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1

Females become infertile as the stored sperm's oxygen radicals increase  

PubMed Central

Predicting infertility is central to reproductive biology, medicine and evolutionary biology. In-vitro studies suggest that oxidative sperm damage causes infertility. Oxidative sperm damage can be reduced via two fundamental pathways: the removal of oxygen radicals by antioxidants, or the interference with cell metabolism to reduce the formation of oxygen radicals. Oxidative damage protection of spermatozoa should evolve frequently, especially during female sperm storage. However, in-vivo evidence linking oxidative protection and fertility is rare. We show that the intra-sperm production rate of oxygen radicals and the sperm metabolic rate were reduced in female bedbugs, Cimex lectularius, compared to males, and females laid fertile eggs. Females became infertile when sperm oxygen radicals and sperm metabolic rate increased to male levels. Our results link female fitness to sublethal sperm damage, imply adaptive benefits of interfering with sperm metabolism and offer the hypothesis that polyandry may serve to replace low-quality sperm.

Reinhardt, Klaus; Ribou, Anne-Cecile

2013-01-01

2

Snail sperm production characteristics vary with sperm competition risk  

PubMed Central

Sperm competition is widespread and influences both male investment in spermatogenic tissue and ejaculate characteristics. Sperm competition models assume trade-offs between sperm size and number, although such trade-offs may be difficult to detect. This study examines the effects of sperm competition risk on the sperm production characteristics of the freshwater snail Viviparus ater. In this prosobranch, females mate frequently and store sperm, generating sperm competition. Males produce two sperm morphs, fertile eupyrene sperm and non-fertilizing oligopyrene sperm. Non-fertilizing sperm may play a role in sperm competition and therefore, like fertilizing sperm, the number produced could vary relative to sperm competition risk. In addition, trade-offs between sperm number and sperm size may be expected. We manipulated the sex ratio of sexually mature snails and found the presence of rivals affected the ratio of oligopyrene/eupyrene sperm males produced. In experimental and natural populations, the number of oligopyrene sperm produced, but not the number of eupyrene sperm, was significantly higher when the sex ratio was male biased. Testis mass did not vary between experimental treatments. We also found a negative relationship between the number and size of oligopyrene sperm produced, which is consistent with evolutionary models of sperm competition, and is, to our knowledge, the first intraspecific demonstration of a trade-off between these traits.

Oppliger, A.; Hosken, D. J.; Ribi, G.

1998-01-01

3

GENETIC VARIATION IN SPERM PRODUCTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

In boars, the primary determinant of daily sperm production is number of Sertoli cells, which establishes testicular weight. The only breed comparison of fetal testicular development in boars contrasted two diverse breeds, White composite (WC, Landrace-Yorkshire) with Meishan, a Chinese breed that u...

4

An increased frequency of human sperm chromosomal abnormalities after radiotherapy.  

PubMed

13 cancer patients were studied before radiotherapy (RT) and at regular intervals after RT to determine the effect of RT on chromosomal abnormalities in sperm. The men were 19-47 years old and received testicular radiation doses of 0.4-5.0 Gray. Human pronuclear sperm chromosomes were analysed after penetration of zona-pellucida-free hamster eggs. Unfortunately the hamster egg penetration rates were exceedingly low, both before and after RT and this limited the number of sperm chromosome complements which could be analysed. Before RT, the frequency of abnormal sperm chromosome complements was 0% (0/9). After RT, the majority of men were azoospermic for 24 months but complements could be analysed from 4 men. In the first 12 months the frequency of abnormalities was 13% (1/8) and at 24 months it was 13% (7/55). By 36 months after RT, most men had recovered sperm production and the frequency of abnormalities in 8 men was 21% (18/86), which is significantly higher than the rate in control donors (8.5%). For individual men the range was 6-67%, and there was a significant correlation between testicular radiation dose and the frequency of sperm chromosomal abnormalities. The frequencies of both numerical and structural abnormalities were significantly increased after RT. This is the first evidence that radiation may increase the frequency of chromosomal abnormalities in human gametes. PMID:3724785

Martin, R H; Hildebrand, K; Yamamoto, J; Rademaker, A; Barnes, M; Douglas, G; Arthur, K; Ringrose, T; Brown, I S

1986-07-01

5

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

PubMed

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. PMID:23230887

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

2012-12-11

6

A new preparation protocol for measurement of testicular sperm production.  

PubMed

In studies of male reproductive toxicity, measuring daily sperm production is a quite important criterion. However, the accuracy of the values measured by the basic protocol is still controversial. In order to enhance the homogeneity of countable testicular sperm/spermatid heads, this report introduces a new enzymatic method with a subsequent detergent treatment. The testis of rat was firstly homogenized in phosphate-buffered saline. The homogenate (buffer mix) was then treated with collagenase and trypsin, and then sodium dodecyl sulfate (SDS) was added to produce detergent-resistant sperm/spermatid heads (detergent mix). After examination by hemocytometer, the coefficient of variation (CV) of the number of sperm/spermatid heads was compared with that obtained from the buffer mix. In addition, a MicroCell chamber was applied to the examination, and the CV was compared with other cases. In both examinations, homogeneity was improved by the detergent mix preparation. Counting with the hemocytometer showed an increased number of sperm/spermatid heads compared with that of the buffer mix (P<0.001), and the CV was decreased (P<0.05). In addition, when the MicroCell chamber was applied, the numbers increased about 3-hold compared with that of the buffer mix (P<0.001). The CV of the detergent mix was 23.7%, while that of the buffer mix was 38.9%. These results clearly demonstrate that the new preparation protocol generated in this study can provide more actual and accurate values when measuring daily sperm production. PMID:18025776

Choi, Ehn-Kyoung; Tsunekawa, Naoki; Kanai, Yoshiakira; Kurohmaru, Masamichi

2007-11-19

7

Sperm cells as vectors in the production of transgenic animals  

SciTech Connect

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.

Prince, R.M.

1993-04-28

8

Guaifenesin and increased sperm motility: a preliminary case report  

PubMed Central

Background A review of the literature and an extensive Medline search revealed that this is the first case report of the use of guaifenesin to increase sperm motility. Case A 32-year-old male presented for an infertility evaluation. He reported an inability to conceive with his wife after 18 months of unprotected intercourse. A semen analysis was performed that included spermatozoa count, liquefaction, morphology, motility, viscosity and volume. Initial results of the semen analysis demonstrated low sperm count and motility. The provider offered treatment with guaifenesin 600 mg extended release tablets twice daily. Two months after guaifenesin therapy the semen analysis was repeated that demonstrated marked improvement in both total sperm count and motility. Conclusion Evidence for the effectiveness of guaifenesin is almost entirely anecdotal. Given the mechanism of action of guaifenesin, it is not clear from this case why the patient demonstrated such a large improvement in both sperm count and motility. Additional studies of the effects of guaifenesin on male fertility could yield information of the medication’s effect on men with normal or decreased total sperm counts.

Means, Gary; Berry-Caban, Cristobal S; Hammermeuller, Kurt

2011-01-01

9

Sperm pretreatment with dithiothreitol increases male pronucleus formation rates after intracytoplasmic sperm injection (ICSI) in swamp buffalo oocytes.  

PubMed

Failure of male pronucleus formation has hampered the success of intracytoplasmic sperm injection (ICSI) in swamp buffalo. The aim of the present study was to improve male pronucleus formation by pretreating sperm with various chemicals before ICSI. In Experiments1 and 2, sperm were treated according to one of the following protocols: (1) 0.1% Triton-X 100 (TX) for 1 min, (2) 10 ?M calcium ionophore (CaI) for 20 min, (3) freezing and thawing (FT) without any cryoprotectant, or (4) no treatment (control). These sperm treatment groups then either did or did not receive additional sperm treatment with 5 mM dithiothreitol (DTT) for 20 min. Acrosomal integrity (Experiment 1) and DNA fragmentation (Experiment 2) were evaluated in the sperm before ICSI. In Experiment 3, oocytes matured in vitro were subjected to ICSI using pretreated sperm as described above and then were cultured either with or without activation. The TX- and CaI-treated sperm caused an increase in the number of acrosome-loss sperm, whereas the FT treatment and control increased the proportion of acrosome-reacted sperm (P<0.05). The DNA fragmentation did not differ among treatments (P>0.05). At 18 h post-ICSI, pronucleus (PN) formation was found only in activated oocytes. The majority of the activated ICSI oocytes contained intact sperm heads. Normal fertilization was observed in the CaI and FT treatment groups and control group when sperm were treated with DTT before ICSI. In conclusion, DTT treatment of sperm with reacted acrosomes before ICSI together with activation of the ICSI oocytes is important for successful male pronucleus formation. PMID:23132520

Chankitisakul, Vibuntita; Am-In, Nutthee; Tharasanit, Theerawat; Somfai, Tamas; Nagai, Takashi; Techakumphu, Mongkol

2012-11-06

10

Sperm competition, sperm numbers and sperm quality in muroid rodents.  

PubMed

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 developmental pathways underlying processes of sperm formation, maturation, transport in the female reproductive tract, and preparation for fertilization must all evolve in concert. PMID:21464956

Gómez Montoto, Laura; Magaña, Concepción; Tourmente, Maximiliano; Martín-Coello, Juan; Crespo, Cristina; Luque-Larena, Juan José; Gomendio, Montserrat; Roldan, Eduardo R S

2011-03-25

11

Strategic adjustments in sperm production within and between two island populations of house mice.  

PubMed

Sperm production is physiologically costly. Consequently, males are expected to be prudent in their sperm production, and tailor their expenditure according to prevailing social conditions. Differences in sperm production have been found across island populations of house mice that differ in the level of selection from sperm competition. Here, we determined the extent to which these differences represent phenotypic plasticity and/or population divergence in sperm production. We sourced individuals from two populations at the extreme levels of sperm competition, and raised them under common-garden conditions while manipulating the social experience of developing males. Males from the high-sperm competition population produced more sperm and better quality sperm than did males from the low-sperm competition population. In addition, males reared under a perceived "risk" of sperm competition produced greater numbers of sperm than males reared with "no risk." However, our analyses revealed that phenotypic plasticity in sperm production was greater for individuals from the high-sperm competition population. Our results are thus consistent with both population divergence and phenotypic plasticity in sperm production, and suggest that population level of sperm competition might affect the degree of adaptive plasticity in sperm production in response to sperm competition risk. PMID:24094355

Firman, Renée C; Klemme, Ines; Simmons, Leigh W

2013-06-07

12

Effect of divergent selection for testosterone production on testicular morphology and daily sperm production in boars.  

PubMed

The objective of this study was to characterize correlated responses in testicular morphology and daily sperm production to divergent selection for testosterone production. Duroc boars from high and low lines (HTL and LTL, respectively) divergently selected over 10 generations for testosterone production in response to a GnRH challenge followed by random selection were used. Testicular tissues were sampled from all available males of generation 20 (HTL, n = 46; and LTL, n = 13). Volume densities for Leydig cells, seminiferous tubules, and Sertoli cells were estimated along with sperm production. The HTL boars had greater volume densities of Leydig cells than did LTL (P < 0.01). Volume density of seminiferous tubules tended to differ between lines (P < 0.07), but Sertoli cell volume densities did not differ (P < 0.27). Sperm production traits, adjusted for age, did not differ significantly between lines. Body, testicular, and epididymal weights were recorded for boars from HTL (n = 82) and LTL (n = 44) from generations 20 and 21. After adjustment for BW, average paired testicular weights for HTL and LTL were 417 and 457 g (P < 0.01), respectively. Epididymal weights, adjusted for BW, were heavier for HTL (P < 0.01) than for LTL. To demonstrate that the selection lines still differed for testosterone production, lines were evaluated in generation 21. Endogenous testosterone production of the HTL (n = 54) and LTL (n = 44) testosterone production line averaged 49.0 ng/mL and 27.8 ng/mL (P < 0.01), respectively. Plasma FSH concentrations did not differ between lines (P < 0.30). Selection for testosterone production in response to a GnRH challenge was an effective method of changing testosterone concentrations, testicular size, epididymal weight, and volume density of Leydig cells. However, daily sperm production per gram of testes was unchanged. Based on the results of this study, selection for testosterone production is not recommended as a method of increasing sperm production in pigs. PMID:15318722

Walker, S; Robison, O W; Whisnant, C S; Cassady, J P

2004-08-01

13

Interleukin6 Enhances the Fertilizing Capacity of Human Sperm by Increasing Capacitation and Acrosome Reaction  

Microsoft Academic Search

The effects of human recombinant interleukin-6 (IL-6) on human sperm penetration of zona-free hamster ova (SPA) and human sperm cell capacitation and acrosome reaction were inves- tigated. IL-6 at higher concentrations (60-600 pg\\/i 00 l) significantly (P < 0.001) increased rather than decreased the human sperm pen- etration rates in SPA. The effects were specific because immunoad- sorption with the

RAJESH K. NAZ; PAUL KAPLANt

14

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

NASA Astrophysics Data System (ADS)

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.

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

2005-12-01

15

Sperm whale sound production studied with ultrasound time\\/depth-recording tags  

Microsoft Academic Search

Delphinoids (Delphinidae, Odontoceti) produce tonal sounds and clicks by forcing pressurized air past phonic lips in the nasal complex. It has been proposed that homologous, hypertrophied nasal structures in the deep-diving sperm whale (Physeter macrocephalus) (Physeteridae, Odontoceti) are dedicated to the production of clicks. However, air volumes in diving mammals are reduced with increasing ambient pressure, which seems likely to

P. T. Madsen; R. Payne; N. U. Kristiansen; M. Wahlberg; I. Kerr; B. Møhl

2002-01-01

16

Self-incompatibility response induced by calcium increase in sperm of the ascidian Ciona intestinalis  

PubMed Central

Many hermaphroditic organisms possess a self-incompatibility system to avoid self-fertilization. Recently, we identified the genes responsible for self-sterility in a hermaphroditic primitive chordate (ascidian), Ciona intestinalis: sperm-side polycystin 1-like receptors s-Themis-A/B and egg-side fibrinogen-like ligands on the vitelline coat (VC) v-Themis-A/B. Here, we investigated the sperm behavior and intracellular Ca2+ concentration ([Ca2+]i) in response to self/nonself-recognition. We found that sperm motility markedly decreased within 5 min after attachment to the VC of self-eggs but not after attachment to the VC of nonself-eggs and that the apparent decrease in sperm motility was suppressed in low Ca2+ seawater. High-speed video analysis revealed that sperm detached from the self-VC or stopped motility within 5 min after binding to the self-VC. Because s-Themis-B contains a cation channel domain in its C terminus, we monitored sperm [Ca2+]i by real-time [Ca2+]i imaging using Fluo-8H-AM (AAT Bioquest, Inc.). Interestingly, we found that sperm [Ca2+]i rapidly and dramatically increased and was maintained at a high level in the head and flagellar regions when sperm interacted with the self-VC but not when the sperm interacted with the nonself-VC. The increase in [Ca2+]i was also suppressed by low-Ca2+ seawater. These results indicate that the sperm self-recognition signal triggers [Ca2+]i increase and/or Ca2+ influx, which elicits a self-incompatibility response to reject self-fertilization in C. intestinalis.

Saito, Takako; Shiba, Kogiku; Inaba, Kazuo; Yamada, Lixy; Sawada, Hitoshi

2012-01-01

17

Sperm Competition Selects for Sperm Quantity and Quality in the Australian Maluridae  

PubMed Central

When ejaculates from rival males compete for fertilization, there is strong selection for sperm traits that enhance fertilization success. Sperm quantity is one such trait, and numerous studies have demonstrated a positive association between sperm competition and both testes size and the number of sperm available for copulations. Sperm competition is also thought to favor increases in sperm quality and changes in testicular morphology that lead to increased sperm production. However, in contrast to sperm quantity, these hypotheses have received considerably less empirical support and remain somewhat controversial. In a comparative study using the Australian Maluridae (fairy-wrens, emu-wrens, grasswrens), we tested whether increasing levels of sperm competition were associated with increases in both sperm quantity and quality, as well as an increase in the relative amount of seminiferous tubule tissue contained within the testes. After controlling for phylogeny, we found positive associations between sperm competition and sperm numbers, both in sperm reserves and in ejaculate samples. Additionally, as sperm competition level increased, the proportion of testicular spermatogenic tissue also increased, suggesting that sperm competition selects for greater sperm production per unit of testicular tissue. Finally, we also found that sperm competition level was positively associated with multiple sperm quality traits, including the proportion of motile sperm in ejaculates and the proportion of both viable and morphologically normal sperm in sperm reserves. These results suggest multiple ejaculate traits, as well as aspects of testicular morphology, have evolved in response to sperm competition in the Australian Maluridae. Furthermore, our findings emphasize the importance of post-copulatory sexual selection as an evolutionary force shaping macroevolutionary differences in sperm phenotype.

Rowe, Melissah; Pruett-Jones, Stephen

2011-01-01

18

Large-Male Advantages Associated with Costs of Sperm Production in Drosophila hydei, a Species with Giant Sperm  

Microsoft Academic Search

Males of the fruit fly Drosophila hydei were found to produce 23.47 ± 0.46-mm-long spermatozoa, the longest ever described. No relationship was found between male body size and sperm length. We predicted that if these giant gametes are costly for males to produce, then correlations should exist between male body size, rates of sperm production, and fitness attributes associated with

Scott Pitnick; Therese A. Markow

1994-01-01

19

Male contributions to egg production: the role of accessory gland products and sperm in Drosophila melanogaster.  

PubMed Central

Drosophila melanogatser seminal fluid components, accessory gland proteins (Acps) and sperm, induce females to deposit high numbers of fertilized eggs for about 11 days. This high and sustained level of egg deposition requires that oogenesis be stimulated to provide the necessary mature oocytes. To investigate the relative timing and contributions of Acps and sperm in the egg-production process, we examined the rates of oogenic progression and egg deposition in females mated to genetically altered males that have seminal fluid deficient in Acps and/or sperm, and subjected these data to path analysis. We found that Acps and sperm are complementary stimuli necessary for inducing high rates of oogenic progression and rapid egg deposition. While egg deposition and oogenic progression can be induced by Acps alone, both Acps and sperm are required for maximum stimulation of oogenic progression and egg deposition immediately after mating.

Heifetz, Y; Tram, U; Wolfner, M F

2001-01-01

20

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

PubMed Central

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.

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

2012-01-01

21

What Sperm Can Teach us About Energy Production  

PubMed Central

Mammalian sperm have evolved under strict selection pressures that have resulted in a highly polarized and efficient design. A critical component of that design is the compartmentalization of specific metabolic pathways to specific regions of the cell. Although the restricted localization of mitochondria to the midpiece is the best known example of this design, the organization of the enzymes of glycolysis along the fibrous sheath is the primary focus of this review. Evolution of variants of these metabolic enzymes has allowed them to function when tethered, enabling localized energy production that is essential for sperm motility. We close by exploring how this design might be mimicked to provide an energy-producing platform technology for applications in nanobiotechnology.

Mukai, C.; Travis, AJ.

2013-01-01

22

What sperm can teach us about energy production.  

PubMed

Mammalian sperm have evolved under strict selection pressures that have resulted in a highly polarized and efficient design. A critical component of that design is the compartmentalization of specific metabolic pathways to specific regions of the cell. Although the restricted localization of mitochondria to the midpiece is the best known example of this design, the organization of the enzymes of glycolysis along the fibrous sheath is the primary focus of this review. Evolution of variants of these metabolic enzymes has allowed them to function when tethered, enabling localized energy production that is essential for sperm motility. We close by exploring how this design might be mimicked to provide an energy-producing platform technology for applications in nanobiotechnology. PMID:22827366

Mukai, C; Travis, A J

2012-08-01

23

Cryopreservation increases coating of bull sperm by seminal plasma binder of sperm proteins BSP1, BSP3, and BSP5.  

PubMed

Artificial insemination with frozen semen allows affordable, worldwide dissemination of gametes with superior genetics. Nevertheless, sperm are damaged by the cryopreservation process. Elucidating the molecular effects of cryopreservation on sperm could suggest methods for improving fertility of frozen/thawed semen. This study was undertaken to examine the effect of cryopreservation on the coating of sperm by binder of sperm (BSP) proteins in seminal plasma. BSP proteins are secreted by the seminal vesicles and coat the surface of sperm by partially intercalating into the outer leaflet of the sperm plasma membrane. The BSP proteins are known to play roles in the formation of the oviductal sperm storage reservoir and in sperm capacitation. We investigated the effects of cryopreservation on the sperm BSP protein coat using Bovipure to separate live sperm from extended semen and then assaying the amounts of BSP proteins on sperm using quantitative western blotting with custom-made antibodies against unique sequences of each BSP protein. Greater amounts of all three BSP proteins (BSP1, BSP3, and BSP5) were detected on frozen/thawed sperm than on fresh sperm. Furthermore, the reduction of BSP3 from 15 to 13?kDa in mass, which occurs during incubation of sperm under mild capacitating conditions, was enhanced by cryopreservation. We concluded that freezing alters the BSP protein coating on sperm, which could account in part for reduced fertility of cryopreserved semen samples. PMID:23740081

Ardon, Florencia; Suarez, Susan S

2013-06-27

24

Large-male advantages associated with costs of sperm production in Drosophila hydei, a species with giant sperm.  

PubMed

Males of the fruit fly Drosophila hydei were found to produce 23.47 +/- 0.46-mm-long spermatozoa, the longest ever described. No relationship was found between male body size and sperm length. We predicted that if these giant gametes are costly for males to produce, then correlations should exist between male body size, rates of sperm production, and fitness attributes associated with the production of sperm. Smaller males were found to make a greater relative investment in testicular tissue growth, even though they have shorter and thinner testes. Smaller males were also found to (i) be maturing fewer sperm bundles within the testes at any point in time than larger males, (ii) require a longer period of time post-eclosion to become reproductively mature, (iii) mate with fewer females, (iv) transfer fewer sperm per copulation, and (v) produce fewer progeny. The significance of these findings for body size-related fitness and the question of sperm size evolution are discussed. PMID:7937755

Pitnick, S; Markow, T A

1994-09-27

25

Black tea high-molecular-weight polyphenol increases the motility of sea urchin sperm by activating mitochondrial respiration.  

PubMed

Mitochondria activation factor (MAF) is a high-molecular-weight polyphenol purified from black tea that activates mitochondrial respiration. It increased the mitochondrial membrane potential and motility of sea urchin sperm, by up to 8%, to the same extent as sperm-activating peptides (SAPs) secreted by the egg. Unlike SAPs, MAF had no effect on sperm swimming behavior, suggesting that the mechanism of sperm activation by MAF is different from that of SAPs. PMID:23221694

Kikuchi, Ayako; Shiba, Kogiku; Ozawa, Tetsuo; Nakano, Kentaro; Inaba, Kazuo; Numata, Osamu

2012-12-07

26

Production of cloned horse foals using roscovitine-treated donor cells and activation with sperm extract and\\/or ionomycin  

Microsoft Academic Search

We evaluated the effect of different activation treatments on the production of blastocysts and foals by nuclear transfer. Donor cells were prepared using roscovitine treatment, which has previously been associated with increased production of viable offspring. All activation treatments were followed by culture in 6-dimethylaminopurine (6-DMAP) for 4 h. In experiment 1, blastocyst production afteractivation by injection of sperm extract

K Hinrichs; Y H Choi; D D Varner; D L Hartman

2007-01-01

27

Increased Aneuploidy Rate in Sperm With Fragmented DNA as Determined by the Sperm Chromatin Dispersion (SCD) Test and FISH Analysis  

Microsoft Academic Search

Previous studies suggest that sperm DNA fragmen- tation 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,

LOURDES MURIEL; VICENTE GOYANES; ENRIQUE SEGRELLES; JAIME GOSALVEZ; JUAN G. ALVAREZ; JOSELUIS FERNANDEZ

2007-01-01

28

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

PubMed Central

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.

Recio, R; Robbins, W A; Borja-Aburto, V; Moran-Martinez, J; Froines, J R; Hernandez, R M; Cebrian, M E

2001-01-01

29

Sperm counts and sperm sex ratio in male infertility patients.  

PubMed

In recent years, investigators have noted a trend toward a declining proportion of male births in many industrialized nations. While men bear the sex-determining chromosome, the role of the female partner as it pertains to fertilization or miscarriage may also alter the gender ratio. We attempted to determine a man's secondary sex ratio (F1 generation) by directly examining the sex chromosomes of his sperm. We examined our male infertility clinic database for all men who had undergone a semen fluorescence in situ hybridization (FISH). Patient demographic and semen parameters were recorded. Chi-squared analysis was used to compare gender ratios (Y chromosomes/total chromosomes). Multivariable logistic regression was used to predict the odds of possessing a Y-bearing sperm after accounting for demographic and semen parameters. A total of 185 men underwent sperm FISH. For the entire cohort, the proportion of Y chromosome-bearing sperm was 51.5%. Men with less than five million motile sperm had a significantly lower proportion of Y chromosome-bearing sperm (50.8%) compared to men with higher sperm counts (51.6%; P=0.02). After multivariable adjustment, a higher sperm concentration, total motile sperm count and semen volume significantly increased the odds of having a Y chromosome-bearing sperm (P<0.01). As a man's sperm production declines, so does the proportion of Y chromosome-bearing sperm. Thus, a man's reproductive potential may predict his ability to sire male offspring. PMID:22842703

Eisenberg, Michael L; Murthy, Lata; Hwang, Kathleen; Lamb, Dolores J; Lipshultz, Larry I

2012-07-30

30

Sperm counts and sperm sex ratio in male infertility patients  

PubMed Central

In recent years, investigators have noted a trend toward a declining proportion of male births in many industrialized nations. While men bear the sex-determining chromosome, the role of the female partner as it pertains to fertilization or miscarriage may also alter the gender ratio. We attempted to determine a man's secondary sex ratio (F1 generation) by directly examining the sex chromosomes of his sperm. We examined our male infertility clinic database for all men who had undergone a semen fluorescence in situ hybridization (FISH). Patient demographic and semen parameters were recorded. Chi-squared analysis was used to compare gender ratios (Y chromosomes/total chromosomes). Multivariable logistic regression was used to predict the odds of possessing a Y-bearing sperm after accounting for demographic and semen parameters. A total of 185 men underwent sperm FISH. For the entire cohort, the proportion of Y chromosome-bearing sperm was 51.5%. Men with less than five million motile sperm had a significantly lower proportion of Y chromosome-bearing sperm (50.8%) compared to men with higher sperm counts (51.6% P=0.02). After multivariable adjustment, a higher sperm concentration, total motile sperm count and semen volume significantly increased the odds of having a Y chromosome-bearing sperm (P<0.01). As a man's sperm production declines, so does the proportion of Y chromosome-bearing sperm. Thus, a man's reproductive potential may predict his ability to sire male offspring.

Eisenberg, Michael L; Murthy, Lata; Hwang, Kathleen; Lamb, Dolores J; Lipshultz, Larry I

2012-01-01

31

Relief effect of vitamin A on the decreased motility of sperm and the increased incidence of malformed sperm in mice exposed neonatally to bisphenol A  

Microsoft Academic Search

Administration of 50 µg of bisphenol A (BPA) for the first 5 days after birth resulted in a decrease in the percentage of moving sperm, and an increase in the incidence of malformed sperm, in the epididymides of mice at 10 weeks of age, although no marked changes were found in the testicular histology between BPA-treated and vehicle-treated control mice. The deteriorating effects

Hazuki Aikawa; Sachiko Koyama; Manabu Matsuda; Keiko Nakahashi; Yasuhisa Akazome; Takao Mori

2004-01-01

32

Increasing productivity: Another approach  

SciTech Connect

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.

Norton, F.J.

1996-06-10

33

Male mating behaviour and sperm production characteristics under varying sperm competition risk in guppies.  

PubMed

Since natural populations of guppies, Poecilia reticulata, often differ from one another in social structure, the intensity of sperm competition is likely to vary between localities. Guppies are promiscuous, with female choice for colourful males playing a central role in the mating system. In addition, male guppies use forced copulations to circumvent female choice. Both methods of copulation are used interchangeably by individual males, but the degree to which either is used may depend on the social environment into which males are born. Here we show that male mating behaviour varies according to the rearing sex ratio: when reared in male-biased groups, males performed more forced copulations and fewer courtship displays but showed the opposite pattern of behaviour when reared in female-biased groups. Our prediction, based on sperm competition theory, that stripped sperm number would reflect social structure was not supported by our results. Instead, the overall level of sexual activity (gonopodial thrusts+sigmoid displays) was a better predictor of sperm number in the different groups of males. Rearing density, where sex ratio was controlled, did not significantly affect male mating behaviour or sperm traits. Males reared under the different sex ratios continued to show their characteristic behaviour patterns when placed in equal sex ratio tanks. We conclude, therefore, that males adopt mating strategies to suit their social environment, and that these strategies remain fixed, for short periods at least, if population structure changes. Copyright 1999 The Association for the Study of Animal Behaviour. PMID:10564602

Evans; Magurran

1999-11-01

34

Production of Transgenic Pigs Mediated by Pseudotyped Lentivirus and Sperm  

PubMed Central

Sperm-mediated gene transfer can be a very efficient method to produce transgenic pigs, however, the results from different laboratories had not been widely repeated. Genomic integration of transgene by injection of pseudotyped lentivirus to the perivitelline space has been proved to be a reliable route to generate transgenic animals. To test whether transgene in the lentivirus can be delivered by sperm, we studied incubation of pseudotyped lentiviruses and sperm before insemination. After incubation with pig spermatozoa, 62±3 lentiviral particles were detected per 100 sperm cells using quantitative real-time RT-PCR. The association of lentivirus with sperm was further confirmed by electron microscopy. The sperm incubated with lentiviral particles were artificially inseminated into pigs. Of the 59 piglets born from inseminated 5 sows, 6 piglets (10.17%) carried the transgene based on the PCR identification. Foreign gene and EGFP was successfully detected in ear tissue biopsies from two PCR-positive pigs, revealed via in situ hybridization and immunohistochemistry. Offspring of one PCR-positive boar with normal sows showed PCR-positive. Two PCR-positive founders and offsprings of PCR-positive boar were further identified by Southern-blot analysis, out of which the two founders and two offsprings were positive in Southern blotting, strongly indicating integration of foreign gene into genome. The results indicate that incubation of sperm with pseudotyped lentiviruses can incorporated with sperm-mediated gene transfer to produce transgenic pigs with improved efficiency.

Zhang, Yongliang; Xi, Qianyun; Ding, Jinghua; Cai, Weiguang; Meng, Fanmin; Zhou, Junyun; Li, Hongyi; Jiang, Qingyan; Shu, Gang; Wang, Songbo; Zhu, Xiaotong; Gao, Ping; Wu, Zhenfang

2012-01-01

35

Varicocele-related infertility is not associated with increased sperm-bound antibody.  

PubMed

Immunological factors have been implicated as a cause of unexplained infertility. Previous studies have demonstrated increased levels of sperm-bound antibody in infertile men with varicoceles and have postulated their role in varicocele-related infertility. However, these studies were performed using an enzyme-linked immunosorbent assay. We evaluated retrospectively 111 male patients referred for infertility using a direct immunobead assay. Of the patients 29 had grade II or III varicoceles (that is palpable or easily visualized) and 82 were without varicocele. Four patients who had undergone vasovasostomy were included as controls for the assay. A direct immunobead assay was performed for isotype IgG and IgA sperm-bound antibody using a standard protocol. A computerized semen analysis was also performed. Greater than 20% binding, excluding tail tip activity, was considered significant. Of 29 patients with and 82 without a varicocele significant binding was identified in 5 (17%) and 9 (11%), respectively. Chi-square statistical analysis did not reveal this difference to be significant (p < 0.05). All 4 vasovasostomy patients demonstrated significant binding. We conclude from this study that infertile men with varicoceles do not demonstrate significantly increased levels of sperm-bound antibody compared to infertile controls and, therefore, sperm-bound antibody does not appear to have a significant role in varicocele-related infertility. PMID:8345603

Oshinsky, G S; Rodriguez, M V; Mellinger, B C

1993-09-01

36

Male mating behaviour and sperm production characteristics under varying sperm competition risk in guppies  

Microsoft Academic Search

Since natural populations of guppies, Poecilia reticulata, often differ from one another in social structure, the intensity of sperm competition is likely to vary between localities. Guppies are promiscuous, with female choice for colourful males playing a central role in the mating system. In addition, male guppies use forced copulations to circumvent female choice. Both methods of copulation are used

Jonathan P. Evans; Anne E. Magurran

1999-01-01

37

Sperm wars and the evolution of male fertility.  

PubMed

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. PMID:22984191

Simmons, Leigh W; Fitzpatrick, John L

2012-09-14

38

Increasing Public Library Productivity.  

ERIC Educational Resources Information Center

Suggests ways of improving productivity for public libraries faced with increased accountability, dwindling revenues, and continuing inflation. Techniques described include work simplification, work analysis, improved management, and employee motivation. (RAA)

Samuelson, Howard

1981-01-01

39

Potassium-dependent increases in cytosolic pH stimulate metabolism and motility of mammalian sperm.  

PubMed Central

Sperm cytosolic pH, determined by the spectral properties of intracellular carboxyfluorescein, is decreased rapidly by the diffusion and subsequent dissociation of the uncharged weak acids pyruvic, lactic, or hydroxybutyric and is increased by diffusion and subsequent intracellular protonation of the weak base NH3. Metabolic and kinetic activity increases dramatically when intracellular pH is elevated above 6.8-6.9 by addition of 50 mM NH4Cl to sperm suspended in a 120 mM NaCl medium. Respiratory stimulation is not observed upon comparable additions of 50 mM Li+ or K+ or when the pH of the medium is increased from 6.5 to 8.2. However, increases of the external pH to 7.8-8.2 in medium employing 120 mM KCl result in increased metabolic and kinetic activity, comparable to the maximal stimulation induced by the phosphodiesterase inhibitor caffeine. An increase in cytosolic pH from 6.3-6.6 to 6.8 occurs concomitant with the respiratory stimulation induced by KCl in alkaline media. No change in cytosolic pH follows addition of caffeine. Cyclic AMP-dependent protein kinase activity ratios, determined in cellular extracts, are increased by caffeine treatment but are not elevated by 120 mM KCl, by alkaline pH, or by their combination. These observations indicate that cytosolic pH plays a role in the regulation of motility and metabolism of mammalian sperm that is not mediated by cyclic AMP but that may be under control of a plasma membrane voltage-dependent proton channel. However, H+ fluxes across vesicles prepared from sperm membranes are unaffected by variation in the magnitude of the transvesicular K+ concentration gradient.

Babcock, D F; Rufo, G A; Lardy, H A

1983-01-01

40

Mitochondria functionality and sperm quality.  

PubMed

Although mitochondria are best known for being the eukaryotic cell powerhouses, these organelles participate in various cellular functions besides ATP production, such as calcium homoeostasis, generation of reactive oxygen species (ROS), the intrinsic apoptotic pathway and steroid hormone biosynthesis. The aim of this review was to discuss the putative roles of mitochondria in mammalian sperm function and how they may relate to sperm quality and fertilisation ability, particularly in humans. Although paternal mitochondria are degraded inside the zygote, sperm mitochondrial functionality seems to be critical for fertilisation. Indeed, changes in mitochondrial integrity/functionality, namely defects in mitochondrial ultrastructure or in the mitochondrial genome, transcriptome or proteome, as well as low mitochondrial membrane potential or altered oxygen consumption, have been correlated with loss of sperm function (particularly with decreased motility). Results from genetically engineered mouse models also confirmed this trend. On the other hand, increasing evidence suggests that mitochondria derived ATP is not crucial for sperm motility and that glycolysis may be the main ATP supplier for this particular aspect of sperm function. However, there are contradictory data in the literature regarding sperm bioenergetics. The relevance of sperm mitochondria may thus be associated with their role in other physiological features, particularly with the production of ROS, which in controlled levels are needed for proper sperm function. Sperm mitochondria may also serve as intracellular Ca(2)(+) stores, although their role in signalling is still unclear. PMID:23901129

Amaral, Alexandra; Lourenço, Bárbara; Marques, Mónica; Ramalho-Santos, João

2013-10-01

41

Membrane hyperpolarization activates trout sperm without an increase in intracellular pH  

Microsoft Academic Search

Summary Sperm from trout, like other sperm, are immotile in the seminal tract and initiate motility upon dilution into an appropriate fertilizing environment. Trout sperm motility is inhibited by high extracellular (K + ) and can be activated by dilution of extracellular (K + ). Activation of trout sperm by the dilution of extra- cellular (K + ) suggests regulation

SCOTT BOITANO; CHARLOTTE K. OMOTO

1991-01-01

42

Productivity increases in science  

SciTech Connect

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.

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

1993-02-01

43

Productivity increases in science  

SciTech Connect

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.

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

1993-02-01

44

Reinitiation of sperm production in gonadotropin-suppressed normal men by administration of follicle-stimulating hormone  

PubMed Central

The specific roles of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in controlling human spermatogenesis are poorly understood. We studied the effect of an experimentally induced, selective LH deficiency on sperm production in normal men. After a 3-mo control period, five men received 200 mg testosterone enanthate (T) i.m./wk to suppress LH, FSH, and sperm counts. Then, while continuing T at the same dosage, human FSH (hFSH) was administered simultaneously to replace FSH activity, leaving LH activity suppressed. Four men received 100 IU hFSH s.c. daily plus T (high dosage hFSH) for 13-14 wk, while one man received 50 IU hFSH s.c. daily plus T (low dosage hFSH) for 5 mo. The effect on sperm production of the selective LH deficiency produced by hFSH plus T administration was assessed. In the four men who received the high dosage hFSH regimen, sperm counts were markedly suppressed during T administration alone (0.3±0.2 million/cm3, mean±SE, compared with 94±12 million/cm3 during the control period). Serum LH bioactivity (determined by in vitro mouse Leydig cell assay) was suppressd (140±7 ng/ml compared with 375±65 ng/ml during control period) and FSH levels (by radioimmunoassay) were reduced to undetectable levels (<25 ng/ml, compared with 98±21 ng/ml during control period) during T alone. With the addition of 100 IU hFSH s.c. daily to T, sperm counts increased significantly in all subjects (33±7 million/cm3, P < 0.02 compared with T alone). However, no subject consistently achieved sperm counts within his control range. Sperm morphology and motility were normal in all four men and in vitro sperm penetration of hamster ova was normal in the two men tested during the hFSH-plus-T period. During high-dosage hFSH administration, serum FSH levels increased to 273±44 ng/ml (just above the normal range for FSH, 30-230 ng/ml). Serum LH bioactivity was not significantly changed compared with the T-alone period (147±9 ng/ml). After the hFSH-plus-T period, all four men continued to receive T alone after hFSH was stopped. Sperm counts were again severely suppressed (0.2±0.1 million/cm3), demonstrating the dependence of sperm production on hFSH administration. Serum T and estradiol (E2) levels increased two- to threefold during T administration alone compared with the control period. Both T and E2 levels remained unchanged with the addition of hFSH to T, confirming the lack of significant LH activity in the hFSH preparation. In the one man who received low dosage hFSH treatment, sperm counts were reduced to severely oligospermic levels, serum FSH was suppressed to undetectable levels, and serum LH bioactivity was markedly lowered during the T-alone period. With the addition of 50 IU hFSH s.c. daily to T, sperm counts increased, to a mean of 11±3 million/cm3. During this period, serum FSH levels increased to a mean of 105±11 ng/ml (slightly above this man's control range and within the normal adult range), while LH bioactivity remain suppressed. After hFSH was stopped and T alone was continued, sperm counts were again severely reduced to azoospermic levels. We conclude that FSH alone is sufficient to reinitiate sperm production in man during gonadotropin suppression induced by exogenous T administration. FSH may stimulate sperm production in this setting by increasing intratesticular T through androgenbinding protein production or by increasing the sensitivity of the spermatogenic response to the intratesticular T present during exogenous T administration.

