted design procedures we may obtain various variants for the technological model by modifying the machining strategy, tooling, working regimes or the machine-tool that are used. Simulating those variants allows us to compare and establish the optimal manufacturing variant as well as the most productive one.

  13. Turbulence of swarming sperm

    NASA Astrophysics Data System (ADS)

    Creppy, Adama; Praud, Olivier; Druart, Xavier; Kohnke, Philippa L.; Plouraboué, Franck

    2015-09-01

    Collective motion of self-sustained swarming flows has recently provided examples of small-scale turbulence arising where viscous effects are dominant. We report the first observation of universal enstrophy cascade in concentrated swarming sperm consistent with a body of evidence built from various independent measurements. We found a well-defined k-3 power-law decay of a velocity field power spectrum and relative dispersion of small beads consistent with theoretical predictions in 2D turbulence. Concentrated living sperm displays long-range, correlated whirlpool structures of a size that provides an integral scale of turbulence. We propose a consistent explanation for this quasi-2D turbulence based on self-structured laminated flow forced by steric interactions and alignment, a state of active matter that we call "swarming liquid crystal." We develop scaling arguments consistent with this interpretation.

  14. Sperm, Clinics, and Parenthood

    PubMed Central

    2016-01-01

    Abstract In this article I examine a recent approach to regulating assisted reproduction, whereby use of some kind of medical intervention ‘triggers’ laws governing legal parenthood that are more favourable to intending parents and sperm providers. I argue that although perhaps an improvement on the previous legal framework, these laws are problematic for three important reasons. First, they are prone to violating parental rights and unjustly imposing substantial burdens on individuals. Second, they are discriminatory. Third, even if we take a pragmatic approach to the question of parenthood in these cases, these laws fail to properly consider the welfare interests of children. Finally, I conclude by showing that my argument does not entail adopting a laissez‐fair attitude to conception using third‐party sperm. PMID:27523389

  15. Application of intracytoplasmic sperm injection (ICSI) for fertilization and development in birds.

    PubMed

    Shimada, Kiyoshi; Ono, Tamao; Mizushima, Shusei

    2014-01-15

    Intracytoplasmic sperm injection (ICSI) technology in birds has been hampered due to opacity of oocyte. We developed ICSI-assisted fertilization and gene transfer in quail. This paper reviews recent advances of our ICSI experiments. The oocyte retrieved from the oviduct and a quail sperm was injected into the oocyte under a stereomicroscope. The oocyte was cultured for 24h at 41°C under 5% CO2 in air. The fertilization and development was assessed by microscopic observation. The fertility rate ranged 12-18% and development varied from stage II to V in trials. To improve the fertility rate, phospholipase C (PLC) zeta was injected with a sperm. It was increased to 37-50%. Furthermore, injection of inositol trisphosphate increased to over 85%. Quail oocyte can be fertilized with chicken sperm and so can testicular elongated spermatid. To extend embryonic development, chicken eggshell was used as a surrogate culture at 37°C after the 24h incubation at 41°C under 5% CO2 in air. It survived up to 2days thereafter. Finally, gene transfer was attempted in quail egg. The sperm membrane was disrupted with Triton X-100 (TX-100) and was injected with PLCzeta cRNA and enhanced green fluorescent protein (EGFP) gene in oocyte. The GFP expression was evaluated at 24h incubation at 41°C under 5% CO2 in air in the embryos. While the expression was not detected in the control oocytes, the experimental treatment induced blastoderm development (44%) of the oocytes and 86% of blastoderm showed fluorescent emission. In addition, PCR analysis detected EGFP fragments in 50% of GFP-expressing blastoderm. Our ICSI method may be the first step toward the production of transgenic birds.

  16. Biogenesis and function of tRNA fragments during sperm maturation and fertilization in mammals

    PubMed Central

    Shea, Jeremy M.; Boskovic, Ana; Derr, Alan G.; Bing, Xin Y.; Belleannee, Clemence; Kucukural, Alper; Serra, Ryan W.; Sun, Fengyun; Song, Lina; Carone, Benjamin R.; Ricci, Emiliano P.; Li, Xin Z.; Fauquier, Lucas; Moore, Melissa J.; Sullivan, Robert; Mello, Craig C.; Garber, Manuel; Rando, Oliver J.

    2016-01-01

    Several recent studies link parental environments to phenotypes in subsequent generations. Here, we investigate the mechanism by which paternal diet affects offspring metabolism. Protein restriction in mice affects small RNA levels in mature sperm, with decreased let-7 levels and increased levels of 5’ fragments of glycine tRNAs. tRNA fragments are scarce in testicular sperm, but are gained as sperm mature in the epididymis. Epididymosomes – vesicles that fuse with sperm during epididymal transit – carry RNA payloads matching those of mature sperm, and deliver RNAs to immature sperm in vitro. Functionally, tRNA-Gly-GCC fragments repress genes associated with the endogenous retroelement MERVL, both in ES cells and embryos. Our results shed light on small RNA biogenesis, and its dietary regulation, during post-testicular sperm maturation, and link tRNA fragments to regulation of endogenous retroelements active in the preimplantation embryo. PMID:26721685

  17. Current Status of Sperm Cryopreservation in Biomedical Research Fish Models: Zebrafish, Medaka, and Xiphophorus*

    PubMed Central

    Yang, Huiping; Tiersch, Terrence R.

    2009-01-01

    Aquarium fishes are becoming increasingly important because of their value in biomedical research and the ornamental fish trade, and because many have become threatened or endangered in the wild. This review summarizes the current status of sperm cryopreservation in three fishes widely used in biomedical research: zebrafish, medaka, and live-bearing fishes of the genus Xiphophorus, and will focus on the needs and opportunities for future research and application of cryopreservation in aquarium fish. First, we summarize the basic biological characteristics regarding natural habitat, testis structure, spermatogenesis, sperm morphology, and sperm physiology. Second, we compare protocol development of sperm cryopreservation. Third, we emphasize the importance of artificial fertilization in sperm cryopreservation to evaluate the viability of thawed sperm. We conclude with a look to future research directions for sperm cryopreservation and the application of this technique in aquarium species. PMID:18691673

  18. Detection of oocyte perivitelline membrane-bound sperm: a tool for avian collection management.

    PubMed

    Croyle, Kaitlin E; Durrant, Barbara S; Jensen, Thomas

    2015-01-01

    The success and sustainability of an avian breeding programme depend on managing productive and unproductive pairs. Given that each breeding season can be of immeasurable importance, it is critical to resolve pair fertility issues quickly. Such problems are traditionally diagnosed through behavioural observations, egg lay history and hatch rates, with a decision to re-pair generally taking one or more breeding seasons. In pairs producing incubated eggs that show little or no signs of embryonic development, determining fertility is difficult. Incorporating a technique to assess sperm presence on the oocyte could, in conjunction with behaviour and other data, facilitate a more timely re-pair decision. Detection of perivitelline membrane-bound (PVM-bound) sperm verifies successful copulation, sperm production and sperm functionality. Alternatively, a lack of detectable sperm, at least in freshly laid eggs, suggests no mating, lack of sperm production/function or sperm-oviduct incompatibility. This study demonstrated PVM-bound sperm detection by Hoechst staining in fresh to 24-day-incubated exotic eggs from 39 species representing 13 orders. However, a rapid and significant time-dependent loss of detectable PVM-bound sperm was observed following incubation of chicken eggs. The PCR detection of sperm in seven species, including two bacterially infected eggs, demonstrated that this method was not as reliable as visual detection using Hoechst staining. The absence of amplicons in visually positive PVMs was presumably due to large PVM size and low sperm count, resulting in DNA concentrations too low for standard PCR detection. In summary, this study demonstrated the feasibility and limitations of using PVM-bound sperm detection as a management tool for exotic avian species. We verified that sperm presence or absence on fluorescence microscopy can aid in the differentiation of fertile from infertile eggs to assist breeding managers in making prompt decisions for pair