Matsumoto, Alvin M.; Karpas, Anthony E.; Paulsen, C. Alvin; Bremner, William J.

1983-01-01

45

The Ca2+ increase by the sperm factor in physiologically polyspermic newt fertilization: its signaling mechanism in egg cytoplasm and the species-specificity.  

PubMed

The newt, Cynops pyrrhogaster, exhibits physiological polyspermic fertilization, in which several sperm enter an egg before egg activation. An intracellular Ca(2+) increase occurs as a Ca(2+) wave at each sperm entry site in the polyspermic egg. Some Ca(2+) waves are preceded by a transient spike-like Ca(2+) increase, probably caused by a tryptic protease in the sperm acrosome at the contact of sperm on the egg surface. The following Ca(2+) wave was induced by a sperm factor derived from sperm cytoplasm after sperm-egg membrane fusion. The Ca(2+) increase in the isolated, cell-free cytoplasm indicates that the endoplasmic reticulum is the major Ca(2+) store for the Ca(2+) wave. We previously demonstrated that citrate synthase in the sperm cytoplasm is a major sperm factor for egg activation in newt fertilization. In the present study, we found that the activation by the sperm factor as well as by fertilizing sperm was prevented by an inhibitor of citrate synthase, palmitoyl CoA, and that an injection of acetyl-CoA or oxaloacetate caused egg activation, indicating that the citrate synthase activity is necessary for egg activation at fertilization. In the frog, Xenopus laevis, which exhibits monospermic fertilization, we were unable to activate the eggs with either the homologous sperm extract or the Cynops sperm extract, indicating that Xenopus sperm lack the sperm factor for egg activation and that their eggs are insensitive to the newt sperm factor. The mechanism of egg activation in the monospermy of frog eggs is quite different from that in the physiological polyspermy of newt eggs. PMID:21237143

Harada, Yuichirou; Kawazoe, Mari; Eto, Yuki; Ueno, Shuichi; Iwao, Yasuhiro

2011-01-13

46

Multiple paternity and sperm storage lead to increased genetic diversity in Anolis lizards  

Microsoft Academic Search

Question: Are multiple mating and sperm storage important in the evolution of Anolis lizards? Data description: Rates of multiple paternity in field-caught dams, timing of sperm storage from field-caught dams, sire order effects, genetic diversity of progeny, timing of sperm storage from controlled matings in the laboratory. Data are based on the use of eight microsatellite loci, natural and controlled

Ryan Calsbeek; Camille Bonneaud; Setal Prabhu; Nicholas Manoukis; Thomas B. Smith

2007-01-01

47

GROWTH OF HOLSTEIN BULLS AND ITS RELATION TO SPERM PRODUCTION 1  

Microsoft Academic Search

HILE the growth of female dairy cattle and the relation of milk production to age and size has been extensively studied, less atten- tion has been given to growth studies in the male. While some studies have indicated a relationship between growth of young bulls and the onset of sperm production, little evidence has been found showing the relationship of

F. N. BAKER; N. L. VANDEMARK; G. W. SALISBURY

2010-01-01

48

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

PubMed Central

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.

Bretman, Amanda; Fricke, Claudia; Chapman, Tracey

2009-01-01

49

Objective non-intrusive markers of sperm production and sexual activity  

PubMed Central

Objective studies of men's reproductive function are hindered by their reliance on: (i) self-reporting to quantify sexual activity and (ii) masturbation to quantify sperm output rendering both types of estimate vulnerable to unverifiable subjective factors. We therefore examined whether detection of spermatozoa and measurement of prostate-specific antigen (PSA) in urine could provide objective semiquantitative estimates of sperm output and recent ejaculation, respectively, using widely available laboratory techniques. Of 11 healthy volunteers who provided urine samples before and at intervals for 5 days after ejaculation, sperm was present in 2/11 men before, and in all 11/11 samples immediately after ejaculation, but by the second and subsequent void, spermatozoa were present in ?10%. PSA was detectable at high levels in all urine samples, peaking at the first post-ejaculatory sample but returning to baseline levels by the second post-ejaculatory void. We conclude that urinary spermatozoa and PSA are objective biomarkers for sperm production and sexual activity, but only for a short-time window until the first post-ejaculatory urine void. Hence, for a single urine specimen, the presence of spermatozoa and PSA are valid biomarkers, reflecting sperm production and recent ejaculation only until the next micturition, so their measurement should be restricted to the first morning urine void.

Sivananthan, Thilee; Bathur, Franz; Jimenez, Mark; Conway, Ann; Idan, Amanda; Handelsman, David

2012-01-01

50

Objective non-intrusive markers of sperm production and sexual activity.  

PubMed

Objective studies of men's reproductive function are hindered by their reliance on: (i) self-reporting to quantify sexual activity and (ii) masturbation to quantify sperm output rendering both types of estimate vulnerable to unverifiable subjective factors. We therefore examined whether detection of spermatozoa and measurement of prostate-specific antigen (PSA) in urine could provide objective semiquantitative estimates of sperm output and recent ejaculation, respectively, using widely available laboratory techniques. Of 11 healthy volunteers who provided urine samples before and at intervals for 5 days after ejaculation, sperm was present in 2/11 men before, and in all 11/11 samples immediately after ejaculation, but by the second and subsequent void, spermatozoa were present in ?10%. PSA was detectable at high levels in all urine samples, peaking at the first post-ejaculatory sample but returning to baseline levels by the second post-ejaculatory void. We conclude that urinary spermatozoa and PSA are objective biomarkers for sperm production and sexual activity, but only for a short-time window until the first post-ejaculatory urine void. Hence, for a single urine specimen, the presence of spermatozoa and PSA are valid biomarkers, reflecting sperm production and recent ejaculation only until the next micturition, so their measurement should be restricted to the first morning urine void. PMID:22522506

Sivananthan, Thilee; Bathur, Franz; Jimenez, Mark; Conway, Ann; Idan, Amanda; Handelsman, David

2012-04-23

51

Sperm competition, male prudence, and sperm-limited females (2002)  

Microsoft Academic Search

Sperm are produced in astronomical numbers compared with eggs, and there is good evidence that sperm competition is the force behind the evolution of many tiny sperm. However, sperm production inevitably has costs. Recent research shows that male ejaculate expenditure is dynamic in both time and space, and that males are sensitive to risks of sperm competition and can vary

Nina Wedell; Matthew Gage; Geoffrey Parker

52

Production of channel catfish with sperm cryopreserved by rapid non-equilibrium cooling.  

PubMed

This report describes the feasibility of using vitrification for fish sperm. Vitrification can be used to preserve samples in the field and offers an alternative to conventional cryopreservation, although it has not been systematically studied for sperm of aquatic species. The overall goal of the project was to develop streamlined protocols that could be integrated into a standardized approach for vitrification of aquatic species germplasm. The objectives of the present study in channel catfish (Ictalurus punctatus) were to: (1) evaluate the acute toxicity of 5%, 10%, 20% and 30% methanol, N,N-dimethyl acetamide, dimethyl sulfoxide, 1,2-propanediol, and methyl glycol; (2) evaluate a range of devices commonly used for cryopreservation and vitrification of mammalian sperm; (3) compare vitrification with and without cryoprotectants; (4) evaluate the post-thaw membrane integrity of sperm vitrified in different cryoprotectant solutions, and (5) evaluate the ability of vitrified sperm to fertilize eggs. Cryoprotectant concentrations of higher than 20% were found to be toxic to sperm. Methanol and methyl glycol were the least toxic at a concentration of 20% with an exposure time of less than 5 min. We evaluated a method reported for human sperm, using small volumes in loops (15 ?l) or cut standard straws (20 ?l) with and without cryoprotectants plunged into liquid nitrogen. Cryoprotectant-free vitrification using loops did not yield fertilization (assessed by neurulation), and the fertilization rates observed in two trials using the cut standard straws were low (~2%). In general, fertilization values for vitrification experiments were low and the use of low concentrations of cryoprotectants yielded lower fertilization (<10%) than the use of vitrification solutions containing high cryoprotectant concentrations (as high as 25%). The highest neurulation obtained was from a mixture of three cryoprotectants (20% methanol+10% methyl glycol+10% propanediol) with a single-step addition. This was reflected in the flow cytometry data from which the highest membrane integrity using loops was for 20% methanol+10% methyl glycol+10% propanediol (~50%). We report the first successful sperm vitrification in fish and production of offspring from vitrified sperm in channel catfish. Although the fertilization values were low, at present this technique could nevertheless be used to reconstitute lines (especially in small aquarium fishes), but it would require improvement and scaling up before being useful as a production method for large-bodied fishes such as catfish. PMID:21896271

Cuevas-Uribe, Rafael; Leibo, S P; Daly, Jonathan; Tiersch, Terrence R

2011-08-26

53

Guanosine 5'-thiotriphosphate may stimulate phosphoinositide messenger production in sea urchin eggs by a different route than the fertilizing sperm.  

PubMed Central

We show that microinjecting guanosine-5'-thiotriphosphate (GTP gamma S) into unfertilized sea urchin eggs generates an intracellular free calcium concentration [( Ca]i) transient apparently identical in magnitude and duration to the calcium transient that activates the egg at fertilization. The GTP gamma S-induced transient is blocked by prior microinjection of the inositol trisphosphate (InsP3) antagonist heparin. GTP gamma S injection also causes stimulation of the egg's Na+/H+ antiporter via protein kinase C, even in the absence of a [Ca]i increase. These data suggest that GTP gamma S acts by stimulating the calcium-independent production of the phosphoinositide messengers InsP3 and diacylglycerol (DAG). However, the fertilization [Ca]i transient is not affected by heparin, nor can the sperm cause calcium-independent stimulation of protein kinase C. It seems that the bulk of InsP3 and DAG production at fertilization is triggered by the [Ca]i transient, not by the sperm itself. GDP beta S, a G-protein antagonist, does not affect the fertilization [Ca]i transient. Our findings do not support the idea that signal transduction at fertilization operates via a G-protein linked directly to a plasma membrane sperm receptor.

Crossley, I; Whalley, T; Whitaker, M

1991-01-01

54

Gamete therapeutics: recombinant protein adsorption by sperm for increasing fertility via artificial insemination.  

PubMed

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® (PGF2?) (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

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

2013-06-10

55

The Ca 2+ increase by the sperm factor in physiologically polyspermic newt fertilization: Its signaling mechanism in egg cytoplasm and the species-specificity  

Microsoft Academic Search

The newt, Cynops pyrrhogaster, exhibits physiological polyspermic fertilization, in which several sperm enter an egg before egg activation. An intracellular Ca2+ increase occurs as a Ca2+ wave at each sperm entry site in the polyspermic egg. Some Ca2+ waves are preceded by a transient spike-like Ca2+ increase, probably caused by a tryptic protease in the sperm acrosome at the contact

Yuichirou Harada; Mari Kawazoe; Yuki Eto; Shuichi Ueno; Yasuhiro Iwao

2011-01-01

56

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 ...

57

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

PubMed

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 17,20?-dihydroxypregn-4-en-3-one [17,20?-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 17,20?-P amounts showed somewhat opposite trends. These differences could be related with the different role of androgens and progestin during the spermatogenesis. PMID:22806610

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

2012-07-18

58

The effects of increased testicular temperature on testis-specific isoform of Na+/K+ -ATPase in sperm and its role in spermatogenesis and sperm function.  

PubMed

Impaired testicular thermoregulation is commonly implicated in abnormal spermatogenesis and impaired sperm function in animals and humans, with outcomes ranging from subclinical infertility to sterility. Bovine testes must be maintained 4-5 °C below body-core temperature for normal spermatogenesis. The effects of elevated testicular temperature have been extensively studied in cattle using a scrotal insulation model, which results in abnormal spermatogenesis and impaired sperm morphology and function. Using this model and proteomic approaches, we compared normal and abnormal sperm (from the same bulls) to elucidate the molecular basis of impaired function. We identified a cohort of sperm functional proteins differentially expressed between normal vs abnormal sperm, including a testis-specific isoform of Na(+) /K(+) -ATPase. In addition to its role as a sodium pump regulating sperm motility, Na(+) /K(+) -ATPase is also involved as a signalling molecule during sperm capacitation. In conclusion, because of its involvement in regulation of sperm function, this protein has potential as a fertility marker. Furthermore, comparing normal vs abnormal sperm (induced by scrotal insulation) is a useful model for identifying proteins regulating sperm function. PMID:22827367

Thundathil, J C; Rajamanickam, G D; Kastelic, J P; Newton, L D

2012-08-01

59

Common variants in mismatch repair genes associated with increased risk of sperm DNA damage and male infertility  

PubMed Central

Background The mismatch repair (MMR) pathway plays an important role in the maintenance of the genome integrity, meiotic recombination and gametogenesis. This study investigated whether genetic variations in MMR genes are associated with an increased risk of sperm DNA damage and male infertility. Methods We selected and genotyped 21 tagging single nucleotide polymorphisms (SNPs) in five MMR genes (MLH1, MLH3, PMS2, MSH4 and MSH5) using the SNPstream 12-plex platform in a case-control study of 1,292 idiopathic infertility patients and 480 fertile controls in a Chinese population. Sperm DNA damage levels were detected with the Tdt-mediated dUTP nick end labelling (TUNEL) assay in 450 cases. Fluorescence resonance energy transfer (FRET) and co-immunoprecipitation techniques were employed to determine the effects of functional variants. Results One intronic SNP in MLH1 (rs4647269) and two non-synonymous SNPs in PMS2 (rs1059060, Ser775Asn) and MSH5 (rs2075789, Pro29Ser) seem to be risk factors for the development of azoospermia or oligozoospermia. Meanwhile, we also identified a possible contribution of PMS2 rs1059060 to the risk of male infertility with normal sperm count. Among patients with normal sperm count, MLH1 rs4647269 and PMS2 rs1059060 were associated with increased sperm DNA damage. Functional analysis revealed that the PMS2 rs1059060 can affect the interactions between MLH1 and PMS2. Conclusions Our results provide evidence supporting the involvement of genetic polymorphisms in MMR genes in the aetiology of male infertility.

2012-01-01

60

Sperm Chromatin  

PubMed Central

Sperm are remarkably complex cells with a singularly important mission: to deliver paternal DNA and its associated factors to the oocyte to start a new life. The integrity of sperm DNA is a keystone of reproductive success, which includes fertilization and embryonic development. In addition, the significance in these processes of proteins that associate with sperm DNA is increasingly being appreciated. In this review, we highlight proteomic studies that have identified sperm chromatin proteins with fertility roles that have been validated by molecular studies in model organisms or correlations in the clinic. Up to 50% of male-factor infertility cases in the clinic have no known cause and therefore no direct treatment. In-depth study of the molecular basis of infertility has great potential to inform the development of sensitive diagnostic tools and effective therapies that will address this incongruity. Because sperm rely on testis-specific protein isoforms and post-translational modifications for their development and function, sperm-specific processes are ideal for proteomic explorations that can bridge the research lab and fertility clinic.

Wu, Tammy F.; Chu, Diana S.

2008-01-01

61

Metabolic rate limits the effect of sperm competition on Mammalian spermatogenesis.  

PubMed

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. PMID:24069461

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

2013-09-19

62

Metabolic Rate Limits the Effect of Sperm Competition on Mammalian Spermatogenesis  

PubMed Central

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.

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

2013-01-01

63

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

SciTech Connect

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.

Siimes, M.A.; Rautonen, J. (Univ. of Helsinki (Finland))

1990-03-15

64

A Sustained Increase in Intracellular Ca 2+ Is Required for the Acrosome Reaction in Sea Urchin Sperm  

Microsoft Academic Search

The acrosome reaction (AR), necessary for fertilization in many species, requires an increase in intracellular Ca2+ ([Ca2+]i). In sea urchin sperm, the AR is triggered by an egg-jelly factor: the associated [Ca2+]i elevation lasts minutes and involves two Ca2+ permeable channels. Both the opening of the second channel and the onset of the AR occur ?5 s after treatment with

Marco T. González-Martínez; Blanca E. Galindo; Lucia de De La Torre; Otilia Zapata; Esmeralda Rodríguez; Harvey M. Florman; Alberto Darszon

2001-01-01

65

Increased seminal plasma lead levels adversely affect the fertility potential of sperm in IVF  

Microsoft Academic Search

BACKGROUND: Lead remains in high levels in the environment and is known to reduce fertility in animal models, but a direct link between lead exposures and human infertility has not yet been established. METHODS: In a pro- spective, double-blind study of the metal ion levels and sperm function, semen was obtained from partners of 140 consecutive women undergoing their first

Susan Benoff; Grace M. Centola; Colleen Millan; Barbara Napolitano; Joel L. Marmar; Ian R. Hurley

66

No increase in sperm DNA damage and seminal oxidative stress in patients with idiopathic infertility  

Microsoft Academic Search

The most common cause of male infertility is idiopathic. Standard investigations reveal no abnormality in such cases. The aim of the study was to investigate the levels of sperm DNA damage and seminal oxidative stress and their relationships with idiopathic infertility. The study included 30 normozoospermic infertile men seeking infertility treatment and 20 fertile donors. Semen analysis was performed according

Fatma Ferda Verit; Ayhan Verit; Abdurrahim Kocyigit; Halil Ciftci; Hakim Celik; Mete Koksal

2006-01-01

67

Sperm competition and the evolution of sperm design in mammals  

PubMed Central

Background The influence of sperm competition upon sperm size has been a controversial issue during the last 20 years which remains unresolved for mammals. The hypothesis that, when ejaculates compete with rival males, an increase in sperm size would make sperm more competitive because it would increase sperm swimming speed, has generated contradictory results from both theoretical and empirical studies. In addition, the debate has extended to which sperm components should increase in size: the midpiece to accommodate more mitochondria and produce more energy to fuel motility, or the principal piece to generate greater propulsion forces. Results In this study we examined the influence of sperm competition upon sperm design in mammals using a much larger data set (226 species) than in previous analyses, and we corrected for phylogenetic effects by using a more complete and resolved phylogeny, and more robust phylogenetic control methods. Our results show that, as sperm competition increases, all sperm components increase in an integrated manner and sperm heads become more elongated. The increase in sperm length was found to be associated with enhanced swimming velocity, an adaptive trait under sperm competition. Conclusions We conclude that sperm competition has played an important role in the evolution of sperm design in mammals, and discuss why previous studies have failed to detect it.

2011-01-01

68

The Effect of Ambient Air Pollution on Sperm Quality  

PubMed Central

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 ?m 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 [? = 2.64; 95% confidence interval (CI), 0.21–5.06] and abnormal head (? = 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 concentration, count, and morphology.

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

2010-01-01

69

Methods for evaluating the effects of environmental chemicals on human sperm production  

SciTech Connect

Sperm tests provide a direct and effective way of identifying chemical agents that induce spermatogenic damage in man. Four human sperm tests are available: sperm count, motility, morphology (seminal cytology), and the Y-body test. These sperm tests have numerous advantages over other approaches for assessing spermatogenic damage, and they have already been used to assess the effects of at least 85 different occupational, envionmental, and drug-related chemical exposures. When carefully controlled, seminal cytology appears to be statistically more sensitive than the other human sperm tests and should be considered an integral part of semen analysis when assessing induced spermatogenic damage.

Wyrobek, A.J.

1982-04-20

70

Angiotensin-II induced nitric oxide production during buffalo sperm capacitation and acrosome reaction.  

PubMed

The present study was designed to see the effects of Angiotensin-II (Ang-II) on buffalo sperm capacitation, acrosome reaction (AR), and its relation to nitric oxide (NO()) production. The extent of capacitation or AR was determined by dual staining while the NO() production was determined by spectrophotometry. The results thus obtained revealed that Ang-II induced capacitation in a concentration and time dependent manner and 200 nM Ang-II was found to be optimal for capacitation as it was comparable to heparin treatment (50.7±2.45% vs. 51.66±2.33%). In capacitated cells the extent of AR induced by Ang-II was significantly higher than the untreated control (48.13±2.31% vs. 22.16±2.11%) and comparable to lysophosphatidyl Choline (LPC) treatment (51.56±1.94%). The NO() production during Ang-II induced capacitation and AR was gradual and time dependent. These levels were significantly higher when compared to control (3.65±0.53 nmoles/10(8)cells vs. 9.12±0.30 nmoles/10(8)cells). All the actions of Ang-II were inhibited in the presence of Losartan but not PD123319, indicating the role of AT1 receptors in these actions. Further the NO() production was also significantly inhibited in the presence of neomycin and trifluoperazine pointing towards the role of phosphoinositide pathway in this process. In conclusion, Ang-II has a concentration and time dependent effect on buffalo sperm capacitation and AR, mediated via the AT1 receptors. Its effect on NO() production may be indirect involving the phosphoinositide pathway. PMID:21481898

Vedantam, Sivaram; Atreja, Suresh K; Garg, Monika

2011-04-08

71

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

PubMed Central

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 budgets.

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

2011-01-01

72

Methods for evaluating the effects of environmental chemicals on human sperm production.  

PubMed Central

Sperm tests provide a direct and effective way of identifying chemical agents that induce spermatogenic damage in man. Four human sperm tests are available: sperm count, motility, morphology (seminal cytology) and the Y-body test. These sperm tests have numerous advantages over other approaches for assessing spermatogenic damage, and they have already been used to assess the effects of at least 85 different occupational, environmental, and drug-related chemical exposures. When carefully controlled, seminal cytology appears to be statistically more sensitive than the other human sperm tests and should be considered an integral part of semen analysis when assessing induced spermatogenic damage. Human sperm studies have complex requirements and, before sampling, careful consideration should be given to exposure details, group size and makeup, as well as animal and human data that indicate spermatogenic effects. Several study designs are possible and should include questionnaires covering medical and reproductive histories as well as known confounding factors. Animal sperm tests, such as the mouse morphology test, may be used to identify the toxic components of a complex mixture. Animal tests may also help assess the chemical effects on fertility and reproductive outcome in cases when human data are incomplete. Further efforts are needed in these areas to develop improved human sperm tests sensitive to induced spermatogenic damage, to develop improved animal models of induced spermatogenic damage, to understand the relationships among sperm changes, fertility, and reproductive outcome, and to develop sperm tests with express mutational end points.

Wyrobek, A J

1983-01-01

73

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

PubMed Central

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??L sperm samples using inoculating loops plunged into liquid nitrogen. Samples were thawed at 24°C (one loop in 5??L of HBSS or three loops in 500??L of HBSS). Samples thawed in 500??L were concentrated by centrifugation (1000 g for 5?min at 4°C) into 5??L for artificial insemination. Offspring were produced from virgin females inseminated with sperm vitrified with 20% Gly+20% EG and concentrated by centrifugation.

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

2011-01-01

74

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

Microsoft Academic Search

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

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

2003-01-01

75

PUBERTY IN BEEF BULLS: HORMONE CONCENTRATIONS, GROWTH, TESTICULAR DEVELOPMENT, SPERM PRODUCTION AND SEXUAL AGGRESSIVENESS IN BULLS OF DIFFERENT BREEDS I  

Microsoft Academic Search

SUMMARY Postweaning growth and pubertal traits were studied in Hereford, Angus, Red Poll, Brown Swiss, Hereford-Angus crossbred (HXA) and Angus-Hereford crossbred (AX H) bulls from 7 through 13 months of age. Pubertal factors characterized included body weight, testicular size, hormone concentrations, sexual aggressive- ness and sperm production. Puberty was de- fined as the age at which a bull first produced

D. D. Lunstra; J. J. Ford; S. E. Echternkamp

2010-01-01

76

Increased levels of sperm ubiquitin correlate with semen quality in men from an andrology laboratory clinic population  

Microsoft Academic Search

BACKGROUND: Ubiquitin, a house-keeping protein that marks other proteins for proteasomal degradation, tags defective sperm during epididymal passage. To establish ubiquitin as a biomarker of human infertility, the present study examines the relationships between sperm ubiquitin content and clinical semen parameters among men from an infertility clinic population with varied aetiologies. METHODS: Anti-ubiquitin immunoreactivity was measured by flow cytometric sperm-ubiquitin

Peter Sutovsky; Russ Hauser; Miriam Sutovsky

2004-01-01

77

The Sperm Chromatin Dispersion Test: A Simple Method for the Determination of Sperm DNA Fragmentation  

Microsoft Academic Search

Sperm DNA fragmentation is being increasingly rec- ognized 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

JOSE LUIS FERNANDEZ; LOURDES MURIEL; MARIA TERESA RIVERO; VICENTE GOYANES; ROSANA VAZQUEZ; JUAN G. ALVAREZ

2003-01-01

78

Production of channel catfish with sperm cryopreserved by rapid non-equilibrium cooling  

Microsoft Academic Search

This report describes the feasibility of using vitrification for fish sperm. Vitrification can be used to preserve samples in the field and offers an alternative to conventional cryopreservation, although it has not been systematically studied for sperm of aquatic species. The overall goal of the project was to develop streamlined protocols that could be integrated into a standardized approach for

Rafael Cuevas-Uribe; S. P. Leibo; Jonathan Daly; Terrence R. Tiersch

79

In vitro sperm production from mouse spermatogonial stem cell lines using an organ culture method.  

PubMed

The in vitro propagation of mouse spermatogonial stem cells (SSCs) became possible in 2003; these cultured SSCs were named germ-line stem (GS) cells. To date, however, it has not been possible to induce spermatogenesis from GS cells in vitro. Recently, we succeeded in producing functional sperm from primitive spermatogonia in explanted neonatal mouse testis tissues. Here we describe a protocol that can support spermatogenesis from GS cells up to sperm formation in vitro using an organ culture method. GS cells transplanted in the extracted testis form colonies in the tissue fragments and differentiate into sperm under the described in vitro organ culture conditions. It takes about 6 weeks to obtain sperm from GS cells. The sperm are viable, resulting in healthy offspring through micro-insemination. Thus, this protocol should be a valuable tool for the study of mammalian spermatogenesis. PMID:24091557

Sato, Takuya; Katagiri, Kumiko; Kubota, Yoshinobu; Ogawa, Takehiko

2013-10-03

80

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

PubMed

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. PMID:23872356

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

2013-07-18

81

Flue gas desulfurization increasing productivity  

Microsoft Academic Search

This paper presents an analysis of those components of a wet flue gas desulfurization system which can affect the productivity of an electrical power generation plant. These complex systems are very important to an electrical power plant in desulfurizing flue gases in order to comply with Federal and State pollution control regulations. They must approach 100% availability so as not

Zourides

1983-01-01

82

Restoration of seminal plasma to stallion spermatozoa selected by colloid centrifugation increases sperm progressive motility but is detrimental to chromatin integrity.  

PubMed

There is controversy about whether the presence of some seminal plasma (SP) in an equine insemination dose is necessary for promoting fertility. A new technique for improving stallion sperm quality, single layer centrifugation (SLC) using a species-specific colloid, Androcoll-E, selects a sperm subpopulation that is highly motile with normal morphology, intact membranes and good chromatin integrity from the rest of the ejaculate and removes SP. The present study was designed to investigate the effect of restoring homologous SP (5% and 10%) on the progressive motility, velocity, and chromatin integrity of SLC-selected stallion spermatozoa in 44 semen samples over time. Sperm progressive motility (P<0.01) and the proportion with class A velocity (>50 ?m/sec) were increased in samples where SP was restored, whereas the proportion with class B velocity (10 to 50 ?m/sec) was decreased compared with SLC samples. However, after 24 h cold storage of treated samples, progressive motility was not different for the SP-treated groups compared with SLC, whereas chromatin damage DNA fragmentation index (%DFI) was higher. In contrast, adding SP to untreated 24 h-stored SLC samples did not affect progressive motility although it did increase the proportion of spermatozoa with class A velocity. There was individual variation between stallions whether 5% or 10% SP produced a greater increase in progressive motility. In conclusion, 5% to 10% SP can be added back to SLC-selected samples if considered necessary to optimize fertility. However, it should be added immediately before insemination rather than before storage of the sperm dose, to benefit from the transient increase in sperm progressive motility and avoid increased chromatin damage. PMID:22494676

Morrell, J M; Pihl, J; Dalin, A-M; Johannisson, A

2012-04-10

83

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

SciTech Connect

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.

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

1987-01-01

84

Spermatogenic cycle length and sperm production in a feral pig species (collared peccary, Tayassu tajacu).  

PubMed

Although the collared peccary (Tayassu tajacu) is found throughout the Americas, with a high potential for domestication and commercial exploitation, there are few data on the reproductive biology of this mammalian species. The aim of the present study was to investigate testis structure, spermatogenic cycle length, Sertoli cell efficiency, and spermatogenic efficiency. Twelve adult peccaries were used for biometrical, histological, and stereological analyses; 3 of these peccaries received intratesticular injections of (3)H-thymidine for the determination of the duration of spermatogenesis. Testis weight and gonadosomatic index were 23.7 +/- 1.8 g and 0.2% +/- 0.1%, respectively. Seminiferous tubule volume density was 77.4% +/- 1.7%. Leydig cells occupied 12.8% +/- 1.8% of the testis parenchyma and presented a peculiar cytoarchitecture in the periphery of the seminiferous tubule lobes. The premeiotic, meiotic, and postmeiotic stage frequencies were very similar to those found for wild and domestic boars. The spermatogenic cycle and entire spermatogenic process (based on 4.5 cycles) lasted approximately 12.3 +/- 0.2 and 55.1 +/- 0.7 days, respectively. Daily sperm production per gram of testis in the collared peccary was approximately 23.4 +/- 2 x 10(6), which is similar to that of domestic and wild boars. The knowledge generated in the present study could be used in reproduction and animal improvement programs and provides important information that may be used for comparative reproductive biology with previously investigated mammalian species. PMID:19745218

Costa, Guilherme M J; Leal, Marcelo C; Silva, Jurupytan V; Ferreira, Ana Cássia S; Guimarães, Diva A; França, Luiz Renato de

2009-09-10

85

Numerical model estimates fracture production increase  

SciTech Connect

A numerical model has been developed to allow estimation of steady-state production increase for a fracture having variable and finite conductivity. When applied to fracture acidizing, the model will also estimate the contribution of each section to the overall production increase. Projected production increase after treatment is a key parameter in measurement of the effectiveness of a stimulation treatment.

Soliman, M.Y.

1986-10-13

86

In Vitro Production of Sexed Embryos for Gender Preselection: High-Speed Sorting of X-Chromosome-Bearing Sperm to Produce Pigs After Embryo Transfer  

Microsoft Academic Search

The objectives for the present experi- ments were to apply sperm sexing technology to an in vitro production system with porcine oocytes obtained from slaughterhouse material. On six experimental days, ovaries were obtained from an abattoir, and cu- mulus-oocyte-complexes were matured in vitro. Semen was collected from mature boars of proven fertility and was sorted for X-chromosome-bearing sperm, using the

D. Rath; C. R. Long; J. R. Dobrinsky; G. R. Welch; L. L. Schreier; L. A. Johnson

2010-01-01

87

In vitro production of human anti-sperm antibodies: effect of an oligoclonal antibody (F6) on sperm-egg interaction  

Microsoft Academic Search

A method has been developed to establish lines of transformed lymphocytes able to produce in vitro the same anti-sperm antibodies as those naturally occurring in immuno-infertile individuals. We utilized lymphocytes from a male donor whose serum contained anti-sperm antibodies of the IgG class up to the dilution 1:10 000, as detected by means of immunobead binding. T lymphocytes were separated

F. M. Fusi; F. Besuschio; L. De Santis; I. Lorenzetti; A. Ferrari

1995-01-01

88

Sperm swimming speed and energetics vary with sperm competition risk in bluegill ( Lepomis macrochirus )  

Microsoft Academic Search

Under sperm competition, a male’s fertilization success depends largely on the ejaculate characteristics of competing males. Theoretical models predict that, in external fertilizers, increased risk of sperm competition should result in selection for increased sperm swimming speed. To test this prediction, we studied the behavior of sperm from parental and sneaker male bluegill ( Lepomis macrochirus), a fish species characterized

Gary Burness; Stephen J. Casselman; Albrecht I. Schulte-Hostedde; Christopher D. Moyes; Robert Montgomerie

2004-01-01

89

Cryopreservation of domestic animal sperm cells.  

PubMed

Sperm cells are the endpoint of male spermatogenesis and have particular anatomic and metabolic features. Sperm cryopreservation and storage currently require liquid nitrogen or ultralow refrigeration methods for long or short term storage, which requires routine maintenance and extensive space requirements. Conserving sperms have several purposes such as artificial reproductive technologies (ART), species conservation and clinical medicine. The combinations of storage temperature, cooling rate, chemical composition of the extender, cryoprotectant concentration, reactive oxygen species (ROS), seminal plasma composition and hygienic control are the key factors that affect the life-span of spermatozoa. Sperm preservation protocols vary among animal species owing to their inherent particularities that change extenders used for refrigeration and freezing. Extenders for freezing sperm cells contain buffers, carbohydrates (glucose, lactose, raffinose, saccharose and trehalose), salts (sodium citrate, citric acid), egg yolk and antibiotics. The use of different cryoprotectants, like trehalose or glycerol, as well as different concentrations of egg yolk and other constituents in semen extenders are being studied in our laboratory. Several cooling rates have been tested to freeze sperm cells. The use of faster rates (15-60 degrees C/min) gives rise to best sperm survivals after freezing-thawing, but more studies are needed to find the adequate cooling rates for each animal species. Sheep and goat males of some native breeds are being used in studies performed in EZN. Semen from those males has been frozen and stored as part of the Portuguese Animal Germplasm Bank. In small ruminants, individual variations in the quality of frozen semen have been observed, suggesting specific differences in sperm susceptibility to freezing methods, particularly obvious in goat males. Best quality frozen semen from small ruminants is being used in cervical artificial insemination studies aiming to increase productive parameters in selected flocks. PMID:18548333

Barbas, J P; Mascarenhas, R D

2008-06-12

90

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

NASA Astrophysics Data System (ADS)

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.

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

2005-11-01

91

The sperm-specific proteins of the edible oyster (European flat oyster (Ostrea edulis)) are products of proteolytic processing.  

PubMed

Extraction of sperm proteins from the bivalve mollusc Ostrea edulis shows them to contain a normal complement of core histones, together with three sperm-specific proteins, OE1 and OE2, plus the shorter OE3, which shows substantial microheterogeneity. OE1 and OE2 have a very similar amino acid composition, cyanogen bromide (CNBr) cleavage yields products of identical size and possesses a trypsin-resistant core peptide, together indicating that they are closely homologous histone H1-like proteins. Western blotting shows that OE1 and OE2 are closely related to the histone H1-like protein PL-II* of Mytilus trossulus. The amino acid composition of OE3 shows it to be a protamine-like PL-IV type protein. Edman degradation of a CNBr peptide from OE2 gave the sequence (M)KAAFAKGLKSGALVRPKGS-which has 85% identity to a sequence located towards the C-terminal end of the globular domain of the PL-II* protein of M. trossulus. An O. edulis sperm cDNA library yielded a clone of 428 bp. A genomic clone including an open reading frame (ORF) of 750 bp was isolated by PCR amplification from genomic DNA. Hypothetical translation showed the ORF to encode OE1 (or OE2) immediately followed by OE3, separated by a proteolytic processing site. This arrangement (a two-protein ORF) is also found in M. trossulus and Ensis minor. PMID:14732486

Agelopoulou, Barbara; Cary, Peter D; Pataryas, Theocharis; Aleporou-Marinou, Vassiliki; Crane-Robinson, Colyn

2004-01-01

92

Tuning sperm chemotaxis.  

PubMed

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. PMID:20863297

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

2010-10-01

93

Effects of intratesticular zinc gluconate treatment on testicular dimensions, echodensity, histology, sperm production, and testosterone secretion in American black bears (Ursus americanus).  

PubMed

Eight adult American black bears were used to evaluate the effects of chemical castration by intratesticular zinc gluconate treatment on testicular dimensions, echodensity, histology, sperm production, and testosterone secretion. Treatment did not affect testicular dimensions and did not result in decreased resting or GnRH-stimulated testosterone secretion. Multifocal hyperchoic areas in the testicular parenchyma were observed on ultrasound examination, and white foci were observed on gross pathology examination after zinc gluconate treatment. Histologically, there were normal seminiferous tubules containing either round or elongated spermatids, along with abnormal tubules in all bears after treatment. Vacuolation of the seminiferous epithelium, sloughing of germ cells into the tubules' lumen, presence of multinuclear giant cells, and reduced height of the seminiferous epithelium with missing generations of germ cells were commonly observed. The most severe testicular changes were multifocal and included fibrosis, complete degeneration of the seminiferous epithelium with shrinkage of the tubule, and sperm stasis. Epididymal sperm reserve was 982.74 ± 654.16 × 10(6) sperm (mean ± SEM) and motile sperm were observed in the epididymis of all but one of the bears. In conclusion, although intratesticular zinc gluconate treatment in black bears resulted in testicular degenerative changes detected by ultrasound and histology examinations, sperm production was not completely ablated. We inferred that normal fertility might have been compromised, but treatment unlikely resulted in sterility. PMID:21356548

Brito, Leonardo F C; Sertich, Patricia L; Rives, William; Knobbe, Marc; Del Piero, Fabio; Stull, Gordon B

2011-02-26

94

Paradoxical effect of reagents for sulfhydryl and disulfide groups on human sperm capacitation and superoxide production  

Microsoft Academic Search

Spermatozoa must undergo capacitation prior to fertilization. In humans, this process appears regulated by oxidoreduction reactions. We investigated the possibility that these reactions involved the sulfhydryl-disulfide pair, which offers a reversible regulation of cellular processes. The effects of reagents targeted for sulfhydryl and disulfide groups on human sperm capacitation, superoxide (O2•?) generation and protein tyrosine phosphorylation were evaluated. The sulfhydryl

Eve de Lamirande; Claude Gagnon

1998-01-01

95

Sperm precedence and sperm movement under different copulation intervals in the silkworm, Bombyx mori  

Microsoft Academic Search

Sperm precedence and sperm movement were investigated under different copulation intervals in the silkworm, Bombyx mori. The mass of sperm began to enter the spermatheca 1 h after copulation ended, and the number of sperm gradually increased in the spermatheca and attained a plateau when the spermatheca was filled at about 2.5 h after the end of copulation. Thereafter, the

Nobuhiko Suzuki; Takashi Okuda; Hitoshi Shinbo

1996-01-01

96

Sperm preparation for ART.  

PubMed

The onset of clinical assisted reproduction, a quarter of a century ago, required the isolation of motile spermatozoa. As the indication of assisted reproduction shifted from mere gynaecological indications to andrological indications during the years, this urged andrological research to understand the physiology of male germ cell better and develop more sophisticated techniques to separate functional spermatozoa from those that are immotile, have poor morphology or are not capable to fertilize oocytes. Initially, starting from simple washing of spermatozoa, separation techniques, based on different principles like migration, filtration or density gradient centrifugation evolved. The most simple and cheapest is the conventional swim-up procedure. A more sophisticated and most gentle migration method is migration-sedimentation. However, its yield is relatively small and the technique is therefore normally only limited to ejaculates with a high number of motile spermatozoa. Recently, however, the method was also successfully used to isolate spermatozoa for intracytoplasmic sperm injection (ICSI). Sperm separation methods that yield a higher number of motile spermatozoa are glass wool filtration or density gradient centrifugation with different media. Since Percoll as a density medium was removed from the market in 1996 for clinical use in the human because of its risk of contamination with endotoxins, other media like IxaPrep, Nycodenz, SilSelect, PureSperm or Isolate were developed in order to replace Percoll. Today, an array of different methods is available and the selection depends on the quality of the ejaculates, which also includes production of reactive oxygen species (ROS) by spermatozoa and leukocytes. Ejaculates with ROS production should not be separated by means of conventional swim-up, as this can severely damage the spermatozoa. In order to protect the male germ cells from the influence of ROS and to stimulate their motility to increase the yield, a number of substances can be added to the ejaculate or the separation medium. Caffeine, pentoxifylline and 2-deoxyadenosine are substances that were used to stimulate motility. Recent approaches to stimulate spermatozoa include bicarbonate, metal chelators or platelet-activating factor (PAF). While the use of PAF already resulted in pregnancies in intrauterine insemination, the suitability of the other substances for the clinical use still needs to be tested. Finally, the isolation of functional spermatozoa from highly viscous ejaculates is a special challenge and can be performed enzymatically to liquefy the ejaculate. The older method, by which the ejaculate is forcefully aspirated through a narrow-gauge needle, should be abandoned as it can severely damage spermatozoa, thus resulting in immotile sperm. PMID:14617368

Henkel, Ralf R; Schill, Wolf-Bernhard

2003-11-14

97

Sperm preparation for ART  

PubMed Central

The onset of clinical assisted reproduction, a quarter of a century ago, required the isolation of motile spermatozoa. As the indication of assisted reproduction shifted from mere gynaecological indications to andrological indications during the years, this urged andrological research to understand the physiology of male germ cell better and develop more sophisticated techniques to separate functional spermatozoa from those that are immotile, have poor morphology or are not capable to fertilize oocytes. Initially, starting from simple washing of spermatozoa, separation techniques, based on different principles like migration, filtration or density gradient centrifugation evolved. The most simple and cheapest is the conventional swim-up procedure. A more sophisticated and most gentle migration method is migration-sedimentation. However, its yield is relatively small and the technique is therefore normally only limited to ejaculates with a high number of motile spermatozoa. Recently, however, the method was also successfully used to isolate spermatozoa for intracytoplasmic sperm injection (ICSI). Sperm separation methods that yield a higher number of motile spermatozoa are glass wool filtration or density gradient centrifugation with different media. Since Percoll® as a density medium was removed from the market in 1996 for clinical use in the human because of its risk of contamination with endotoxins, other media like IxaPrep®, Nycodenz, SilSelect®, PureSperm® or Isolate® were developed in order to replace Percoll®. Today, an array of different methods is available and the selection depends on the quality of the ejaculates, which also includes production of reactive oxygen species (ROS) by spermatozoa and leukocytes. Ejaculates with ROS production should not be separated by means of conventional swim-up, as this can severely damage the spermatozoa. In order to protect the male germ cells from the influence of ROS and to stimulate their motility to increase the yield, a number of substances can be added to the ejaculate or the separation medium. Caffeine, pentoxifylline and 2-deoxyadenosine are substances that were used to stimulate motility. Recent approaches to stimulate spermatozoa include bicarbonate, metal chelators or platelet-activating factor (PAF). While the use of PAF already resulted in pregnancies in intrauterine insemination, the suitability of the other substances for the clinical use still needs to be tested. Finally, the isolation of functional spermatozoa from highly viscous ejaculates is a special challenge and can be performed enzymatically to liquefy the ejaculate. The older method, by which the ejaculate is forcefully aspirated through a narrow-gauge needle, should be abandoned as it can severely damage spermatozoa, thus resulting in immotile sperm.

Henkel, Ralf R; Schill, Wolf-Bernhard

2003-01-01

98

Sperm competition: linking form to function  

PubMed Central

Background Using information from physics, biomechanics and evolutionary biology, we explore the implications of physical constraints on sperm performance, and review empirical evidence for links between sperm length and sperm competition (where two or more males compete to fertilise a female's eggs). A common theme in the literature on sperm competition is that selection for increased sperm performance in polyandrous species will favour the evolution of longer, and therefore faster swimming, sperm. This argument is based on the common assumption that sperm swimming velocity is directly related to sperm length, due to the increased thrust produced by longer flagella. Results We critically evaluate the evidence for links between sperm morphology and swimming speed, and draw on cross-disciplinary studies to show that the assumption that velocity is directly related to sperm length will rarely be satisfied in the microscopic world in which sperm operate. Conclusion We show that increased sperm length is unlikely to be driven by selection for increased swimming speed, and that the relative lengths of a sperm's constituent parts, rather than their absolute lengths, are likely to be the target of selection. All else being equal, we suggest that a simple measure of the ratio of head to tail length should be used to assess the possible link between morphology and speed. However, this is most likely to be the case for external fertilizers in which females have relatively limited opportunity to influence a sperm's motility.

2008-01-01

99

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  

Microsoft Academic Search

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 (625mg·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

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

2010-01-01

100

Mating system evolution in sperm-heteromorphic Drosophila  

Microsoft Academic Search

In Drosophila species of the obscura group, males exhibit sperm-heteromorphism, simultaneously producing both long sperm, capable of fertilization, and short sperm that are not. The production of multiple sperm types calls into question whether mating system correlates, such as sperm length and number trade-offs and female remating behavior, are the same as previously described in sperm-monomorphic systems. We examine three

Rhonda R. Snook; Therese A. Markow

2001-01-01

101

Gestational and lactational exposure of rats to xenoestrogens results in reduced testicular size and sperm production.  

PubMed Central

This study assessed whether exposure of male rats to two estrogenic, environmental chemicals, 4-octylphenol (OP) and butyl benzyl phthalate (BBP) during gestation or during the first 21 days of postnatal life, affected testicular size or spermatogenesis in adulthood (90-95 days of age). Chemicals were administered via the drinking water or concentrations of 10-1000 micrograms/l (OP) or 1000 micrograms/l (BBP), diethylstilbestrol (DES; 100 micrograms/l) and an octylphenol polyethoxylate (OPP; 1000 micrograms/l), which is a weak estrogen or nonestrogenic in vitro, were administered as presumptive positive and negative controls, respectively. Controls received the vehicle (ethanol) in tap water. In study 1, rats were treated from days 1-22 after births in studies 2 and 3, the mothers were treated for approximately 8-9 weeks, spanning a 2-week period before mating throughout gestation and 22 days after giving birth. With the exception of DES, treatment generally had no major adverse effect or body weight: in most instances, treated animals were heavier than controls at day 22 and at days 90-95. Exposure to OP, OPP, or BBP at a concentration of 1000 micrograms/1 resulted in a small (5-13%) but significant (p < 0.01 or p < 0.0001) reduction in mean testicular size in studies 2 and 3, an effect that was still evident when testicular weight was expressed relative to body, weight or kidney weight. The effect of OPP is attributed to its metabolism in vivo to OP. DES exposure caused similar reductions in testicular size but also caused reductions in body weight, kidney weight, and litter size. Ventral prostate weight was reduced significantly in DES-treated rats and to minor extent in OP-treated rats. Comparable but more minor effects of treatment with DES or OP on testicular size were observed in study 1. None of the treatments had any adverse effect on testicular morphology or on the cross-sectional area of the lumen or seminiferous epithelium at stages VII-VIII of the spermatogenic cycle, but DES, OP, and BBP caused reductions of 10-21% (p < 0.05 to p < 0.001) in daily sperm production. Humans are exposed to phthalates, such as BBP, and to alkylphenol polyethoxylates, such as OP, but to what extent is unknown. More detailed studies are warranted to assess the possible risk to the development of the human testis from exposure to these and other environmental estrogens. Images Figure 1. Figure 2. Figure 3. A Figure 3. B Figure 3. C Figure 3. D Figure 4.

Sharpe, R M; Fisher, J S; Millar, M M; Jobling, S; Sumpter, J P

1995-01-01

102

Sperm Donation  

MedlinePLUS

... for infectious diseases, such as HIV. If all of your test results come back negative, your frozen sample will be thawed and sperm quantity, quality and movement will be evaluated again. Sperm samples from some men are more susceptible to damage during the freezing ...

103

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

NASA Astrophysics Data System (ADS)

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.

Cournault, Laurent; Aron, Serge

2009-12-01

104

Preventive maintenance, the key to increased productivity  

SciTech Connect

In order to increase availability of equipment and therefore increase productivity, a new Preventive Maintenance Program was developed at Martin County Coal Corporation. Over the course of the first two years of the program, software and the method of compiling input information was developed. As soon as the program was in motion an increase in equipment availability was realized. As the program progressed, overburden removal and coal production began an upward trend while maintenance cost began to drop.

Bradbury, P.; Beatty, B.

1982-12-01

105

Sperm studies in anesthesiologists  

SciTech Connect

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.

Wyrobek, A.J. (Lawrence Livermore National Lab., CA); Brodsky, J.; Gordon, l.; Moore, D.H., II; Watchmaker, G.; Cohen, E.N.

1981-11-01

106

Egypt: Major Constraints to Increasing Agricultural Productivity.  

National Technical Information Service (NTIS)

This report presents findings and major recommendations of the Egyptian-U.S. Agricultural Sector Assessment Team, assigned to appraise major constraints to increasing agricultural productivity in Egypt. Necessary background information is included. Major ...

M. K. Hindy W. S. Hoofnagle

1976-01-01

107

Binding pattern and toxicological effects of lectins from genus Canavalia on bovine sperm.  

PubMed

The aim of this study was to determine the binding patterns of Canavalia ensiformis (ConA), Canavalia boliviana (ConBol) and Canavalia brasiliensis (ConBr) lectins to bovine sperm and their effects on sperm motility, viability, lipid peroxidation, reactive oxygen species production and fertilization ability. ConA bound to whole spermatozoa, with the exception of the equatorial segment, ConBol did not interact with the acrosome region and ConBr exhibited a fragmented binding pattern. The three lectins decreased sperm motility but did not affect cell viability or lipid peroxidation. Nevertheless, ROS production was increased in comparison to controls and a reduction in the cleavage and blastocyst ratio was induced in comparison to controls. In conclusion, this study determined that structurally similar lectins interact differently with bovine sperm and affect sperm motility, viability, lipid peroxidation, ROS production and fertilization ability in various ways. PMID:23524305

Kaefer, Cristian; Komninou, Eliza R; Campos, Vinicius F; de Leon, Priscila M; Arruda, Francisco Vassiliepe S; Nascimento, Kyria S; Teixeira, Edson H; Stefanello, Francielli M; Barschak, Alethéa G; Deschamps, João Carlos; Seixas, Fabiana K; Cavada, Benildo S; Collares, Tiago

2013-03-21

108

Effect of astaxanthin on human sperm capacitation.  

PubMed

In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS) plays a key role in causing cells to undergo a massive acrosome reaction (AR). Astaxanthin (Asta), a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC). Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam) and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P) pattern and percentages of ARC and non-viable cells (NVC). Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting the ROS generation curve, whereas Diam succeeded in enhancing the Tyr-P level but only of the flagellum without increasing ARC values. It is suggested that Asta can be inserted in the membrane and therefore create capacitation-like membrane alteration which allow Tyr-P of the head. Once this has occurred, AR can take place and involves a higher numbers of cells. PMID:23736766

Donà, Gabriella; Kožuh, Ivana; Brunati, Anna Maria; Andrisani, Alessandra; Ambrosini, Guido; Bonanni, Guglielmo; Ragazzi, Eugenio; Armanini, Decio; Clari, Giulio; Bordin, Luciana

2013-06-03

109

Effect of male age on sperm traits and sperm competition success in the guppy (Poecilia reticulata).  

PubMed

Deleterious mutations can accumulate in the germline with age, decreasing the genetic quality of sperm and imposing a cost on female fitness. If these mutations also affect sperm competition ability or sperm production, then females will benefit from polyandry as it incites sperm competition and, consequently, minimizes the mutational load in the offspring. We tested this hypothesis in the guppy (Poecilia reticulata), a species characterized by polyandry and intense sperm competition, by investigating whether age affects post-copulatory male traits and sperm competition success. Females did not discriminate between old and young males in a mate choice experiment. While old males produced longer and slower sperm with larger reserves of strippable sperm, compared to young males, artificial insemination did not reveal any effect of age on sperm competition success. Altogether, these results do not support the hypothesis that polyandry evolved in response to costs associated with mating with old males in the guppy. PMID:19912453

Gasparini, C; Marino, I A M; Boschetto, C; Pilastro, A

2009-11-13

110

Sperm storage in caecilian amphibians  

PubMed Central

Background Female sperm storage has evolved independently multiple times among vertebrates to control reproduction in response to the environment. In internally fertilising amphibians, female salamanders store sperm in cloacal spermathecae, whereas among anurans sperm storage in oviducts is known only in tailed frogs. Facilitated through extensive field sampling following historical observations we tested for sperm storing structures in the female urogenital tract of fossorial, tropical caecilian amphibians. Findings In the oviparous Ichthyophis cf. kohtaoensis, aggregated sperm were present in a distinct region of the posterior oviduct but not in the cloaca in six out of seven vitellogenic females prior to oviposition. Spermatozoa were found most abundantly between the mucosal folds. In relation to the reproductive status decreased amounts of sperm were present in gravid females compared to pre-ovulatory females. Sperm were absent in females past oviposition. Conclusions Our findings indicate short-term oviductal sperm storage in the oviparous Ichthyophis cf. kohtaoensis. We assume that in female caecilians exhibiting high levels of parental investment sperm storage has evolved in order to optimally coordinate reproductive events and to increase fitness.

2012-01-01

111

Offsetting Effects of Wolbachia Infection and Heat Shock on Sperm Production in Drosophila simulans: Analyses of Fecundity, Fertility and Accessory Gland Proteins  

Microsoft Academic Search

Infection in Drosophila simulans with the endocellular symbiont Wolbachia pipientis results in egg lethality caused by failure to properly initiate diploid development (cytoplasmic incompatibility, CI). The relation- ship between Wolbachia infection and reproductive factors influencing male fitness has not been well examined. Here we compare infected and uninfected strains of D. simulans for (1) sperm production, (2) male fertility, and

Rhonda R. Snook; Sophia Y. Cleland; Mariana F. Wolfner; Timothy L. Karr

112

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

PubMed

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. PMID:19308348

Evans, Jonathan P

2009-03-24

113

The Effects of Sperm Concentration, Sperm:Egg Ratio, and Gamete Age on Fertilization Success in Crown-of-Thorns Starfish (Acarzthaster plan@ in the Laboratory  

Microsoft Academic Search

Laboratory experiments varying gamete con- centrations and gamete age demonstrated significant re- ductions in fertilization success of the starfish Acanthaster planci (L.) with decreasing sperm concentration and in- creasing age of both eggs and sperm. The effect of aging in sperm was faster than that of eggs, and the speed of sperm aging increased with increasing dilution of sperm. Fertilization

J. A. H. BENZIE; P. DIXON

114

Identification and validation of mouse sperm proteins correlated with epididymal maturation  

PubMed Central

Sperm need to mature in the epididymis to become capable of fertilization. To understand the molecular mechanisms of mouse sperm maturation, we conducted a proteomic analysis using saturation dye labeling to identify proteins of caput and cauda epididymal sperm that exhibited differences in amounts or positions on two-dimensional gels. Of eight caput epididymal sperm-differential proteins, three were molecular chaperones and three were structural proteins. Of nine cauda epididymal sperm-differential proteins, six were enzymes of energy metabolism. To validate these proteins as markers of epididymal maturation, immunoblotting and immunofluorescence analyses were performed. During epididymal transit, heat shock protein 2 was eliminated with the cytoplasmic droplet and smooth muscle ?-actin exhibited reduced fluorescence from the anterior acrosome while the signal intensity of aldolase A increased, especially in the principal piece. Besides these changes, we observed protein spots, such as glutathione S-transferase mu 5 and the E2 component of pyruvate dehydrogenase complex, shifting to more basic isoelectric points, suggesting post-translational changes such dephosphorylation occur during epididymal maturation. We conclude that most caput epididymal sperm-differential proteins contribute to the functional modification of sperm structures and that many cauda epididymal sperm-differential proteins are involved in ATP production that promotes sperm functions such as motility.

Ijiri, Takashi W.; Merdiushev, Tanya; Cao, Wenlei; Gerton, George L.

2012-01-01

115

Ejaculate quality and constraints in relation to sperm competition levels among eutherian mammals.  

PubMed

The outcome of sperm competition is influenced by the relative quantity and quality of sperm among competing ejaculates. Whereas it is well established that individual ejaculate traits evolve rapidly under postcopulatory sexual selection, little is known about other factors that might influence the evolution of ejaculates. For example, the metabolic rate is likely to affect the sperm production rate and the cellular activity or metabolism of sperm, and it has recently been suggested to constrain the evolution of sperm length in large but not small mammals. I thus examined in eutherian mammals how ejaculate quality traits vary with one another and with testis mass, body size, and metabolism. I found all ejaculate traits to covary positively with one another and to increase with relative testis mass. When controlling for testis mass, small-bodied species showed superior sperm quality (but not sperm number). Furthermore, sperm motility and viability were positively associated with the mass-corrected metabolic rate, but the percentage of morphologically normal and acrosome-intact sperm were not. These results indicate that body size and the energy budget may also influence the evolution of ejaculate quality, although these influences appear to vary among traits. PMID:24094354

Lüpold, Stefan

2013-05-22

116

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

PubMed

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. PMID:23740083

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

2013-07-01

117

Effect of long-term supplementation with arachidonic or docosahexaenoic acids on sperm production in the broiler chicken.  

PubMed

The possibility was investigated that dietary supplementation of the male chicken with long-chain polyunsaturated fatty acids of the n-6 and n-3 series may prevent the decrease in sperm output that normally occurs by 60 weeks of age. From 26 weeks of age, birds were raised on wheat-based diets supplemented with either maize oil (rich in linoleic acid, 18:2n-6), arasco oil (rich in arachidonic acid, 20:4n-6) or tuna orbital oil (rich in docosahexaenoic acid, 22:6n-3). The effects of the last two oils were investigated at two levels of vitamin E supplementation (40 and 200 mg kg(-1) feed). By 60 weeks of age, there was a small increase in the proportion of the main polyunsaturate of chicken sperm phospholipid, docosatetraenoic acid 22:4n-6, in chickens fed arasco oil diet compared with chickens given the maize oil diet, an effect that was potentiated at the higher dietary intake of vitamin E. Supplementation with tuna orbital oil significantly reduced the proportions of 20:4n-6 and 22:4n-6 in the sperm phospholipid and increased the proportion of 22:6n-3. The diet supplemented with tuna orbital oil and the lower level of vitamin E markedly depleted vitamin E from the tissues of the birds and decreased the concentration of vitamin E in the semen; these effects were largely prevented by the higher level of vitamin E in the diet. The susceptibility of semen to lipid peroxidation in vitro was increased in chickens fed arasco and tuna orbital oils with 40 mg vitamin E kg(-1) feed, but was reduced when 200 mg vitamin E kg(-1) feed was provided in the diet. The number of spermatozoa per ejaculate decreased by 50% between 26 weeks and 60 weeks of age in the birds fed the maize oil diet. This age-related decrease in the number of spermatozoa was almost completely prevented by feeding the birds with the oils enriched in either 20:4n-6 or 22:6n-3. Testis mass at 60 weeks of age was approximately 1.5 times greater in birds given of the arasco and tuna orbital oil diets compared with those given the maize oil diet. PMID:11058441

Surai, P F; Noble, R C; Sparks, N H; Speake, B K

2000-11-01

118

Surflo-H35 increases production  

Microsoft Academic Search

Calcium sulfate scale, long a plague to oil men, is yielding to Baroid's Surflo-H35 in W. Texas, and the removal of this sulfate scale is significantly increasing production. The inhibitor, when properly applied, will disintegrate deposited calcium sulfate scale. Increasing the pH of the system with sodium or potassium hydroxide accelerates and enhances the action of the inhibitor on scale,

Hogue

1969-01-01

119

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

Microsoft Academic Search

BACKGROUND: 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 ICSI, which can enable men with severely impaired sperm production to father children. Several papers have been published reporting aneuploidy in oligo-

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

2004-01-01

120

Increasing the productivity of continuous mercerization equipment  

Microsoft Academic Search

An increase of the hemieellulose content in the alkali being squeezed out causes a rise in the viscosity of the alkali, a retardation in the rate of alkali removal, and correspondingly, a decrease in the productivity of the CMU. Reduction of the hemicellulose content of the mercerization alkali is usually attained by dialysis of the squeezed-out alkali. However, this is

A. A. Serkov; S. N. Klinova; I. L. Voitenko

1983-01-01

121

Production of F 1 and F 2 diploid gynogenetic tilapias and analysis of the “Hertwig curve” obtained using ultraviolet irradiated sperm  

Microsoft Academic Search

In this study, a Hertwig effect with a non-typical biphasic curve was obtained using sperm irradiated with increasing intensities of UV. The first phase of the UV curve appeared to be quite different from that normally demonstrated using ? or x-ray irradiation. This difference is characterised throughout the length of the first phase by (1) low and stable embryo hatching

J. Don; R. R. Avtalion

1988-01-01

122

Sperm Digestion and Reciprocal Sperm Transfer Can Drive Hermaphrodite Sex Allocation to Equality  

Microsoft Academic Search

abstract:,The intensity of sperm,competition,determines,how much,reproductive,effort should be invested in sperm. One impor- tant factor affecting sperm,competition,in internally fertilizing or- ganisms is the mating frequency of females, since it determines the extent of competition,between,ejaculates. In simultaneous,her- maphrodites, energy spent on sperm has to be traded off against energy expended on ova production. By extending an existing model, we consider how,the number,of

Jaco M. Greeff; Nico K. Michiels

1999-01-01

123

Biofuels versus food production: Does biofuels production increase food prices?  

Microsoft Academic Search

Rapidly growing fossil energy consumption in the transport sector in the last two centuries caused problems such as increasing greenhouse gas emissions, growing energy dependency and supply insecurity. One approach to solve these problems could be to increase the use of biofuels.Preferred feedstocks for current 1st generation biofuels production are corn, wheat, sugarcane, soybean, rapeseed and sunflowers. The major problem

Amela Ajanovic

2011-01-01

124

Production of androgenetic diploid loach by cold-shock of eggs fertilized with diploid sperm.  

PubMed

Diploid androgenotes were produced without egg irradiation in the loach, Misgurnus anguillicaudatus. Eggs of wild-type diploid females were fertilized with diploid sperm of a neo-tetraploid male and then cold-shock treated at 3 °C (range, ±0.5 °C) for 30 minutes just after fertilization to eliminate the female nucleus. After hatching, ploidy status of the hatched larvae was analyzed by flow cytometry, which revealed putative diploid androgenotes as well as larvae possessing other ploidies. Five independent microsatellite DNA markers were genotyped to confirm all-male inheritance of the resultant diploid larvae. The mean ± SD yield rate of diploid androgenetic larvae to total eggs used was 12.29 ± 3.25% in the cold-shock group and 22.23 ± 13.42% in the UV-irradiated group (P > 0.05). No diploid androgenetic larvae were detected in the intact control group. To our knowledge, this is the first report demonstrating successful induction of diploid androgenotes without egg irradiation in fish. PMID:23602217

Hou, Jilun; Fujimoto, Takafumi; Yamaha, Etsuro; Arai, Katsutoshi

2013-04-18

125

Intrauterine insemination of isolated motile sperm.  

PubMed

Semen from infertile males was filtered through liquid albumin, and sperm retrieved from the most distal fraction were used for intrauterine insemination. Compared with the ejaculate, the isolated specimens contained fewer sperm but an increased percentage of motile sperm. The fractions were also free of the debris (white cells, agglutinated sperm, immature forms, and particulate matter) commonly seen in the ejaculates. Despite the improvement in motility none of the 19 women who were treated for a total of 67 cycles became pregnant. It is possible that even the best sperm from a poor specimen may have intrinsic defects that interfere with their ability to fertilize. PMID:668936

Glass, R H; Ericsson, R J

1978-05-01

126

[Current progress in cryopreservation of small numbers of sperm].  

PubMed

Human sperm cryopreservation is an increasingly mature technique in assisted reproduction. However, conventional sperm cryopreservation is not suitable for the cryopreservation of small numbers of sperm. The solution to the cryopreservation of small numbers of sperm may contribute a lot to the clinical treatment of asthenospermia, oligospermia and azoospermatism. Recently, many researchers focus on searching for appropriate carriers for the cryopreservation of small numbers of sperm. This article outlines the effects of current cryopreservation methods including empty zona pellucida, microdrops, other mocrocarriers, testicular tissue cryopreservation and testicular sperm and epididymal sperm refrigeration. PMID:24010214

Chen, Chun-Hua; Sha, Yan-Wei; Li, Ping

2013-08-01

127

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

SciTech Connect

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.

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

2006-03-08

128

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

Microsoft Academic Search

BACKGROUND: The trend for men to have children at older age raises concerns that advancing age may increase the production of genetically defective sperm, increasing the risks of transmitting germ-line mutations. METHODS: We investigated the associations between male age and sperm DNA damage and the influence of several lifestyle fac- tors in a healthy non-clinical group of 80 non-smokers (mean

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

2006-01-01

129

Increase productivity with novel reactor design  

SciTech Connect

Hydrocarbon processing industry (HPI) operators have always desired flexible control over process temperature as the chemical reactions proceeded. By managing reaction temperature, petrochemical manufacturers can optimize other processing variables, thus increasing product yields and minimizing wastes and byproducts. Diverse requirements of the HPI have spawned many different reactor types. Each design has benefits but also limitations. Ongoing challenges in reactor development include large pressure drop, high catalyst inventory, labor-intensive change-out of catalysts, etc. Two case histories explore using adiabatic and nonadiabatic reactor technology for exothermic and endothermic reactions.

Arakawa, S.T.; Mulvaney, R.C.; Felch, D.E.; Petri, J.A.; Vandenbussche, K.; Dandekar, H.W. [UOP LLC, Des Plaines, IL (United States)

1998-03-01

130

Female presence influences sperm velocity in the guppy.  

PubMed

As sperm production is costly, males are expected to strategically allocate resources to sperm production according to mating opportunities. While sperm number adjustments have been reported in several taxa, only a few studies investigated whether sperm quality shows adaptive plasticity as well. We tested this prediction in the guppy, Poecilia reticulata. A total of 46 males were initially stripped of all retrievable sperm before being randomly allocated to one of two treatments simulating different levels of mating opportunities (visual contact with females or female deprived). After 3 days, males were stripped and sperm velocity was assayed using Computer Assisted Sperm Analysis. Males in the presence of females produced significantly faster sperm than their counterparts. Implications for the evolution of this ejaculate plasticity in the light of results of sperm competition studies are discussed. PMID:19656863

Gasparini, Clelia; Peretti, Alfredo V; Pilastro, Andrea

2009-08-05

131

The Effects of Four Insect Growth-Regulating (IGR) Insecticides on Honeybee ( Apis mellifera L.) Colony Development, Queen Rearing and Drone Sperm Production  

Microsoft Academic Search

This study assessed the effects of exposure to IGRs on the long-term development of the honeybee colony, viability of queens\\u000a and sperm production in drones and integrated the data into a honeybee population model. Colonies treated with diflubenzuron\\u000a resulted in a short-term reduction in the numbers of adult bees and brood. Colonies treated with fenoxycarb declined during\\u000a the season earlier

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

2005-01-01

132

Sperm Swimming Velocity Predicts Competitive Fertilization Success in the Green Swordtail Xiphophorus helleri  

Microsoft Academic Search

Sperm competition is expected to favour the evolution of traits that influence the performance of sperm when they compete to fertilize a female's eggs. While there is considerable evidence that selection favours increases in sperm numbers, much less is known about how sperm quality contributes towards competitive fertilization success. Here, we determine whether variation in sperm quality influences competitive fertilization

Clelia Gasparini; Leigh W. Simmons; Maxine Beveridge; Jonathan P. Evans

2010-01-01

133

A comparison of chromosomal aberrations induced by in vivo radiotherapy in human sperm and lymphocytes.  

PubMed

Chromosomal aberrations in human sperm and lymphocytes were compared before and after in vivo radiation treatment of 13 cancer patients. The times of analyses after radiotherapy (RT) were 1, 3, 12, 24, 36, 48 and 60 months. The median total radiation dose was 30 Gy and the testicular dose varied from 0.4 to 5.0 Gy. Human sperm chromosome complements were analysed after fusion with golden hamster eggs. There were no abnormalities in sperm or lymphocytes before RT. Following RT there was an increase in the frequency of numerical and structural chromosomal abnormalities in both lymphocytes and sperm. For structural abnormalities there were more rejoined lesions (dicentrics, rings) in lymphocytes and more unrejoined lesions (chromosome breaks, fragments) in sperm. After RT there was a dramatic increase in the frequency of chromosomal abnormalities in lymphocytes: at 1 mo. the frequency was 42%, at 3 mo. 25%, at 12 mo. 14%, at 24 mo. 11%, at 36 mo. 9%, at 48 mo. 7% and at 6 mo. 4%. Since the majority of men were azoospermic after RT, there is little data on sperm chromosome complements before the analyses performed at 24 mo. post-RT. At 24 mo. the frequency of abnormalities was 13%, followed by 21% at 36 mo., 12% at 48 mo. and 22% at 60 mo. Thus it appears that the frequency of lymphocyte chromosomal abnormalities had an initial marked increase after RT followed by a gradual decrease with time whereas the frequency of sperm chromosomal abnormalities was elevated when sperm production recovered and remained elevated from 24 to 60 mo. post-RT. This difference in the effect of time makes it very difficult to compare abnormality rates in lymphocytes and sperm and to use analysis of induced damage in somatic cells as surrogates for germ cells since the ratio between sperm and lymphocytes varied from 1:1 (at 24 mo. post-RT) to 5:1 (at 60 mo. post-RT). PMID:2716765

Martin, R H; Rademaker, A; Hildebrand, K; Barnes, M; Arthur, K; Ringrose, T; Brown, I S; Douglas, G

1989-05-01

134

Aquaporin3 is a sperm water channel essential for postcopulatory sperm osmoadaptation and migration  

PubMed Central

In the journey from the male to female reproductive tract, mammalian sperm experience a natural osmotic decrease (e.g., in mouse, from ?415 mOsm in the cauda epididymis to ?310 mOsm in the uterine cavity). Sperm have evolved to utilize this hypotonic exposure for motility activation, meanwhile efficiently silence the negative impact of hypotonic cell swelling. Previous physiological and pharmacological studies have shown that ion channel-controlled water influx/efflux is actively involved in the process of sperm volume regulation; however, no specific sperm proteins have been found responsible for this rapid osmoadaptation. Here, we report that aquaporin3 (AQP3) is a sperm water channel in mice and humans. Aqp3-deficient sperm show normal motility activation in response to hypotonicity but display increased vulnerability to hypotonic cell swelling, characterized by increased tail bending after entering uterus. The sperm defect is a result of impaired sperm volume regulation and progressive cell swelling in response to physiological hypotonic stress during male-female reproductive tract transition. Time-lapse imaging revealed that the cell volume expansion begins at cytoplasmic droplet, forcing the tail to angulate and form a hairpin-like structure due to mechanical membrane stretch. The tail deformation hampered sperm migration into oviduct, resulting in impaired fertilization and reduced male fertility. These data suggest AQP3 as an essential membrane pathway for sperm regulatory volume decrease (RVD) that balances the “trade-off” between sperm motility and cell swelling upon physiological hypotonicity, thereby optimizing postcopulatory sperm behavior.

Chen, Qi; Peng, Hongying; Lei, Li; Zhang, Ying; Kuang, Haibin; Cao, Yujing; Shi, Qi-xian; Ma, Tonghui; Duan, Enkui

2011-01-01

135

Mating system evolution in sperm-heteromorphic Drosophila.  

PubMed

In Drosophila species of the obscura group, males exhibit sperm-heteromorphism, simultaneously producing both long sperm, capable of fertilization, and short sperm that are not. The production of multiple sperm types calls into question whether mating system correlates, such as sperm length and number trade-offs and female remating behavior, are the same as previously described in sperm-monomorphic systems. We examine three obscura group species, D. pseudoobscura, D. persimilis, and D. affinis that differ significantly in the lengths of their long fertilizing sperm, to test predictions about the relationship between sperm length and four mating system characters: male age at sexual maturity; sperm number; female remating; and male reproductive output. In D. affinis, where males produce the longest fertilizing sperm, their sexual maturity is delayed and they produce fewer long sperm compared to the other two species, as predicted if long sperm are costly to produce. Female D. affinis, although they receive fewer sperm than females of the other two species, do not remate more frequently or produce fewer progeny from a single mating. Different responses between sperm-heteromorphic and sperm-monomorphic systems underscore the complex nature of the coevolution between male and female mating system characters. PMID:11472758

Snook, R R.; Markow, T A.

2001-09-01

136

ESP's placed in horizontal lateral increase production  

SciTech Connect

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.

Gallup, A.; Wilson, B.L. (Oil Dynamics Inc., Tulsa, OK (US)); Marshall, R. (Oryx Energy Co., Dallas, TX (US))

1990-06-18

137

The effects of deletions of the mouse Y chromosome long arm on sperm function--intracytoplasmic sperm injection (ICSI)-based analysis.  

PubMed

In mouse and man, Y chromosome deletions are frequently associated with spermatogenic defects. XY(Tdy)(m1)qdelSry males have an extensive Yq deletion that almost completely abolishes the expression of two gene families, Ssty and Sly, located within the male-specific region of the mouse Y long arm. These males exhibit severe sperm defects and sterility. XY(RIII)qdel males have a smaller interstitial Yq deletion, removing approximately two thirds of Ssty/Sly gene copies, and display an increased incidence of mild sperm head anomalies with impairment of fertility and an intriguing distortion in the sex ratio of offspring in favor of females. Here we used intracytoplasmic sperm injection (ICSI) to investigate the functional capacity of sperm from these Yq deletion males. Any selection related to the ability of sperm to fertilize in vitro is removed by ICSI, and we obtained two generations of live offspring from the infertile males. Genotyping of ICSI-derived offspring revealed that the Y(Tdym1)qdel deletion does not interfere with production of Y chromosome-bearing gametes, as judged from the frequency of Y chromosome transmission to the offspring. ICSI results for XY(RIII)qdel males also indicate that there is no deficiency of Y sperm production in this genotype, although the data show an excess of females following in vitro fertilization and natural mating. Our findings suggest that 1) Yq deletions in mice do not bias the primary sex ratio and 2) Y(RIII)qdel spermatozoa have poorer fertilizing ability than their X-bearing counterparts. Thus, a normal complement of the Ssty and/or Sly gene families on mouse Yq appears necessary for normal sperm function. Summary: ICSI was successfully used to reproduce infertile mice with Yq deletions, and the analysis of sperm function in obtained offspring demonstrated that gene families located within the deletion interval are necessary for normal sperm function. PMID:16354792

Ward, Monika A; Burgoyne, Paul S

2005-12-14

138

Sperm viability - Determination of sperm viability using fluorescence microscopy  

Technology Transfer Automated Retrieval System (TEKTRAN)

To determine the percentage of viable sperm in a semen sample using stains that differentiates viable (live) sperm from nonviable (dead) sperm. Viable sperm are detected by SYBR-14, which stains the sperm nuclei green. Nonviable sperm are detected by propidium iodide (PI), which stains the sperm red...

139

Testicular structure and sperm production in flounders from a polluted estuary: a preliminary study  

Microsoft Academic Search

Discharges of industrial and domestic waste have been linked with the production of vitellogenin and intersex conditions in wild male flounder from industrialized estuaries. The chemicals act as xenoestrogens or hormone mimics causing feminisation in male fish.This initial study follows seasonal changes, between July and March, in testicular development and spermatogenesis in 17 male flounder. The fish were taken from

Margaret E Gill; John Spiropoulos; Christian Moss

2002-01-01

140

The Clinical Relevance of Sperm Aneuploidy  

Microsoft Academic Search

The relevance and predictive capabilities of sperm aneuploidy frequencies have been assessed in normal men, men with a constitutional\\u000a chromosomal abnormality, and infertile men with a normal karyotype. Sperm aneuploidy assessment by fluorescence in situ hybridization analysis (FISH) appears to be valuable and reliable. A number of studies have demonstrated that increased frequencies\\u000a of aneuploidy in human sperm are mirrored

Renee H. Martin

141

Movement of sea urchin sperm flagella  

PubMed Central

The motion of the sea urchin sperm flagellum was analyzed from high-speed cinemicrographs. At all locations on the flagellum the transversal motion and the curvature were found to vary sinusoidally in time. The curvatures of the flagella increase strongly near the proximal junction. Two sperm are described in transient from rest to normal motion. The full wave motion developed in both sperm within 40 ms.

Rikmenspoel, R.

1978-01-01

142

How nematode sperm crawl  

Microsoft Academic Search

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

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

143

A configuration tool to increase product competitiveness  

Microsoft Academic Search

The salesPLUS product configuration tool effectively solves complex configuration problems, reducing costs while meeting customer expectations in real-world applications. This commercial AI-based system effectively and intuitively models and configures products. It effectively produces and maintains consistent, accurate configurations that meet customer demands while significantly reducing costs

Bei Yu; H. J. Skovgaard

1998-01-01

144

Understanding email interaction increases organizational productivity  

Microsoft Academic Search

To minimize the effect of email interruption on employee productivity, limit the frequency of new-email alerts (silence them, too), make it easier to assess each message's importance, and remove the reply-to-all facility.

Thomas W. Jackson; Ray Dawson; Darren Wilson

2003-01-01

145

Long-Term Effects of Triethylenemelamine Exposure on Mouse Testis Cells and Sperm Chromatin Structure Assayed by Flow Cytometry.  

National Technical Information Service (NTIS)

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 experim...

D. P. Evenson R. K. Baer L. K. Jost

1989-01-01

146

LONG-TERM EFFECTS OF TRIETHYLENEMELAMINE EXPOSURE ON MOUSE TESTIS CELLS AND SPERM CHROMATIN STRUCTURE ASSAYED BY FLOW CYTOMETRY  

EPA Science Inventory

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. he first experiment examined effects of fo...

147

Fine structure of sperm cells in pollen grains of Beta  

Microsoft Academic Search

Summary The structure of sperm cells in mature trinucleate pollen grains ofBeta vulgaris L. was studied with the electron microscope. The ellipsoidal sperm cell nuclei and cytoplasm are products of mitosis and cytokinesis of the ellipsoidal generative cell. Each sperm cell is separated from the vegetative cytoplasm by two contiguous membranes which enclose its cytoplasm and nucleus. Microtubules present in

Lynn L. Hoefert

1969-01-01

148

Capacitation and the acrosome reaction in equine sperm  

Microsoft Academic Search

During sexual reproduction, the sperm and oocyte must fuse before the production of a diploid zygote can proceed. In mammals such as equids, fusion depends critically on complex changes in the plasma membrane of the sperm and, not surprisingly, this membrane differs markedly from that of somatic cells. After leaving the testes, sperm cease to synthesize plasma membrane lipids or

B. M. Gadella; R. Rathi; J. F. H. M. Brouwers; T. A. E. Stout; B. Colenbrander

2001-01-01

149

Wolbachia infection reduces sperm competitive ability in an insect  

Microsoft Academic Search

The maternally inherited bacterium Wolbachia pipientis imposes significant fitness costs on its hosts. One such cost is decreased sperm production resulting in reduced fertility of male Drosophila simulans infected with cytoplasmic incompatibility (CI) inducing Wolbachia. We tested the hypothesis that Wolbachia infection affects sperm competitive ability and found that Wolbachia infection is indeed associated with reduced success in sperm competition

Fleur E. Champion de Crespigny; Nina Wedell

2006-01-01

150

Cryopreservation of Fish Sperm  

NASA Astrophysics Data System (ADS)

Present status of research activities in cryopreservation of fish gamete in aquaculture field was introduced. More than 59 fish species have been reported in the research histories and nearly half of them were studied during recent 10 years. This means that the research activities are increasing, though commercial profit have not obtained yet. Fish species of which sperm can successfully cryopreserved is still limited comparing to numerous species in telost. One of the major obstacle for improvement of the technique is existence of wide specie specific variance in the freezing tolerance of fish sperm. The varianc can possibly be explaind thorugh the informations obtained by the studies in comparative spermatology, which is recently activated field in fish biology.