  19. Cinnamic Acid Increases Lignin Production and Inhibits Soybean Root Growth

    PubMed Central

    Salvador, Victor Hugo; Lima, Rogério Barbosa; dos Santos, Wanderley Dantas; Soares, Anderson Ricardo; Böhm, Paulo Alfredo Feitoza; Marchiosi, Rogério; Ferrarese, Maria de Lourdes Lucio; Ferrarese-Filho, Osvaldo

    2013-01-01

    Cinnamic acid is a known allelochemical that affects seed germination and plant root growth and therefore influences several metabolic processes. In the present work, we evaluated its effects on growth, indole-3-acetic acid (IAA) oxidase and cinnamate 4-hydroxylase (C4H) activities and lignin monomer composition in soybean (Glycine max) roots. The results revealed that exogenously applied cinnamic acid inhibited root growth and increased IAA oxidase and C4H activities. The allelochemical increased the total lignin content, thus altering the sum and ratios of the p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) lignin monomers. When applied alone or with cinnamic acid, piperonylic acid (PIP, a quasi-irreversible inhibitor of C4H) reduced C4H activity, lignin and the H, G, S monomer content compared to the cinnamic acid treatment. Taken together, these results indicate that exogenously applied cinnamic acid can be channeled into the phenylpropanoid pathway via the C4H reaction, resulting in an increase in H lignin. In conjunction with enhanced IAA oxidase activity, these metabolic responses lead to the stiffening of the cell wall and are followed by a reduction in soybean root growth. PMID:23922685

  20. Increased calf production in cattle selected for twin ovulations.

    PubMed

    Echternkamp, S E; Thallman, R M; Cushman, R A; Allan, M F; Gregory, K E

    2007-12-01

    The effects of increasing fetal numbers and their distribution between the left and right uterine horns on calf survival, calf BW at birth and weaning, gestation length, dystocia, and calf sex ratio were evaluated for single (n = 1,587), twin (n = 2,440), and triplet calves (n = 147) born to primiparous and multiparous females in the Twinner population at the US Meat Animal Research Center between 1994 and 2004. Cattle were distributed equally between the spring and fall breeding seasons. Fetal number and distribution in utero were determined by real-time ultrasonography at 40 to 70 d postbreeding. For cows and heifers combined, number of calves per parturition increased from 1.34 in 1994 to 1.56 in 2004. Gestation length was 6.8 d shorter (P < 0.01) for twins compared with singles (277.5 +/- 0.2 vs. 284.3 +/- 0.2 d) and 12.7 d shorter for triplets (271.6 +/- 0.8 d). Survival and BW of individual calves at birth decreased (P < 0.01) but total calf BW per dam increased (P < 0.01) as fetal number increased from single to triplet births. Twins resulting from bilateral twin ovulations had increased (P < 0.01) survival and BW at birth, a longer (P < 0.01) gestation length, and less (P < 0.01) dystocia than twins resulting from unilateral twin ovulations. Calf survival and BW at birth were 97.2 +/- 0.3% and 48.0 +/- 0.1 kg for singles, 92.0 +/- 0.4% and 39.0 +/- 0.2 kg for bilateral twins, 83.2 +/- 0.4% and 36.7 +/- 0.2 kg for unilateral twins, 73.8 +/- 1.4% and 30.6 +/- 0.7 kg for bilateral triplets, and 51.9 +/- 3.2% and 31.7 +/- 1.6 kg for unilateral triplets. Birth weight of single calves increased by 0.51 kg/d for each additional day of gestation length vs. 0.38 kg/d for individual twins. Calf BW at birth increased (P < 0.01) with age of dam from 2 to 4 yr. Twin and triplet births had a greater (P < 0.01) incidence of dystocia than single births. The ratio of male:female calves (0.52:0.48) at birth was not affected by type of birth. Postnatal calf survival was

  1. Sperm function test

    PubMed Central

    Talwar, Pankaj; Hayatnagarkar, Suryakant

    2015-01-01

    With absolute normal semen analysis parameters it may not be necessary to shift to specialized tests early but in cases with borderline parameters or with history of fertilization failure in past it becomes necessary to do a battery of tests to evaluate different parameters of spermatozoa. Various sperm function tests are proposed and endorsed by different researchers in addition to the routine evaluation of fertility. These tests detect function of a certain part of spermatozoon and give insight on the events in fertilization of the oocyte. The sperms need to get nutrition from the seminal plasma in the form of fructose and citrate (this can be assessed by fructose qualitative and quantitative estimation, citrate estimation). They should be protected from the bad effects of pus cells and reactive oxygen species (ROS) (leukocyte detection test, ROS estimation). Their number should be in sufficient in terms of (count), structure normal to be able to fertilize eggs (semen morphology). Sperms should have intact and functioning membrane to survive harsh environment of vagina and uterine fluids (vitality and hypo-osmotic swelling test), should have good mitochondrial function to be able to provide energy (mitochondrial activity index test). They should also have satisfactory acrosome function to be able to burrow a hole in zona pellucida (acrosome intactness test, zona penetration test). Finally, they should have properly packed DNA in the nucleus to be able to transfer the male genes (nuclear chromatic decondensation test) to the oocyte during fertilization. PMID:26157295

  2. Intracytoplasmic sperm injection (ICSI) in small ruminants.

    PubMed

    López-Saucedo, J; Paramio-Nieto, M T; Fierro, R; Piña-Aguilar, R E

    2012-08-01

    Small ruminants are an important component of the global production systems of meat and wool, and their reproductive biology is well known. However, the incorporation of assisted reproduction techniques (ART) in the production systems of small ruminants is not as well developed as for other domestic species. Normally, production systems that incorporate ARTs are restricted to artificial insemination or in vivo embryo transfer. Intracytoplasmic sperm injection (ICSI) is one of the ARTs techniques reported for small ruminants and consists of the injection of spermatozoa inside an oocyte, bypassing the natural process of sperm-oocyte interaction. In goats and sheep, there are few live births by ICSI reported, with no reports from other species of small ruminants. Currently, there has not been intensive research about ICSI in small ruminants. However, ICSI has potentially important applications in animal production systems, primarily its use with semen of valued animals, with epididymal sperm, in the fertilization of prepubertal or cryopreserved oocytes. Other applications include more advanced techniques, such as transgenic-ICSI or its combination with spermatogonial transplantation. In this article, we review the "state of the art" of this technique in small ruminants including its historical development, research needs for its improvement and future applications.