Kurokura, Hisashi

151

Sperm trajectories form chiral ribbons.  

PubMed

We report the discovery of an entirely new three-dimensional (3D) swimming pattern observed in human and horse sperms. This motion is in the form of 'chiral ribbons', where the planar swing of the sperm head occurs on an osculating plane creating in some cases a helical ribbon and in some others a twisted ribbon. The latter, i.e., the twisted ribbon trajectory, also defines a minimal surface, exhibiting zero mean curvature for all the points on its surface. These chiral ribbon swimming patterns cannot be represented or understood by already known patterns of sperms or other micro-swimmers. The discovery of these unique patterns is enabled by holographic on-chip imaging of >33,700 sperm trajectories at >90-140 frames/sec, which revealed that only ~1.7% of human sperms exhibit chiral ribbons, whereas it increases to ~27.3% for horse sperms. These results might shed more light onto the statistics and biophysics of various micro-swimmers' 3D motion. PMID:23588811

Su, Ting-Wei; Choi, Inkyum; Feng, Jiawen; Huang, Kalvin; McLeod, Euan; Ozcan, Aydogan

2013-01-01

152

Sperm Trajectories Form Chiral Ribbons  

NASA Astrophysics Data System (ADS)

We report the discovery of an entirely new three-dimensional (3D) swimming pattern observed in human and horse sperms. This motion is in the form of `chiral ribbons', where the planar swing of the sperm head occurs on an osculating plane creating in some cases a helical ribbon and in some others a twisted ribbon. The latter, i.e., the twisted ribbon trajectory, also defines a minimal surface, exhibiting zero mean curvature for all the points on its surface. These chiral ribbon swimming patterns cannot be represented or understood by already known patterns of sperms or other micro-swimmers. The discovery of these unique patterns is enabled by holographic on-chip imaging of >33,700 sperm trajectories at >90-140 frames/sec, which revealed that only ~1.7% of human sperms exhibit chiral ribbons, whereas it increases to ~27.3% for horse sperms. These results might shed more light onto the statistics and biophysics of various micro-swimmers' 3D motion.

Su, Ting-Wei; Choi, Inkyum; Feng, Jiawen; Huang, Kalvin; McLeod, Euan; Ozcan, Aydogan

2013-04-01

153

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

PubMed Central

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.

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

2011-01-01

154

Cytometry of mammalian sperm  

SciTech Connect

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.

Gledhill, B.L.

1983-10-11

155

Investigation on dispermic androgenesis in sturgeon fish. The first successful production of androgenetic sturgeons with cryopreserved sperm  

Microsoft Academic Search

Induced diploid androgenesis is considered as a valuable tool for restoration of endangered or extinct species from cryopreserved spermatozoa. The method of dispermic androgenesis was developed in sturgeon fishes whose threatened status requires urgent conservation efforts. The method includes genetic inactivation of eggs, their insemination with concentrated sperm (to cause polyspermy), and the heat shock that facilitates the fusion of

A. S. Grunina; A. V. Recoubratsky; L. I. Tsvetkova; V. A. Barmintsev

2006-01-01

156

Effect of 655nm laser different powers on dog sperm motility parameters  

NASA Astrophysics Data System (ADS)

Introduction: One of the most appreciated features of the sperm is its motility, which depends on a big energy consumption despite differences among species. Laser acts direct or indirectly on mitochondria increasing ATP production. Material and method: By means of a Computer Aided Sperm Analysis (CASA) we have studied the effects of a 655 nm continuous wave diode laser irradiation at different power outputs with a dose of 3.3418 J on sperm motility. After an eosine-nigrosine stain to establish its quality, the second fraction of fresh beagle dog sperm was divided into 5 groups, 1 control and four to be irradiated respectively with an average output power of 6.84 mW, 15.43 mW, 33.05 mW and 49.66 mW. At times 0 and 45 minutes from irradiation pictures were taken and analysed with the Sperm class Analyzer SCA2002 programme. The motility parameters of 4987 spermatozoa studied were: curvilinear velocity (VCL), progressive velocity (VSL), straightness (STR), wobble (WOB), average path velocity (VAP), linearity (LIN), mean amplitude of lateral head displacement (ALHmed), beat cross frequency (BCF) and the total motility (MT). At time 15 minutes after irradiation a hypoosmotic swelling test (HOST) was done. Results: Several motility parameters that affect the overall motile sperm subpopulation structure have been changed by different output powers of a 655 nm diode laser irradiation, and prevents the decrease of the sperm motility properties along time.

Corral-Baqués, M. I.; Rigau, T.; Rivera, M. M.; Rodríguez-Gil, J. E.; Rigau, J.

2006-05-01

157

Prudent sperm use by leaf-cutter ant queens  

PubMed Central

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.

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

2009-01-01

158

Enhanced reservoir definition for increased production  

Microsoft Academic Search

New production techniques such as the use of horizontal holes for drainage and injection purposes, require detailed and accurate reservoir characterization. Three methods were used: 3D seismic, computerized reservoir modeling using geostastical theories and advanced correlation techniques, and the use of outcrop data to provide reservoir analog models. It is important to construct realistic reservoir models as soon as possible.

1993-01-01

159

Vacuum mixing increases productivity saves energy  

Microsoft Academic Search

Rexnord Chemical Products, Inc. produces clear caulking, architectural sealants and other commercial building materials at its 42,000 sq ft plant in Pottstown, PA. Clear caulking is made by mixing together thermoplastic rubber, powdered resins, stabilizers, adhesion promoters and other additives. The materials have a high viscosity, more than 500,000 centipoise. The older manufacturing technology required more than 16 hours of

Haring

1985-01-01

160

A Work Schedule to Increase Productivity.  

ERIC Educational Resources Information Center

|Outlines a technique for making a tight economy and energy shortages more palatable by supplementing employee wage increases with benefits such as alternative three and four day "weekends" without loss of regular pay and by enabling business to increase profits. (Author/IRT)|

Atwood, Caleb S.

1979-01-01

161

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

PubMed

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 for the screening of sperm DNA fragmentation in the andrology laboratory. PMID:12514084

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

162

Products to safely increase lean muscle mass.  

PubMed

Pharmaceutical companies are promoting injectable HGH or rHGH to promote the gain of muscle mass in persons with AIDS. Side effects can include high triglycerides, thyroid dysfunction, and increased tumor growth. A possible alternative is a Homeopathic HGH produced by Biomed Comm. Contact information for Biomed Comm is provided. Marinol, which contains THC, the active ingredient in marijuana, also promotes appetite and an increase in body mass. Immunocal, Optimune, and Designer Protein also appear effective in increasing lean muscle mass. Whole lemon olive oil drink is also discussed. PMID:11366553

1998-01-01

163

Metabolism, sperm and fluid production of the isolated perfused testis of the sheep and goat  

PubMed Central

1. A total of nineteen ram and three goat testes have been perfused in isolation at 34-35° C for 3½-9 hr with heparinized blood and an added 5-HT antagonist (bromolysergic acid diethylamide) and their function compared with that of the normal ram testes in vivo. 2. The metabolism of the perfused testes and the testes in vivo was similar but blood flow through the perfused testes was two to three times normal. 3. Vasoconstriction was produced by adrenaline and noradrenaline (10-20 ?g I.A.) and by electrical stimulation of nerves in the spermatic cord or of the lumbar sympathetic chain; these responses were abolished or reduced by phenoxybenzamine. 4. Flow of fluid from the rete testis continued only if ischaemia was reduced to a minimum and glucose concentration in the blood perfusing the testis was kept above about 25 mg/100 ml.; the fluid secreted during perfusion was of normal composition. 5. The perfused testis showed no evidence of autoregulation and the flow of fluid was not affected by changes in perfusion pressure. 6. When the temperature of three testes was raised to 40° C for 2 hr, metabolism increased but blood flow was unaltered; the flow of fluid and the concentration of spermatozoa decreased during heating. 7. The testes perfused at normal scrotal temperatures (34-35° C) were histologically normal but some abnormalities were observed in the heated testes. ImagesFig. 3Fig. 4

Linzell, J. L.; Setchell, B. P.

1969-01-01

164

Turkey Sperm Reside in the Tubular Glands in the Urodeum Following Artificial Insemination  

Technology Transfer Automated Retrieval System (TEKTRAN)

A turkey hen in egg production requires 48 hr after the last insemination to maximize the number of sperm in the uterovaginal junction sperm-storage tubules. Where the sperm that continue to fill the oviductal sperm-storage sites during this 48 hr period reside remains unknown. Histological sectio...

165

Consequences of autoimmunity to sperm antigens in vasectomized men.  

PubMed

The development by a large percentage of vasectomized men of sperm autoantibodies is discussed in this monograph chapter. The production of anti-sperm antibodies is attributed to: 1) granuloma formation; 2) increased permeability of epithelial barriers in the rete testis and epididymis; and 3) transport of phagocytic cells to regional lymph nodes. Individual variation in type of antibodies and response to antibody production is documented and is thought to depend on such factors as rate of sperm production, the structure of the blood-testis barrier, surgical technique, and expression of immune response genes. Morphological changes in spermatozoa and testes occurring after vasectomy may be induced by immunological mechanisms. Tests of cell-mediated immunity to sperm antigens are described, and more accurate tests are needed. Animal studies provide evidence that chronic immune stimulation can result in formation of circulating immune complexes, resulting in deleterious systemic effects, including damage to kidneys, blood vessels, and cells of the immune system. Further studies of the autoimmune orchitis phenomenon may aid in avoidance of immunologically mediated side effects of vasectomy. PMID:92384

Anderson, D J; Alexander, N J

1979-12-01

166

Movement of sea urchin sperm flagella  

Microsoft Academic Search

The motion of the sea urchin sperm flagellum was analyzed from high-speed cinemicrographs. At all locations on the flagellum the transversal motion and the curvature were found to vary sinusoidally in time. The curvatures of the flagella increase strongly near the proximal junction. Two sperm are described in transient from rest to normal motion. The full wave motion developed in

ROBERT RIKMENSPOEL

1978-01-01

167

[Dispermic androgenesis in sturgeons with the help of cryopreserved sperm: production of androgenetic hybrids between Siberian and Russian sturgeons].  

PubMed

Dispermic androgenesis was used to produce, for the first time, an androgenetic progeny of the Siberian sturgeon (Acipenser baerii) and the androgenetic nuclear cytoplasmic hybrids (Siberian sturgeon, A. baerii x Russian sturgeon, A. gueldenstaedtii) using cryopreserved sperm. Microsatellite DNA analysis confirmed exclusively paternal inheritance in the androgenetic progeny of Siberian sturgeon. Heterozygotes for certain microsatellite loci were detected among the androgenetic hybrids, thereby confirming a dispermic nature of androgenesis. According to the data of comparative morphological analysis, the obtained androgenetic hybrid, by the age of 15 months old, was completely identical to the paternal species. Both a female and a male were detected in the androgenetic sturgeon progenies, which is of interest for producing bisexual progenies via androgenesis. The data of this study confirm the feasibility of dispermic androgenesis using cryopreserved sperm to preserve and recover the gene pools of endangered sturgeon species. PMID:21542342

Grunina, A S; Rekubratski?, A V; Tsvetkova, L I; Barmintseva, A E; Vasil'eva, E D; Kovalev, K V; Poluéktova, O G

168

Experimental evolution of sperm competitiveness in a mammal  

PubMed Central

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.

2011-01-01

169

Female choice of young sperm in a genetically monogamous bird.  

PubMed Central

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.

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

2004-01-01

170

Increasing Labour Productivity in Agriculture and Its Implications  

ERIC Educational Resources Information Center

|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…

van den Ban, Anne

2011-01-01

171

Increasing Labour Productivity in Agriculture and Its Implications  

ERIC Educational Resources Information Center

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…

van den Ban, Anne

2011-01-01

172

Has the Prevalence of Congenital Abnormalities after Intracytoplasmic Sperm Injection Increased? The Leuven Data 1994–2000 and a Review of the Literature  

Microsoft Academic Search

Background: Although intracytoplasmic sperm injection (ICSI) is now accepted as the treatment of choice for severe male infertility, concerns about its safety and the potential risks for the offspring remain. We reviewed the literature with respect to the prevalence of major congenital malformations after the ICSI technique and supplemented these data with the results of a prospective follow-up study performed

An Hindryckx; Karen Peeraer; Sophie Debrock; Eric Legius; Francis de Zegher; Inge Francois; Dirk Vanderschueren; Koen Demyttenaere; Anna Rijkers; Thomas D’Hooghe

2010-01-01

173

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

SciTech Connect

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.

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

2003-11-10

174

Flow Cytometry of Sperm.  

National Technical Information Service (NTIS)

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 chromoso...

B. L. Gledhill

1987-01-01

175

Sperm Whales (Physeter catodon) React to Pingers.  

National Technical Information Service (NTIS)

Sperm whales, Physeter catodon, temporarily interrupted their own sound production in reaction to underwater pulses produced by our calibration sound sources (pingers). All seven whales that passed close to the hydrophone array at different times reacted ...

W. A. Watkins W. E. Schevill

1974-01-01

176

Flow cytometry of sperm  

SciTech Connect

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.

Gledhill, B.L.

1987-09-21

177

Contraceptive vaccines targeting sperm.  

PubMed

Overpopulation is a global problem of significant magnitude, with grave implications for the future. Development of new contraceptives is necessary, as existing forms of birth control are unavailable, impractical and/or too expensive for many individuals due to sociological, financial or educational limitations. Immunocontraception and, in particular, the targeting of antibodies to sperm-specific antigens implicated in sperm-egg binding and fertilisation offers an attractive approach to control fertility. Sperm-specific antibodies may impair fertility by inhibiting sperm motility, by reducing penetration of the cervical mucus by sperm, or by interfering in sperm capacitation or the acrosome reaction; alternatively, antisperm antibodies may invoke the complement cascade, resulting in sperm lysis. The antibodies raised against sperm-specific antigens have proved to be extremely effective at reducing sperm-egg interactions in vitro; fertility trials in subhuman primates will eventually be needed to prove the effectiveness of the sperm antigens in terms of contraceptive efficacy before trials in humans can be justified. In addition, existing and emerging strategies (such as sperm proteomics, the determination of molecular and structural details of sperm proteins, and the modelling of protein-ligand interactions using X-ray and/or NMR structures to name a few) are expected to provide the experimental foundation for the design of small molecule inhibitors with antifertility effects. The technology underpinning vaccine development is constantly being developed and the introduction of DNA/RNA vaccines is certain to impact upon the field of immunocontraception. PMID:15833075

Suri, Anil

2005-03-01

178

Sperm competition in bats  

Microsoft Academic Search

SUMMARY Sperm competition is a widespread phenomenon influencing the evolution of male anatomy, physiology and behaviour. Bats are an ideal group for studying sperm competition. Females store fertile sperm for up to 200 days and the size of social groups varies from single animals to groups of hundreds of thousands. This study examines the relationship between social group size and

D. J. Hosken

1997-01-01

179

Sperm chromatin structure assay (SCSA®).  

PubMed

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) related to retained nuclear histones consistent with immature sperm; high HDS values are predictive of pregnancy failure.The SCSA(®) is considered to be the most technician friendly, time- and cost-efficient, precise and repeatable DNA fragmentation assay, with the most data and the only fragmentation assay with an accepted clinical threshold for placing a man at risk for infertility. SCSA(®) data are more predictive of male factor infertility than classical semen analyses. PMID:22992911

Evenson, Donald P

2013-01-01

180

Estrogens and falling sperm counts.  

PubMed

Extravagant claims have been made repeatedly in recent years that human sperm counts are falling and that global exposure to environmental estrogens are responsible. The basis for these two distinct claims is reviewed. The claims of falling human sperm output, reviving an old debate, are prompted by a paper by Carlsen et al. (1992). This meta-analysis, however, is marred by numerous flaws that invalidate its claims. Major defects include severe heterogeneity of component studies, rendering them unsuitable for aggregation, and defective data analysis based on arithmetic mean rather than median, which showed no significant changes over time. This debate is likely to remain unresolved until valid, representative population-based studies of human sperm output can be achieved. None have been reported, or seem feasible in the near future, and so alternative strategies, based on surrogate variables for human male fertility not requiring sperm counts, need to be developed and validated. The plausible hypothesis that prenatal estrogen exposure might influence development of the human testis through effects on Sertoli cell replication and sperm carrying capacity has, however, been conclusively refuted by studies of boys born to women exposed to high doses of oral diethylstilbestrol during pregnancy. Neither fertility nor sperm output were adversely influenced by massive maternal estrogen exposure during pregnancy, although minor urogenital malformations did occur. The still wider claims of deteriorating male reproductive health, notably changes in prevalence or incidence of hypospadias or cryptorchidism, also lack convincing population-based evidence, although cancer registry data indicate a gradual increase in testis cancer in some countries. In summary, the available evidence does not support claims of falling sperm counts or any general deterioration in male reproductive health. Population-based studies of valid surrogate variables for male fertility not requiring semen analysis are needed. If population-based evidence regarding male fertility or sperm output could be generated, it is highly unlikely that prenatal estrogen exposure could be a valid explanation of any deterioration as massive maternal exposure to oral estrogen has negligible effects on male fertility or sperm output. PMID:11800170

Handelsman, D J

2001-01-01

181

Rapid adjustments of sperm characteristics in relation to social status  

PubMed Central

Sperm competition models predict that males typically mating in disfavoured roles should be selected to compensate for their disadvantage by investing more into sperm. We studied the effect of rapid changes in social status on ejaculate investments during experimental trials with an externally fertilizing teleost—the Arctic charr (Salvelinus alpinus). We document that males becoming dominant produce less sperm with lower velocity, but have higher sex steroid concentrations than subordinate males. These differences in sperm characteristics seem mainly to result from a decreased investment in sperm among fish that become dominant compared to pre-trial levels. Moreover, these adjustments of sperm production and sperm velocity seem not to be traded against sperm longevity. Our results support theoretical models of sperm competition, as males forced to mate in disfavoured roles seem to invest more into ejaculate quality than males in favoured roles. Additionally, we are the first to report that males, in a species with status-dependent shifts in reproductive tactics, have evolved rapid tactic specific adjustments of sperm production and sperm velocity corresponding to what could be predicted from their reproductive roles.

Rudolfsen, Geir; Figenschou, Lars; Folstad, Ivar; Tveiten, Helge; Figenschou, Marie

2005-01-01

182

Ovarian fluid of receptive females enhances sperm velocity  

NASA Astrophysics Data System (ADS)

The females of several internal fertilizers are able to store sperm for a long time, reducing the risk of sperm limitation. However, it also means that males can attempt to mate outside females' receptive period, potentially increasing the level of sperm competition and exacerbating sexual conflict over mating. The guppy ( Poecilia reticulata), an internally fertilizing fish, is a model system of such competition and conflict. Female guppies accept courtship and mate consensually only during receptive periods of the ovarian cycle but receive approximately one (mostly forced) mating attempt per minute both during and outside their sexually receptive phase. In addition, females can store viable sperm for months. We expected that guppy females would disfavour sperm received during their unreceptive period, possibly by modulating the quality and/or quantity of the components present in the ovarian fluid (OF) over the breeding cycle. Ovarian fluid has been shown to affect sperm velocity, a determinant of sperm competition success in this and other fishes. We found that in vitro sperm velocity is slower in OF collected from unreceptive females than in OF from receptive females. Visual stimulation with a potential partner prior to collection did not significantly affect in vitro sperm velocity. These results suggest that sperm received by unreceptive females may be disfavoured as sperm velocity likely affects the migration process and the number of sperm that reach storage sites.

Gasparini, Clelia; Andreatta, Gabriele; Pilastro, Andrea

2012-05-01

183

Drosophila Sperm Motility in the Reproductive Tract1  

PubMed Central

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.

Yang, Yong; Lu, Xiangyi

2011-01-01

184

Blastocyst production by in vitro maturation and development of porcine oocytes in defined media following intracytoplasmic sperm injection.  

PubMed

The present study was carried out to establish porcine defined IVP. In Experiments 1 and 2, we investigated the efficacy of additional 0.6 mM cystine and/or 100 microM cysteamine (Cys) to a defined TCM199 maturation medium with regard to the intracellular glutathione (GSH) concentration and the developmental competence of in vitro matured porcine oocytes following intracytoplasmic sperm injection (ICSI). The control medium was a modified TCM199 containing 0.05% (w/v) polyvinyl alcohol (PVA). Cys and/or cystine were added to the control medium. The control group and immature oocytes (presumptive germinal vesicle oocytes; GV) were prepared for GSH assay. In Experiment 3, the efficacy of epidermal growth factor (EGF) addition to a modified porcine zygote medium (mPZM) for in vitro culture (IVC) medium was investigated on embryonic development and the mean cell number of blastocysts following ICSI. As a positive or negative control, 0.3% BSA (mPZM-3) or 0.3% PVA (mPZM-4), respectively, was added to the base medium. The defined IVC medium was supplemented with 5 or 10 ng/ml EGF. In Experiment 1, no significant difference was found in the rates of cleavage (31.4-64.3%) and blastocyst formation (6.5-22.9%) among the treatment and control groups. The mean cell numbers per blastocyst ranged from 30 to 48 among the groups without significant differences. However, in Experiment 2, the intracellular GSH concentrations in the oocytes cultured in the medium supplemented with 100 microM Cys (9.6 pmol/oocyte) or Cys + cystine (9.9 pmol/oocyte) were significantly (p < 0.05) higher than the control (2.5 pmol/oocyte) and 0.6 mM cystine (6.5 pmol/oocyte) groups, but not different from the GV group (9.0 pmol/oocyte). The GSH concentration in the cystine group was also significantly (p < 0.05) higher than that in the control group, but not different from the GV group. In Experiment 3, the rates of cleavage and blastocyst formation and the mean cell numbers of blastocysts were not significantly different among the groups. However, the addition of 5 ng/ml EGF into the mPZM-4 resulted in a significantly (p < 0.05) higher blastocyst rate per cleaved embryo than the other two defined groups (mPZM-4 + 5 ng/ml: 48.6%, mPZM-4 and mPZM-4 +10 ng/ml: 23.4% and 23.1%, respectively). The present results indicate that the addition of Cys to a defined medium for in vitro maturation (IVM) of porcine oocytes increases intracellular GSH concentration. Further addition of cystine into the IVM medium containing 100 microM Cys is not necessary and TCM199 plus Cys (100 microM) could be used as a defined IVM medium for porcine oocytes. The addition of 5 ng/ml EGF to a defined IVC medium has enhanced subsequent development after ICSI. This study shows that porcine blastocysts can be produced by defined media throughout the steps of IVP (IVM, ICSI and IVC). PMID:17462101

Kobayashi, M; Asakuma, S; Fukui, Y

2007-05-01

185

Immune activation decreases sperm viability in both sexes and influences female sperm storage  

PubMed Central

All animals are under the constant threat of pathogenic infection. However, little is known regarding the influence of acute infection on sperm viability, particularly in female insects. This information is crucial for our understanding of mating and immune system coevolution, considering that females store sperm and serve as the site of sperm competition. Using the fruitfly, Drosophila melanogaster, we examined the influence of infection on sperm viability and storage. Twenty-four hours after haemocoel inoculation with a pathogen mimic (peptidoglycan, PGN) both sexes exhibited reduced sperm viability, indicating that systemic immune activation played a significant role in gamete survival. Surprisingly, sperm death did not appear to result from a reproductive-immune system trade-off, considering that sperm survived 24 h in vitro once removed from their somatic resources. Instead, our results are most consistent with death owing to immune effector collateral damage. We also examined the potential for sexually transmitted pathogens to influence sperm storage. Females mated with ‘infected’ males (created by dipping genitalia into a PGN solution) exhibited a higher proportion of empty sperm stores 48 h after mating compared to their controls. Remarkably, these data indicate that females may increase their fitness by removing ‘infected’ ejaculates from storage over time.

Radhakrishnan, Preethi; Fedorka, Kenneth M.

2012-01-01

186

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

SciTech Connect

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.

Evenson, D.P.; Baer, R.K.; Jost, L.K. (South Dakota State Univ., Brookings (USA))

1989-01-01

187

Is sperm motility maturation affected by static magnetic fields?  

PubMed Central

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.

Tablado, L; Perez-Sanchez, F; Soler, C

1996-01-01

188

Sperm-activating peptide induces asymmetric flagellar bending in sea urchin sperm.  

PubMed

Speract, a sperm-activating peptide (SAP) from sea urchin eggs, induces various sperm responses including a transient increase in the intracellular Ca2+ concentration. However, it has not been clarified how speract modulates sperm motility and whether it functions as a chemoattractant. To confirm the effect of speract on sperm motility, we observed the flagellar bending response to speract in sperm of Hemicentrotus pulcherrimus, in experiments using caged speract and a lighting system for a microscope newly developed with a power LED. We found that speract induces increases in curvature of swimming paths and changes flagellar bending shape to asymmetric. These facts show that speract directly regulates flagellar motility, and suggest that speract-induced increases in intracellular Ca2+ concentration play an actual role in regulation of the flagellar movement. PMID:15795491

Shiba, Kogiku; Ohmuro, Junko; Mogami, Yoshihiro; Nishigaki, Takuya; Wood, Christopher D; Darszon, Alberto; Tatsu, Yoshiro; Yumoto, Noboru; Baba, Shoji A

2005-03-01

189

Developmental exposure to decabrominated diphenyl ether (BDE-209): effects on sperm oxidative stress and chromatin DNA damage in mouse offspring.  

PubMed

Polybrominated diphenyl ethers (PBDEs) are used as brominated flame retardants and have been found in human milk in recent years. This study investigates whether prenatal exposure to decabrominated diphenyl ether (BDE-209) induces sperm dysfunction in male offspring. Pregnant CD-1 mice were gavaged once daily with corn oil (control), 10, 500, and 1500 mg kg(-1) body weight of BDE-209 from day 0 of gestation to day 17. The outcomes of male reproductive parameters were assessed on postnatal day 71. Anogenital distance, sperm-head abnormalities, and testicular histopathology were significantly affected in male offspring prenatally exposed to 1500 mg kg(-1). Significant increases in the tendency for sperm DNA denaturation (?T) induction and the DNA fragmentation index (DFI) were found in those exposed to 10, 500, and 1500 mg kg(-1) (P < 0.05). We observed a significant increase of sperm hydrogen peroxide (H(2)O(2)) generation in the 10 and 1500 mg/kg/day groups compared to the control group (P < 0.05). Although our findings suggested that the mechanisms underlying BDE-209-induced sperm DNA damage and H(2)O(2) generation might not be represented as a dose-response relationship, we found that the greater the excess production of sperm H(2)O(2), the greater the sperm ?T (r = 0.65, P = 0.0155) and DFI (r = 0.53, P = 0.002). In conclusion, developmental exposure to BDE-209 induced sperm-head abnormality, oxidative stress, chromatin DNA damage, and testicular histopathological changes. These findings suggest that BDE-209-induced male reproductive effects might involve the formation of sperm H(2)O(2) which attacks nucleic acids via H(2)O(2) generation. PMID:21626651

Tseng, Li-Ho; Hsu, Ping-Chi; Lee, Chia-Wei; Tsai, Shinn-Shyong; Pan, Min-Hsiung; Li, Mei-Hui

2011-05-27

190

Ultrastructure of anterior uterus of the oviduct and the stored sperm in female soft-shelled turtle, Trionyx sinensis.  

PubMed

Ultrastructure of sperm storage in female soft-shelled turtle, Trionyx sinensis was examined under light and electron microscopes. Sperm storage tubules are restricted to the anterior of the uterus. These tubules developed either by folding or fusion of the oviductal mucosal folds and are lined by both ciliated and secretory cells. Ciliated cells are characterized by a few microvilli and prominent cilia in the apical membranes. A prominent feature of the secretory cell is the presence of secretory granules in the supranuclear region. The size, shape, and electron density of these granules vary markedly. The secretory product is released mainly by exocytosis into the oviductal lumen, where it appears as flocculent material. The unique structure in the base of the epithelium, the basal border of the cell -- the basal lamina -- and a blood vessel layer, is presumed to be a important barrier, by which the nourishment exchange and the microenvironment maintenance are ensured. The gland cell is presented with numerous, round, membrane-bound secretory granules of moderate to high electron densities. We divide these granules into three types according to their appearance: (1) membrane bounded granules with high-homogeneous electron density, (2) membrane bounded granules with moderate-homogeneous electron density, (3) membrane bounded, electron dense granules with concentric structures. These granules are presented as different stages of the secretions in the gland cell. The junction complexes are markedly distributed between cells, which are important in keeping stability and the microenvironment maintenance of the sperm storage tubules. Sperm stored in the tubules are heterogeneous in cytology. In addition to the mature sperm in the lumen, sperm with large chromatic granules are found, which are presumed to be immature sperm and are being in the process of nuclear condensation. Several spermatozoa in the tubules are exhibited with definitive indications of degeneration of the nuclei. The nuclear volume increases. The electron density of the central cores in mitochondria declines, combined with the deterioration of concentric membrane structure. Those changes are possibly due to the long time storage of the sperm in sperm storage tubules, and the leakage of reactive oxygen species is suggested to be a major cause. We conclude that the ultrastructure character of sperm storage in the oviduct of Trionyx sinensis is unique, in addition to having a basal function in secretion and the cilia swing, the tubules also provide an available microenvironment for the sperm to long time stored. The degenerative sperm in the tubules might be related to paternity-specific reproductive adaptations, and the sperm competition might occur during long time storage. PMID:18231967

Han, Xiangkun; Zhangli, Li; Li, Meiying; Bao, Huijun; Hei, Nainan; Chen, Qiusheng

2008-03-01

191

Glycolysis and mitochondrial respiration in mouse LDHC-null sperm.  

PubMed

We demonstrated previously that a knockout (KO) of the lactate dehydrogenase type C (Ldhc) gene disrupted male fertility and caused a considerable reduction in sperm glucose consumption, ATP production, and motility. While that study used mice with a mixed genetic background, the present study used C57BL/6 (B6) and 129S6 (129) Ldhc KO mice. We found that B6 KO males were subfertile and 129 KO males were infertile. Sperm from 129 wild-type (WT) mice have a lower glycolytic rate than sperm from B6 WT mice, resulting in a greater reduction in ATP production in 129 KO sperm than in B6 KO sperm. The lower glycolytic rate in 129 sperm offered a novel opportunity to examine the role of mitochondrial respiration in sperm ATP production and motility. We observed that in media containing a mitochondrial substrate (pyruvate or lactate) as the sole energy source, ATP levels and progressive motility in 129 KO sperm were similar to those in 129 WT sperm. However, when glucose was added, lactate was unable to maintain ATP levels or progressive motility in 129 KO sperm. The rate of respiration (ZO2) was high when 129 KO or WT sperm were incubated with lactate alone, but addition of glucose caused a reduction in ZO2. These results indicate that in the absence of glucose, 129 sperm can produce ATP via oxidative phosphorylation, but in the presence of glucose, oxidative phosphorylation is suppressed and the sperm utilize aerobic glycolysis, a phenomenon known as the Crabtree effect. PMID:23486916

Odet, Fanny; Gabel, Scott; London, Robert E; Goldberg, Erwin; Eddy, Edward M

2013-04-18

192

Ethanol extract of the leaves of Psidium guajava Linn enhances sperm output in healthy Wistar rats.  

PubMed

Reactive oxygen species (ROS), among other factors, have been implicated in the aetiology of male infertility. Thus, the roles of antioxidants at improving sperm production and quality are being investigated. The present study was designed to assess the effect of the ethanol extract of fresh leaves of Psidium guajava Linn. on the sperm parameters of healthy male Wistar rats. A total of 18 rats, weighing between 108-124 g, were divided into 3 groups of 6 animals each. Animals in groups 1 and 2 were administered 250 mg/kg/d and 500 mg/kg/d of guava leaf extract (GLE) orally for 53 days respectively. Group 3 animals received normal saline. Sperm count increased from 56.2+/-0.3 (x10(6)) in the control to 57.1+/-0.2 (x10(6)) in group 1 animals, and from 56.2+/-0.3 (x10(6)) in the control to 72.3+/-0.4 (x10(6)) in group 2 animals. Similarly, dose-dependent increases in the percentages of motile spermatozoa were observed in GLE-treated animals compared to the control group. These findings suggest that the extracts of the leaves of Psidium guajava Linn. possess beneficial effects on sperm production and quality, and may thus improve the sperm parameters of infertile males with oligospermia and nonobstructive azoospermia. PMID:19205576

Akinola, O B; Oladosu, O S; Dosumu, O O

2007-06-01

193

Cryopreservation of Sperm from the Endangered Colorado Pikeminnow  

USGS Publications Warehouse

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.

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

2004-01-01

194

Egg jelly proteins stimulate directed motility in Xenopus laevis sperm.  

PubMed

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. PMID:21692128

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

2011-06-01

195

Ion channels in sperm motility and capacitation.  

PubMed

Spermatozoa depend upon ion channels to rapidly exchange information with the outside world and to fertilise the egg. These efficient ion transporters participate in many of the most important sperm processes, such as motility and capacitation. It is well known that sperm swimming is regulated by [Ca2+]i. In the sea urchin sperm speract, a decapeptide isolated from egg outer envelope, induces changes in intracellular Ca2+ ([Ca2+]i), Na+, cAMP and cGMP, membrane potential (Em) and pH (pHi). Photoactivation of a speract analogue induces Ca2+ fluctuations that generate turns that are followed by straighter swimming paths. A fast component of the [Ca2+], increase that most likely occurs through voltage dependent Ca2+ channels (Ca(v)s) is essential for these turns. The Ca(v)s involved are modulated by the Em changes triggered by speract. On the other hand, mammalian sperm gain the ability to fertilise the egg after undergoing a series of physiological changes in the female tract. This maturational process, known as capacitation, encompasses increases in [Ca2+]i and pHi, as well as an Em hyperpolarization in mouse sperm. Our electrophysiological, immunological and molecular-biological experiments indicate that inwardly rectifying K+ channels regulated by ATP (KATP channels) and epithelial Na+ channels (ENaCs) are functionally present in mouse spermatogenic cells and sperm. Notably, pharmacological experiments indicate that the opening of KATP channels and closure of ENaCs may contribute to the hyperpolarization that accompanies mouse sperm capacitation. Remarkably, both in the sea urchin sperm speract response and in the mouse sperm capacitation, Em hyperpolarization seems necessary to remove inactivation from Ca(v) channels so they can then open. PMID:17644965

Darszon, A; Treviño, C L; Wood, C; Galindo, B; Rodríguez-Miranda, E; Acevedo, J J; Hernandez-González, E O; Beltrán, C; Martínez-López, P; Nishigaki, T

2007-01-01

196

Oxidative Stress in Zebrafish (Danio rerio) Sperm  

PubMed Central

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 cryopreserve a genetic line.

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

2012-01-01

197

Sperm motility: is viscosity fundamental to progress?  

PubMed

The success of internal fertilization is reliant upon successful sperm migration through the female tract. Timely location of the oocyte in what is a complex three-dimensional, highly invaginated series of moist opposed surfaces is a challenge at which only tens of sperm ever succeed. In part this could be due to the differences in scale, with a 50 µm long cell facing a probable migration of well over 20 cm due to the complex architecture. Many groups have focused upon the role for a chemotactic 'attractive egg' effect in guiding sperm to increase numbers at the fertilization site. What most research has neglected to consider is the role that the viscosity of the mucous layers, which coat the entire tract and through which sperm must swim, plays in both sperm selection and ongoing modulation of their behaviour. From allowing sperm to enter through the cervix during the ovulation phase, to denying them entrance through action of the female contraceptive pill, viscous effects are fundamental in controlling the migrating sperm population throughout the tract. The physiological effects of viscosity are also crucial to consider when designing and extrapolating data from in vitro experiments to the in vivo situation. PMID:21653751

Kirkman-Brown, Jackson C; Smith, David J

2011-06-08

198

Fish sperm cryopreservation in France: from laboratory studies to application in selective breeding programs  

Microsoft Academic Search

Application of sperm cryopreservation by the fish farming industry is still limited, despite great interest in optimising genetic resource conservation; limiting risks associated with horizontal disease transmission; increasing genetic progress; and accelerating genetic selection from prime specimens, as in other livestock production. Several factors are listed. With the aim of developing coherent broodstock selection programmes, SYSAAF (Union of the French

Pierrick Haffray; Catherine Labbe; Gérard MaIsse

199

Modernization and optimization of irrigation systems to increase water productivity  

Microsoft Academic Search

Population increase and the improvement of living standards brought about by development will result in a sharp increase in food demand during the next decades. Most of this increase will be met by the products of irrigated agriculture. At the same time, the water input per unit irrigated area will have to be reduced in response to water scarcity and

Enrique Playán; Luciano Mateos

2004-01-01

200

THEORETICAL ASSESSMENT OF POTENTIAL FOR INCREASING PRODUCTIVITY OF SUGARCANE THROUGH INCREASED NITROGEN FERTILISATION  

Microsoft Academic Search

The growth of sugarcane crops in an environment repre­ senting that of the Natal coastal belt was simulated on a computer to estimate the likely increases in productivity that could be obtained by increasing the supply of nitrogen (N) to the crop. Increased fertilisation should cause faster growth in leaf area and thus more rapid accumulation of dry matter in

I J. C. S. ALLISON; R. J. HASLAM

201

Decreasing Epididymal Sperm Reserves Enhances the Detection of Ethoxyethanol-Induced Spermatotoxicity.  

National Technical Information Service (NTIS)

Current test strategies for assessing male reproductive toxicity may be inadequate for estimating risk in humans. High levels of sperm production and existence of large epididymal sperm reserves in most test species may impede the detection of spermatoxic...

M. E. Hurtt H. Zenick

1986-01-01

202

Organophosphorous pesticide exposures and sperm quality.  

PubMed

Many Americans are exposed to low levels of organophosphorous (OP) pesticides. It 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

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

2010-09-17

203

Organophosphorous pesticide exposures and sperm quality  

PubMed Central

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.

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

2010-01-01

204

Effect of Mucuna pruriens on oxidative stress mediated damage in aged rat sperm.  

PubMed

Mucuna pruriens Linn., a leguminous plant, has been recognized as an aphrodisiac and spermatogenic agent. Protective efficacy of M. pruriens on reactive oxygen species (ROS)-induced pathophysiological alterations in structural and functional integrity of epididymal sperm in aged Wister albino rat was analysed. Animals were grouped as groups I, II, III and IV, i.e. young (control), aged, aged treated with ethanolic extract (200 mg/kg b.w.) of M. pruriens and young rats treated with M. pruriens, respectively. At the end of the experimental period, i.e. after 60 days animals were sacrificed, epididymal sperm were collected and subjected to count, viability, motility, morphology and morphometric analysis. Enzymatic and non-enzymatic antioxidants, ROS, lipid peroxidation (LPO), DNA damage, chromosomal integrity and mitochondrial membrane potential were estimated. Results obtained from the aged animals showed significant reduction in sperm count, viability and motility, increased morphological damage and an increase in the number of sperm with cytoplasmic remnant, and these alterations were significantly reversed in M. pruriens treated group. Significant increase in LPO, HO and H(2)O(2) production and significant decline in the levels of the enzymatic and non-enzymatic antioxidants were observed in the aged animals. Supplementation of M. pruriens significantly reduced ROS and LPO production and significant increase in both enzymatic and non-enzymatic antioxidant levels. There were significant DNA damage, loss of chromosomal integrity and increase in mitochondrial membrane permeability in aged rat sperm. This was significantly reduced in group III. Present observation indicates the antioxidant enhancing property, free radical quenching ability and spermatogenic efficacy of the M. pruriens. Collectively, sperm damage in ageing was significantly reduced by quenching ROS, improving antioxidant defence system and mitochondrial function. PMID:19207619

Suresh, Sekar; Prithiviraj, Elumalai; Prakash, Seppan

2009-01-08

205

The Marketing Challenge. Distributing Increased Production in Developing Nations.  

National Technical Information Service (NTIS)

Inadequate transportation and storage, poor market information, lack of capital, and other chronic marketing problems in developing countries have been dramatized by recent production increases. The document is based on a symposium which was organized to ...

M. Kriesberg

1970-01-01

206

Sperm competition risk generates phenotypic plasticity in ovum fertilizability.  

PubMed

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

Firman, Renée C; Simmons, Leigh W

2013-10-16

207

Cellular Stretch Increases Superoxide Production in the Thick Ascending Limb  

PubMed Central

Superoxide (O2?) is an important regulator of kidney function. We have recently shown that luminal flow stimulates O2? production in the thick ascending limb (TAL), attributable in part to mechanical factors. Stretch, pressure and shear stress all change when flow increases in the TAL. We hypothesized that stretch rather than shear stress or pressure per se stimulates O2? production by TALs. We measured O2? production in isolated perfused rat TALs using fluorescence microscopy and dihydroethidium. Tubules were perfused with a Na-free solution to eliminate the confounding effect of Na transport. Flow induced an increase in O2? production from 29±4 to 90±8 AU/s (P<0.002; n=5). The response to flow is rapidly reversible. O2? production by TALs perfused at 10 nL/min decreased from 113±6 to 25±10 AU/s (P<0.003; n=4) 15 minutes after flow was stopped. Increasing pressure and stretch in the absence of shear stress caused a significant increase in O2? production (40±6 to 118±17 AU/s; P<0.02; n=5). In contrast, eliminating shear stress had no effect (107±9 versus 108±10 AU/s; n=5). Increasing stretch by 27±2% in the presence of flow while reducing pressure stimulated O2? production from 66±7 to 84±9 AU/s (29±8%; P<0.02; n=5). Tempol inhibited this increase (n=5). We conclude that increasing stretch rather than pressure or shear stress accounts for the mechanical aspect of flow-induced O2? production in the TAL. Stretch of the TAL during hypertension, diabetes, and salt loading may contribute to renal damage.

Garvin, Jeffrey L.; Hong, Nancy J.

2009-01-01

208

Aroclor 1254 induced oxidative stress and mitochondria mediated apoptosis in adult rat sperm in vitro.  

PubMed

Aroclor 1254, a commercial mixture of highly toxic environmental pollutant, is known to cause testicular toxicity. The present study was undertaken to delineate and elucidate the nature and the mechanism of action of Aroclor 1254 on rat sperm in vitro. Sperm of adult rat were incubated with 10(-9)M, 10(-8)M or 10(-7)M of Aroclor 1254 for 3h. Sperm motility was significantly decreased. Moreover, sperm viability, acrosome reaction and mitochondrial membrane potential (??m) were significantly decreased in a dose-related pattern. DNA integrity was significantly decreased at 10(-8)M and 10(-7)M of Aroclor 1254, while it did not show any significant change at 10(-9)M. Aroclor 1254 induced downstream events included cytochrome c release and caspase-3 activation, in a dose-related manner. ATP content was decreased while protein carbonyl content was significantly increased in a dose-related manner. The oxidative stress status was also assessed. Hydrogen peroxide (H2O2) production and lipid peroxidation (LPO) were significantly increased in a dose-related pattern. The antioxidant enzymes SOD, CAT and GPx were significantly decreased, while at a concentration of 10(-9)M of Aroclor 1254, GR activity did not show any significant change. The non-enzymatic antioxidant (GSH) was significantly decreased in a dose-dependent manner. In conclusion; our data clearly show that Aroclor 1254 induces toxicity, oxidative stress and culminating in mitochondria mediated apoptosis in rat sperm. PMID:23686007

Aly, Hamdy A A

2013-04-23

209

Increasing children's ASL classifier production: a multicomponent intervention.  

PubMed

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 multiple-baseline-across-participants design, was followed by visual analysis and calculation of the percentage of non-overlapping data (Scruggs, Mastropieri, & Casto, 1987). Following the intervention, most students increased specific elements within their classifier production during narrative retells of stories they had watched and showed improved performance from pre- to postintervention measures. Picture support and fading of teacher mediation during retells variably affected classifier production. The results suggest that students may benefit from tailored intervention, including repeated viewings of ASL models paired with teacher mediation and possibly picture support, to increase classifier production during narrative retells. PMID:24133957

Beal-Alvarez, Jennifer S; Easterbrooks, Susan R

2013-01-01

210

Comparison of FACSCount AF system, Improved Neubauer hemocytometer, Corning 254 photometer, SpermVision, UltiMate and NucleoCounter SP100 for determination of sperm concentration of boar semen  

Microsoft Academic Search

Current research aims at reducing the number of sperm per insemination dose thereby making measurement of sperm concentration in raw semen and the production of uniform insemination doses much more crucial.The present study evaluated the determination of sperm concentration using FACSCount AF System (FACS), Improved Neubauer hemocytometer (HEMO), Corning 254 photometer (Photo C254), SpermVision CASA System (SpermVision), UltiMate CASA System

C. Hansen; T. Vermeiden; J. P. W. Vermeiden; C. Simmet; B. C. Day; H. Feitsma

2006-01-01

211

Mammalian Sperm Motility: Observation and Theory  

NASA Astrophysics Data System (ADS)

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.

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

2011-01-01

212

Feeding strategies to increase small ruminant production in dry environments  

Microsoft Academic Search

In the low-rainfall areas of much of Africa and Asia, small ruminants represent the principal economic output, contributing a large share of the income of farmers. Animal numbers have increased over the last two decades, driven by a rising demand for animal products and subsidized feed price (e.g. barley, maize). Side effects of this and changing climatic patterns are increasing

H. Ben Salem; T. Smith

2008-01-01

213

Methods for sperm concentration determination.  

PubMed

Proper assessment of the number of spermatozoa is essential not only as an initial step in every clinical infertility investigation [Björndahl et al (2010) A practical guide to basic laboratory andrology, 1st edn. Cambridge University Press, Cambridge] but also when attempting to establish the total sperm production in the testis [Amann (Hum Reprod 25:22-28, 2010); Amann (J Androl 30:626-641, 2009); Amann and Chapman (J Androl 30:642-649, 2009)]. Reliable methods combined with an understanding of the specific physiology involved as well as the main sources of errors related to the assessment of sperm concentration are critical for ensuring accurate concentration determination [Björndahl et al (2010) A practical guide to basic laboratory andrology, 1st edn. Cambridge University Press, Cambridge; World Health Organization (2010) WHO laboratory manual for the examination and processing of human semen. WHO, Geneva]. This chapter therefore focuses on these three aspects. PMID:22992898

Björndahl, Lars

2013-01-01

214

Assay of sperm motility to study the effects of metal ions  

SciTech Connect

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.

Timourian, H.; Watchmaker, G.

1984-01-01

215

Family of sperm associated antigens: relevance in sperm-egg interaction and immunocontraception.  

PubMed

Overpopulation is a global problem of significant magnitude, with grave implications for the future. Development of new contraceptives is necessary, since current forms of birth control are unavailable, impractical and/or too expensive to many individuals due to sociological, financial, or educational limitations. A novel contraceptive strategy that is receiving considerable attention is that of immunocontraception. The targeting of antibodies to gamete-specific antigens implicated in sperm function, sperm-egg binding and fertilization offers an attractive approach to the growing global problem of over population. The sermatozoon has proteins that are unique, cell specific, immunogenic and accessible to antibodies. Immunological interaction with such molecules can cause block of sperm binding to the oocyte and thus fertilization. Modern biotechnologies (such as sperm proteomics, the determination of molecular and structural details of sperm proteins, and the modelling of protein-ligand interaction using X-ray and/or NMR structures to name a few) are trying to make intervention into the domain of human reproduction possible through the development of a variety of new methods and products to control fertility. The present article highlights the various sperm associated antigens involved in various aspects of sperm-egg interaction. PMID:17566289

Suri, A

2007-01-01

216

Increased Ethylene Production during Clinostat Experiments May Cause Leaf Epinasty.  

PubMed

Ethylene production from tomato (Lycopersicum esculentum L. cv. Rutgers) plants based on a clinostat doubled during the first 2 hours of rotation. Carbon dioxide blocked the appearance of leaf epinasty normally associated with plants rotated on a clinostat. These results support the idea that epinasty of clinostated plants was due to increased ethylene production and not to the cancellation of the gravitational pull on auxin transport in the petiole. PMID:16657920

Leather, G R; Forrence, L E

1972-02-01

217

Effects of molybdenum on sperm quality and testis oxidative stress.  

PubMed

In order to investigate the effects of molybdenum (Mo) on sperm parameters and testicular oxidative stress, the ICR strain of adult mice were exposed to different doses of molybdenum for a sub-acute toxicity test. Compared to the control, our results showed that the sperm parameters, including the epididymis index, sperm motility, sperm count, and morphology, increased by a moderate dose of Mo (25?mg/L), but were negatively affected at high doses (? 100?mg/L). In addition, the changes of sperm parameters were accompanied with changes of the superoxide dismutase (SOD) activities, the glutathione peroxidase (GPx) activities, and the malondialdehyde (MDA) levels in testes. In conclusion, Mo affects the sperm quality through regulating the testicular oxidative stress in a complex manner. PMID:23651332

Zhai, Xiao-Wei; Zhang, Yu-Ling; Qi, Qiao; Bai, Yu; Chen, Xiao-Li; Jin, Li-Jun; Ma, Xue-Gang; Shu, Run-Zhe; Yang, Zi-Jun; Liu, Feng-Jun

2013-05-08

218

Metabolism of motile zebrafish sperm  

Microsoft Academic Search

As metabolism of motile fish sperm is not well understood, the current study examined the metabolism of saline-activated zebrafish (Danio rerio) sperm. Activation of sperm with inhibitors of oxidative phosphorylation (potassium cyanide, 2,4 dinitrophenol or carbonyl cyanide 3-cholorophenylhydrazone) negatively impacted sperm motility by 60–90s postactivation. Incubation of quiescent sperm with 2,4 dinitrophenol prior to activation resulted in a 67% decrease

R. L. Ingermann; C. L. F. Schultz; M. K. Kanuga; J. G. Wilson-Leedy

2011-01-01

219

Towards a physiological role for cytochrome P450 aromatase in ejaculated human sperm  

Microsoft Academic Search

BACKGROUND: Advances in the definition of the function and the mechanism of estrogen action in different tis- sues have come from human and animal models of estrogen insufficiency. Recently we have demonstrated that aromatase is present and biologically active in human ejaculated sperm, suggesting that autonomous estradiol sperm production may influence sperm functions. In the present study we investigate a

Saveria Aquila; Diego Sisci; Mariaelena Gentile; Amalia Carpino; Emilia Middea; Stefania Catalano; Vittoria Rago

2003-01-01

220

Tuning sperm chemotaxis by calcium burst timing.  

PubMed

Marine invertebrate oocytes establish chemoattractant gradients that guide spermatozoa towards their source. In sea urchin spermatozoa, this relocation requires coordinated motility changes initiated by Ca(2+)-driven alterations in sperm flagellar curvature. We discovered that Lytechinus pictus spermatozoa undergo chemotaxis in response to speract, an egg-derived decapeptide previously noted to stimulate non-chemotactic motility alterations in Strongylocentrotus purpuratus spermatozoa. Sperm of both species responded to speract gradients with a sequence of turning episodes that correlate with transient flagellar Ca(2+) increases, yet only L. pictus spermatozoa accumulated at the gradient source. Detailed analysis of sperm behavior revealed that L. pictus spermatozoa selectively undergo Ca(2+) fluctuations while swimming along negative speract gradients while S. purpuratus sperm generate Ca(2+) fluctuations in a spatially non-selective manner. This difference is attributed to the selective suppression of Ca(2+) fluctuations of L. pictus spermatozoa as they swim towards the source of the chemoattractant gradient. This is the first study to compare and characterize the motility components that differ in chemotactic and non-chemotactic spermatozoa. Tuning of Ca(2+) fluctuations and associated turning episodes to the chemoattractant gradient polarity is a central feature of sea urchin sperm chemotaxis and may be a feature of sperm chemotaxis in general. PMID:20435032

Guerrero, Adan; Nishigaki, Takuya; Carneiro, Jorge; Yoshiro Tatsu; Wood, Christopher D; Darszon, Alberto

2010-05-16

221

Sperm plasma membrane damage prior to intracytoplasmic sperm injection: a necessary condition for sperm nucleus decondensation.  

PubMed

In the present study we investigated the relevance of sperm immobilization prior to intracytoplasmic sperm injection (ICSI) in the fertilization process. Using supravital staining of the spermatozoa with eosin and studying sperm decondensation with 2 mM dithiothreitol (DTT) in conditions imitating sperm handling during ICSI, we demonstrated that immobilization of the spermatozoon by squeezing its tail between the glass pipette and the bottom of the dish damages the sperm plasma membrane. Polyvinylpyrrolidone (PVP), which is usually present in the drop with the spermatozoon to facilitate its handling, was found to impede the access of both eosin and DTT to the sperm nucleus. We conclude that (i) sperm immobilization prior to ICSI damages the sperm plasma membrane, that (ii) this damage is sufficient for thiol-reducing agents to gain access to the sperm nucleus, and finally that (iii) PVP possibly interferes with sperm nucleus decondensation. PMID:8747054

Dozortsev, D; Rybouchkin, A; De Sutter, P; Dhont, M

1995-11-01

222

Positive feedback between increasing atmospheric CO2 and ecosystem productivity  

NASA Astrophysics Data System (ADS)

Increasing atmospheric CO2 will likely affect both the hydrologic cycle and ecosystem productivity. Current assumptions that increasing CO2 will lead to increased ecosystem productivity and plant water use efficiency (WUE) are driving optimistic predictions of higher crop yields as well as greater availability of freshwater resources due to a decrease in evapotranspiration. The plant physiological response that drives these effects is believed to be an increase in carbon uptake either by (a) stronger CO2 gradient between the stomata and the atmosphere, or by (b) reduced CO2 limitation of enzymatic carboxylation within the leaf. The (a) scenario will lead to increased water use efficiency (WUE) in plants. However, evidence for increased WUE is mostly based on modeling studies, and experiments producing a short duration or step-wise increase in CO2 concentration (e.g. free-air CO2 enrichment). We hypothesize that the increase in atmospheric CO2 concentration is having a positive effect on ecosystem productivity and WUE. To investigate this hypothesis, we analyzed meteorological, ANPP, and soil CO2 flux datasets together with carbon isotopic ratio (13C/12C) of archived plant samples from the long term ecological research (LTER) program at Kellogg Biological Station. The datasets were collected between 1989 and 2007 (corresponding to an increase in atmospheric CO2 concentration of ~33 ppmv at Mauna Loa). Wheat (Triticum aestivum) samples taken from 1989 and 2007 show a significant decrease in the C isotope discrimination factor (?) over time. Stomatal conductance is directly related to ?, and thus ? is inversely related to plant intrinsic WUE (iWUE). Historical changes in the 13C/12C ratio (?13C) in samples of a perennial forb, Canada goldenrod (Solidago canadensis), taken from adjacent successional fields, indicate changes in ? upon uptake of CO2 as well. These temporal trends in ? suggest a positive feedback between the increasing CO2 concentration in the atmosphere, air temperature, and plant iWUE. This positive feedback is expressed by (a) nonparallel changes of ?13C signal of atmospheric CO2 (?a) and plant samples (?p), (b) negative correlation between the ? and average temperatures during the growth season, although only for temperatures up to 21°C. The lack of effect at higher temperatures suggests a negative influence of growing season warming on the iWUE. These results suggest a complex feedback between atmospheric CO2 increase, plant physiology, ecosystem productivity, and soil CO2 fluxes. These complex effects support our hypothesis of a CO2 fertilization effect on plant productivity, and they raise additional questions regarding adaptation of plants to changing atmospheric CO2 and climate.

Gelfand, I.; Hamilton, S. K.; Robertson, G. P.

2009-12-01

223

Breeding Technologies to Increase Crop Production in a Changing World  

NSDL National Science Digital Library

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. Crop improvement through breeding brings immense value relative to investment and offers an effective approach to improving food security.

Mark Tester (University of Adelaide;); Peter Langridge (University of Adelaide;)

2010-02-12

224

The potential for suspension feeding bivalves to increase seagrass productivity  

Microsoft Academic Search

Suspension feeding bivalves are commonly associated with seagrass habitats in the Gulf of Mexico and Caribbean Sea. Biodeposits of some suspension feeding bivalves have been shown to be high in nitrogen and phosphorus. Consequently, filter feeding bivalves may act as a bentho-pelagic couple bringing planktonic production to the benthos, thereby elevating submerged aquatic vegetation growth by increasing the nutrients available

Bradley J. Peterson; Kenneth L. Heck

1999-01-01

225

Process for increasing deasphalted oil production from upgraded residua  

Microsoft Academic Search

This patent describes a process for increasing the production of deasphalted oil from a hydrocarbon feedstock comprising the steps of: (a) passing the hydrocarbon feedstock into a first distillation zone where the feedstock is separated into distillates and a first residuum; (b) passing the first residuum into a hydrotreating zone operating between about 315C to 425C, at an absolute pressure

D. J. Bristow; B. U. Achia; L. J. Evers

1987-01-01

226

Pretreatment of date syrup to increase citric acid production  

Microsoft Academic Search

Pretreatment of date syrup with sulfuric acid, tricalcium phosphate, tricalcium phosphate with hydrochloric acid, potassium ferrocyanide, and EDTA to increase the production of citric acid was investigated. Among the above techniques used for the removal of heavy metals, 2% tricalcium phosphate treatment gave better results regarding citric acid concentration (55 ± 1.5 g l?1), citric acid yield (50 ± 1.5%),

T. Roukas; P. Kotzekidou

1997-01-01

227

Rainfall concentration for increasing corn production under semiarid climate  

Microsoft Academic Search

The ridge and furrow farming of rainfall concentration (RC) system is being promoted to increase water availability to crops for improving and stabilizing agricultural production in the semiarid Loess region of northwest China. In the system, plastic-covered ridges serve as rainfall harvesting zones and furrows serve as planting zones. In recent years, however, the current RC practices are still confined

Xiaolong Ren; Zhikuan Jia; Xiaoli Chen

2008-01-01

228

Increasing Loyalty to Breastfeeding: Investigating a Product Development Strategy  

Microsoft Academic Search

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

Joy Parkinson; Rebekah Russell-Bennett; Josephine Previte

2012-01-01

229

Using brain skill assessments to increase productivity in development administration  

Microsoft Academic Search

This article describes how brain skill assessments can be used in developing countries to increase organizational productivity. Three broad styles (left, right and integrative) are first identified and described. Then the article explains how brain style assessments can be specifically used to help solve many typical organizational management problems such as organizing cross-cultural groups to implement programs effectively.

Weston H. Agor

1984-01-01

230

Finch, Pruyn cleans air and water while increasing steam production  

SciTech Connect

It is shown how a paper manufacturing company in Glens Falls, NY, employs primary and secondary water-treatment plants, chemical recovery from SO/sub 2/ -laden flue gas, a bark boiler, and waste-liquor boilers to balance the conflicting demands of a changing market, increasing power needs, stringent, pollution regulations, higher fuel costs, and limited production space.

Reason, J.; Bauer, P.; Makansi, J.

1981-11-01

231

Pretreatment of beet molasses to increase pullulan production  

Microsoft Academic Search

Pretreatment of beet molasses with cation exchange resin, sulphuric acid, tricalcium phosphate, potassium ferrocyanide, and ethylenediaminetetraacetic acid and disodium salt (EDTA) to increase the production of pullulan was investigated. Among the above techniques used for the removal of heavy metals, sulphuric acid treatment gave better results regarding polysaccharide concentration, polysaccharide yield, and sugar utilization. Aureobasidium pullulans grown on beet molasses

T. Roukas

1998-01-01

232

Increasing Dominance - the Role of Advertising, Pricing and Product Design  

Microsoft Academic Search

Despite the empirical relevance of advertising strategies in concentrated markets, the economics literature is largely silent on the effect of persuasive advertising strategies on pricing, market structure and increasing (or decreasing) dominance. In a simple model of persuasive advertising and pricing with differentiated goods, we analyze the interdependencies between ex-ante asymmetries in consumer appeal, advertising and prices. Products with larger

Tobias Kretschmer; Mariana Rösner

2010-01-01

233

How to evaluate productivity increase after vertical fracturing  

Microsoft Academic Search

Most methods of evaluating the productivity increase after vertical fracturing assumes that the fracture extends from top to bottom of the reservoir formation and that the propped height equals the created height. Field studies have shown that the propping agent is distributed in a vertical fracture until an equilibrium height is reached, after which all additional sand injected is washed

Kotb

1967-01-01

234

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

PubMed

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. PMID:19150124

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

2009-01-15

235

Early persistent activation of sperm K+ channels by the egg peptide speract.  

PubMed

Transduction by sperm of the instructive signal provided by the egg peptide speract involves rapid, complex changes in internal ion and cyclic nucleotide content. Here, investigations of hypotonically swollen sperm provide insight into the underlying processes and identify K+ channel activation as an initial ionic event in gamete recognition. A sustained hyperpolarization of swollen sperm is promoted by less than 2.5 pM speract and is followed (with greater than 100 pM speract) by transient repolarization and (with greater than 10 nM speract) by depolarization that is dependent on external Ca2+. Monophasic increases in pHi are produced only by greater than 25 pM speract, indicating that hyperpolarization may not directly promote alkalinization. Increased K(+)-selective (K+ greater than Rb+ greater than Cs+ greater than Na+) membrane permeability is found after all speract greater than 2.5 pM, suggesting that hyperpolarization results from persistent activation of K+ channels and that repolarization has a different ionic basis. Supporting this contention, the K+ channel blocker tetraethylammonium (20 mM) inhibits the increased K+ permeability that follows treatment of swollen sperm (and of sperm in seawater) with 2.5 pM speract. Such induced activation of K+ channels is observed in patch-clamped swollen sperm examined in the cell-attached configuration, upon application of 5-50 pM speract to the bath medium. The efficacy of externally applied speract and its potency indicate that activation is indirect and probably involves an as yet unidentified diffusible mediator whose production is promoted by speract at concentrations 0.01-0.001 times those predicted from reported estimates of the Kd for the known speract receptor. PMID:1631086

Babcock, D F; Bosma, M M; Battaglia, D E; Darszon, A

1992-07-01

236

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

PubMed

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. PMID:23940385

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

2013-10-01

237

Sperm Whale Population Analysis.  

National Technical Information Service (NTIS)

Techniques which have been used to analyze whale populations and the resulting understanding of the sperm whale population of the North Pacific have been based on population estimates which are biased. Where variability is important to the understanding o...

C. W. Fowler R. J. Ryel L. J. Nelson

1982-01-01

238

Sperm Quality Control  

NSDL National Science Digital Library

New research from the University of Missouri-Columbia suggests how defective sperm are tagged for destruction. This 57 second audio recording from Science Update originally aired on Monday, February 11, 2008.

Science Update (AAAS;)

2008-05-06

239

Sperm Chromatin: An Overview  

Microsoft Academic Search

\\u000a The dramatic changes in the structure and function of sperm chromatin that occur during spermatogenesis have continued to\\u000a intrigue researchers for more than a century. In addition to wanting to understand how these changes in chromatin organization\\u000a affect genome function, many of the studies conducted in placental mammals have been driven by a desire to understand the\\u000a relationship between sperm

Rod Balhorn

240

Centrifugation on Percoll density gradient enhances motility, membrane integrity and in vitro fertilizing ability of frozen-thawed boar sperm.  

PubMed

Summary The effects of Percoll density gradient centrifugation on sperm quality, in vitro fertilizability and developmental capacity of frozen-thawed boar sperm were evaluated. Two-step density gradient centrifugation by Percoll enhanced significantly the motility parameters of sperm compared with a simple centrifugation procedure. Percentages of motile sperm and sperm with intact plasma and acrosome membranes after Percoll separation were significantly greater than those after simple centrifugation. The rates of penetration, cleavage and blastocyst formation after in vitro fertilization were significantly improved by Percoll separation compared with simple centrifugation and were influenced positively by the intactness of sperm head membranes, but not any sperm motility parameters. However, insemination with increased concentrations of sperm prepared by Percoll gradient centrifugation did not improve the success of fertilization and embryo development in vitro. Our results indicate that the integrity of sperm head membranes after Percoll separation is important for successful embryo development in vitro, more so than sperm motility. PMID:23659202

Noguchi, Michiko; Yoshioka, Koji; Hikono, Hirokazu; Iwagami, Gentaro; Suzuki, Chie; Kikuchi, Kazuhiro

2013-05-01

241

Female promiscuity promotes the evolution of faster sperm in cichlid fishes  

PubMed Central

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.

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

2009-01-01

242

Mouse sperm desiccated and stored in trehalose medium without freezing.  

PubMed

Mouse sperm with and without trehalose were desiccated under nitrogen gas and stored at 4 degrees C and 22 degrees C. After rehydration, sperm were injected into oocytes using intracytoplasmic sperm injection and embryonic development was followed. Sperm were dried for 5.0, 6.25, or 7.5 min, stored at 22 degrees C for 1 wk with and without trehalose. The percentages of blastocysts that developed from sperm with trehalose were 51%, 31%, and 20%, respectively, which was significantly higher than sperm without trehalose (10%, 3%, and 5%, respectively). Desiccation and storage in medium with trehalose significantly increased sperm developmental potential compared to medium without trehalose. Sperm dried for 5 min produced more blastocysts than sperm dried for 6.25 or 7.5 min. When sperm were dried in trehalose for 5 min and stored for 1 wk, 2 wk, 1 mo, or 3 mo at 4 degrees C, the percentages of blastocysts were 73%, 84%, 63%, and 39%; whereas those stored at 22 degrees C for 1 wk, 2 wk, or 1 mo were significantly lower (53%, 17%, and 6%, respectively). Embryos from sperm partially desiccated in trehalose for 5 min and stored at 4 degrees C for 1 or 3 mo were transferred to 10 pseudopregnant recipients. Implantation rates were 81% and 48%; live fetuses were 26% and 5%, respectively. One of the recipients delivered three live fetuses. The results show that trehalose has a significant beneficial effect in preserving the developmental potential of mouse sperm following partial desiccation and storage at temperatures above freezing. PMID:15930320

McGinnis, Lynda K; Zhu, Liben; Lawitts, Joel A; Bhowmick, Sankha; Toner, Mehmet; Biggers, John D

2005-06-01

243

Immune Activation Reduces Sperm Quality in the Great Tit  

PubMed Central

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.

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

2011-01-01

244

Seasonal functional relevance of sperm characteristics in equine spermatozoa.  

PubMed

A group of stallions with different reproductive indexes were used to study seasonal variations in sperm quality (Equus caballus). Semen samples were collected from late September to July and analyzed according to four seasonal periods: late September-December, January-March, late March-May, and June-July. Parameters monitored included sperm concentration, sperm motility, sperm morphology, sperm viability, acrosomal status, plasma membrane stability, and sperm mitochondrial membrane potential. Overall, seminal parameters monitored are affected mostly by time period, followed by animal and lastly by fertility, stressing the importance of individual variations in out-bred animal models. The analysis of multiple ejaculates from the same animals showed clear seasonal-based differences (P<0.05) with poor semen quality in winter and a noticeable improvement in sperm quality with increasing photoperiod. Better semen quality was observed between late March and May. Interactions between month period, animal, and fertility were evident (P<0.05) for sperm concentration, head and tail sperm anomalies, and acrosomal integrity. Thus, it may be advisable to adjust the use of stallion semen according to seasonal variations. PMID:20083300

Gamboa, S; Rodrigues, A S; Henriques, L; Batista, C; Ramalho-Santos, J

2010-01-18

245

An efficient method of guinea fowl sperm cryopreservation.  

PubMed

France is the only country that practices pedigree selection of guinea fowl for meat production. The increasing risk of line extinction for sanitary or breeding failure reasons makes clear the need for an efficient method of reproductive cell cryopreservation in this species. However, an efficient method of guinea fowl sperm freezing in secured packaging is still lacking. The aim of the present study was to develop such a method. Based on results previously obtained in chickens, different cryoprotectants and freezing/thawing processes were tested and then adapted to guinea fowl. Semen quality was measured by semen viability evaluation and then by fertility measured after intravaginal artificial insemination. The best results (70% fertility with frozen-thawed sperm) were obtained by the use of the permeant cryoprotectant agents dimethyl formamide combined with a freezing rate of 30°C/min. The initial insemination frequency also affected the fertility results: 2 consecutive days of inseminations were needed in the first week to ensure enough filling of the utero-vaginal glands of the guinea fowl hen and thus to get successive fertile eggs. Thereafter, a 2-wk insemination frequency was sufficient. This new method, combining biophysical (cryoprotectant agents, freeze/thaw rate) and zootechnical (artificial insemination frequency) features, is the first cryopreservation method successfully developed in secured packaging for guinea fowl sperm. This method is now available for the practice of gene bank conservation and male reproductive management. PMID:24135603

Seigneurin, F; Grasseau, I; Chapuis, H; Blesbois, E

2013-11-01

246

Inhibition of Prolyl Hydroxylases Increases Erythropoietin Production in ESRD  

PubMed Central

The reasons for inadequate production of erythropoietin (EPO) in patients with ESRD are poorly understood. A better understanding of EPO regulation, namely oxygen-dependent hydroxylation of the hypoxia-inducible transcription factor (HIF), may enable targeted pharmacological intervention. Here, we tested the ability of fibrotic kidneys and extrarenal tissues to produce EPO. In this phase 1 study, we used an orally active prolyl-hydroxylase inhibitor, FG-2216, to stabilize HIF independent of oxygen availability in 12 hemodialysis (HD) patients, six of whom were anephric, and in six healthy volunteers. FG-2216 increased plasma EPO levels 30.8-fold in HD patients with kidneys, 14.5-fold in anephric HD patients, and 12.7-fold in healthy volunteers. These data demonstrate that pharmacologic manipulation of the HIF system can stimulate endogenous EPO production. Furthermore, the data indicate that deranged oxygen sensing—not a loss of EPO production capacity—causes renal anemia.

Wiesener, Michael S.; Scigalla, Paul; Chou, James; Schmieder, Roland E.; Gunzler, Volkmar; Eckardt, Kai-Uwe

2010-01-01

247

The effect of interspecific oocytes on demethylation of sperm DNA  

Microsoft Academic Search

In contrast to mice, in sheep no genome-wide demethylation of the paternal genome occurs within the first postfertilization cell cycle. This difference could be due either to an absence of a sheep demethylase activity that is present in mouse ooplasm or to an increased protection of methylated cytosine residues in sheep sperm. Here, we use interspecies intracytoplasmic sperm injection to

Nathalie Beaujean; Jane E. Taylor; Michelle McGarry; John O. Gardner; Ian Wilmut; Pasqualino Loi; Grazyna Ptak; Cesare Galli; Giovanna Lazzari; Adrian Bird; Lorraine E. Young; Richard R. Meehan

2004-01-01

248

Programming adaptive control to evolve increased metabolite production.  

PubMed

The complexity inherent in biological systems challenges efforts to rationally engineer novel phenotypes, especially those not amenable to high-throughput screens and selections. In nature, increased mutation rates generate diversity in a population that can lead to the evolution of new phenotypes. Here we construct an adaptive control system that increases the mutation rate in order to generate diversity in the population, and decreases the mutation rate as the concentration of a target metabolite increases. This system is called feedback-regulated evolution of phenotype (FREP), and is implemented with a sensor to gauge the concentration of a metabolite and an actuator to alter the mutation rate. To evolve certain novel traits that have no known natural sensors, we develop a framework to assemble synthetic transcription factors using metabolic enzymes and construct four different sensors that recognize isopentenyl diphosphate in bacteria and yeast. We verify FREP by evolving increased tyrosine and isoprenoid production. PMID:24131951

Chou, Howard H; Keasling, Jay D

2013-01-01

249

Production of fertile unreduced sperm by hybrid males of the Rutilus alburnoides complex (Teleostei, cyprinidae). An alternative route to genome tetraploidization in unisexuals.  

PubMed Central

The hybrid minnow Rutilus alburnoides comprises diploid and polyploid females and males. Previous studies revealed that diploid and triploid females exhibit altered oogenesis that does not involve random segregation and recombination of the genomes of the two ancestors, constituting unisexual lineages. In the present study, we investigated the reproductive mode of hybrid males from the Tejo basin, using experimental crosses and flow cytometric analysis of blood and sperm. The results suggest that diploid hybrids produced fertile unreduced sperm, transmitting their hybrid genome intact to offspring. Triploid hybrids also produced unreduced sperm, but it was not possible to obtain data concerning their fertility. Finally, tetraploid hybrids produced fertile diploid sperm, which exhibited Mendelian segregation. Tetraploid R. alburnoides may reestablish biparental reproduction, as individuals of both sexes with the appropriate constitution for normal meiosis (two haploid genomes from each parental species) are likely to occur in natural populations. Tetraploids probably have arisen from syngamy of diploid eggs and diploid sperm produced by diploid hybrid males. Diploid hybrid males may therefore play a significant role in the dynamics of the complex, starting the evolutionary process that may ultimately lead to a new sexually reproducing species.

Alves, M J; Coelho, M M; Prospero, M I; Collares-Pereira, M J

1999-01-01

250

Clinic Overbooking to Improve Patient Access and Increase Provider Productivity  

Microsoft Academic Search

The problem of patient no-shows (patients who do not arrive for scheduled appoint- ments) is significant in many health care settings, where no-show rates can vary widely. No-shows reduce provider productivity and clinic efficiency, increase health care costs, and limit the ability of a clinic to serve its client population by reducing its effective capacity. In this article, we examine

Linda R. LaGanga; Stephen R. Lawrence

2007-01-01

251

Evaluation of Oxidative DNA Damage in Human Sperm and Its Association with Male Infertility  

Microsoft Academic Search

Recently, there is increasing evidence suggesting that oxidative sperm DNA damage is closely associated with impaired sperm function and male infertility. 8-Hydroxydeoxyguanosine (8- OHdG) is considered to be a precise and sensitive biomarker of oxidative DNA damage. The present study was thus designed to evaluate the extent of oxidative DNA damage in sperm and its as- sociation with male infertility

HAN-MING SHEN; SIN-ENG CHIA; CHOON-NAM ONG

252

Andrology Lab Corner* The Clinical Implementation of Sperm Chromosome Aneuploidy Testing: Pitfalls and Promises  

Microsoft Academic Search

Severe male infertility has been shown to be associated with improper meiotic recombination and elevated sperm chromosome aneuploidy. Elevated sperm aneuploidy increases the risk of embryo lethality or fetal anomalies. Although difficulties in interpreting aneuploidy data still exist, advances in fluorescent in situ hybridization (FISH) technology have facilitated the study of sperm from patients with severe spermatogenesis defects, which has

DOUGLAS T. CARRELL

253

A cAMP Regulated K +Selective Channel from the Sea Urchin Sperm Plasma Membrane  

Microsoft Academic Search

Ion channels are deeply involved in sperm physiology. In sea urchin sperm cyclic nucleotide levels increase during quimotaxis and in the acrosome reaction (AR). Although cyclic nucleotides are second messengers known to directly or indirectly modulate ion channels, it is not clear how they modulate sperm responses to the egg outer layer. Here, we describe a cAMP regulated K+-selective channel

Pedro Labarca; Celia Santi; Otilia Zapata; Ezequiel Morales; Carmen Beltrán; Arturo Liévano; Alberto Darszon

1996-01-01

254

Sperm competition as a mechanism of female choice in the field cricket, Gryllus bimaculatus  

Microsoft Academic Search

While traditionally viewed as an extension of intermale competition, mechanisms of sperm competition may be used by multiply mating females for mate choice. In the field cricket G. bimaculatus sperm were shown to mix in the spermatheca. The proportion of offspring sired by the second male increased with spermatophore attachment duration and, therefore, the number of sperm transferred. There was

L. W. Simmons

1987-01-01

255

Role of Carbonic Anhydrase IV in the Bicarbonate-Mediated Activation of Murine and Human Sperm  

Microsoft Academic Search

HCO3? is the signal for early activation of sperm motility. In vivo, this occurs when sperm come into contact with the HCO3? containing fluids in the reproductive tract. The activated motility enables sperm to travel the long distance to the ovum. In spermatozoa HCO3? stimulates the atypical sperm adenylyl cyclase (sAC) to promote the cAMP-mediated pathway that increases flagellar beat

Petra M. Wandernoth; Michael Raubuch; Nadja Mannowetz; Holger M. Becker; Joachim W. Deitmer; William S. Sly; Gunther Wennemuth; Rafael Linden

2010-01-01

256

Quantification of mammalian sperm morphology by slit-scan flow cytometry  

SciTech Connect

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.

Benaron, D.A.; Gray, J.W.; Gledhill, B.L.; Lake, S.; Wyrobek, A.J.; Young, I.T.

1982-03-01

257

Zymomonas mobilis mutants with an increased rate of alcohol production  

SciTech Connect

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.

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

1987-07-01

258

Flow-cytometric analyses of viability biomarkers in pesticide-exposed sperm of three aquatic invertebrates.  

PubMed

Toxicity studies on sperm often use fertilization success as the end point. This type of assay can be affected by sperm density, egg quality, and sperm-egg compatibility. Testing sperm viability biomarkers with flow cytometry is a fast, high-throughput technique for seminal analysis. In this study, we detected sperm viability biomarkers with several fluorescent reporter dyes using flow cytometry in three aquatic invertebrates (Crassostrea virginica, Dreissena polymorpha, and Lytechinus variegatus) after exposure to a pesticide and herbicide. The pesticide, Bayluscide, appeared to affect mitochondrial membrane potential in the sperm of all three species, as measured with MitoTracker Red CMXRos. A decrease in the percentage of sperm stained with SYBR-14 (indicating uncompromised plasma membrane) was observed in C. virginica and D. polymorpha sperm exposed to Bayluscide, but propidium iodide staining (indicating compromised plasma membranes) appeared to be inhibited by Bayluscide. Acrosome-reacted sperm, as measured by FITC-PNA, decreased after Bayluscide exposure in C. virginica and D. polymorpha sperm. The herbicide, Roundup Ready To-Use-Plus, did not affect the overall percentages of sperm stained with MitoTracker but did cause an increase in MitoTracker fluorescence intensity at 16 mg/L in D. polymorpha. Roundup also caused significant decreases in SYBR-14 staining, significant increases in propidium iodide staining, and significant increases in FITC-PNA staining in D. polymorpha sperm. By not having to rely on egg availability and optimal sperm density, sperm toxicity can be more accurately assessed with flow cytometry as being directly correlated to sperm viability rather than the possibility of altered toxicity results due to sperm-to-egg compatibility. PMID:19876686

Favret, Karen P; Lynn, John W

2009-10-30

259

Laboratory processing and intracytoplasmic sperm injection using epididymal and testicular spermatozoa: what can be done to improve outcomes?  

PubMed Central

There are two main reasons why sperm may be absent from semen. Obstructive azoospermia is the result of a blockage in the male reproductive tract; in this case, sperm are produced in the testicle but are trapped in the epididymis. Non-obstructive azoospermia is the result of severely impaired or non-existent sperm production. There are three different sperm-harvesting procedures that obstructive azoospermic males can undergo, namely MESA (microsurgical epididymal sperm aspiration), PESA (percutaneous epididymal sperm aspiration), and TESA (testicular sperm aspiration). These three procedures are performed by fine-gauge needle aspiration of epididymal fluid that is examined by an embryologist. Additionally, one technique, called TESE (testicular sperm extraction), is offered for males with non-obstructive azoospermia. In this procedure, a urologist extracts a piece of tissue from the testis. Then, an embryologist minces the tissue and uses a microscope to locate sperm. Finding sperm in the testicular tissue can be a laborious 2- to 3-hour process depending on the degree of sperm production and the etiology of testicular failure. Sperm are freed from within the seminiferous tubules and then dissected from the surrounding testicular tissue. It is specifically these situations that require advanced reproductive techniques, such as ICSI, to establish a pregnancy. This review describes eight different lab processing techniques that an embryologist can use to harvest sperm. Additionally, sperm cryopreservation, which allows patients to undergo multiple ICSI cycles without the need for additional surgeries, will also be discussed.