  3. Effect of different monosaccharides and disaccharides on boar sperm quality after cryopreservation.

    PubMed

    Gómez-Fernández, José; Gómez-Izquierdo, Emilio; Tomás, Cristina; Mocé, Eva; de Mercado, Eduardo

    2012-07-01

    The aim of the present study was to evaluate the cryoprotectant effect of different non-permeating sugars for boar sperm. Pooled semen from three boars was used for the experiments. In the first experiment, the sperm quality of boar sperm cryopreserved with an egg-yolk based extender supplemented with different monosaccharides (glucose, galactose or fructose) was compared to a control cryopreserved in lactose-egg yolk extender. In the second experiment, the effect of five disaccharides (lactose, sucrose, lactulose, trehalose or melibiose) on boar sperm cryosurvival was studied. Several sperm quality parameters were assessed by flow cytometry in samples incubated for 30 and 150 min at 37°C after thawing: percentages of sperm with intact plasma membrane (SIPM), sperm presenting high plasma membrane fluidity (HPMF), sperm with intracellular reactive oxygen substances production (IROSP) and apoptotic sperm (AS). In addition, the percentages of total motile (TMS) and progressively motile sperm (PMS) were assessed at the same incubation times with a computer-assisted sperm analysis system. Freezing extenders supplemented with each of the monosaccharide presented smaller cryoprotective effect than the control extender supplemented with lactose (P<0.05). However, from the three monosaccharides tested, glucose provided the best sperm quality after freezing-thawing. With respect to the disaccharides studied, samples frozen with the extender supplemented with lactulose exhibited in general the lowest sperm quality, except for the percentage of capacitated sperm, which was highest (P<0.05) in the samples cryopreserved with the trehalose extender. Our results suggest that disaccharides have higher cryoprotective effect than monosaccharides, although the monosaccharide composition of the disaccharides is also important, since the best results were obtained with those disaccharides presenting glucose in their composition.

  4. Downhole tools can increase deep drilling rig productivity

    SciTech Connect

    Thiessen, D.A.; Doiron, H.H.

    1983-01-01

    Explains how there is much to be gained by better utilization of current drilling equipment, particularly for the much more expensive deep drilling. Optimized mud weight, better hydraulics, and higher rpm offer the best opportunities with increased bit weight as a fourth possibility. Current RandD in such areas as shock absorbers, downhole motors, new materials and designs for bits, and improved instrumentation will decrease drilling costs. Concludes that a reasonable projection is that drilling time for deep wells can be halved within the next decade.

  5. Mutant E. coli strain with increased succinic acid production

    DOEpatents

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    2001-09-25

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which has been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  6. Mutant E. coli strain with increased succinic acid production

    DOEpatents

    Donnelly, M.; Millard, C.S.; Stols, L.

    1998-06-23

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which as been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria. 2 figs.

  7. Mutant E. coli strain with increased succinic acid production

    DOEpatents

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    2002-01-01

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which has been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  8. Mutant E. coli strain with increased succinic acid production

    DOEpatents

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    1998-01-01

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which as been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  9. Effects of environment factors on initiation of sperm motility in sea cucumber Apostichopus japonicus (Selenka)

    NASA Astrophysics Data System (ADS)

    Yu, Li; Shao, Mingyu; Bao, Zhenmin; Hu, Jingjie; Zhang, Zhifeng

    2011-06-01

    Sperm of sea cucumber Apostichopus japonicus (Selenka) were quiescent in electrolyte NaCl solution and artificial seawater (ASW) and nonelectrolyte glucose and mannitol solutions when the osmolality was less than 200 mOsm kg-1. The sperm started to be motile as a result of increased osmolality, indicating an osmolality-dependent initiation of sperm motility in sea cucumber. After a brief incubation in hypotonic NaCl and glucose solutions with osmolalities of 200 and 400 mOsm kg-1, sperm lost partial motile ability. Sperm became immobilized when pH was 6.0 in NaCl, glucose and mannitol solutions, suggesting that an H+ release is involved in sperm activation. The decreased pH had no effect on the percentage of motile sperm in ASW, whereas it delayed the time period to reach the maximum motility (motilitymax). Extracellular Ca2+ in electrolyte solutions was not essential for motility stimulation but shortened the time of reaching motilitymax. When Ca2+ was mixed in nonelectrolyte solutions the sperm motility was completely suppressed. The K+ channel blocker, quinine, suppressed the sperm motility in electrolyte solution, showing a possible involvement of K+ transport in the process. High K+ concentration did not affect the sperm motility in NaCl solution, but decreased it in ASW and almost entirely suppressed it in nonelectrolyte solutions. The different effects of pH and K+ in ASW and NaCl solution indicate that external ions may also regulate sperm motility.

  10. Effect of cholesterol-loaded-cyclodextrin on sperm viability and acrosome reaction in boar semen cryopreservation.

    PubMed

    Lee, Yong-Seung; Lee, Seunghyung; Lee, Sang-Hee; Yang, Boo-Keun; Park, Choon-Keun

    2015-08-01

    This study was undertaken to examine the effect of cholesterol-loaded-cyclodextrin (CLC) on boar sperm viability and spermatozoa cryosurvival during boar semen cryopreservation, and methyl-β-cyclodextrin (MBCD) was treated for comparing with CLC. Boar semen treated with CLC and MBCD before freezing process to monitor the effect on survival and capacitation status by flow cytometry with appropriate fluorescent probes. Sperm viability was higher in 1.5mg CLC-treated sperm (76.9±1.01%, P<0.05) than un-treated and MBCD-treated sperm before cryopreservation (58.7±1.31% and 60.3±0.31%, respectively). For CTC patterns, F-pattern was higher in CLC treated sperm than MBCD-treated sperm, for B-pattern was higher in CLC-treated sperm than fresh sperm (P<0.05). For AR pattern (an acrosome-reacted sperm) was lower in CLC-treated sperm than MBCD-treated sperm (P<0.05). Moreover, we examined in vitro development of porcine oocytes after in vitro fertilization using CLC-treated frozen-thawed semen, in which CLC treatment prior to freezing and thawing increased the development of oocytes to blastocyst stage in vitro. In conclusion, CLC could protect the viability of spermatozoa from cryodamage prior to cryopreservation in boar semen.

  11. Mechanical tuning of mammalian sperm behaviour by hyperactivation, rheology and substrate adhesion: a numerical exploration

    PubMed Central

    Gaffney, Eamonn A.

    2016-01-01

    The great mammalian sperm race encounters numerous microenvironments to which sperm must adapt and a fundamental sperm response is the change in its waveform owing to both fluid rheology and capacitation, with the latter associated with a hyperactivated beat pattern. Hence, in this modelling study, we examine the effect of different flagellar waveforms for sperm behaviour near adhesive substrates, which are representative of epithelia in female tract sperm reservoirs and the zona pellucida (ZP), which surrounds the mammalian egg. On contact with an adhesive surface, virtual sperm rotate to become nearly tangential with the surface, as generally observed. Hyperactivation also induces many effects: sperm exert greater forces on the substrate and periodically tug way from adhesions under circumstances reflecting binding at sperm reservoirs, but with extensive fluid elasticity, as found in the cumulus surrounding the ZP, sperm instead continually push into the substrate. Furthermore, with weak adhesion, rheological media increase the duration hyperactivated sperm remain in the proximity of a substrate. More generally, such results predict that changes owing to both hyperactivation of the flagellar waveform and the rheology of the surrounding medium provide a means of tuning sperm behaviour near, or attached to, adhesive substrates. PMID:27852807

  12. Galvanotactic response of mouse epididymal sperm: in vitro effects of zinc and diethyldithiocarbamate.

    PubMed

    Zhang, X; Jin, L; Takenaka, I

    2000-01-01

    This study was conducted to evaluate the galvanotactic response of mouse epididymal sperm as well as the in vitro effects of Zn-acetate and diethyldithiocarbamate (DEDTC) on the galvanotaxis of sperm. The galvanotaxis of sperm was observed in a direct current (DC) electric field between 0 and 10 V/cm. The sperm were treated with Zn-acetate or DEDTC at concentrations of 0.02, 0.20, and 2.00 mM before the observations. The sperm exhibited galvanotaxis toward both cathode and anode in the fields between 1 and 9 V/cm. The number of sperm that accumulated at both electrodes was found to reach the highest level between 5 and 7 V/cm. In comparison with the results from untreated sperm, the number of accumulated sperm at the electrodes increased with the addition of 0.20 and 2.00 mM Zn-acetate, but decreased with the addition of DEDTC at all 3 concentrations. The galvanotaxis of mouse epididymal sperm is related to the field strengths, and the guidance of sperm migration may be influenced by the sex chromosomes. The galvanotaxis of the sperm may be improved by addition of Zn-acetate but depressed by DEDTC in the presence of DC electric fields.