Popal, Wana; Nagy, Zsolt P

2013-01-01

260

Thyrotropin Receptor Activation Increases Hyaluronan Production in Preadipocyte Fibroblasts  

PubMed Central

The thyrotropin receptor (TSHR) is expressed during lineage-specific differentiation (e.g. adipogenesis) and is activated by TSH, thyroid-stimulating antibodies, and gain-of-function mutations (TSHR*). Comparison of gene expression profiles of nonmodified human preadipocytes (n = 4) with the parallel TSHR* population revealed significant up-regulation of 27 genes including hyaluronan (HA) synthases (HAS) 1 and 2. The array data were confirmed by quantitative PCR of HAS1 and HAS2 and enzyme-linked immunosorbent assay measurement of HA; all values were significantly increased (p < 0.03) in TSHR*-expressing preadipocytes (n = 10). Preadipocytes (n = 8) treated with dibutyryl (db)-cAMP display significantly increased HAS1 and HAS2 transcripts, HAS2 protein, and HA production (p < 0.02). HAS1 or HAS2 small interfering RNA treatment of db-cAMP-stimulated preadipocytes (n = 4) produced 80% knockdown in HAS1 or 61% knockdown in HAS2 transcripts (compared with scrambled), respectively; the corresponding HA production was reduced by 49 or 38%. Reporter assays using A293 cells transfected with HAS1 promoter-driven plasmids containing or not containing the proximal CRE and treated with db-cAMP revealed that it is functional. Chromatin immunoprecipitation, using a cAMP-responsive element-binding protein antibody, of db-cAMP-treated preadipocytes (n = 4) yielded products for HAS1 and HAS2 with relative fold increases of 3.3 ± 0.8 and 2.6 ± 0.9, respectively. HA accumulates in adipose/connective tissues of patients with thyroid dysfunction. We investigated the contributions of TSH and thyroid-stimulating antibodies and obtained small (9–24%) but significant (p < 0.02) increases in preadipocyte HA production with both ligands. Similar results were obtained with a TSHR monoclonal antibody lacking biological activity (p < 0.05). We conclude that TSHR activation is implicated in HA production in preadipocytes, which, along with thyroid hormone level variation, explains the HA overproduction in thyroid dysfunction.

Zhang, Lei; Bowen, Timothy; Grennan-Jones, Fiona; Paddon, Carol; Giles, Peter; Webber, Jason; Steadman, Robert; Ludgate, Marian

2009-01-01

261

Genetic diversity increases population productivity in a sessile marine invertebrate.  

PubMed

Reductions in genetic diversity can have widespread ecological consequences: populations with higher genetic diversity are more stable, productive and resistant to disturbance or disease than populations with lower genetic diversity. These ecological effects of genetic diversity differ from the more familiar evolutionary consequences of depleting genetic diversity, because ecological effects manifest within a single generation. If common, genetic diversity effects have the potential to change the way we view and manage populations, but our understanding of these effects is far from complete, and the role of genetic diversity in sexually reproducing animals remains unclear. Here, we examined the effects of genetic diversity in a sexually reproducing marine invertebrate in the field. We manipulated the genetic diversity of experimental populations and then measured individual survival, growth, and fecundity, as well as the size of offspring produced by individuals in high and low genetic diversity populations. Overall, we found greater genetic diversity increased performance across all metrics, and that complementarity effects drove the increased productivity of our high-diversity populations. Our results show that differences in genetic diversity among populations can have pervasive effects on population productivity within remarkably short periods of time. PMID:22764499

Aguirre, J David; Marshall, Dustin J

2012-05-01

262

Healthy Sperm: Improving Your Fertility  

MedlinePLUS

... Maintain a healthy weight. Some research suggests that obesity negatively affects sperm quality, reducing both sperm count ... America. 2011;38:359. The effects of workplace hazards on male reproductive health. Centers for Disease Control and Prevention. http://www. ...

263

Mobilisation of Ca2+ stores and flagellar regulation in human sperm by S-nitrosylation: a role for NO synthesised in the female reproductive tract.  

PubMed

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 Ca(2+) 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 [Ca(2+)](i). The effects of NO, GSNO and dithiothreitol on sperm protein S-nitrosylation, assessed using the biotin switch method, closely paralleled their actions on [Ca(2+)](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 Ca(2+) in human sperm. Pre-treatment of sperm with NO greatly enhanced the effect of progesterone on [Ca(2+)](i), resulting in a prolonged increase in flagellar excursion. We conclude that NO regulates mobilisation of stored Ca(2+) in human sperm by protein S-nitrosylation, that this action is synergistic with that of progesterone and that this synergism is potentially highly significant in gamete interactions leading to fertilisation. PMID:18842814

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

2008-10-08

264

Conspecific sperm precedence in Callosobruchus subinnotatus (Coleoptera: Bruchidae): mechanisms and consequences.  

PubMed

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

Rugman-Jones, Paul F; Eady, Paul E

2007-04-01

265

Sperm Proteasomes Degrade Sperm Receptor on the Egg Zona Pellucida during Mammalian Fertilization  

PubMed Central

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 the fertilization/polyspermy rates after IVF, accompanied by en-mass detachment of zona bound sperm. Thus, the sperm borne 26S proteasome is a candidate zona lysin in mammals. This new paradigm has implications for contraception and assisted reproductive technologies in humans, as well as animals.

Zimmerman, Shawn W.; Manandhar, Gaurishankar; Yi, Young-Joo; Gupta, Satish K.; Sutovsky, Miriam; Odhiambo, John F.; Powell, Michael D.; Miller, David J.; Sutovsky, Peter

2011-01-01

266

Sperm proteasomes degrade sperm receptor on the egg zona pellucida during mammalian fertilization.  

PubMed

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 the fertilization/polyspermy rates after IVF, accompanied by en-mass detachment of zona bound sperm. Thus, the sperm borne 26S proteasome is a candidate zona lysin in mammals. This new paradigm has implications for contraception and assisted reproductive technologies in humans, as well as animals. PMID:21383844

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

267

Oviducal sperm storage in poultry  

Technology Transfer Automated Retrieval System (TEKTRAN)

Hens are capable of fertilizing a daily succession of ovulated ova due to their ability to store sperm in the oviduct for several weeks. However, the precise biological mechanisms describing how sperm are selected and survive in the oviduct, and which sperm actually reach the site of fertilization c...

268

An automatic system to study sperm motility and energetics.  

PubMed

An integrated robotic laser and microscope system has been developed to automatically analyze individual sperm motility and energetics. The custom-designed optical system directs near-infrared laser light into an inverted microscope to create a single-point 3-D gradient laser trap at the focal spot of the microscope objective. A two-level computer structure is described that quantifies the sperm motility (in terms of swimming speed and swimming force) and energetics (measuring mid-piece membrane potential) using real-time tracking (done by the upper-level system) and fluorescent ratio imaging (done by the lower-level system). The communication between these two systems is achieved by a gigabit network. The custom-built image processing algorithm identifies the sperm swimming trajectory in real-time using phase contrast images, and then subsequently traps the sperm by automatically moving the microscope stage to relocate the sperm to the laser trap focal plane. Once the sperm is stably trapped (determined by the algorithm), the algorithm can also gradually reduce the laser power by rotating the polarizer in the laser path to measure the trapping power at which the sperm is capable of escaping the trap. To monitor the membrane potential of the mitochondria located in a sperm's mid-piece, the sperm is treated with a ratiometrically-encoded fluorescent probe. The proposed algorithm can relocate the sperm to the center of the ratio imaging camera and the average ratio value can be measured in real-time. The three parameters, sperm escape power, sperm swimming speed and ratio values of the mid-piece membrane potential of individual sperm can be compared with respect to time. This two-level automatic system to study individual sperm motility and energetics has not only increased experimental throughput by an order of magnitude but also has allowed us to monitor sperm energetics prior to and after exposure to the laser trap. This system should have application in both the human fertility clinic and in animal husbandry. PMID:18299996

Shi, Linda Z; Nascimento, Jaclyn M; Chandsawangbhuwana, Charlie; Botvinick, Elliot L; Berns, Michael W

2008-08-01

269

Long Polyglutamine Tracts in the Androgen Receptor Are Associated with Reduced TransActivation, Impaired Sperm Production, and Male Infertility  

Microsoft Academic Search

The X-linked androgen receptor (AR) gene contains two polymor- phic trinucleotide repeat segments that code for polyglutamine and polyglycine tracts in the N-terminal trans-activation domain of the AR protein. Changes in the lengths of these polymorphic repeat seg- ments have been associated with increased risk of prostate cancer, an androgen-dependent tumor. Expansion of the polyglutamine tract causes a rare neuromuscular

THEIN G. TUT; FARID J. GHADESSY; M. A. TRIFIRO; L. PINSKY; E. L. YONG

2010-01-01

270

Incubation of sperm heads impairs fertilization and early embryo development following intracytoplasmic sperm injection (ICSI) by decreasing oocyte activation in mice.  

PubMed

When intracytoplasmic sperm injection (ICSI) is performed in mice, isolation of sperm heads is usually performed prior to injections in order to increase the efficiency of the procedure. Consequently, the isolated sperm heads undergo an inevitable incubation in vitro. However, little is known about the effects of this incubation step on fertilization and embryo development following ICSI. When we incubated sperm heads at 37 °C, there was a significant time-dependent decrease in fertilization and blastocyst formation. Moreover, the DNA integrity of the sperm heads was maintained over 12 h incubation. Using assisted oocyte activation, these defects in fertilization and embryo development were rescued. Taken together, incubation of sperm heads following isolation can affect the oocyte-activating capacity of sperm thereby compromising fertilization and embryo development associated with ICSI. PMID:23881325

Long, Hui; Lu, Sheng-Sheng; Kuang, Yan-Ping; Yan, Zhi-Guang; Liang, Hong-Xing; Yu, Sha; Chai, Wei-Ran; Yan, Zheng; Lyu, Qi-Feng

2013-07-24

271

Load reduction sintering for increasing productivity and decreasing fuel consumption  

NASA Astrophysics Data System (ADS)

The technical and economical indexes and the physical properties of load reduction sintering processes with the supporting stands of installation at different height levels (300, 350, and 400 mm) in a sintering bed were studied under the same conditions of raw material, bed height, and sintering parameters. Sintering pot tests with different bed heights and fuel ratios of the mixture with or without supporting stands were performed to decrease the fuel consumption. The airflow rate through the sintering bed was measured with an anemoscope fixed on the bed surface to reveal the effects of supporting stands. The utilization of load reduction sintering can improve the permeability of the sintering bed, and the airflow rate through the sintering bed is increased. When the stand height is half of the sintering bed, the productivity increases by 27.9%, and the drum index slightly decreases. Keeping at the same productivity level with normal sintering, the utilization of load reduction sintering can decrease the solid fuel consumption by 9.2%.

Zuo, Hai-bin; Zhang, Jian-liang; Hu, Zheng-wen; Yang, Tian-jun

2013-02-01

272

Methodical approach to increase productivity and reduce lead time in assembly and production-logistic processes  

Microsoft Academic Search

The introduced methodical approach connects Value Stream Mapping (VSM) and Methods-Time Measurement (MTM) and offers new distinct advantages to reduce lead time and increase productivity based on lean principles and standardised processes. The mutually aligned design and improvement of assembly and (production) logistic processes takes either the workplaces, their surroundings and the supply areas as well as the overall value

P. Kuhlang; T. Edtmayr; W. Sihn

2011-01-01

273

Informed consent in posthumous sperm procurement  

Microsoft Academic Search

Introduction  Assisted reproductive technologies are increasingly more present in our everyday life: from classical sperm\\/egg donation or\\u000a in vitro fertilization to newer, more controversial methods such as surrogate motherhood, male pregnancies or posthumous sperm\\u000a procurement. Every year, new concepts are emerging in this field and the medical world is not always prepared to deal with\\u000a them.\\u000a \\u000a \\u000a \\u000a \\u000a Material and method  The greatest problem

Sorin Hostiuc; Cristian George Curca

2010-01-01

274

Interaction of acrosome-reacted macaque sperm with the macaque zona pellucida.  

PubMed

In this study we investigated the ultrastructure of macaque sperm induced to acrosome-react with calcium ionophore A23187, and the interaction between these acrosome-reacted sperm and the macaque zona pellucida. Transmission electron microscopy revealed that the majority of ionophore-treated sperm retained the vesiculated acrosomal cap or "shroud." Untreated, acrosome-reacted sperm on the zona had a similar ultrastructural appearance. In sperm-zona binding experiments, a mean of 4.5 ionophore-treated sperm were bound per zona after 1 min of coincubation compared with 41 sperm per zona in the solvent control. Vigorous pipetting was used to remove the acrosomal shrouds from approximately 50% of acrosome-reacted sperm before incubation with oocytes. Significantly more of these mechanically treated sperm were bound to the zona after a 4-min coincubation compared with acrosome-reacted sperm that were not pipetted. The number of mechanically treated sperm bound to the zona was the same whether the sperm and oocytes were coincubated in calcium-free medium or in control medium. The percentage of mechanically treated sperm that were acrosome-reacted on the zona also was not different in the two media. We conclude that macaque sperm that undergo the acrosome reaction on the zona surface are bound by the acrosomal shroud before zona penetration. When sperm acrosome-react before interaction with the oocyte, their zona binding capacity is significantly reduced. Removal of the acrosomal shroud and exposure of the inner acrosomal membrane increases the affinity of sperm for the zona. This sequence occurs naturally during the transition from primary binding to secondary binding on the zona surface. PMID:9160732

VandeVoort, C A; Yudin, A I; Overstreet, J W

1997-05-01

275

Group X phospholipase A2 is released during sperm acrosome reaction and controls fertility outcome in mice  

PubMed Central

Ejaculated mammalian sperm must undergo a maturation process called capacitation before they are able to fertilize an egg. Several studies have suggested a role for members of the secreted phospholipase A2 (sPLA2) family in capacitation, acrosome reaction (AR), and fertilization, but the molecular nature of these enzymes and their specific roles have remained elusive. Here, we have demonstrated that mouse group X sPLA2 (mGX) is the major enzyme present in the acrosome of spermatozoa and that it is released in an active form during capacitation through spontaneous AR. mGX-deficient male mice produced smaller litters than wild-type male siblings when crossed with mGX-deficient females. Further analysis revealed that spermatozoa from mGX-deficient mice exhibited lower rates of spontaneous AR and that this was associated with decreased in vitro fertilization (IVF) efficiency due to a drop in the fertilization potential of the sperm and an increased rate of aborted embryos. Treatment of sperm with sPLA2 inhibitors and antibodies specific for mGX blocked spontaneous AR of wild-type sperm and reduced IVF success. Addition of lysophosphatidylcholine, a catalytic product of mGX, overcame these deficiencies. Finally, recombinant mGX triggered AR and improved IVF outcome. Taken together, our results highlight a paracrine role for mGX during capacitation in which the enzyme primes sperm for efficient fertilization and boosts premature AR of a likely phospholipid-damaged sperm subpopulation to eliminate suboptimal sperm from the pool available for fertilization.

Escoffier, Jessica; Jemel, Ikram; Tanemoto, Akemi; Taketomi, Yoshitaka; Payre, Christine; Coatrieux, Christelle; Sato, Hiroyasu; Yamamoto, Kei; Masuda, Seiko; Pernet-Gallay, Karin; Pierre, Virginie; Hara, Shuntaro; Murakami, Makoto; De Waard, Michel; Lambeau, Gerard; Arnoult, Christophe

2010-01-01

276

Sperm DNA tests as useful adjuncts to semen analysis.  

PubMed

Male infertility has traditionally been diagnosed by microscopic assessment of concentration, motility and morphology of sperm in the ejaculate. Most laboratories use sperm isolated by various methods such as density gradient centrifugation to enrich for subpopulations of sperm believed to have greater fertilization potential. These tests are essential to provide the fundamental information on which clinicians base their initial diagnosis. However, in the clinical setting, tests with superior prognostic value are needed. Tests showing much promise are those determining sperm DNA integrity, particularly the Comet, TUNEL, and Sperm Chromatin Structure assays. Sperm nuclear DNA fragmentation has been positively correlated with lower fertilization rates in IVF, impaired implantation rates, an increased incidence of abortion and disease in offspring, including childhood cancer. The mitochondrial genome of sperm has also been shown to be a sensitive marker of sperm health. Although the usefulness of these tests is recognized, insufficient resources have been available to develop standardized tests and protocols that could lead to universally accepted clinical thresholds. Associated with the lack of useful prognostic tests is the lack of improvement in assisted conception success rates despite thirty years of worldwide use. International collaborations should be initiated to develop agreed protocols and establish clinical thresholds. PMID:18570047

Lewis, Sheena E M; Agbaje, Ishola; Alvarez, Juan

277

Sperm phospholipid methyltransferase activity during preparation for exocytosis.  

PubMed

The present report describes experiments to evaluate phospholipid methyltransferase activity in golden hamster spermatozoa incubated under different conditions. Washed cauda epididymal sperm were incubated with taurine, in the presence or absence of epinephrine. At various times, the sperm were separated, and phospholipid methyltransferase activity measured. Also, at each time, aliquots of the sperm suspension were assayed for motility, and acrosome reactions. Some sperm incubated in the presence of taurine and epinephrine were capacitated by 3.5 h, because about 40 per cent of them can undergo the acrosome reaction 10 min after addition of the fusogen lysophosphatidylcholine. In epinephrine-free incubations the fusogen failed to stimulate acrosome reactions. On the other hand, epinephrine stimulated by twofold phospholipid methyltransferase activity from '0 time' incubated sperm, in comparison to that observed in taurine-treated cells. Enzyme activities from both taurine or epinephrine plus taurine-treated cells decreased as the incubation time of the sperm suspension increased. Kinetic properties of the sperm phospholipid methyltransferase activity were modified by the presence of taurine and epinephrine when S-adenosylmethionine was used as the substrate. These results suggest that refined molecular events occur in the sperm cell during the acquisition of fertilizing ability. PMID:7834819

Llanos, M N; Ronco, A M

1994-12-01

278

Motility measurement of a mouse sperm by atomic force microscopy.  

PubMed

Eukaryotic flagella are responsible for the motile organelles that cause the migration of mammalian sperms. The lashing force and torque of the sperm flagellum contain critical information regarding the sperm health, as important evaluation factors for sperm screening. The objective of the study was to investigate the lashing force and torque of a sperm under physiological conditions using atomic force microscopy (AFM). At a distance of about 18.5 ?m from its head-tail junction, a lashing force of 0.96 ± 0.20 nN was measured. Its corresponding lashing torque was 1.77(± 0.37)× 10(-14) N·m. The torque increases in proportion to the square of the head-tail junction distance. Our results reasonably conclude that the axonemal motility is linear dependent on the flagellum length of the sperm. Our developed measurement system can consistently determine the lashing force and torque of a sperm, which can contribute to further studies concerning the mechanism of sperm transport and fertilization. PMID:23303076

Hsiao, Wesley W; Liao, Hsien-Shun; Lin, Hsing-Hung; Ding, Ren-Feng; Huang, Kuang-Yuh; Chang, Chia-Seng

2013-01-01

279

Increased Production of Sonic Hedgehog by Ballooned Hepatocytes  

PubMed Central

Ballooned hepatocytes distinguish nonalcoholic steatohepatitis (NASH) from steatosis. Such cells contain dilated endoplasmic reticulum and ubiquitin aggregates, characteristics of endoplasmic reticulum stress. Hepatocyte ballooning increases risk for fibrosis in NASH, suggesting ballooned hepatocytes release pro-fibrogenic factors. Hedgehog ligands function as pro-fibrogenic factors in liver diseases, but mechanisms for Hedgehog ligand production remain poorly understood. We evaluated the hypothesis that endoplasmic reticulum stress induces hepatocyte production of hedgehog ligands that provide paracrine pro-fibrogenic signals to neighboring cells. In livers from NASH patients, keratin 8/18 and ubiquitin staining demonstrated enlarged, keratin 8/18-negative/ubiquitin-positive hepatocytes (ballooned hepatocytes) that were positive for Sonic hedgehog. In order to model endoplasmic reticulum stress in vitro, primary mouse hepatocytes were treated with tunicamycin. Compared to vehicle, tunicamycin significantly increased Sonic hedgehog and Indian hedgehog expression. Furthermore, conditioned medium from tunicamycin-treated hepatocytes increased Gli-luciferase reporter activity 14-fold more than conditioned medium from vehicle-treated hepatocytes. Cyclopamine (hedgehog signaling inhibitor) abrogated the effect of conditioned medium from tunicamycin-treated hepatocytes, verifying that soluble hepatocyte-derived factors activate hedgehog signaling. Ballooned hepatocytes in NASH patients did not express the hedgehog target gene, Gli2, ?-smooth muscle actin or vimentin but were surrounded by Gli2-positive stromal cells expressing these myofibroblast markers. Trichrome staining demonstrated accumulation of ballooned hepatocytes in areas of matrix deposition, and numbers of Sonic hedgehog-positive, hepatocytes correlated with degree of ballooning and fibrosis stage. Hepatocytes undergoing endoplasmic reticiulum stress generate hedgehog ligands which act as paracrine pro-fibrogenic factors for hedgehog-responsive stromal cells. These results help to explain why fibrosis stage correlates with hepatocyte ballooning in NASH.

Rangwala, Fatima; Guy, Cynthia D.; Lu, Jiuyi; Suzuki, Ayako; Burchette, James L.; Abdelmalek, Manal F.; Chen, Wei; Diehl, Anna Mae

2013-01-01

280

Effects of L-Carnitine and Pentoxifylline on Carbohydrate Distribution of Mouse Testicular Sperm Membrane  

PubMed Central

Background: The glycoconjugate content of sperms indicates their physiological and fertility properties. Lectin reactivity is indicative of intact, capacitated, and acrosome-reacted sperms. In the epididymis, sperms experience maturation, glycoconjugate modification, and simultaneously, higher L-carnitine (LC) concentrations. The aim of this project was to evaluate the effects of LC and Pentoxifylline (PF) on the integrity, capacitation, and acrosomal reaction of sperms by studying their lectin reactivity. Methods: Mouse testicular sperm samples were divided into three parts. Each sample was added Ham’s F10 (control) or media containing 1.76 mM LC or PF. At 30 and 90 minutes after incubation, sperm motility was assessed. Peanut agglutinin (PNA), wheat germ agglutinin (WGA), and Concanavalin A (Con A) were used to detect non-acrosome-reacted, non-capacitated, and acrosome-reacted sperms, respectively and the frequency was evaluated by flow cytometry. Statistical analysis was performed using the ANOVA. Results: Sperm motility increased after 30 and 90 minutes of incubation in the LC- and PF-treated cultures (P=0.001). LC administration created a significant increase in the percentage of the non-acrosome-reacted sperms compared to the control sperms after 30 and 90 minutes (P=0.02 and P=0.03, respectively). The frequency of the non-capacitated sperms in the LC-treated group increased compared to the control sperms after 30 minutes significantly (P=0.01). Conclusion: Although the administration of LC and PF enhanced sperm motility, LC also impacted glycoconjugates on the sperm surface. Glycoconjugates are involved in the interaction between the sperm and the zona pellucida and subsequently fertilization, thereby probably influencing the male fertility state.

Aliabadi, Elham; Karimi, Fatemeh; Talaei-Khozani, Tahereh

2013-01-01

281

Raman Spectroscopy of DNA Packaging in Individual Human Sperm Cells distinguishes Normal from Abnormal Cells  

SciTech Connect

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.

Huser, T; Orme, C; Hollars, C; Corzett, M; Balhorn, R

2009-03-09

282

Response of boar sperm to the treatment with cholesterol-loaded cyclodextrins added prior to cryopreservation.  

PubMed

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. PMID:22372766

Blanch, E; Tomás, C; Graham, J K; Mocé, E

2012-02-29

283

Glucose is a pH-Dependent Motor for Sperm Beat Frequency during Early Activation  

PubMed Central

To reach the egg in the ampulla, sperm have to travel along the female genital tract, thereby being dependent on external energy sources and substances to maintain and raise the flagellar beat. The vaginal fluid is rich in lactate, whereas in the uterine fluid glucose is the predominant substrate. This evokes changes in the lactate content of sperm as well as in the intracellular pH (pHi) since sperm possess lactate/proton co-transporters. It is well documented that glycolysis yields ATP and that HCO3? is a potent factor in the increase of beat frequency. We here show for the first time a pathway that connects both parts. We demonstrate a doubling of beat frequency in the mere presence of glucose. This effect can reversibly be blocked by 2-deoxy-D-glucose, dichloroacetate and aminooxyacetate, strongly suggesting that it requires both glycolysis and mitochondrial oxidation of glycolytic end products. We show that the glucose-mediated acceleration of flagellar beat and ATP production are hastened by a pHi ?7.1, whereas a pHi ?7.1 leaves both parameters unchanged. Since we observed a diminished rise in beat frequency in the presence of specific inhibitors against carbonic anhydrases, soluble adenylyl cyclase and protein kinase, we suggest that the glucose-mediated effect is linked to CO2 hydration and thus the production of HCO3? by intracellular CA isoforms. In summary, we propose that, in sperm, glycolysis is an additional pHi-dependent way to produce HCO3?, thus enhancing sperm beat frequency and contributing to fertility.

Mannowetz, Nadja; Wandernoth, Petra M.; Wennemuth, Gunther

2012-01-01

284

Glucose is a pH-dependent motor for sperm beat frequency during early activation.  

PubMed

To reach the egg in the ampulla, sperm have to travel along the female genital tract, thereby being dependent on external energy sources and substances to maintain and raise the flagellar beat. The vaginal fluid is rich in lactate, whereas in the uterine fluid glucose is the predominant substrate. This evokes changes in the lactate content of sperm as well as in the intracellular pH (pH(i)) since sperm possess lactate/proton co-transporters. It is well documented that glycolysis yields ATP and that HCO(3)- is a potent factor in the increase of beat frequency. We here show for the first time a pathway that connects both parts. We demonstrate a doubling of beat frequency in the mere presence of glucose. This effect can reversibly be blocked by 2-deoxy-D-glucose, dichloroacetate and aminooxyacetate, strongly suggesting that it requires both glycolysis and mitochondrial oxidation of glycolytic end products. We show that the glucose-mediated acceleration of flagellar beat and ATP production are hastened by a pH(i) ?7.1, whereas a pH(i) ?7.1 leaves both parameters unchanged. Since we observed a diminished rise in beat frequency in the presence of specific inhibitors against carbonic anhydrases, soluble adenylyl cyclase and protein kinase, we suggest that the glucose-mediated effect is linked to CO(2) hydration and thus the production of HCO(3)- by intracellular CA isoforms. In summary, we propose that, in sperm, glycolysis is an additional pH(i)-dependent way to produce HCO(3)-, thus enhancing sperm beat frequency and contributing to fertility. PMID:22911736

Mannowetz, Nadja; Wandernoth, Petra M; Wennemuth, Gunther

2012-07-20

285

Methods for increasing the production of ethanol from microbial fermentation  

DOEpatents

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.

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

2007-10-23

286

Transgenic zebrafish produced by retroviral infection of in vitro-cultured sperm.  

PubMed

Transgenic modification of sperm before fertilization has distinct advantages over conventional transgenic methods. The primary advantage is that the mosaicism inherent in those other techniques is avoided. A culture system using primary cultures of zebrafish male germ cells, in which the differentiation from spermatogonia to functional sperm can occur in vitro, provides the opportunity for genetic modification of sperm in vitro. Here, we report the production of transgenic zebrafish from cultured sperm. The sperm were differentiated from premeiotic germ cells infected with a pseudotyped retrovirus in vitro. The collected sperm were used to perform successful in vitro fertilizations, and transgenic embryos were identified. The transgenic fish transmitted the proviral integration to the next generation in a Mendelian fashion. We report the generation of a transgenic animal by cultured sperm and open the door to many exciting possibilities for the rapid generation of transgenic lines in model organisms such as zebrafish or other animal systems that are otherwise intractable to transgenesis. PMID:14745028

Kurita, Kayoko; Burgess, Shawn M; Sakai, Noriyoshi

2004-01-26

287

Hyaluronan production increases the malignant properties of mesothelioma cells  

PubMed Central

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

Li, Y; Heldin, P

2001-01-01

288

Mathematical modeling of calcium signaling during sperm hyperactivation  

PubMed Central

Mammalian sperm must hyperactivate in order to fertilize oocytes. Hyperactivation is characterized by highly asymmetrical flagellar bending. It serves to move sperm out of the oviductal reservoir and to penetrate viscoelastic fluids, such as the cumulus matrix. It is absolutely required for sperm penetration of the oocyte zona pellucida. In order for sperm to hyperactivate, cytoplasmic Ca2+ levels in the flagellum must increase. The major mechanism for providing Ca2+ to the flagellum, at least in mice, are CatSper channels in the plasma membrane of the principal piece of the flagellum, because sperm from CatSper null males are unable to hyperactivate. There is some evidence for the existence of other types of Ca2+ channels in sperm, but their roles in hyperactivation have not been clearly established. Another Ca2+ source for hyperactivation is the store in the redundant nuclear envelope of sperm. To stabilize levels of cytoplasmic Ca2+, sperm contain Ca2+ ATPase and exchangers. The interactions between channels, Ca2+ ATPases, and exchangers are poorly understood; however, mathematical modeling can help to elucidate how they work together to produce the patterns of changes in Ca2+ levels that have been observed in sperm. Mathematical models can reveal interesting and unexpected relationships, suggesting experiments to be performed in the laboratory. Mathematical analysis of Ca2+ dynamics has been used to develop a model for Ca2+ clearance and for CatSper-mediated Ca2+ dynamics. Models may also be used to understand how Ca2+ patterns produce flagellar bending patterns of sperm in fluids of low and high viscosity and elasticity.

Olson, S.D.; Fauci, L.J.; Suarez, S.S.

2011-01-01

289

Dispermic androgenesis in sturgeons with the use of cryopreserved sperm: Production of androgenetic siberian sturgeon and androgenetic hybrids between Siberian and Russian sturgeons  

Microsoft Academic Search

Dispermic androgenesis was used to produce, for the first time, an androgenetic progeny of the Siberian sturgeon (Acipenser baerii) and the androgenetic nucleo-cytoplasmic hybrids (Siberian sturgeon, A. baerii × Russian sturgeon, A. gueldenstaedtii) using cryopreserved sperm. Microsatellite DNA analysis confirmed exclusively paternal inheritance in the androgenetic progeny\\u000a of Siberian sturgeon. Heterozygotes for certain microsatellite loci were detected among the androgenetic

A. S. Grunina; A. V. Rekoubratsky; L. I. Tsvetkova; A. E. Barmintseva; E. D. Vasil’eva; K. V. Kovalev; O. G. Poluektova

2011-01-01

290

Interaction of blood lead and delta-aminolevulinic acid dehydratase genotype on markers of heme synthesis and sperm production in lead smelter workers.  

PubMed

The gene that encodes gamma-aminolevulinic acid dehydratase (ALAD) has a polymorphism that may modify lead toxicokinetics and ultimately influence individual susceptibility to lead poisoning. To evaluate the effect of the ALAD polymorphism on lead-mediated outcomes, a cross-sectional study of male employees from a lead-zinc smelter compared associations between blood lead concentration and markers of heme synthesis and semen quality with respect to ALAD genotype. Male employees were recruited via postal questionnaire to donate blood and urine for analysis of blood lead, zinc protoporphyrin (ZPP), urinary coproporphyrin (CPU), and ALAD genotype, and semen samples for semen analysis. Of the 134 workers who had ALAD genotypes completed, 114 (85%) were ALAD1-1 (ALAD1) and 20 (15%) were ALAD1-2 (ALAD2). The mean blood lead concentrations for ALAD1 and ALAD2 were 23.1 and 28.4 microg/dl (p = 0.08), respectively. ZPP/heme ratios were higher in ALAD1 workers (68.6 vs. 57.8 micromol/ml; p = 0.14), and the slope of the blood lead ZPP linear relationship was greater for ALAD1 (2.83 vs. 1.50, p = 0.06). No linear relationship between CPU and blood lead concentration was observed for either ALAD1 or ALAD2. The associations of blood lead concentration with ZPP, CPU, sperm count, and sperm concentration were more evident in workers with the ALAD1 genotype and blood lead concentrations >/= 40 microg/dl. The ALAD genetic polymorphism appears to modify the association between blood lead concentration and ZPP. However, consistent modification of effects were not found for CPU, sperm count, or sperm concentration. PMID:9495797

Alexander, B H; Checkoway, H; Costa-Mallen, P; Faustman, E M; Woods, J S; Kelsey, K T; van Netten, C; Costa, L G

1998-04-01

291

Royal jelly increases collagen production in rat skin after ovariectomy.  

PubMed

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

Park, Hye Min; Cho, Min Hyoung; Cho, Yunhi; Kim, Sun Yeou

2012-04-02

292

Hyperoxia increases hepatic arginase expression and ornithine production in mice  

SciTech Connect

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.

Malleske, Daniel T. [Center for Developmental Pharmacology and Toxicology, Columbus Children's Research Institute, Department of Pediatrics, Ohio State University, Columbus, OH 43205 (United States); Rogers, Lynette K. [Center for Developmental Pharmacology and Toxicology, Columbus Children's Research Institute, Department of Pediatrics, Ohio State University, Columbus, OH 43205 (United States); Velluci, Sean M. [Center for Developmental Pharmacology and Toxicology, Columbus Children's Research Institute, Department of Pediatrics, Ohio State University, Columbus, OH 43205 (United States); Young, Tamara L. [Center for Developmental Pharmacology and Toxicology, Columbus Children's Research Institute, Department of Pediatrics, Ohio State University, Columbus, OH 43205 (United States); Park, Min S. [Center for Developmental Pharmacology and Toxicology, Columbus Children's Research Institute, Department of Pediatrics, Ohio State University, Columbus, OH 43205 (United States); Long, Donald W. [Center for Developmental Pharmacology and Toxicology, Columbus Children's Research Institute, Department of Pediatrics, Ohio State University, Columbus, OH 43205 (United States); Welty, Stephen E. [Center for Developmental Pharmacology and Toxicology, Columbus Children's Research Institute, Department of Pediatrics, Ohio State University, Columbus, OH 43205 (United States); Smith, Charles V. [Center for Developmental Pharmacology and Toxicology, Columbus Children's Research Institute, Department of Pediatrics, Ohio State University, Columbus, OH 43205 (United States); Nelin, Leif D. [Center for Developmental Pharmacology and Toxicology, Columbus Children's Research Institute, Department of Pediatrics, Ohio State University, Columbus, OH 43205 (United States)]. E-mail: NelinL@pediatrics.ohio-state.edu

2006-08-15

293

Fertilization by proxy: rival sperm removal and translocation in a beetle  

PubMed Central

Competition between different males' sperm for the fertilization of ova has led to the evolution of a diversity of characters in male reproductive behaviour, physiology and morphology. Males may increase sperm competition success either by enhancing the success of their own sperm or by negating or eliminating the success of rival sperm. Here, we find that in the flour beetle Tribolium castaneum, the second male to mate gains fertilization precedence over previous males' sperm and fertilizes approximately two-thirds of the eggs. It is not known what mechanism underlies this pattern of last-male sperm precedence; however, the elongate tubules of the female sperm storage organ may encourage a 'last-in, first-out' sperm use sequence. Here we present an additional or alternative mechanism of sperm precedence whereby previously deposited sperm are removed from the female tract by the mating male's genitalia. In addition to providing evidence for sperm removal in T. castaneum, we also show that removed, non-self sperm may be translocated back into the reproductive tracts of new, previously unmated females, where the translocated sperm go on to gain significant fertilization success. We found that, in 45 out of 204 crosses, sperm translocation occurred and in these 45 crosses over half of the offspring were sired by spermatozoa which had been translocated between females on the male genitalia. In the natural environment of stored food, reproductively active T. castaneum adults aggregate in dense mating populations where copulation is frequent (we show in three naturally occurring population densities that copula duration and intermating intervals across three subsequent matings average 1 to 2 min). Selection upon males to remove rival sperm may have resulted in counter-selection upon spermatozoa to survive removal and be translocated into new females where they go on to fertilize in significant numbers.

Haubruge, E.; Arnaud, L.; Mignon, J.; Gage, M. J. G.

1999-01-01

294

Sperm storage mediated by cryptic female choice for nuptial gifts.  

PubMed

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. PMID:24153384

Albo, Maria J; Bilde, Trine; Uhl, Gabriele

2013-10-23

295

Cryopreservation of rooster sperm.  

PubMed

Successful cryopreservation of sperm requires: 1) selection of proper diluent; 2) selection of the best cryoprotectant; 3) determination of freezing and thawing rates for optimum retention of fertilization potential; and 4) removal of any materials deleterious to fertility (e.g., glycerol) before insemination. An economically useful process must allow recovery of sperm with sufficient fertilization capacity to enable maximum use of any given superior male. A series of experiments tested a novel semen freezing container (BioPore CryoCell container) having physical characteristics that permit reproducible freezing and thawing plus facile removal of glycerol from the sample after processing. Experiments tested the effect of: a) residual glycerol; b) initial glycerol concentrations on retention of fertility when samples were frozen and thawed at 6 C/min; c) Beltsville Poultry Semen Extender and Minnesota A buffers used during the dialysis procedure; and d) dialysis time. Respectively, the results were: a) .8% (vol/vol) reduced fertility by 5 to 10%; b) 12% glycerol was superior to 10% and 8% glycerol; c) no difference was observed between the two buffers; and d) 90 and 120 min were both superior to 60 min. Numerous pools of rooster sperm cryopreserved in CryoCell containers and dialyzed after thawing in a prototype BioStore environmental control chamber for 90 or 120 min resulted in a mean fertility of 55.6%. This mean fertility of frozen-thawed sperm was based on 3,263 eggs laid by 400 hens on Days +1 through 9 after inseminations on Days -1, 2, and 5. It is likely that broiler stocks might have lower fertility than that obtained from the Barred Plymouth Rock males and the Single Comb White Leghorn females used in these studies. Nevertheless, the procedure described is the first to consistently result in > 50% fertilized eggs as a result of conventional intravaginal insemination (< 200 x 10(6) sperm in 100 microL extender) of sperm processed after thawing by a procedure amenable to the scaleup required for commercial applications. PMID:8502616

Buss, E G

1993-05-01

296

Increased nitric oxide production by neutrophils in bronchial asthma  

Microsoft Academic Search

This study was designed to assess the production of nitric oxide (NO) by neutrophils in bronchial asthma. Thirty asthmatic patients (ten each of mild, moderate and severe asthma) and ten healthy controls were included in the study. Neutrophils from peripheral venous blood were stimulated with latex, and production of nitrite (an NO metabolise) and L-citrulline (a co-product of NO) was

G. Ramesh; S. K. Jindal; N. K. Ganguly; V. Dhawan

2001-01-01

297

Ultraviolet damages sperm mitochondrial function and membrane integrity in the sea urchin Anthocidaris crassispina.  

PubMed

Effects of ultraviolet A (UVA) and ultraviolet B (UVB) on mitochondrial function and membrane integrity of sea urchin sperm were investigated using flow cytometry and fluorescent probes. Both UVA and UVB impaired sperm mitochondrial function in a dose-dependent manner. Covariance analysis further showed that the slopes of change in mitochondrial function in relation to UVA and UVB were significantly different, suggesting that the modes of action were different. UVA did not affect membrane integrity, while membrane integrity showed a linear reduction with increasing UVB doses. Sperm mitochondria function showed significant positive correlations with sperm motility and subsequent fertilization success. Overall, our results showed that both UVA and UVB could decrease sperm motility and fertilization success through impairment of mitochondrial function, whereas UVB alone could cause additional damage through impairing the functional integrity of sperm membrane. Mitochondrial function of sperm may also offer a reliable ecotoxicological biomarker for predicting fertilization success in urchins. PMID:15814310

Lu, X Y; Wu, R S S

2005-05-01

298

Current Status of Sperm Cryopreservation in Biomedical Research Fish Models: Zebrafish, Medaka, and Xiphophorus*  

PubMed Central

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.