  13. Biochemical and topological analysis of bovine sperm cells induced by low power laser irradiation

    NASA Astrophysics Data System (ADS)

    Dreyer, T. R.; Siqueira, A. F. P.; Magrini, T. D.; Fiorito, P. A.; Assumpção, M. E. O. A.; Nichi, M.; Martinho, H. S.; Milazzotto, M. P.

    2011-07-01

    Low-level laser irradiation (LLLI) increases ATP production and energy supply to the cell which could increase sperm motility, acrossomal reaction and consequently the fertilizing potential. The aim of this study was to characterize the biochemical and topological changes induced by low power laser irradiation on bull sperm cells. Post-thawing sperm were irradiated with a 633nm laser with fluence rates of 30, 150 and 300mJ.cm-2 (power of 5mW for 1, 5 and 10minutes, respectively); 45, 230, and 450mJ.cm-2 (7.5mW for 1, 5 and 10 minutes); and 60, 300 and 600mJ.cm-2 (10mW for 1, 5 and 10 minutes). Biochemical and metabolical changes were analyzed by FTIR and flow cytometry; oxygen reactive species production was assessed by TBARS and the morphological changes were evaluated by AFM. Motility had no difference among times or powers of irradiation. Increasing in ROS generation was observed with power of 5mW compared to 7.5 and 10mW, and with 10min of irradiation in comparison with 5 and 1min of irradiation. This higher ROS generation was related to an increase in acrossomal and plasma membrane damage. FTIR results showed that the amount of lipids was inversely proportional to the quantity of ROS generated. AFM images showed morphological differences in plasma/acrossomal membrane, mainly on the equatorial region. We conclude that LLLI is an effective method to induce changes on sperm cell metabolism but more studies are necessary to establish an optimal dose to increase the fertility potential of these cells.

  14. Decreasing sperm quality: a global problem?

    PubMed Central

    2010-01-01

    Background Carlsen and coworkers (1992) reviewed 61 heterogeneous observational studies on semen quality published between 1938 and 1990. This review indicates that mean sperm density decreased significantly between 1940 and 1990. An extended meta-analysis with 101 studies confirmed a decline in sperm density for the period from 1934 to 1996 (2000). The key message of the meta-analyses is that sperm counts have decreased globally by about 50% over the past decades. This assessment has been questioned. Discussion A major methodological problem of the meta-analysis is the use of data collected in different countries, at different times, on different populations and with different methods of semen analysis. Furthermore, the results of studies concerning semen analysis are frequently biased e.g. by selection criteria of volunteers. In most studies on human semen characteristics the populations under study are insufficiently defined and the study participants are not a representative population sample. The incidence of testicular cancer has increased in Caucasian men worldwide. The investigation of common risk factors for male reproductive disorders requires well designed epidemiological studies and the collection of individual data. Summary Former meta-analyses of sperm count data show a global downward trend. This conclusion should be interpreted with caution. The included studies are of great heterogeneity due to geographical and/or ethnical variation, different study designs and different methodological standards. Population-based prospective studies are needed to investigate secular trends in male reproductive disorders. PMID:20085639

  15. Role of glucocorticoids in increased muscle glutamine production in starvation

    NASA Technical Reports Server (NTRS)

    Tischler, Marc E.; Henriksen, Erik J.; Cook, Paul H.

    1988-01-01

    The role of glucocorticoids in the synthesis of muscle glutamine during starvation was investigated in adrenalectomized fasted rats injected with cortisol (1 mg/100 g body weight). It was found that administration of cortisol in vivo increased (compared to nontreated starved adrenalectomized controls) the glutamine/glutamate ratio and the activity of glutamine synthetase in the diaphragm and the extensor digitorum muscles, and that these effects were abolished by prior treatment with actinomycin D or proflavine. The results obtained in in vitro experiments, using fresh-frozen soleus, extensor digitorum longus, and diaphragm muscle preparations, supported the in vivo indications of the cortisol-enhanced glutamine synthesis and protein turnover in starved adrenalectomized animals.

  16. Effects of supplemental conjugated linoleic acids (CLA) on fresh and post-thaw sperm quality of Holstein bulls.

    PubMed

    Karimi, R; Towhidi, A; Zeinoaldini, S; Rezayazdi, K; Mousavi, M; Safari, H; Martinez-Pastor, F

    2017-02-07

    This study was designed to investigate the effects of feeding-protected conjugated linoleic acid (CLA) on the semen production and sperm freezability in Holstein bulls. Twelve bulls were randomly assigned to two groups (n = 6 per group). Bulls received the normal diet (control group) or the normal diet top-dressed with 50 g of CLA (treated group) for 10 weeks. The control group received 40 g/day calcium soap of fatty acid. Fresh and post-thaw semen quality was assessed on ejaculates collected at the 0, 4, 6, 8 and 10 week of supplementation. Semen evaluations including sperm concentration, motion characteristics (subjective and computer-assisted), viability (Eosin-Nigrosin), membrane integrity (hypo-osmotic swelling test) and abnormality were conducted. Semen volume, sperm concentration and total sperm output were not affected by dietary treatment (p > .05). The proportion of spermatozoa with abnormal morphology in fresh semen significantly increased (p < .05) in the CLA-fed group compared to control group. Also, in CLA-fed group, the proportion of post-thaw spermatozoa with abnormal morphology at week 10 of trial was significantly higher in CLA than control group (p < .05). Progressive motility tended to be increased in the CLA-fed group, although dietary supplementation did not affect other CASA parameters or viability in fresh and frozen-thawed sperm. In this study, CLA supplementation had little positive effect on fresh or post-thaw sperm quality of Holstein bulls.

  17. Predictive factors of successful microdissection testicular sperm extraction.

    PubMed

    Bernie, Aaron M; Ramasamy, Ranjith; Schlegel, Peter N

    2013-01-01

    Azoospermia in men requires microsurgical reconstruction or a procedure for sperm retrieval with assisted reproduction to allow fertility. While the chance of successful retrieval of sperm in men with obstructive azoospermia approaches >90%, the chances of sperm retrieval in men with non-obstructive azoospermia (NOA) are not as high. Conventional procedures such as fine needle aspiration of the testis, testicular biopsy and testicular sperm extraction are successful in 20-45% of men with NOA. With microdissection testicular sperm extraction (micro-TESE), the chance of successful retrieval can be up to 60%. Despite this increased success, the ability to counsel patients preoperatively on their probability of successful sperm retrieval has remained challenging. A combination of variables such as age, serum FSH and inhibin B levels, testicular size, genetic analysis, history of Klinefelter syndrome, history of cryptorchidism or varicocele and histopathology on diagnostic biopsy have provided some insight into the chance of successful sperm retrieval in men with NOA. The goal of this review was to evaluate the preoperative factors that are currently available to predict the outcome for success with micro-TESE.