Yang, Huiping; Tiersch, Terrence R.

2009-01-01

299

Process for increasing deasphalted oil production from upgraded residua  

SciTech Connect

This patent describes a process for increasing the production of deasphalted oil from a hydrocarbon feedstock comprising the steps of: (a) passing the hydrocarbon feedstock into a first distillation zone where the feedstock is separated into distillates and a first residuum; (b) passing the first residuum into a hydrotreating zone operating between about 315C to 425C, at an absolute pressure between 4000 to 10,000 cmHg where a hydrotreated first residuum is produced; (c) passing the hydrotreated first residuum into a second distillation zone where it is separated into distillates and a hydrotreated distillation residuum; and (d) mixing the hydrotreated distillation residuum with a solubilizing aid selected from the group consisting of catalytic cracker fractionator bottoms having an initial boiling point not less than 260C and not more than 430C (at 1 atmosphere), heavy cycle gas oil having a boiling point range of 200C to 420C (at 1 atmosphere) and heavy coker gas oil having a boiling point range of 300C to 550C (at 1 atmosphere) and feeding the resultant mixture into a deasphalting zone where the solubilizing aid comprises 30 to 60 LV% of the total feed to the deasphalting zone. The hydrotreated distillation residuum and solubilizing aid are contacted with a deasphalting solvent producing a liquid deasphalted oil extract and an asphaltic raffinate. The solubilizing aid inhibits the formation of a third asphaltic phase by promoting the solubility of the third phase in the asphaltic raffinate.

Bristow, D.J.; Achia, B.U.; Evers, L.J.

1987-06-16

300

Estrogen increases nitric-oxide production in human bronchial epithelium.  

PubMed

Although sex differences in asthma severity are recognized, the mechanisms by which sex steroids such as estrogen influence the airway are still under investigation. Airway tone, a key aspect of asthma, represents a balance between bronchoconstriction and dilation. Nitric oxide (NO) from the bronchial epithelium is an endogenous bronchodilator. We hypothesized that estrogens facilitate bronchodilation by generating NO in bronchial epithelium. In acutely dissociated human bronchial epithelial cells from female patients exposure to 17?-estradiol (E(2); 10 pM-100 nM) resulted in rapid increase of diaminofluorescein fluorescence (NO indicator) within minutes, comparable with that induced by ATP (20 ?M). Estrogen receptor (ER) isoform-specific agonists (R,R)-5,11-diethyl-5,6,11,12-tetrahydro-2,8-chrysenediol (THC) (ER?) and diaryl-propionitrile (DPN) (ER?) stimulated NO production to comparable levels and at comparable rates, whereas the ER antagonist 7?,17?-[9-[(4,4,5,5,5-pentafluoropentyl)sulfinyl]nonyl]estra-1,3,5(10)-triene-3,17-diol (ICI 182,780) (1 ?M) was inhibitory. Estrogen effects on NO were mediated via caveolin-1 (blocked using the caveolin-1 scaffolding domain peptide) and by increased intracellular calcium concentration [prevented by 20 ?M 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra(acetoxymethyl) ester but not by blocking Ca(2+) influx using LaCl(3)]. Estrogen increased endothelial NO synthase activation (inhibited by 100 ?M N(G)-nitro-l-arginine methyl ester) and phosphorylated Akt. In epithelium-intact human bronchial rings contracted with acetylcholine (1 ?M), E(2), THC, and DPN all produced acute bronchodilation in a dose-dependent fashion. Such bronchodilatory effects were substantially reduced by epithelial denudation. Overall, these data indicate that estrogens, acting via ER? or ER?, can acutely produce NO in airway epithelium (akin to vascular endothelium). Estrogen-induced NO and its impairment may contribute to altered bronchodilation in women with asthma. PMID:21940647

Townsend, Elizabeth A; Meuchel, Lucas W; Thompson, Michael A; Pabelick, Christina M; Prakash, Y S

2011-09-22

301

Detection and tracking of low contrast human sperm tail  

Microsoft Academic Search

Tracking sperm tail movement provides important information for clinical sperm research. It is also a crucial step for sperm immobilization in Intracytoplasmic Sperm Injection (ICSI). However, the low visibility of the sperm tail under optical microscopy, coupled with the sperm fast motility, render sperm tail identification and tracking challenging tasks to execute. This paper presents two approaches for sperm tail

Clement Leung; Zhe Lu; Navid Esfandiari; Robert F. Casper; Yu Sun

2010-01-01

302

Frozen-thawed rhinoceros sperm exhibit DNA damage shortly after thawing when assessed by the sperm chromatin dispersion assay.  

PubMed

This study reports on the successful validation (via in situ nick translation and neutral comet assay) of the equine Sperm-Halomax kit as an appropriate methodology for the assessment of sperm DNA fragmentation in three species of rhinoceros. Rhinoceros sperm nuclei with fragmented DNA (validated using in situ nick translation) were evident as large halos with dispersed DNA fragments, whereas those with nonfragmented DNA displayed small halos of nondispersed DNA within the microgel. There was a high correlation (r) of 0.974 (R(2) value=0.949; P<0.01; n=16) between the respective assessments of the Sperm Chromatin Dispersion test (SCDt) and the neutral comet assay. Application of the SCDt to determine the DNA fragmentation dynamics of rhinoceros (n=6) sperm frozen in liquid nitrogen vapor and incubated postthaw at 37 degrees C for up to 48 h to mimic in vitro conditions in the female reproductive tract, revealed an increase (P=0.001) in DNA damage, as soon as 4h after the start of incubation. Linear regression equations were calculated for all six rhinoceroses over the first 6h of incubation and revealed individual animal variation. Freshly collected and incubated (37 degrees C) rhinoceros (n=3) sperm had no increase in the basal level of DNA fragmentation for up to 48 h, indicating that the cryopreservation of rhinoceros sperm in liquid nitrogen vapor, as used in this study, appeared to result in freeze-thaw DNA damage. PMID:19560805

Portas, T; Johnston, S D; Hermes, R; Arroyo, F; López-Fernadez, C; Bryant, B; Hildebrandt, T B; Göritz, F; Gosalvez, J

2009-06-27

303

Mammalian Sperm Fertility Related Proteins  

PubMed Central

Infertility is an important aspect of human and animal reproduction and still presents with much etiological ambiguity. As fifty percent of infertility is related to the male partner, molecular investigations on sperm and seminal plasma can lead to new knowledge on male infertility. Several comparisons between fertile and infertile human and other species sperm proteome have shown the existence of potential fertility markers. These proteins have been categorized into energy related, structural and other functional proteins which play a major role in sperm motility, capacitation and sperm-oocyte binding. The data from these studies show the impact of sperm proteome studies on identifying different valuable markers for fertility screening. In this article, we review recent development in unraveling sperm fertility related proteins.

Ashrafzadeh, Ali; Karsani, Saiful Anuar; Nathan, Sheila

2013-01-01

304

Genome amplification of single sperm using multiple displacement amplification  

PubMed Central

Sperm typing is an effective way to study recombination rate on a fine scale in regions of interest. There are two strategies for the amplification of single meiotic recombinants: repulsion-phase allele-specific PCR and whole genome amplification (WGA). The former can selectively amplify single recombinant molecules from a batch of sperm but is not scalable for high-throughput operation. Currently, primer extension pre-amplification is the only method used in WGA of single sperm, whereas it has limited capacity to produce high-coverage products enough for the analysis of local recombination rate in multiple large regions. Here, we applied for the first time a recently developed WGA method, multiple displacement amplification (MDA), to amplify single sperm DNA, and demonstrated its great potential for producing high-yield and high-coverage products. In a 50 ?l reaction, 76 or 93% of loci can be amplified at least 2500- or 250-fold, respectively, from single sperm DNA, and second-round MDA can further offer >200-fold amplification. The MDA products are usable for a variety of genetic applications, including sequencing and microsatellite marker and single nucleotide polymorphism (SNP) analysis. The use of MDA in single sperm amplification may open a new era for studies on local recombination rates.

Jiang, Zhengwen; Zhang, Xingqi; Deka, Ranjan; Jin, Li

2005-01-01

305

Intracytoplasmic Sperm Injection (ICSI)  

NSDL National Science Digital Library

Video microscopy demonstrating how sperm from an infertile male can be injected into a female egg. This video featured on the HHMI DVD, The Meaning of Sex: Genes and Gender, available free from HHMI. Also, this video is one minute and 15 seconds in length, and available in Quicktime (7 MB) and Windows Media (12 MB). All sex determination videos are located at: http://www.hhmi.org/biointeractive/gender/video.html.

Howard Hughes Medical Institute (HHMI;)

2008-06-06

306

GMOs: Prospects for Productivity Increases in Developing Countries  

Microsoft Academic Search

There are two mechanisms by which modern genetically modified organism (GMO) products can affect productivity in developing countries. The first is the ‘Genes for Rent’ mechanism where a recipient country agrees with a GMO company to incorporate a GMO product (e.g., a Bt gene in cotton varieties) and pay a technology fee. The second is the ‘Transgenic Breeding’ mechanism in

Robert E. Evenson

2004-01-01

307

Sperm Chromatin and Environmental Factors  

Microsoft Academic Search

\\u000a Available experimental and human data show that a number of lifestyle- and environment-related exposures may have negative\\u000a effects on sperm DNA integrity. The extent of the sperm DNA damage seems to differ between different studies. Such a discrepancy\\u000a may partly be due to the use of ­several methods for assessment of sperm DNA integrity, techniques that do not measure exactly

Aleksander Giwercman

308

Absolute Polymorphic Teratozoospermia in Patients With Oligo-Asthenozoospermia Is Associated With an Elevated Sperm Aneuploidy Rate  

Microsoft Academic Search

Infertile patients with abnormal sperm parameters have an increased sperm aneuploidy rate, despite a normal blood karyo- type. The evaluation of sperm chromosome aberrations in patients with teratozoospermia only has shown a rate similar to that found in patients exhibiting oligo-astheno-teratozoospermia, which suggests that teratozoospermia is the critical parameter associated with aneu- ploidy. However, it is not known which alteration

ENZO VICARI; ADELE DE PALMA; NUNZIATINA BURRELLO; GIUSI LONGO; CATERINA GRAZIOSO; NUNZIATA BARONE; MOHAMED ZAHI; ALDO E. CALOGERO

309

Multilocus ordering strategies based on sperm typing.  

PubMed

Sperm typing is a promising new approach for fine-structure human gene mapping. We examine three-locus sperm typing and its implications for the estimation of recombination fractions and for locus ordering. In particular, we compare some sequential stopping rules for three-locus assignment and develop methods for approximating their mean stopping times and error probabilities. A stopping rule recently described by Thompson and Boehnke et al. appears to be nearly optimal. Under this rule, one stops sampling as soon as the number of sperm of the least frequent recombinant type is s fewer than the number of sperm of the next least frequent type. We develop a random-walk algorithm and some heuristic formulas for assessing the performance of this rule. Since the broader goal of linkage analysis is to order many more than three loci, we propose a trisection strategy for ordering a new locus relative to an existing ordered set of loci. The crux of the trisection strategy is to restrict attention to the smallest block of ordered loci among which the new locus can fall and to divide this block into thirds for the next comparison. This trisection strategy is optimal in the sense that it has the best worse-case performance of any strategy. When it is applied sequentially to order a collection of loci, it is only nearly optimal, as we demonstrate by specific counter-example. However, it does become asymptotically optimal as the size of the collection increases. PMID:2321913

Goradia, T M; Lange, K

1990-01-01

310

Inhibition of In Vitro Fertilizing Capacity of Cryopreserved Mouse Sperm by Factors Released by Damaged Sperm, and Stimulation by Glutathione  

PubMed Central

Background In vitro fertilization (IVF) of eggs by frozen and thawed C57BL/6J mouse sperm is inhibited by dead sperm and enhanced by preincubation of the sperm in calcium-free medium. In other species, the presence of sperm killed by freezing and thawing has been associated with the generation of hydrogen peroxide. Methodology/Principal Findings The proportion of eggs fertilized by cryopreserved C57BL/6J mouse sperm was increased significantly by increasing the volume of fertilization medium in which sperm and eggs were coincubated. Enhanced fertilization occurred even though the concentration of potentially fertile sperm was decreased fivefold. This suggested that if a putative soluble factor was inhibiting fertilization, dilution of that factor, but not the sperm, should increase the fertilization rate. This was achieved by coincubation of the gametes in cell culture inserts (Transwells®) that during incubation were transferred progressively to wells containing fresh fertilization medium. Fertilization rates using inserts were high (66.6±2.4% versus 27.3%±2.8% in wells alone). On the assumption that the soluble factor could be H2O2, reduced glutathione was added to the fertilization medium. This enhanced fertilization rate significantly (76.6%±2.0% versus 21.2%±1.9%), while addition of oxidized glutathione did not (82.7%±6.5% with reduced glutathione; 44.5±8.8% with oxidized glutathione; 47.8%±12.1% with no glutathione). Positive effects of reduced glutathione on IVF were also seen with frozen 129S1, FVB, and C3H sperm, and sperm from two lines of genetically modified C57BL/6J mice. Conclusions/Significance IVF in cell culture inserts and addition of glutathione to fertilization medium significantly increased the proportion of eggs fertilized by cryopreserved mouse sperm from four inbred strains, suggesting that reactive oxygen species generated during fertilization inhibit fertilization. The modified IVF techniques developed here enhance the feasibility and efficiency of using cryopreserved sperm from genetically modified lines of inbred mice.

Bath, Mary L.

2010-01-01

311

Viewing Death on Television Increases the Appeal of Advertised Products  

Microsoft Academic Search

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,

Ilan Dar-Nimrod

2012-01-01

312

Role of carbonic anhydrase IV in the bicarbonate-mediated activation of murine and human sperm.  

PubMed

HCO(3) (-) is the signal for early activation of sperm motility. In vivo, this occurs when sperm come into contact with the HCO(3) (-) containing fluids in the reproductive tract. The activated motility enables sperm to travel the long distance to the ovum. In spermatozoa HCO(3) (-) stimulates the atypical sperm adenylyl cyclase (sAC) to promote the cAMP-mediated pathway that increases flagellar beat frequency. Stimulation of sAC may occur when HCO(3) (-) enters spermatozoa either directly by anion transport or indirectly via diffusion of CO(2) with subsequent hydration by intracellular carbonic anhydrase (CA). We here show that murine sperm possess extracellular CA IV that is transferred to the sperm surface as the sperm pass through the epididymis. Comparison of CA IV expression by qRT PCR analysis confirms that the transfer takes place in the corpus epididymidis. We demonstrate murine and human sperm respond to CO(2) with an increase in beat frequency, an effect that can be inhibited by ethoxyzolamide. Comparing CA activity in sperm from wild-type and CA IV(-/-) mice we found a 32.13% reduction in total CA activity in the latter. The CA IV(-/-) sperm also have a reduced response to CO(2). While the beat frequency of wild-type sperm increases from 2.86±0.12 Hz to 6.87±0.34 Hz after CO(2) application, beat frequency of CA IV(-/-) sperm only increases from 3.06±0.20 Hz to 5.29±0.47 Hz. We show, for the first time, a physiological role of CA IV that supplies sperm with HCO(3) (-), which is necessary for stimulation of sAC and hence early activation of spermatozoa. PMID:21124840

Wandernoth, Petra M; Raubuch, Michael; Mannowetz, Nadja; Becker, Holger M; Deitmer, Joachim W; Sly, William S; Wennemuth, Gunther

2010-11-24

313

Role of Carbonic Anhydrase IV in the Bicarbonate-Mediated Activation of Murine and Human Sperm  

PubMed Central

HCO3? is the signal for early activation of sperm motility. In vivo, this occurs when sperm come into contact with the HCO3? containing fluids in the reproductive tract. The activated motility enables sperm to travel the long distance to the ovum. In spermatozoa HCO3? stimulates the atypical sperm adenylyl cyclase (sAC) to promote the cAMP-mediated pathway that increases flagellar beat frequency. Stimulation of sAC may occur when HCO3? enters spermatozoa either directly by anion transport or indirectly via diffusion of CO2 with subsequent hydration by intracellular carbonic anhydrase (CA). We here show that murine sperm possess extracellular CA IV that is transferred to the sperm surface as the sperm pass through the epididymis. Comparison of CA IV expression by qRT PCR analysis confirms that the transfer takes place in the corpus epididymidis. We demonstrate murine and human sperm respond to CO2 with an increase in beat frequency, an effect that can be inhibited by ethoxyzolamide. Comparing CA activity in sperm from wild-type and CA IV?/? mice we found a 32.13% reduction in total CA activity in the latter. The CA IV?/? sperm also have a reduced response to CO2. While the beat frequency of wild-type sperm increases from 2.86±0.12 Hz to 6.87±0.34 Hz after CO2 application, beat frequency of CA IV?/? sperm only increases from 3.06±0.20 Hz to 5.29±0.47 Hz. We show, for the first time, a physiological role of CA IV that supplies sperm with HCO3?, which is necessary for stimulation of sAC and hence early activation of spermatozoa.

Mannowetz, Nadja; Becker, Holger M.; Deitmer, Joachim W.; Sly, William S.; Wennemuth, Gunther

2010-01-01

314

Biodiversity Increases the Productivity and Stability of Phytoplankton Communities  

PubMed Central

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 alteration in consumer functioning. Our findings underscore the importance of predator-prey dynamics in determining the relationships between biodiversity, productivity and stability in producer communities.

Corcoran, Alina A.; Boeing, Wiebke J.

2012-01-01

315

Non-viral transfection of goat germline stem cells by nucleofection results in production of transgenic sperm after germ cell transplantation.  

PubMed

Germline stem cells (GSCs) can be used for large animal transgenesis, in which GSCs that are genetically manipulated in vitro are transplanted into a recipient testis to generate donor-derived transgenic sperm. The objectives of this study were to explore a non-viral approach for transgene delivery into goat GSCs and to investigate the efficiency of nucleofection in producing transgenic sperm. Four recipient goats received fractionated irradiation at 8 weeks of age to deplete endogenous GSCs. Germ cell transplantations were performed 8-9 weeks post-irradiation. Donor cells were collected from testes of 9-week-old goats, enriched for GSCs by Staput velocity sedimentation, and transfected by nucleofection with a transgene construct harboring the human growth hormone gene under the control of the goat beta-casein promoter (GBC) and a chicken beta-globin insulator (CBGI) sequence upstream of the promoter. For each recipient, transfected cells from 10 nucleofection reactions were pooled, mixed with non-transfected cells to a total of 1.5?×?10(8) cells in 3?ml, and transplanted into one testis (n?=?4 recipients) by ultrasound-guided cannulation of the rete testis. The second testis of each recipient was removed. Semen was collected, starting at 9 months after transplantation, for a period of over a year (a total of 62 ejaculates from four recipients). Nested genomic PCR for hGH and CBGI sequences demonstrated that 31.3%?±?12.6% of ejaculates were positive for both hGH and CBGI. This study provides proof-of-concept that non-viral transfection (nucleofection) of primary goat germ cells followed by germ cell transplantation results in transgene transmission to sperm in recipient goats. PMID:22231935

Zeng, W; Tang, L; Bondareva, A; Luo, J; Megee, S O; Modelski, M; Blash, S; Melican, D T; Destrempes, M M; Overton, S A; Gavin, W G; Ayres, S; Echelard, Y; Dobrinski, I

2012-01-09

316

Sperm ultrastructure, morphometry, and abnormal morphology in American black bears (Ursus americanus).  

PubMed

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 ?m, respectively, whereas sperm head length, width, and base width were 6.6, 4.8, and 2.3 ?m, and midpiece, tail (including midpiece), and total sperm lengths were 9.8, 68.8, and 75.3 ?m. 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. PMID:20708230

Brito, L F C; Sertich, P L; Stull, G B; Rives, W; Knobbe, M

2010-08-12

317

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

Microsoft Academic Search

An extension of a male reproductive study conducted in a boric acid\\/borate production zone at Band?rma, Turkey, is presented.\\u000a The relation between DNA-strand breaks (COMET assay, neutral and alkaline version) in sperm cells and previously described\\u000a sperm quality parameters was investigated in boron-exposed males. A correlation between blood boron levels and mean DNA-strand\\u000a breaks in sperm was weak, and DNA-strand

Yalç?n Duydu; Nur?en Ba?aran; Aylin Üstünda?; Sevtap Ayd?n; Ülkü Ünde?er; Osman Yavuz Ataman; Kaan Aydos; Yalç?n Düker; Katja Ickstadt; Britta Schulze Waltrup; Klaus Golka; Hermann M. Bolt

318

Youth WorxIncreasing youth participation through media production  

Microsoft Academic Search

The YouthWorx project is a recently established initiative in inner urban Melbourne that enables ‘at risk’ and marginalized young people to participate in community radio and in multimedia production. YouthWorx seeks to offer direct pathways from youth arts to skill-building, and to entice disaffected young people into more socially productive pathways, through the provision of high-quality media and multimedia training.

Liza Hopkins

2011-01-01

319

The effects of male age on sperm analysis by motile sperm organelle morphology examination (MSOME)  

PubMed Central

Background This study aimed to investigate the influence of age on sperm quality, as analysed by motile sperm organelle morphology examination (MSOME). Methods Semen samples were collected from 975 men undergoing evaluation or treatment for infertility. Sperm cells were evaluated at 8400× magnification using an inverted microscope equipped with Nomarski (differential interference contrast) optics. Two forms of spermatozoa were considered: normal spermatozoa and spermatozoa with large nuclear vacuoles (LNV, defined as vacuoles occupying > 50% of the sperm nuclear area). At least 200 spermatozoa per sample were evaluated, and the percentages of normal and LNV spermatozoa were determined. The subjects were divided into three groups according to age: Group I, less than or equal to 35 years; Group II, 36-40 years; and Group III, greater than or equal to 41 years. Results There was no difference in the percentages of normal sperm between the two younger (I and II) groups (P >0.05). The percentage of normal sperm in the older group (III) was significantly lower than that in the younger (I and II) groups (P < 0.05). There was no difference in the percentage of LNV spermatozoa between the younger (I and II) groups (P >0.05). The percentage of LNV spermatozoa was significantly higher in the older group (III) than in the younger (I and II) groups (P < 0.05). Regression analysis demonstrated a significant decrease in the incidence of normal sperm with increasing age (P < 0.05; r = -0.10). However, there was a significant positive correlation between the percentage of spermatozoa with LNV and male age (P < 0.05, r = 0.10). Conclusion The results demonstrated a consistent decline in semen quality, as reflected by morphological evaluation by MSOME, with increased age. Considering the relationship between nuclear vacuoles and DNA damage, these age-related changes predict that increased paternal age should be associated with unsuccessful or abnormal pregnancy as a consequence of fertilisation with damaged spermatozoa. Given that sperm nuclear vacuoles can be evaluated more precisely at high magnification, these results support the routine use of MSOME for ICSI as a criterion for semen analysis.

2012-01-01

320

Sunscreen products increase virus production through prophage induction in marine bacterioplankton.  

PubMed

Classical pollutants (e.g., hydrocarbon, pesticides) have been recently recognized to induce lytic cycle in lysogenic bacteria, but information on micro-pollutants is almost completely lacking. We investigated the effects of cosmetic sun products (sunscreen and solar oil) on viral abundance and bacterial activity. We found that both sunscreen and solar oil acted as pollutants, inducing viral development and controlling bacterial abundance and production, thus leading to an increase of the virus to bacterium ratio. Short-term experiments revealed that sunscreen supplementation induced the lytic cycle in a large fraction of total bacterial abundance (13-24% of bacteria, at low and high concentrations, respectively), whereas solar oil had a lower impact (6-9%). A synchronized development of the phage-host system was observed only after sunscreen addition. The addition of sunscreen, even at low concentrations, had a significant impact on all enzymatic activities (aminopeptidase, glucosidase, and phosphatase), which increased significantly. However, when enzymatic activities were normalized per cell, a selective enhancement was observed for certain enzymes (e.g., aminopeptidase) and inhibition for others (e.g., glucosidase). These results indicate that sunscreen products can modify C, N, and P biogeochemical cycling in seawater and increase virus abundance through prophage induction in marine bacterioplankton. PMID:12545312

Danovaro, R; Corinaldesi, C

2003-01-28

321

Engineering precursor flow for increased erythromycin production in Aeromicrobium erythreum.  

PubMed

Metabolic engineering technology for industrial microorganisms is under development to create rational, more reliable, and more cost-effective approaches to strain improvement. Strain improvement is a critical component of the drug development process, yet the genetic basis for high production by industrial microorganisms is still a mystery. In this study, a search was begun for genetic modifications critical for high-level antibiotic production. The model system used was erythromycin production studied in the unicellular actinomycete, Aeromicrobium erythreum. A tagged-mutagenesis approach allowed reverse engineering of improved strains, revealing two genes, mutB and cobA, in the primary metabolic branch for methylmalonyl-CoA utilization. Knockouts in these genes created a permanent metabolic switch in the flow of methylmalonyl-CoA, from the primary branch into a secondary metabolic branch, driving erythromycin overproduction. The model provides insights into the regulation and evolution of secondary metabolism. PMID:15491860

Reeves, Andrew R; Cernota, William H; Brikun, Igor A; Wesley, Roy K; Weber, J Mark

2004-10-01

322

Intra-industry trade in intermediate products, pollution and internationally increasing returns  

Microsoft Academic Search

This paper examines the relationship between intra-industry trade in intermediate products, pollution and increasing returns. We develop a two-country model in which production occurs in two stages, final and intermediate good production. Intermediate goods are produced under monopolistic competition and final good production exhibits increasing returns with respect to the number of varieties of intermediates. Pollution occurs in the production

Michael Benarroch; Rolf Weder

2006-01-01

323

CO sub 2 and HC injection lead EOR production increase  

SciTech Connect

This worldwide survey of enhanced oil recovery shows that although chemical EOR has drastically decreased in the U.S., the production gain from CO{sub 2} and low-molecular-weight hydrocarbon gas injection has more than offset losses from chemical and steam. Steam EOR may have peaked in the U.S., but internationally such projects as the Duri field in Indonesia will substantially boost enhanced oil production through the mid-1990s. The continued importance of enhanced oil recovery is reflected in the survey.

Moritis, G

1990-04-23

324

Changing World Product Markets and Potential Refining Capacity Increases  

EIA Publications

The presentation explores potential refinery capacity increases over the next 5 years in various world regions, based on changing demand patterns, changing price incentives, and capacity expansion announcements.

Information Center

2006-03-20

325

Methods of sperm vitality assessment.  

PubMed

Sperm vitality is a reflection of the proportion of live, membrane-intact spermatozoa determined by either dye exclusion or osmoregulatory capacity under hypo-osmotic conditions. In this chapter we address the two most common methods of sperm vitality assessment: eosin-nigrosin staining and the hypo-osmotic swelling test, both utilized in clinical Andrology laboratories. PMID:22992899

Moskovtsev, Sergey I; Librach, Clifford L

2013-01-01

326

Sustainable Harvests Through Increased Utilization of Salmon By-Products  

Technology Transfer Automated Retrieval System (TEKTRAN)

The growing demand for fish meals and oils has produced a steady rise in the market price garnered by these commodities. However, the practice of discarding fish-processing wastes is still widespread. Alaska’s fishing industry generates over one million metric tons of fish by-products each year, muc...

327

Sperm donation in Israel.  

PubMed

Science and technology in the field of human reproduction present new legal, ethical and religious questions which do not always have immediate answers. The first step in the rapidly developed field of reproductive technology was the use of sperm donation (artificial insemination by donor, AID) and the establishment of sperm banks. The state of Israel faced these problems when the regulations for sperm donation were discussed. The fact that the main holy places for the three monotheistic religions are in Israel directly influences the make-up of the population constituents. Therefore, besides a majority of secular people, a high percentage of the population of Israel is very religious: Jews, Moslems and Christians. Thus any resolution relating to AID should take this demographic combination into account. The practice of AID is opposed by the different monotheistic religions. To avoid the conflict between secular and religious people, and between the different religions' perspectives, the legal problem of AID in Israel was solved not by laws but by regulations which were published by the Ministry of Health. The main idea behind this attitude is that the state and its authorities should not and do not deal with ethical or religious questions. Thus, the decision was left to the couples and to the donors. The regulations address technical requirements, health problems and confidential issues concerning the couple, the donor and the child. In this paper we present the different views relating to these problems as perceived by the different religions, and describe the solution that was accepted by the Israeli Ministry of Health. PMID:7650152

Mor-Yosef, S; Schenker, J G

1995-04-01

328

Murine SPAM1 is secreted by the estrous uterus and oviduct in a form that can bind to sperm during capacitation: acquisition enhances hyaluronic acid-binding ability and cumulus dispersal efficiency  

Microsoft Academic Search

Sperm uptake of epididymal sperm adhesion molecule 1 (SPAM1) in vitro has recently been shown to be a marker of sperm maturation, since acquisition of this surface hyaluronidase increases cumulus dispersal efficiency. Here, we demonstrate that this glycosyl phosphatidylinositol-linked sperm antigen, previously shown to be expressed during estrous in the female reproductive tract, is secreted in the uterine and oviductal

Genevieve S Griffiths; Kimberly A Miller; Deni S Galileo; Patricia A Martin-DeLeon

2008-01-01

329

A biomarker approach to endocrine disruption in flounder--estrogen receptors, hepatocyte proliferation, and sperm motility.  

PubMed

Three different physiological parameters were assessed to determine their potential for serving as biomarkers to predict abnormally elevated vitellogenin (VTG) production in male and immature flounder. Whereas abnormally elevated mean VTG plasma concentrations clearly distinguished the Mersey and Dee flounder studied, the results showed no significant differences in estrogen receptor binding capacity or binding affinity between the two groups. Hepatocyte proliferation was not found to be a "biomarker of effect" that could specifically be used to assess an increase in VTG-related proliferation. Nevertheless, immunohistochemical staining for proliferating cell nuclear antigen did show a significantly higher proliferative activity in the livers of Mersey flounder than that in Dee flounder. Sperm motility also was not found to be a biomarker of effect linked to an abnormal elevation of VTG plasma concentration. The results (higher sperm quality in terms of motility in Mersey flounder) were unexpected but interesting. PMID:15223258

Kleinkauf, Anne; Macfarlane, Chris; Yeates, Sarah; Simpson, Michael G; Leah, Richard T

2004-07-01

330

Viewing death on television increases the appeal of advertised products.  

PubMed

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. PMID:22468421

Dar-Nimrod, Ilan

331

Impact of biofuel production and other supply and demand factors on food price increases in 2008  

Microsoft Academic Search

The prices of some grain commodities more than doubled from March 2007 to March 2008. Increased food prices coincided with increasing global biofuel production, leading to speculation that biofuel production was responsible for the increased food prices. However, over the six-month period after March 2008, grain prices declined by 50% while biofuel production continued to increase. It is not possible

Sherry A. Mueller; James E. Anderson; Timothy J. Wallington

2011-01-01

332

Increasing in vitro microrhizome production of ginger ( Zingiber officinale Roscoe)  

Microsoft Academic Search

In this study, using the quadratic saturation 310 D-optimal design method, we examined the effect of kinetin (KT), gibberellic\\u000a acid (GA), and naphthalene acetic acid (NAA) on microrhizome production in ginger. The effect of GA on rhizome induction was\\u000a larger than that of KT or NAA. Using simulation and optimality selection for tissue culture, we found that concentrations\\u000a of GA,

Yongqiang Zheng; Yanmei Liu; Mi Ma; Kun Xu

2008-01-01

333

CO sub 2 and HC injection lead EOR production increase  

Microsoft Academic Search

This worldwide survey of enhanced oil recovery shows that although chemical EOR has drastically decreased in the U.S., the production gain from COâ and low-molecular-weight hydrocarbon gas injection has more than offset losses from chemical and steam. Steam EOR may have peaked in the U.S., but internationally such projects as the Duri field in Indonesia will substantially boost enhanced oil

Moritis

1990-01-01

334

Increased biological hydrogen production with reduced organic loading  

Microsoft Academic Search

An experimental matrix consisting of reactor hydraulic retention time (HRT) and glucose loading rate was tested to understand the effect of organic loading on H2 production in chemostat reactors. In order to vary the glucose loading rate over a range of 0.5–18.9g\\/h, the glucose concentration in the feed was varied from 2.5 to 10gCOD\\/L under conditions where the HRT varied

Steven W. Van Ginkel; Bruce Logan

2005-01-01

335

Fertilization Is Not a New Beginning: The Relationship between Sperm Longevity and Offspring Performance  

PubMed Central

Sperm are the most diverse cell type known: varying not only among- and within- species, but also among- and within-ejaculates of a single male. Recently, the causes and consequences of variability in sperm phenotypes have received much attention, but the importance of within-ejaculate variability remains largely unknown. Correlative evidence suggests that reduced within-ejaculate variation in sperm phenotype increases a male’s fertilization success in competitive conditions; but the transgenerational consequences of within-ejaculate variation in sperm phenotype remain relatively unexplored. Here we examine the relationship between sperm longevity and offspring performance in a marine invertebrate with external fertilization, Styela plicata. Offspring sired by longer-lived sperm had higher performance compared to offspring sired by freshly-extracted sperm of the same ejaculate, both in the laboratory and the field. This indicates that within-ejaculate differences in sperm longevity can influence offspring fitness – a source of variability in offspring phenotypes that has not previously been considered. Links between sperm phenotype and offspring performance may constrain responses to selection on either sperm or offspring traits, with broad ecological and evolutionary implications.

Crean, Angela J.; Dwyer, John M.; Marshall, Dustin J.

2012-01-01

336

Quantification of mammalian sperm morphology by slit-scan flow cytometry  

SciTech Connect

The head shapes of mammalian sperm were measured by slit-scan flow cytometry (SSFCM). Fluorescence profiles were measured for sperm from mice, rabbits, hamsters, and bulls, and for sperm from mice, rabbits, hamsters, and bulls, and for sperm from mice exposed to testicular x-irradiation from 0 to 900 rads. Some of the fluorescence profiles for sperm from the irradiated mice differed significantly from the profiles usually measured for sperm from unexposed mice. An algorithm was developed to determine the frequency of these sperm. The estimated frequencies of atypical profiles correlated well with the frequencies of abnormally shaped sperm determined by microscopic scoring. The maximum SSFCM sensitivity was not as high as that for the visual assay. 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 coupled 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.

Benaron, D.A.; Gray, J.W.; Gledhill, B.L.; Lake, S.; Wyrobek, A.J.; Young, I.T.

1982-01-01

337

Effects of progesterone on sperm motility in fathead minnow (Pimephales promelas).  

PubMed

The steroid hormone progesterone (P4) is found at relatively high concentrations (?300 ng/L) in association with concentrated animal feeding operations (CAFOs). In an effort to better understand the potential endocrine disrupting effects of P4 in male fish, computer assisted sperm analysis (CASA) was used to evaluate the effects of this steroid on sperm motility in the fathead minnow (Pimephales promelas). The rationale for focusing on sperm motility is that certain progestins have been shown to bind to surface membrane receptors on fish spermatozoa and increase sperm swimming velocity. It was hypothesized, therefore, that sperm swimming velocity might be a useful indicator of progestin exposure in fish. Adult male fathead minnows (ages 6-12 months) were exposed to environmentally relevant doses of P4, both longer-term (1 week, in vivo exposure) and short-term (minutes, in vitro exposure). Sperm were then video recorded and analyzed by CASA. When fathead minnows were continuously exposed for 1 week to low levels of progesterone in vivo there was a significant dose-dependent reduction in sperm motility. There was no effect of short-term P4 exposure on fathead minnow sperm swimming characteristics. Additional research is required to elucidate the mechanism by which progesterone alters sperm swimming in the fathead minnow. With further validation, the fathead minnow sperm motility assay may be a useful tool to rapidly screen for endocrine disrupting chemicals in the aquatic environment. PMID:21569753

Murack, Patrick J; Parrish, John; Barry, Terence P

2011-04-15

338

The importance of redox regulated pathways in sperm cell biology.  

PubMed

Redox regulated events are fundamental to our understanding of many cellular pathways and pathological processes. On the one hand, production of reactive oxygen species by mammalian spermatozoa has been associated with a loss of cell function and DNA integrity as a consequence of oxidative stress. These cells are exquisitely sensitive to such damage as a consequence of their relative lack of cytosolic antioxidant enzymes and relative abundance of polyunsaturated fatty acids. Given this susceptibility, it is surprising to discover that spermatozoa are intensely redox active cells and professional generators of reactive oxygen species. The latter are physiologically important to the spermatozoa in regulating every aspect of sperm function examined, including their movement characteristics, capacitation, sperm-zona interaction, the acrosome reaction and sperm-oocyte fusion. The molecular basis of this redox drive is still poorly understood in terms of the source of the reactive oxygen species and the mechanisms by which these reactive metabolites enhance sperm function. Recent advances include the discovery of NOX5 in the male germ line and elucidation of the role of reactive oxygen species in controlling a unique signal transduction cascade associated with sperm capacitation. Given the central importance of redox chemistry in the control of sperm function further research in this area may uncover valuable targets for contraceptive intervention. PMID:15109744

Baker, Mark A; Aitken, R John

2004-03-15

339

Sperm fate and function in reproductive isolation in Drosophila.  

PubMed

Central to the study of speciation is the identification of the isolating mechanisms that reduce gene flow. Of special interest are those isolating mechanisms that are the earliest to arise. Sperm fate and function play a major role in two distinct types of reproductive isolation in the genus Drosophila. First, postcopulatory-prezygotic (PCPZ) incompatibilities between the male ejaculate and a heterospecific female reproductive tract can result in a reduction in sperm fertilisation success. Although PCPZ incompatibilities have, until recently, received little attention, overwhelming diversity in reproductive morphology and biochemistry indicates that they may play an important role in speciation in this genus. The second type of isolating mechanism that affects sperm occurs in the testes of hybrid males produced by heterospecific matings. These individuals often suffer from dysfunction in spermatogenesis, resulting in the production of aberrant sperm. Hybrid male sterility and hybrid inviability are examples of postzygotic (PZ) reproductive isolation. The observation that hybrid sterility is pervasive among males of all taxonomic groups is known as Haldane's rule. Here we discuss both the evolutionary origins, and functional causes of both PCPZ incompatibilities, which affects sperm fate and function in females, and one type of PZ incompatibility, hybrid male sterility, or sperm dysfunction in hybrid males. Although these two mechanisms of isolation are quite distinct, they are similarly caused by breakdowns in epistatic interactions which occur in the encounter between two divergent genomes. Molecular, cytological, and empirical data are discussed, as is relevant evolutionary theory. PMID:17644960

Markow, Therese Ann; Reed, Laura K; Kelleher, Erin S

2007-01-01

340

Sulfate addition increases methylmercury production in an experimental wetland.  