  18. Increasing precipitation event size increases aboveground net primary productivity in a semi-arid grassland.

    PubMed

    Heisler-White, Jana L; Knapp, Alan K; Kelly, Eugene F

    2008-11-01

    Water availability is the primary constraint to aboveground net primary productivity (ANPP) in many terrestrial biomes, and it is an ecosystem driver that will be strongly altered by future climate change. Global circulation models predict a shift in precipitation patterns to growing season rainfall events that are larger in size but fewer in number. This "repackaging" of rainfall into large events with long intervening dry intervals could be particularly important in semi-arid grasslands because it is in marked contrast to the frequent but small events that have historically defined this ecosystem. We investigated the effect of more extreme rainfall patterns on ANPP via the use of rainout shelters and paired this experimental manipulation with an investigation of long-term data for ANPP and precipitation. Experimental plots (n = 15) received the long-term (30-year) mean growing season precipitation quantity; however, this amount was distributed as 12, six, or four events applied manually according to seasonal patterns for May-September. The long-term mean (1940-2005) number of rain events in this shortgrass steppe was 14 events, with a minimum of nine events in years of average precipitation. Thus, our experimental treatments pushed this system beyond its recent historical range of variability. Plots receiving fewer, but larger rain events had the highest rates of ANPP (184 +/- 38 g m(-2)), compared to plots receiving more frequent rainfall (105 +/- 24 g m(-2)). ANPP in all experimental plots was greater than long-term mean ANPP for this system (97 g m(-2)), which may be explained in part by the more even distribution of applied rain events. Soil moisture data indicated that larger events led to greater soil water content and likely permitted moisture penetration to deeper in the soil profile. These results indicate that semi-arid grasslands are capable of responding immediately and substantially to forecast shifts to more extreme precipitation patterns.

  19. The 5’-AMP-Activated Protein Kinase (AMPK) Is Involved in the Augmentation of Antioxidant Defenses in Cryopreserved Chicken Sperm

    PubMed Central

    Nguyen, Thi Mong Diep; Seigneurin, François; Froment, Pascal; Combarnous, Yves; Blesbois, Elisabeth

    2015-01-01

    Semen cryopreservation is a unique tool for the management of animal genetic diversity. However, the freeze-thaw process causes biochemical and physical alterations which make difficult the restoration of sperm energy-dependent functions needed for fertilization. 5’-AMP activated protein kinase (AMPK) is a key sensor and regulator of intracellular energy metabolism. Mitochondria functions are known to be severely affected during sperm cryopreservation with deleterious oxidative and peroxidative effects leading to cell integrity and functions damages. The aim of this study was thus to examine the role of AMPK on the peroxidation/antioxidant enzymes defense system in frozen-thawed sperm and its consequences on sperm functions. Chicken semen was diluted in media supplemented with or without AMPK activators (AICAR or Metformin [MET]) or inhibitor (Compound C [CC]) and then cryopreserved. AMPKα phosphorylation, antioxidant enzymes activities, mitochondrial potential, ATP, citrate, viability, acrosome reaction ability (AR) and various motility parameters were negatively affected by the freeze-thaw process while reactive oxygen species (ROS) production, lipid peroxidation (LPO) and lactate concentration were dramatically increased. AICAR partially restored superoxide dismutase (SOD), Glutathione Peroxidase (GPx) and Glutathione Reductase (GR), increased ATP, citrate, and lactate concentration and subsequently decreased the ROS and LPO (malondialdehyde) in frozen-thawed semen. Motility parameters were increased (i.e., + 23% for motility, + 34% for rapid sperm) as well as AR (+ 100%). MET had similar effects as AICAR except that catalase activity was restored and that ATP and mitochondrial potential were further decreased. CC showed effects opposite to AICAR on SOD, ROS, LPO and AR and motility parameters. Taken together, our results strongly suggest that, upon freeze-thaw process, AMPK stimulated intracellular anti-oxidative defense enzymes through ATP regulation, thus

  20. Insights into the molecular basis of long-term storage and survival of sperm in the honeybee (Apis mellifera)

    PubMed Central

    Paynter, Ellen; Millar, A. Harvey; Welch, Mat; Baer-Imhoof, Barbara; Cao, Danyang; Baer, Boris

    2017-01-01

    Honeybee males produce ejaculates consisting of large numbers of high quality sperm. Because queens never re-mate after a single mating episode early in life, sperm are stored in a specialised organ for years but the proximate mechanisms underlying this key physiological adaptation are unknown. We quantified energy metabolism in honeybee sperm and show that the glycolytic metabolite glyceraldehyde-3-phosphate (GA3P) is a key substrate for honeybee sperm survival and energy production. This reliance on non-aerobic energy metabolism in stored sperm was further supported by our findings of very low levels of oxygen inside the spermatheca. Expression of GA3P dehydrogenase (GAPDH), the enzyme involved in catabolism of GA3P, was significantly higher in stored compared to ejaculated sperm. Therefore, long-term sperm storage seems facilitated by the maintenance of non-aerobic energy production, the need for only the ATP-producing steps of glycolysis and by avoiding sperm damage resulting from ROS production. We also confirm that honeybee sperm is capable of aerobic metabolism, which predominates in ejaculated sperm while they compete for access to the spermatheca, but is suppressed during storage. Consequently, the remarkable reproductive traits of honeybees are proximately achieved by differential usage of energy production pathways to maximise competitiveness and minimise damage of sperm. PMID:28091518

  1. A mutant gene that increases gibberellin production in Brassica

    SciTech Connect

    Rood, S.B. ); Williams, P.H. ); Pearce, D.; Pharis, R.P. ); Murofushi, Noboru ); Mander, L.N. )

    1990-07-01

    A single gene mutant (elongated internode (ein/ein)) with accelerated shoot elongation was identified from a rapid cycling line of Brassica rapa. Relative to normal plants, mutant plants had slightly accelerated floral development, greater stem dry weights, and particularly, increased internode and inflorescence elongation. The application of the triazole plant growth retardant, paclobutrazol, inhibited shoot elongation, returning ein to a more normal phenotype. Conversely, exogenous gibberellin A{sub 3} (GA{sub 3}) can convert normal genotypes to a phenotype resembling ein. The content of endogenous GA{sub 1} and GA{sub 3} were estimated by gas chromatography-selected ion monitoring using ({sup 2}H)GA{sub 1} as a quantitative internal standard and at day 14 were 1.5- and 12.1-fold higher per stem, respectively, in ein than in normal plants, although GA concentrations were more similar. The endogenous levels of GA{sub 20} and GA{sub 1}, and the rate of GA{sub 19} metabolism were simultaneously analyzed. Levels of GA{sub 1} and GA{sub 20} were 4.6- and 12.9-fold higher, respectively, and conversions to GA{sub 20} and GA{sub 1} were 8.3 and 1.3 times faster in ein than normal plants. Confirming the enhanced rate of GA{sub 1} biosynthesis in ein, the conversion of ({sup 3}H)GA{sub 20} to ({sup 3}H) GA{sub 1} was also faster in ein than in the normal genotype. Thus, the ein allele results in accelerated GA{sub 1} biosynthesis and an elevated content of endogenous GAs, including the dihydroxylated GAs A{sub 1} and A{sub 3}.

  2. A simulation study of sperm motility hydrodynamics near fish eggs and spheres.

    PubMed

    Ishimoto, Kenta; Cosson, Jacky; Gaffney, Eamonn A

    2016-01-21

    For teleost fish fertilisation, sperm must proceed through a small opening on the egg surface, referred to as the micropyle. In this paper, we have used boundary element simulations to explore whether the hydrodynamic attraction between sperm and a fish egg can be a sperm guidance cue. Hydrodynamical egg-sperm interactions alone do not increase the chances of an egg encounter, nor do they induce surface swimming for virtual turbot fish sperm across smooth spheres with a diameter of 1mm, which is representative of a turbot fish egg. When a repulsive surface force between the virtual turbot sperm and the egg is introduced, as motivated by surface charge and van-der-Waals interactions for instance, we find that extended surface swimming of the virtual sperm across a model turbot egg occurs, but ultimately the sperm escapes from the egg. This is due to the small exit angle of the scattering associated with the initial sperm-egg interaction at the egg surface, leading to a weak drift away from the egg, in combination with a weak hydrodynamical attraction between both gametes, though the latter is not sufficient to prevent eventual escape. The resulting transience is not observed experimentally but is a detailed quantitative difference between theory and observation in that stable surface swimming is predicted for eggs with radii larger than about 1.8mm. Regardless, the extended sperm swimming trajectory across the egg constitutes a two-dimensional search for the micropyle and thus the egg is consistently predicted to provide a guidance cue for sperm once they are sufficiently close. In addition, the observation that the virtual turbot sperm swims stably next to a flat plane given repulsive surface interactions, but does not swim stably adjacent to a turbot-sized egg, which is extremely large by sperm-lengthscales, also highlights that the stability of sperm swimming near a boundary is very sensitive to geometry.

  3. Proteins involved in motility and sperm-egg interaction evolve more rapidly in mouse spermatozoa.

    PubMed

    Vicens, Alberto; Lüke, Lena; Roldan, Eduardo R S

    2014-01-01

    Proteomic studies of spermatozoa have identified a large catalog of integral sperm proteins. Rapid evolution of these proteins may underlie adaptive changes of sperm traits involved in different events leading to fertilization, although the selective forces underlying such rapid evolution are not well understood. A variety of selective forces may differentially affect several steps ending in fertilization, thus resulting in a compartmentalized adaptation of sperm proteins. Here we analyzed the evolution of genes associated to various events in the sperm's life, from sperm formation to sperm-egg interaction. Evolutionary analyses were performed on gene sequences from 17 mouse strains whose genomes have been sequenced. Four of these are derived from wild Mus musculus, M. domesticus, M. castaneus and M. spretus. We found a higher proportion of genes exhibiting a signature of positive selection among those related to sperm motility and sperm-egg interaction. Furthermore, sperm proteins involved in sperm-egg interaction exhibited accelerated evolution in comparison to those involved in other events. Thus, we identified a large set of candidate proteins for future comparative analyses of genotype-phenotype associations in spermatozoa of species subjected to different sexual selection pressures. Adaptive evolution of proteins involved in motility could be driven by sperm competition, since this selective force is known to increase the proportion of motile sperm and their swimming velocity. On the other hand, sperm proteins involved in gamete interaction could be coevolving with their egg partners through episodes of sexual selection or sexual conflict resulting in species-specific sperm-egg interactions and barriers preventing interspecies fertilization.

  4. Sperm ultrastructure, morphometry, and abnormal morphology in American black bears (Ursus americanus).

    PubMed

    Brito, L F C; Sertich, P L; Stull, G B; Rives, W; Knobbe, M

    2010-11-01

    The objective of this study was to describe sperm ultrastructure, morphometry, and abnormal morphology in American black bears. Electroejaculation was successful in 53.8% (7/13) of the attempts, but urine contamination was common. Epididymal sperm samples were also obtained from five bears. Sperm had a paddle-like head shape and the ultrastructure was similar to that of most other mammals. The most striking particularity of black bear sperm ultrastructure was a tightening of the nucleus in the equatorial region. Although the differences were not significant in all bears, the overall decrease in sperm nucleus dimensions during transport from the caput epididymis to the cauda suggested increasing compaction of the nucleus during maturation. For ejaculated sperm, nucleus length, width, and base width were 4.9, 3.7, and 1.8 μm, respectively, whereas sperm head length, width, and base width were 6.6, 4.8, and 2.3 μm, and midpiece, tail (including midpiece), and total sperm lengths were 9.8, 68.8, and 75.3 μm. Evaluation of sperm cytoplasmic droplets in the epididymis revealed that proximal droplets start migrating toward a distal position in the caput epididymis and that the process was mostly completed by the time sperm reached the cauda epididymis. The proportion of morphologically normal sperm in the ejaculate was 35.6%; the most prevalent sperm defects were distal cytoplasmic droplets and bent/coiled tails. The morphology of abnormal sperm and the underlying ultrastructural defects were similar to that in other large domestic animals thus suggesting similar underlying pathogenesis of specific sperm defects and similar effects on fertility.

  5. Influence of female reproductive anatomy on the outcome of sperm competition in Drosophila melanogaster.

    PubMed Central

    Bangham, J; Chapman, T; Smith, H K; Partridge, L

    2003-01-01

    Females as well as males can influence the outcome of sperm competition, and may do so through the anatomy of their reproductive tracts. Female Drosophila melanogaster store sperm in two morphologically distinct organs: a single seminal receptacle and, normally, two spermathecae. These organs have different temporal roles in sperm storage. To examine the association between sperm storage organ morphology and sperm competition, we used a mutant type of female with three spermathecae. Although the common measure of sperm competition, P(2), did not differ between females with two and three spermathecae, the pattern of sperm use over time indicated that female morphology did affect male reproductive success. The rate of offspring production by females with three spermathecae rose and fell more rapidly than by females with two spermathecae. If females remate or die before using up second male sperm, then second male reproductive success will be higher when they mate with females with three spermathecae. The results indicate that temporal patterns of sperm use as well as P(2) should be taken into account when measuring the outcome of sperm competition. PMID:12641908

  6. Influence of female reproductive anatomy on the outcome of sperm competition in Drosophila melanogaster.

    PubMed

    Bangham, J; Chapman, T; Smith, H K; Partridge, L

    2003-03-07

    Females as well as males can influence the outcome of sperm competition, and may do so through the anatomy of their reproductive tracts. Female Drosophila melanogaster store sperm in two morphologically distinct organs: a single seminal receptacle and, normally, two spermathecae. These organs have different temporal roles in sperm storage. To examine the association between sperm storage organ morphology and sperm competition, we used a mutant type of female with three spermathecae. Although the common measure of sperm competition, P(2), did not differ between females with two and three spermathecae, the pattern of sperm use over time indicated that female morphology did affect male reproductive success. The rate of offspring production by females with three spermathecae rose and fell more rapidly than by females with two spermathecae. If females remate or die before using up second male sperm, then second male reproductive success will be higher when they mate with females with three spermathecae. The results indicate that temporal patterns of sperm use as well as P(2) should be taken into account when measuring the outcome of sperm competition.

  7. Biphasic Role of Calcium in Mouse Sperm Capacitation Signaling Pathways

    PubMed Central

    Alvau, Antonio; Escoffier, Jessica; Krapf, Dario; Sánchez-Cárdenas, Claudia; Salicioni, Ana M.; Darszon, Alberto; Visconti, Pablo E.

    2016-01-01

    Mammalian sperm acquire fertilizing ability in the female tract in a process known as capacitation. At the molecular level, capacitation is associated with up-regulation of a cAMP-dependent pathway, changes in intracellular pH, intracellular Ca2+ and an increase in tyrosine phosphorylation. How these signaling systems interact during capacitation is not well understood. Results presented in this study indicate that Ca2+ ions have a biphasic role in the regulation of cAMP-dependent signaling. Media without added Ca2+ salts (nominal zero Ca2+) still contain micromolar concentrations of this ion. Sperm incubated in this medium did not undergo PKA activation or the increase in tyrosine phosphorylation suggesting that these phosphorylation pathways require Ca2+. However, chelation of the extracellular Ca2+ traces by EGTA induced both cAMP-dependent phosphorylation and the increase in tyrosine phosphorylation. The EGTA effect in nominal zero Ca2+ media was mimicked by two calmodulin antagonists, W7 and calmidazolium, and by the calcineurin inhibitor cyclosporine A. These results suggest that Ca2+ ions regulate sperm cAMP and tyrosine phosphorylation pathways in a biphasic manner and that some of its effects are mediated by calmodulin. Interestingly, contrary to wild type mouse sperm, sperm from CatSper1 KO mice underwent PKA activation and an increase in tyrosine phosphorylation upon incubation in nominal zero Ca2+ media. Therefore, sperm lacking Catsper Ca2+ channels behave as wild-type sperm incubated in the presence of EGTA. This latter result suggests that Catsper transports the Ca2+ involved in the regulation of cAMP-dependent and tyrosine phosphorylation pathways required for sperm capacitation. PMID:25597298

  8. Dietary fatty acids influence sperm quality and function.

    PubMed

    Ferramosca, A; Moscatelli, N; Di Giacomo, M; Zara, V

    2017-03-23

    Recently, obesity has been linked to male infertility. In animal models the administration of a high-fat diet caused a reduction in sperm quality, by impairing gamete energy metabolism. The aim of this study was to investigate a possible effect of dietary fatty acids supplementation in the modulation of sperm energy metabolism and, in turn, in the improvement of sperm quality in rats fed a high-fat diet. Sexually mature male Sprague-Dawley rats were divided into four groups and fed for 4 weeks a standard diet (control group), a high-fat diet (enriched in 35% of fat and 15% sucrose), a high-fat diet supplemented with 2.5% olive oil (a source of monounsaturated fatty acids) or a high-fat diet supplemented with 2.5% krill oil (a source of n-3 polyunsaturated fatty acids). Liver and adipose tissue weight, plasma glucose, insulin and lipid concentrations were determined. Activities of enzymes involved in sperm energetic metabolism were evaluated by spectrophotometric assays. Sperm mitochondrial respiratory efficiency was also assayed. The obtained results suggest that olive oil partially counteracts the negative effects of a high-fat diet on sperm quality, by increasing gamete motility, by reducing oxidative stress and slightly improving mitochondrial respiration efficiency. On the other hand, krill oil determines an increase in sperm concentration and motility, an increase in the activities of lactate dehydrogenase, Krebs cycle enzymes and respiratory chain complexes; a parallel increase in the cellular levels of ATP and a reduction in oxidative damage were also observed. These results suggest that dietary fatty acids are able to positively influence sperm quality and function.

  9. Sperm proteome and reproductive technologies in mammals.

    PubMed

    Li, Chun-Jin; Wang, Dong; Zhou, Xu

    2016-10-01

    Sperm is highly differentiated cell that can be easily obtained and purified. Mature sperm is considered to be transcriptionally and translationally silent and incapable of protein synthesis. Recently, a large number of proteins have been identified in sperm from different species by using the proteomic approaches. Clinically, sperm proteins can be used as markers for male infertility due to different protein profiles identified in sperm from fertile and infertile male animals. Recent evidences have shown that the conditions of sperm preservation in vitro can also change the sperm protein profiles. This paper reviews the recent scientific publications available to address sperm proteome and their relationship with sperm cryopreservation, capacitation, fertilization, and separation of X and Y sperm. Future directions in the application of sperm proteomics to develop or optimize reproductive technologies in mammals are also discussed.

  10. Decreased flight performance and sperm production in drones of the honey bee (Apis mellifera) slightly infested by Varroa destructor mites during pupal development.

    PubMed

    Duay, Pedro; De Jong, David; Engels, Wolf

    2002-09-30

    We developed a bioassay to measure the flying power of drone, in order to determine which drones could reach a drone congregation area. A wind tunnel was used to test unparasitized drones and drones slightly parasitized by one or two mites during pupal development, and counts were made of the number of spermatozoa that they produced. Drones parasitized with one mite flew as long as control drones (x= 6'55" and 6'48", respectively, P = 0.512); however, those that had been infested by two mites flew significantly less (x= 2'16", P<0.001). There was a significant positive correlation (P<0.01) between flight duration and the number of spermatozoa per drone in control group (r = 0.53), and in both the one mite (r = 0.43) and two mite (r = 0.54) groups. Drones infested during development with one or two mites produced 24 and 45% fewer sperm, respectively.

  11. Sperm Morphology Assessment in Captive Neotropical Primates.

    PubMed

    Swanson, W F; Valle, R R; Carvalho, F M; Arakaki, P R; Rodas-Martínez, A Z; Muniz, Japc; García-Herreros, M

    2016-08-01

    The main objective of this study was to evaluate sperm morphology in four neotropical primate species to compare the sperm morphological traits and the sperm morphometric parameters as a basis for establishing normative sperm standards for each species. Data from 80 ejaculates collected from four primate species, Callithrix jacchus, Callimico goeldii, Alouatta caraya and Ateles geoffroyi, were analysed for detection of sperm morphological alterations using subjective World Health Organization (WHO-2010) standards and Sperm Deformity Index (SDI) criteria, objective computer-assisted sperm morphometry analysis (CASMA) and subpopulation sperm determination (SSD) methods. There were multiple differences (p < 0.01) observed among primate species in values obtained from WHO-2010, SDI, CASMA and SSD sperm analysis methods. In addition, multiple significant positive and negative correlations were observed between the sperm morphological traits (SDI, Sperm Deformity Index Head Defects, Sperm Deformity Index Midpiece Defects, Sperm Deformity Index Tail Defects, Normal Sperm, Head Defects, Midpiece Defects and Tail Defects) and the sperm morphometric parameters (SSD, Area (A), Perimeter (P), Length (L), Width (W), Ellipticity, Elongation and Rugosity) (p ≤ 0.046). In conclusion, our findings using different evaluation methods indicate that pronounced sperm morphological variation exists among these four neotropical primate species. Because of the strong relationship observed among morphological and morphometric parameters, these results suggest that application of objective analysis methods could substantially improve the reliability of comparative studies and help to establish valid normative sperm values for neotropical primates.

  12. Detection of oocyte perivitelline membrane-bound sperm: a tool for avian collection management

    PubMed Central

    Croyle, Kaitlin E.; Durrant, Barbara S.; Jensen, Thomas

    2015-01-01

    The success and sustainability of an avian breeding programme depend on managing productive and unproductive pairs. Given that each breeding season can be of immeasurable importance, it is critical to resolve pair fertility issues quickly. Such problems are traditionally diagnosed through behavioural observations, egg lay history and hatch rates, with a decision to re-pair generally taking one or more breeding seasons. In pairs producing incubated eggs that show little or no signs of embryonic development, determining fertility is difficult. Incorporating a technique to assess sperm presence on the oocyte could, in conjunction with behaviour and other data, facilitate a more timely re-pair decision. Detection of perivitelline membrane-bound (PVM-bound) sperm verifies successful copulation, sperm production and sperm functionality. Alternatively, a lack of detectable sperm, at least in freshly laid eggs, suggests no mating, lack of sperm production/function or sperm–oviduct incompatibility. This study demonstrated PVM-bound sperm detection by Hoechst staining in fresh to 24-day-incubated exotic eggs from 39 species representing 13 orders. However, a rapid and significant time-dependent loss of detectable PVM-bound sperm was observed following incubation of chicken eggs. The PCR detection of sperm in seven species, including two bacterially infected eggs, demonstrated that this method was not as reliable as visual detection using Hoechst staining. The absence of amplicons in visually positive PVMs was presumably due to large PVM size and low sperm count, resulting in DNA concentrations too low for standard PCR detection. In summary, this study demonstrated the feasibility and limitations of using PVM-bound sperm detection as a management tool for exotic avian species. We verified that sperm presence or absence on fluorescence microscopy can aid in the differentiation of fertile from infertile eggs to assist breeding managers in making prompt decisions for pair

  13. Effect of caffeine on motility and vitality of sperm and in vitro fertilization of outbreed mouse in T6 and M16 media

    PubMed Central

    Nabavi, Narges; Todehdehghan, Fatemeh; Shiravi, Abdollhossein

    2013-01-01

    Background: Caffeine increases the CAMP production that stimulates spermatozoa movement. Caffeine is also used for induction of in vitro acrosome reaction in mammalian spermatozoa, an important step in achieving fertilization. Objective: The aim of this study was to assess the effect of caffeine on sperm's motility, vitality and laboratory fertilization rates in mouse in two T6 and M16 media. Materials and Methods: Epididymal mouse sperms were collected and treated by caffine in T6 and M16 media and their motility and vitality rates were evaluated. The pretreated sperms were added to oocytes in T6 and M16 media with and without caffeine and fertilization rates were recorded after 24 hours incubation. Results: Sperm's motility (81.7±1.67%) and vitality (88.7±1.33%) rates and percentage of fertilized oocytes (67.52±8.16%) in T6 medium plus caffeine compare to control group have increased and shown significant differences at p≤0.01. While the percentages of these parameters in M16 medium supplemented with caffeine were 68.3±6.01%, 78±6.11%, and 42.6±12.96 respectively and in comparison to control group (M16 without caffeine) have not shown significant differences. Conclusion: Addition of caffeine to T6 medium promotes the sperm's motility and vitality and enhances fertilization and early in vitro development of mouse embryos. This article extracted from M.Sc. thesis. (Narges Navabi) PMID:24639814

  14. Sperm mitochondria in reproduction: good or bad and where do they go?

    PubMed

    Luo, Shi-Ming; Schatten, Heide; Sun, Qing-Yuan

    2013-11-20

    The mitochondrion is the major energy provider to power sperm motility. In mammals, aside from the nuclear genome, mitochondrial DNA (mtDNA) also contributes to oxidative phosphorylation to impact production of ATP by coding 13 polypeptides. However, the role of sperm mitochondria in fertilization and its final fate after fertilization are still controversial. The viewpoints that sperm bearing more mtDNA will have a better fertilizing capability and that sperm mtDNA is actively eliminated during early embryogenesis are widely accepted. However, this may be not true for several mammalian species, including mice and humans. Here, we review the sperm mitochondria and their mtDNA in sperm functions, and the mechanisms of maternal mitochondrial inheritance in mammals.

  15. Effect of Palm Pollen on Sperm Parameters of Infertile Man.

    PubMed

    Rasekh, Athar; Jashni, Hojjatollah Karimi; Rahmanian, Karamatollah; Jahromi, Abdolreza Sotoodeh

    2015-04-01

    There is a rapidly growing trend in the consumption of herbal remedies in the developing countries. The aim of this study was to determine the effects of orally administered Date Palm Pollen (DPP) on the results of semen analysis in adult infertile men. Forty infertile men participated in our study. They were treated by Pollen powder 120 mg kg(-1) in gelatinous capsules every other day, for two months. Before and at the end of therapy, the semen was collected after masturbation and sperm numbers, motility and morphology were determined. Our findings revealed that consumption of DPP improved the sperm count. The treatment was significantly increased sperm motility, morphology and forward progressive motility. Date palm pollen seems to cure male infertility by improving the quality of sperm parameters.

  16. A Systematic Analysis of a Deep Mouse Epididymal Sperm Proteome

    SciTech Connect

    Chauvin, Theodore; Xie, Fang; Liu, Tao; Nicora, Carrie D.; Yang, Feng; Camp, David G.; Smith, Richard D.; Roberts, Kenneth P.

    2012-12-21

    Spermatozoa are highly specialized cells that, when mature, are capable of navigating the female reproductive tract and fertilizing an oocyte. The sperm cell is thought to be largely quiescent in terms of transcriptional and translational activity. As a result, once it has left the male reproductive tract, the sperm cell is essentially operating with a static population of proteins. It is therefore theoretically possible to understand the protein networks contained in a sperm cell and to deduce its cellular function capabilities. To this end we have performed a proteomic analysis of mouse sperm isolated from the cauda epididymis and have confidently identified 2,850 proteins, which is the most comprehensive sperm proteome for any species reported to date. These proteins comprise many complete cellular pathways, including those for energy production via glycolysis, β-oxidation and oxidative phosphorylation, protein folding and transport, and cell signaling systems. This proteome should prove a useful tool for assembly and testing of protein networks important for sperm function.

  17. Does exposure to inhalation anesthesia gases change the ratio of X-bearing sperms and Y-bearing Sperms? A worth exploring project into an uncharted domain.

    PubMed

    Gupta, Deepak; Mckelvey, George; Kaminski, Edward; Zestos, Maria Markakis

    2016-09-01

    According to recent surveys performed in United States and India, anesthesia care providers were observed to have sired female offspring in a higher proportion than male offspring as their firstborn progeny; however, the reasons for the skew are not clear. Our hypothesis is that the underlying biological evidence may be elucidated by unraveling differences (if any) between the concentrations of X-bearing sperms and Y-bearing sperms in the semen samples obtained from males exposed to varied levels of anesthetics in their lifetimes. Therefore, the objectives of the envisaged study would be to conduct a three-stage investigative study on in-vitro human semen samples to determine (a) X-bearing sperms and Y-bearing sperms concentrations' ratio in male pediatric anesthesia care providers' semen samples, (b) changes in X-bearing sperms and Y-bearing sperms concentrations' ratios between the pre-rotation and post-rotation semen samples of male medical student volunteers/observers, and (c) changes in X-bearing sperms and Y-bearing sperms concentrations' ratios between the pre-operative and post-operative day-3 semen samples of male patients presenting for outpatient procedures under inhalational anesthesia. The expected outcomes would be (a) linear and positive correlation of the anesthetic gas usage (exposure) with increased X-bearing sperms/Y-bearing sperms ratio in post-anesthesia day 3 sample as compared to the baseline preoperative sample, (b) linear and positive correlation of the anesthetic gas usage (exposure) with increased X-bearing sperms/Y-bearing sperms ratio in post-rotation sample as compared to the baseline sample, and (c) observation of high X-bearing sperms/Y-bearing sperms ratio in the pediatric anesthesia care providers. In summary, effects (if any) of occupational or personal exposure to inhalational anesthetic gases on the X-bearing sperms and Y-bearing sperms ratio is a worthy