PubMed

Atmospheric mercury is the dominant Hg source to fish in northern Minnesota and elsewhere. However, atmospherically derived Hg must be methylated prior to accumulating in fish. Sulfate-reducing bacteria are thought to be the primary methylators of Hg in the environment. Previous laboratory and field mesocosm studies have demonstrated an increase in methylmercury (MeHg) levels in sediment and peatland porewaters following additions of sulfate. In the current ecosystem-scale study, sulfate was added to half of an experimental wetland at the Marcell Experimental Forest located in northeastern Minnesota, increasing annual sulfate load by approximately four times relative to the control half of the wetland. Sulfate was added on four separate occasions during 2002 and delivered via a sprinkler system constructed on the southeast half (1.0 ha) of the S6 experimental wetland. MeHg levels were monitored in porewater and in outflow from the wetland. Prior to the first sulfate addition, MeHg concentrations (filtered, 0.7 microm) were not statistically different between the control (0.47 +/- 0.10 ng L(-1), n = 12; mean +/- one standard error) and experimental 0.52 +/- 0.05 ng L(-1), n = 18) halves. Following the first addition in May 2002, MeHg porewater concentrations increased to 1.63 +/- 0.27 ng L(-1) two weeks after the addition, a 3-fold increase. Subsequent additions in July and September 2002 did not raise porewater MeHg, but the applied sulfate was not observed in porewaters 24 h after addition. MeHg concentrations in outflow from the wetland also increased leading to an estimated 2.4x increase of MeHg flux from the wetland. Our results demonstrate enhanced methylation and increased MeHg concentrations within the wetland and in outflow from the wetland suggesting that decreasing sulfate deposition rates would lower MeHg export from wetlands. PMID:16830545

Jeremiason, Jeff D; Engstrom, Daniel R; Swain, Edward B; Nater, Edward A; Johnson, Brian M; Almendinger, James E; Monson, Bruce A; Kolka, Randy K

2006-06-15

341

Liposomes for cryopreservation of bovine sperm.  

PubMed

In this study, the effect of various unilamellar liposomes on cryopreservation of bovine spermatozoa has been investigated. Liposomes were composed of saturated lipids with various acyl chain lengths: DSPC (18:0), DPPC (16:0), DMPC (14:0), or DLPC (12:0). Alternatively, liposomes were prepared using unsaturated egg phosphatidylcholine (EPC) or DOPC (18:1, neutral), alone or in combination with lipids with various head groups: DOPS (negatively charged), DOPG (negatively charged), and DOPE (neutral). Fourier transform infrared spectroscopy studies showed that bovine sperm membranes display a gradual phase transition from 10 to 24 (o)C. Phase transition temperatures of the liposomes varied from -20 to +53 (o)C. Sperm was incubated in the presence of liposomes for either 6 or 24 h at 4 °C prior to freezing. Postfreeze survival rates were determined based on the percentage of progressively motile cells as well as the percentage of acrosome- and plasma membrane-intact cells. With DOPC liposomes a postthaw progressive motility of 43% was obtained compared with 59% using standard egg yolk freezing extender. Postthaw progressive motility increased up to 52% using DOPC:DOPG (9:1) liposomes, whereas DOPC:DOPS or DOPC:DOPE liposomes did not increase survival compared with DOPC liposomes. Among the saturated lipids, only DMPC was found to increase cryosurvival, up to 44% based on progressive motility. DLPC liposomes caused a complete loss in cell viability, already prior to freezing, whereas DPPC and DSPC liposomes neither positively nor negatively affected cryosurvival. Taken together, the higher postthaw survival obtained with DOPC:DOPG liposomes as compared with DOPC liposomes can likely be attributed to increased liposome-sperm interactions between the charged phosphatidylglycerol groups and charged regions in the sperm membranes. Interestingly, the lipid phase state of the liposomes during preincubation is not the decisive factor for their cryoprotective action. PMID:21820724

Röpke, T; Oldenhof, H; Leiding, C; Sieme, H; Bollwein, H; Wolkers, W F

2011-08-06

342

The CatSper channel mediates progesterone-induced Ca2+ influx in human sperm  

Microsoft Academic Search

In the oviduct, cumulus cells that surround the oocyte release progesterone. In human sperm, progesterone stimulates a Ca2+ increase by a non-genomic mechanism. The Ca2+ signal has been proposed to control chemotaxis, hyperactivation and acrosomal exocytosis of sperm. However, the underlying signalling mechanism has remained mysterious. Here we show that progesterone activates the sperm-specific, pH-sensitive CatSper Ca2+ channel. We found

Timo Strünker; Normann Goodwin; Christoph Brenker; Nachiket D. Kashikar; Ingo Weyand; Reinhard Seifert; U. Benjamin Kaupp

2011-01-01

343

Functional Nonequivalence of Sperm in Drosophila pseudoobscura  

Microsoft Academic Search

We report on a form of sperm polymorphism, termed polymegaly, that occurs in species of the Drosophila obscura group. Individual males of species in this group characteristically produce more than one discrete length of nucleated, motile sperm. Hypotheses suggested to explain the evolutionary significance of sperm polymorphism have been either nonadaptive or adaptive, with the latter focusing on sperm competition

Rhonda R. Snook; Therese A. Markow; Timothy L. Karr

1994-01-01

344

Calibrating Ultraviolet Irradiation of Fish Sperm  

Microsoft Academic Search

Milt collected from common carp, Cyprinus carpio, and bluegill, Lepomis macrochirus, was irradiated with ultraviolet (UV) light to evaluate the effects on sperm viability as a function of sperm concentration and UV dose. The optical density of milt samples was determined using UV spectrophotometry. Sperm viability was estimated, based on motility and fertilization of eggs following UV radiation. Sperm samples

Michael D. Porter

1998-01-01

345

Quantitative ultrastructural analysis of barley sperm  

Microsoft Academic Search

Summary Complete serial ultrathin sections of seven sperm pairs, computer-assisted measurements of cell, nuclear and organelle surface areas and volumes, and three-dimensional imagery were used to demonstrate that a process of cytoplasm and organelle elimination occurs during sperm maturation in barley. The number of mitochondria per sperm cell is reduced by 50%; sperm cell surface area and volume are reduced

H. L. Mogensen; Maxine Losoff Rusche

1985-01-01

346

Golbal Economic and Environmental Impacts of Increased Bioenergy Production  

SciTech Connect

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.

Wallace Tyner

2012-05-30

347

Steam treatment of digested biofibers for increasing biogas production  

Microsoft Academic Search

The aim of this study was to elucidate the effect of steam pretreatment on the biomethane potential of biofibers from digested manure. These biofibers were treated for 15min with steam in a pressure vessel. The effect of steam treatment temperature, solids content, catalyst concentration and time of pre-soaking on the methane potential of the biofibers was determined. The highest increase

Emiliano Bruni; Anders Peter Jensen; Irini Angelidaki

2010-01-01

348

Process for increasing Bright Stock raffinate oil production  

Microsoft Academic Search

A process is described for increasing the amount of Bright Stock raffinate oil derived from the solvent extraction of deasphalted lube oil involving the steps of: (a) extracting a vacuum residuum with a low molecular weight alkane hydrocarbon solvent resulting in a deasphalted lube oil solution and asphaltic residue; (b) separating the deasphalted lube oil and the residue; (c) separating

D. J. Bristow; B. U. Achia; L. J. Evers

1986-01-01

349

Gestational protein restriction increases angiotensin II production in rat lung.  

PubMed

Gestational protein restriction (PR) alters the renin-angiotensin system in uterine arteries and placentas and elevates plasma levels of angiotensin II in pregnant rats. To date, how PR increases maternal plasma levels of angiotensin II remains unknown. In this study, we hypothesize that the expression and/or the activity of angiotensin I converting enzyme (peptidyl-dipeptidase A) 1 (ACE) in lungs, but not kidneys and blood, largely contribute to elevated plasma angiotensin II levels in pregnant rats subject to gestational PR. Time-scheduled pregnant Sprague-Dawley rats were fed a normal or low-protein diet from Day 3 of pregnancy until euthanized at Day 19 or 22. Expressions of Ace and Ace2 (angiotens in I converting enzyme [peptidyl-dipeptidase A] 2) in lungs and kidneys from pregnant rats by quantitative real-time PCR and Western blotting, and the activities of these proteins in lungs, kidneys, and plasma, were measured. The mRNA levels of Ace and Ace2 in lungs were elevated by PR at both Days 19 and 22 of pregnancy. The abundance of ACE protein in lungs was increased, but ACE2 protein was decreased, by PR. The activities of ACE, but not ACE2, in lungs were increased by PR. PR did not change expressions of Ace and Ace2, the activities of both ACE and ACE2 in kidneys, and the abundance and activity of plasma ACE. These findings suggest that maternal lungs contribute to the elevated plasma levels of angiotensin II by increasing both the expression and the activity of ACE in response to gestational PR. PMID:23365412

Gao, Haijun; Yallampalli, Uma; Yallampalli, Chandra

2013-03-14

350

Cinnamic Acid Increases Lignin Production and Inhibits Soybean Root Growth  

PubMed Central

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.

Salvador, Victor Hugo; Lima, Rogerio Barbosa; dos Santos, Wanderley Dantas; Soares, Anderson Ricardo; Bohm, Paulo Alfredo Feitoza; Marchiosi, Rogerio; Ferrarese, Maria de Lourdes Lucio; Ferrarese-Filho, Osvaldo

2013-01-01

351

Comparative sperm ultrastructure in Nemertea.  

PubMed

Although the monophyly of Nemertea is strongly supported by unique morphological characters and results of molecular phylogenetic studies, their ingroup relationships are largely unresolved. To contribute solving this problem we studied sperm ultrastructure of 12 nemertean species that belong to different subtaxa representing the commonly recognized major monophyletic groups. The study yielded a set of 26 characters with an unexpected variation among species of the same genus (Tubulanus and Procephalothrix species), whereas other species varied in metric values or only one character state (Ramphogordius). In some species, the sperm nucleus has grooves (Zygonemertes virescens, Amphiporus imparispinosus) that may be twisted and give a spiral shape to the sperm head (Paranemertes peregrina, Emplectonema gracile). To make the characters from sperm ultrastructure accessible for further phylogenetic analyses, they were coded in a character matrix. Published data for eight species turned out to be sufficiently detailed to be included. Comparative evaluation of available information on the sperm ultrastructure suggests that subtaxa of Heteronemertea and Hoplonemertea are supported as monophyletic by sperm morphology. However, the data do not provide information on the existing contradictions regarding the internal relationships of "Palaeonemertea." Nevertheless, our study provides evidence that sperm ultrastructure yields numerous potentially informative characters that will be included in upcoming phylogenetic analyses. PMID:20544873

von Döhren, J; Beckers, P; Vogeler, R; Bartolomaeus, T

2010-07-01

352

Calaxin drives sperm chemotaxis by Ca2+-mediated direct modulation of a dynein motor  

PubMed Central

Sperm chemotaxis occurs widely in animals and plants and plays an important role in the success of fertilization. Several studies have recently demonstrated that Ca2+ influx through specific Ca2+ channels is a prerequisite for sperm chemotactic movement. However, the regulator that modulates flagellar movement in response to Ca2+ is unknown. Here we show that a neuronal calcium sensor, calaxin, directly acts on outer-arm dynein and regulates specific flagellar movement during sperm chemotaxis. Calaxin inhibition resulted in significant loss of sperm chemotactic movement, despite normal increases in intracellular calcium concentration. Using a demembranated sperm model, we demonstrate that calaxin is essential for generation and propagation of Ca2+-induced asymmetric flagellar bending. An in vitro motility assay revealed that calaxin directly suppressed the velocity of microtubule sliding by outer-arm dynein at high Ca2+ concentrations. This study describes the missing link between chemoattractant-mediated Ca2+ signaling and motor-driven microtubule sliding during sperm chemotaxis.

Mizuno, Katsutoshi; Shiba, Kogiku; Okai, Masahiko; Takahashi, Yusuke; Shitaka, Yuji; Oiwa, Kazuhiro; Tanokura, Masaru; Inaba, Kazuo

2012-01-01

353

?1 Integrin is an Adhesion Protein for Sperm Binding to Eggs  

PubMed Central

We investigated the role of ?1 integrin in mammalian fertilization and the mode of inhibition of fertilin?-derived polymers. We determined that polymers displaying the Glu-Cys-Asp peptide from the fertilin? disintegrin domain mediate inhibition of mammalian fertilization through a ?1 integrin receptor on the egg surface. Inhibition of fertilization is a consequence of competition with sperm binding to the cell surface, not activation of an egg-signaling pathway. The presence of the ?1 integrin on the egg surface increases the rate of sperm attachment, but does not alter the total number of sperm that can attach or fuse to the egg. We conclude that the presence of ?1 integrin enhances the initial adhesion of sperm to the egg plasma membrane and that subsequent attachment and fusion are mediated by additional egg and sperm proteins present in the ?1 integrin complex. Therefore, the mechanisms by which sperm fertilize wild-type and ?1 knockout eggs are different.

Baessler, Keith A.; Lee, Younjoo; Sampson, Nicole S.

2009-01-01

354

A High-Throughput Method For Zebrafish Sperm Cryopreservation and In Vitro Fertilization  

PubMed Central

This is a method for zebrafish sperm cryopreservation that is an adaptation of the Harvey method (Harvey et al., 1982). We have introduced two changes to the original protocol that both streamline the procedure and increase sample uniformity. First, we normalize all sperm volumes using freezing media that does not contain the cryoprotectant. Second, cryopreserved sperm are stored in cryovials instead of capillary tubes. The rates of sperm freezing and thawing (?°C/time) are probably the two most critical variables to control in this procedure. For this reason, do not substitute different tubes for those specified. Working in teams of 2 it is possible to freeze the sperm of 100 males per team in ~2 hrs. Sperm cryopreserved using this protocol has an average of 25% fertility (measured as the number of viable embryos generated in an in vitro fertilization divided by the total number of eggs fertilized) and this percent fertility is stable over many years.

Draper, Bruce W.; Moens, Cecilia B.

2009-01-01

355

Electrofusion-mediated transmission of cytoplasmic organelles through the in vitro fertilization process, fusion of sperm cells with synergids and central cells, and cell reconstitution in maize  

Microsoft Academic Search

Fusion products were created by the electrofusion of single sperm cells with single synergids and central cells. The synergid was also fused with the sperm cell, occasionally in the presence of adhering second synergids, egg cells, and central cells. Single egg cells were fused with single sperm cells in the presence of adhering synergids and the central cell. Cytoplasmic organelles

E. Kranz; J. Bautor; H. Lörz

1991-01-01

356

Radiation-induced DNA content variability in mouse sperm  

SciTech Connect

Mouse sperm collected from the cauda epididymidis 35 days after acute testicular x-ray exposure and fluorescently stained for DNA show dose-dependent increases in the coefficient of variation (CV) of flow cytometrically obtained fluorescence distributions. By comparing dose-response curves obtained with three protocols which overcome the optical and cytochemical difficulties of sperm measurement in different ways we conclude the response is due to x-ray-induced DNA content variability. Computer modeling of the shapes of the fluorescence distributions show that at 600 rad 30 to 40% of the sperm have abnormal DNA content. Some have errors as large as two whole chromosomes, but it is not clear whether they are due to whole chromosome nondisjunction or a finer fragmentation of the genome. Exposures to benzo(a)pyrene and mitomycin C cause no detectable DNA content variability. We conclude mouse sperm DNA content measurements are not sensitive to small amounts of aneuploidy and as such will only be useful in detecting agents that produce substantial DNA content variability. Another animal with a smaller number of chromosomes might be more favorable. These sperm measurement techniques may find additional application in other areas of reproductive biology, such as the determination of the relative numbers of X and Y chromosome-bearing sperm in semen that may be artifically enriched in one population.

Pinkel, D.; Gledhill, B.L.; van Dilla, M.A.; Lake, S.; Wyrobek, A.J.

1983-09-01

357

Downhole tools can increase deep drilling rig productivity  

SciTech Connect

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.

Thiessen, D.A.; Doiron, H.H.

1983-01-01

358

Polymer flooding increases production in giant oil field  

SciTech Connect

Daqing field, discovered in 1959, is the largest oil field in the People's Republic of China, with original oil in place exceeding two billion tons. Reservoir heterogeneity and oil viscosity have resulted in moderate displacement efficiency and high watercut. To increase recovery, polymer injection was tested in two pilots between 1987 and 1992, after lab and reservoir studies. Both pilots proved highly successful and led to the decision to extend polymer injection to the whole field. This article presents the history of Daqing polymer flooding, from preliminary studies to full-field extension.

Delamaide, E.; Corlay, P. (Inst. Francais du Petrole, Paris (France))

1994-12-01

359

How does increased corn-ethanol production affect US natural gas prices?  

Microsoft Academic Search

In recent years, there has been a push to increase biofuel production in the United States. The biofuel of choice, so far, has been ethanol produced from corn. The effects of increased corn-ethanol production on the consumer prices of food and energy continue to be studied and debated. This study examines, in particular, the effects of increased corn-ethanol production on

Jarrett Whistance; Wyatt Thompson

2010-01-01

360

No association between sperm competition and sperm length variation across dung flies (Scathophagidae).  

PubMed

Sperm length is extremely variable across species, but a general explanation for this variation is lacking. However, when the risk of sperm competition is high, sperm length is predicted to be less variable within species, and there is some evidence for this in birds and social insects. Here, we examined intraspecific variation in sperm length, both within and between males, and its potential associations with sperm competition risk and variation in female reproductive tract morphology across dung flies. We used two measures of variation in sperm size, and testis size was employed as our index of sperm competition risk. We found no evidence of associations between sperm length variation and sperm competition or female reproductive tract variation. These results suggest that variation in sperm competition risk may not always be associated with variation in sperm morphology, and the cause(s) of sperm length variation in dung flies remains unclear. PMID:24016061

Sharma, M D; Minder, A M; Hosken, D J

2013-09-10

361

Shorter sperm confer higher competitive fertilization success.  

PubMed

Spermatozoa exhibit taxonomically widespread patterns of divergent morphological evolution. However, the adaptive significance of variation in sperm morphology remains unclear. In this study we examine the role of natural variation in sperm length on fertilization success in the dung beetle Onthophagus taurus. We conducted sperm competition trials between males that differed in the length of their sperm and determined the paternity of resulting offspring using amplified fragment length polymorphism (AFLP) markers. We also quantified variation in the size and shape of the female's sperm storage organ to determine whether female morphology influenced the competitiveness of different sperm morphologies. We found that fertilization success was biased toward males with relatively shorter sperm, but that selection on sperm length was dependent on female tract morphology; selection was directional for reduced sperm length across most of the spermathecal size range, but stabilizing in females with the smallest spermathecae. Our data provide empirical support for the theory that sperm competition should favor the evolution of numerous tiny sperm. Moreover, because sperm length is both heritable and genetically correlated with condition, our results are consistent with a process by which females can accrue genetic benefits for their offspring from the incitement of sperm competition and/or cryptic female choice, as proposed by the "sexy sperm" and "good sperm" models for the evolution of polyandry. PMID:17439614

García-González, Francisco; Simmons, Leigh W

2007-04-01

362

Methods for Cryopreservation of Guinea Fowl Sperm  

PubMed Central

Conservation of indigenous poultry species is an important part of the new Hungarian agricultural strategy. Semen cryopreservation is the most practical method for the long term storage of poultry genetic material. The objective was to compare four protocols for cryopreservation of guinea fowl sperm (slow and fast programmable, freezing in nitrogen vapor, and pellet) and three cryoprotectants (10% ethylene glycol, 6% dimethyl-formamide and 6% dimethyl-acetamide). The efficiency of the methods was examined by in vitro tests (subjective motility scoring, sperm concentration, morphological and live/dead sperm analysis with eosin-aniline staining). Thereafter, the two most promising methods were tested by artificial insemination of frozen-thawed semen (3 times a week for 3 weeks using 300 million spermatozoa/hen), followed by candling of incubated eggs, assessment of fertilization, embryonic death, and hatching rate. The survival rate of live, intact spermatozoa was greatest (p?0.05) in pellet method and the slow programmable protocol (with 10% ethylene glycol) (28.6 and 23.5%). The two best protocols (based on in vitro assessment of post-thaw semen quality) were subsequently tested in vivo with artificial insemination. The pellet method yielded a 64% fertility rate compared to slow protocol with only 30% fertility. Regardless, both freezing protocols significantly increased embryonic deaths compared to the control group (16,7; 9,1 and 8,3%, respectively). During the 3-week in vivo trial, fertility increased and early embryonic death decreased over time. According to the results the guinea fowl sperm could tolerate the fast freezing in pellet better than the slower freezing rates and resulted acceptable fertility rate.

Varadi, Eva; Vegi, Barbara; Liptoi, Krisztina; Barna, Judit

2013-01-01

363

Oligodeoxyribonucleotides derived from salmon sperm DNA: an alternative to defibrotide.  

PubMed

Defibrotide is a single-stranded nucleic acid polymer originally derived from porcine mucosa. Cheap salmon sperm DNA is commercially available and widely used in drug production. In this study, oligodeoxyribonucleotides were successfully obtained from the controlled depolymerization of salmon sperm DNA. The obtained product shared similar chemical and biological properties with defibrotide produced by Gentium SpA, Italy. It was also found that oligodeoxyribonucleotides derived from non-mammalian origins could also directly stimulate tissue plasminogen activator (t-PA) release from cultured human endothelial cells, and enhance fibrinolytic activity in the rabbit. PMID:23375586

Hui, Chang-Ye; Guo, Yan; Zhang, Xi; Shao, Jian-Hua; Yang, Xue-Qin; Zhang, Wen

2013-01-30

364

Sea urchin sperm antigens mediating the acrosome reaction  

SciTech Connect

The study of sea urchin sperm antigens mediating the acrosome reactions (AR) has been undertaken. Monoclonal antibodies (mAbs) have been isolated reacting with a number of sperm surface antigens. These mAbs have been used in functional assays to attempt to infer the roles of these proteins in the induction of the AR. These mAbs have also been used to isolate protein for biochemical characterization and reconstitution studies. mAbs reacting with a 210 kD protein of the sea urchin sperm plasma membrane have been used to identify this protein as playing a role in the regulation of ion fluxes during the induction of the AR. mAbs reacting with certain extracellular regions inhibit the induction of: the AR, the long duration {sup 45}Ca{sup 2+} uptake into the mitochondrion, and H{sup +} efflux. Addition of these same mAbs, however, induces an increase in sperm (Ca{sup 2+}){sub i} to levels much higher than those induced by FSG, as monitored by the fluorescent Ca{sup 2+} indicators fura 2 and indo 1. This (Ca{sup 2+}){sub i} increase occurs without an increase in pH{sub i}, and thus allows for the first time the analysis of the effects of increasing sperm (Ca{sup 2+}){sub i} ion the absence of increased pH{sub i}.

Trimmer, J.S.

1987-01-01

365

Sperm aggregations in female Agkistrodon piscivorus (Reptilia:Squamata): a histological and ultrastructural investigation.  

PubMed

Upon copulation in female Agkistrodon piscivorus, sperm migrate up the oviduct to sperm storage tubules (SSTs) in the posterior infundibulum. The epithelium of the SSTs is composed of ciliated and secretory cells and differs ultrastructurally from that of the epithelium lining the lumen of the posterior infundibulum. Sperm pass through an area composed primarily of ciliated cells at the opening of each gland before aligning themselves in parallel arrays with their nuclei facing an area composed primarily of secretory cells at the base of the tubules. Sperm are also found embedded inter- and intracellularly in the SSTs. The secretory vacuoles in the SSTs become highly electron dense after the start of the fall mating season along with the synthesis of lipid droplets. Histochemical analysis reveals that the alteration in secretory material density is caused by the production of neutral carbohydrates. Some sperm remain in aggregates in the nonglandular section of the posterior uterus until the time of ovulation. However, ultrastructural evidence indicates these sperm degrade before ovulation. Therefore, sperm in posterior aggregates have no role in fertilization of ovulated ova. The data presented here support the hypothesis that infundibular sperm storage is the mode that snakes utilize to sequester viable sperm until ovulation. PMID:17935196

Siegel, Dustin S; Sever, David M

2008-02-01

366

Membrane phase behavior during cooling of stallion sperm and its correlation with freezability.  

PubMed

Stallion sperm exhibits great male-to-male variability in survival after cryopreservation. In this study, we have investigated if differences in sperm freezability can be attributed to membrane phase and permeability properties. Fourier transform infrared spectroscopy (FTIR) was used to determine supra and subzero membrane phase transitions and characteristic subzero membrane hydraulic permeability parameters. Sperm was obtained from stallions that show differences in sperm viability after cryopreservation. Stallion sperm undergoes a broad and gradual phase transition at suprazero temperatures, from 30-10°C, whereas freezing-induced dehydration of the cells causes a more severe phase transition to a highly ordered gel phase. Sperm from individual stallions showed significant differences in post-thaw progressive motility, percentages of sperm with abnormal cell morphology, and chromatin stability. The biophysical membrane properties evaluated in this study, however, did not show clear differences amongst stallions with differences in sperm freezability. Cyclodextrin treatment to remove cholesterol from the cellular membranes increased the cooperativity of the suprazero phase transition, but had little effects on the subzero membrane phase behavior. In contrast, freezing of sperm in the presence of protective agents decreased the rate of membrane dehydration and increased the total extent of dehydration. Cryoprotective agents such as glycerol decrease the amount of energy needed to transport water across cellular membranes during freezing. PMID:22480267

Oldenhof, Harriëtte; Friedel, Katharina; Akhoondi, Maryam; Gojowsky, Marina; Wolkers, Willem F; Sieme, Harald

2012-04-05

367

Increased local cytokine production at culprit superficial femoral artery plaques.  

PubMed

Characterization of local inflammation at culprit superficial femoral artery (SFA) stenosis has not been studied. We hypothesized that arterial cytokine concentrations would be greater at sites of stenosis. Twenty patients with ?50 % angiographic stenosis of the SFA had blood drawn just proximal to the lesion and from a contralateral site free of disease. A microplate immunoassay was used to determine the concentrations of 42 distinct cytokines and growth factors. Exact conditional logistic analysis was used to compare measures at the two sites with interaction terms describing clinical factors used to identify difference mediators. Interaction terms identified clinical factors that could predict cytokine levels. The concentrations of soluble CD40 ligand (sCD40L; mean 212 and 177 pg/ml, p = 0.01) and tumor necrosis factor beta (TNF-B; mean 16.6 and 15.9 pg/ml, p = 0.04) were increased immediately proximal to areas of stenosis. Factors associated with greater concentrations at sites of stenosis were bilateral ankle-brachial index ?0.90 (p = 0.04), no statin use (p = 0.02), claudication (p = 0.03), low leukocyte count (p = 0.03), absence of limb ischemia (p = 0.04) and lack of aspirin or clopidogrel therapy (p ? 0.06). Greater concentrations of sCD40L and TNF-B at sites of stenosis suggest that these cytokines play a role in the pathogenesis of symptomatic SFA disease. Our results also suggest that statin, aspirin and clopidogrel therapy may attenuate localized inflammation in the SFA, though due to a small sample size and the use of multiple comparisons across groups, these findings can be viewed as hypothesis generating only. In conclusion, selected cytokines are heightened at culprit SFA lesions and inflammation may be modulated by statin and antiplatelet therapy. PMID:23299818

Donaldson, Cameron W; Schneider, David J; Bertges, Daniel J; Adams, Julie E; Elgharib, Nader Z; Mueller, Enkhtuyaa L; Prabhu, William; Ashikaga, Taka; Dauerman, Harold L

2013-10-01

368

A mutant gene that increases gibberellin production in Brassica  

SciTech Connect

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}.

Rood, S.B. (Univ. of Lethbridge, Alberta (Canada)); Williams, P.H. (Univ. of Wisconsin, Madison (USA)); Pearce, D.; Pharis, R.P. (Univ. of Calgary, Alberta (Canada)); Murofushi, Noboru (Univ. of Tokyo (Japan)); Mander, L.N. (Australian National Univ., Canberra (Australia))

1990-07-01

369

Ask the experts: increasing and maintaining productivity in the bioanalytical laboratory.  

PubMed

Bioanalysis invited a selection of leading researchers to express their views on increasing and maintaining productivity in the bioanalytical laboratory. The topics discussed include the challenges of maintaining productivity when integrating new innovations into existing processes, the impact of automation on productivity, and how they effectively manage productivity in their own bioanalytical laboratories. Their enlightening responses provide a valuable insight into current methods of increasing productivity and the future of the constantly evolving bioanalytical laboratory. PMID:23862703

Beato, Brian D; Briscoe, Chad; Rajarao, Joe; Sangster, Timothy

2013-07-01

370

Mechanisms underlying the inhibition of murine sperm capacitation by the seminal protein, SPINKL.  

PubMed

SPINKL, a serine protease inhibitor kazal-type-like protein initially found in mouse seminal vesicle secretions, possesses structurally conserved six-cysteine residues of the kazal-type serine protease inhibitor family. However, it has no inhibitory activity against serine proteases. Previously, it was found to have the ability to suppress murine sperm capacitation in vitro. Herein, we investigated the mechanisms underlying the suppressive effect of SPINKL on sperm capacitation. Three in vitro capacitation-enhancing agents, including bovine serum albumin (BSA), methyl-beta-cyclodextrin (MBCD), and dibutyryl cyclic AMP (dbcAMP), coupled with 3-isobutyl-1-methylxanthine (IBMX), were used to evaluate the influence of SPINKL on capacitation signaling. Preincubation of sperm with SPINKL suppressed BSA- and MBCD-induced sperm capacitation by blocking three upstream signals of capacitation that is the cholesterol efflux from sperm plasma membranes, extracellular calcium ion influx into sperm, and increases in intracellular cAMP. Moreover, SPINKL also inhibited downstream signal transduction of capacitation since it suppressed dbcAMP/IBMX and N(6) -phenyl cAMP (6-Phe-cAMP)-activated cAMP-dependent protein kinase-associated protein tyrosine phosphorylation. Such inhibition is probably mediated by attenuation of SRC tyrosine kinase activity. Furthermore, SPINKL could not reverse capacitation once sperm had been capacitated by capacitation-enhancing agents or capacitated in vivo in the oviduct. SPINKL bound to sperm existed in the uterus but had disappeared from sperm in the oviduct during the sperm's transit through the female reproductive tract. Therefore, SPINKL may serve as an uncapacitation factor in the uterus to prevent sperm from precocious capacitation and the subsequent acrosome reaction and thus preserve the fertilization ability of sperm. PMID:23097296

Tseng, Huan-Chin; Lee, Robert Kuo-Kuang; Hwu, Yuh-Ming; Lu, Chung-Hao; Lin, Ming-Huei; Li, Sheng-Hsiang

2013-04-01

371

Assessment of chromosomal abnormalities in sperm of infertile men using sperm karyotyping and multicolour fluorescence in situ hybridization (FISH)  

SciTech Connect

Individuals with male factor infertility resulting from idiopathic oligo-, astheno- or teratozoospermia are frequently offered IVF in an attempt to increase their chances of having a child. A concern remains whether these infertile males have an elevated risk of transmitting chromosomal abnormalities to their offspring. Sperm chromosomal complements from these men were assayed using the human sperm/hamster oocyte fusion system and fluorescence in situ hybridization (FISH) on sperm nuclei. For each of 5 infertile patients, 100 sperm karyotypes were analyzed and multicolour FISH analysis was performed on a minimum of 10,000 sperm nuclei for each chromosome-specific DNA probe for chromosomes 1 (pUC1.77), 12 (D12Z3), X (XC) and Y (DYZ3). As a group, the infertile patients showed increased frequencies of both numerical ({chi}{sup 2}=17.26, {proportional_to} <0.001) and total abnormalities ({chi}{sup 2}=7.78, {proportional_to} <0.01) relative to control donors when assessed by sperm karyotypes. Analysis of sperm nuclei by FISH indicated a significant increase in the frequency of disomy for chromosome 1 in three of the five patients as compared to control donors ({chi}{sup 2}>8.35, {proportional_to} <0.005). In addition, the frequency of XY disomy was significantly higher in four of the five patients studied by FISH ({chi}{sup 2}>10.58, {proportional_to}<0.005), suggesting that mis-segregation caused by the failure of the XY bivalent to pair may play a role in idiopathic male infertility.

Moosani, N.; Martin, R.H. [Alberta Children`s Hospital and Univ. of Calgary (Canada)

1994-09-01

372

Ionic regulation of sea urchin sperm motility, metabolism and fertilizing capacity.  

PubMed Central

In order to pursue the significance of the ionic regulation of sea urchin sperm behaviour, alterations in the cation composition of sea water were tested for their effects on sperm fertilizing capacity. Nearly all changes which resulted in lowered sperm intracellular pH, including lowered sea-water pH, inclusion of the divalent ion chelator EGTA, addition of dithiothreitol, or removal of sea-water Na+, enhanced sperm viability for periods of up to a week. These conditions caused decreased cell motility and elevated ATP concentrations, and prevented the acrosome reaction. Conversely, changes which increased the intracellular pH, decreased sperm ATP concentrations, or induced the acrosome reaction, reduced sperm viability. A single medium, high sea-water K+ concentrations (greater than 100 mM), provided an exception to these general trends. At elevated K+ concentrations sperm were quiescent but became completely infertile. These data show that sperm fertilizing capacity is generally extended by maintenance of the sperm in an inactive state, and the results suggest that decreased cellular energy levels contribute to decreased fertility.

Christen, R; Schackmann, R W; Shapiro, B M

1986-01-01

373

Sperm chromatin structure assay (SCSA): a tool in diagnosis and treatment of infertility  

PubMed Central

Diagnosis of male infertility has mainly been based on the World Health Organization (WHO) manual-based semen parameter's concentration, motility and morphology. It has, however, become apparent that none of these parameters are reliable markers for evaluation of the fertility potential of a couple. A search for better markers has led to an increased focus on sperm chromatin integrity testing in fertility work-up and assisted reproductive techniques. During the last couple of decades, numerous sperm DNA integrity tests have been developed. These are claimed to be characterized by a lower intraindividual variation, less intralaboratory and interlaboratory variation and thus less subjective than the conventional sperm analysis. However, not all the sperm chromatin integrity tests have yet been shown to be of clinical value. So far, the test that has been found to have the most stable clinical threshold values in relation to fertility is the sperm chromatin structure assay (SCSA), a flow cytometric test that measures the susceptibility of sperm DNA to acid-induced DNA denaturation in situ. Sperm DNA fragmentation as measured by SCSA has shown to be an independent predictor of successful pregnancy in first pregnancy planners as well as in couples undergoing intrauterine insemination, and can be used as a tool in investigation, counseling and treatment of involuntary childlessness. More conflicting data exist regarding the role of sperm DNA fragmentation in relation to fertilization, pre-embryo development and pregnancy outcome in in vitro fertilization and intracytoplasmic sperm injection (ICSI).

Bungum, Mona; Bungum, Leif; Giwercman, Aleksander

2011-01-01

374

Comparison of the effects of Percoll and PureSperm on the common marmoset (Callithrix jacchus) semen.  

PubMed

Density gradient centrifugation is a widely used technique for the separation of motile from non-motile sperm, for the removal of contaminating agents such as bacteria and viruses, and for the removal of seminal plasma or cryoprotectant. In the choice of a density gradient medium for a new species, it is important to perform toxicity tests. The present study was carried out to evaluate the potential toxic effects of two silica-based density gradient products (Percoll and PureSperm), on the sperm of the common marmoset. We assessed two different batches of Percoll (polyvinylpyrrolidone (PVP)-coated colloidal silica particles) and one of PureSperm (saline-coated colloidal silica suspension) by means of a computer-aided sperm analysis on semen collected by vibrostimulation. The results showed that although some of the sperm patterns of movement and viability changed significantly over time, and provide a first description of marmoset sperm motility changes under capacitating conditions, there was no significant difference in the sperm treated with Percoll or PureSperm in comparison with the control. We conclude that simple exposure to either of these products does not have a negative effect on viability or motility of marmoset sperm. PMID:15860114

Hernández-López, L; Umland, N; Mondragón-Ceballos, R; Nayudu, P L

2005-04-01

375

Chemosensory assessment of sperm competition levels and the evolution of internal spermatophore guarding  

Microsoft Academic Search

Males of many species adjust their reproductive behaviour according to the perceived risk of sperm competition. Although this phenomenon is widespread in insects and other animals, the mechanisms that allow mates to assess sperm competition levels remain largely unexplored. In this study, we analysed the mating behaviour of pairs of Tenebrio molitor beetles under three odour treatments representing increasing levels

P. Carazo; B. Alfthan

2007-01-01

376

Environmental salinity-induced shifts in sperm motility activation in Fundulus grandis  

Microsoft Academic Search

Motility activation of fish sperm typically responds to levels of specific ions or osmotic pressure differences between the surrounding water and body tissues. In general, the sperm of marine fishes are activated by an increase in osmotic pressure (hypertonic salinity), and that of freshwater species by a decrease (hypotonic salinity). These stenohaline species exist in relatively stable environments, however, estuarine

Terrence R. Tiersch; Huiping Yang

377

A volatile inhibitor immobilizes sea urchin sperm in semen by depressing the intracellular pH  

Microsoft Academic Search

Sea urchin spermatozoa are normally immotile in semen, but motility can be initiated by increasing gas flow over the semen--for example, by blowing N2 gas over a thin layer of semen. This result indicates that sperm motility is not O2 limited and suggests that seminal fluid contains a volatile inhibitor of motility which is responsible for the paralysis of sperm

C. H. Johnson; D. L. Clapper; M. M. Winkler; H. C. Lee; D. Epel

1983-01-01

378

Foraging behavior of fish-eating sperm whales in the Gulf of Alaska in the presence and absence of fishing vessels  

Microsoft Academic Search

Historical whaling records indicate that sperm whales off southeast Alaska incorporate fish into their diets, particularly black cod (Anoploploma fimbria). Since 1995 this fact has become relevant to fisheries' concerns in the form of increased depredation encounters between longline fishermen and over 40 sperm whales. Since 2002 the SE Alaska Sperm Whale Avoidance Project (SEASWAP) has been studying this phenomenon

Aaron Thode; Jan Straley; Kendall Folkert; Victoria O'Connell; Christopher Tiemann

2005-01-01

379

Participation of a K + Channel Modulated Directly by cGMP in the Speract-Induced Signaling Cascade of Strongylocentrotus purpuratus Sea Urchin Sperm  

Microsoft Academic Search

Speract, a decapeptide from Strongylocentrotus purpuratus sea urchin eggs, transiently stimulates a membrane guanylyl cyclase and activates a K+-selective channel that hyperpolarizes sperm. However, previous studies of sperm and of sperm membrane vesicles reached conflicting conclusions about the mechanisms that open these channels. We find that speract hyperpolarizes and increases the cGMP content of flagellar vesicles. We confirm previous findings

Blanca Estela Galindo; Carmen Beltrán; Edward J. Cragoe; Alberto Darszon

2000-01-01

380

Consumer Surplus in the Digital Economy: Estimating the Value of Increased Product Variety at Online Booksellers  

Microsoft Academic Search

e present a framework and empirical estimates that quantify the economic impact of increased product variety made available through electronic markets. While efficiency gains from increased competition significantly enhance consumer surplus, for instance, by leading to lower average selling prices, our present research shows that increased product variety made available through electronic markets can be a significantly larger source of

Erik BrynjolfssonYu; Michael D. Smith

2003-01-01

381

Sperm characteristics and androgens in Acipenser ruthenus after induction of spermiation by carp pituitary extract or GnRHa implants.  

PubMed

Spermiation and changes in androgen (testosterone, T and 11-ketotestosterone, 11-KT) levels were studied in sterlet (Acipenser ruthenus) treated with GnRH agonist implants (DAla(6)-Pro(9)-LHRHa) at 25 and 75 ?g kg(-1) b.w. and compared with those males treated with 4 mg kg(-1) b.w. of carp pituitary extract (CPE) and 3 pellets of Ovopel kg(-1) b.w., which contains DAla(6)-Pro(9)NEt-mGnRH and metoclopramide. Sperm quality (sperm mass, spermatozoa concentration and sperm motility and velocity) was evaluated 24, 48 and 72 h after hormonal treatments. Males did not release sperm in the control group injected with physiological solution, while sperm could not be collected 7 days after treatments in all hormonally treated groups. Spermiation rates were 100 % in the CPE and Ovopel groups and 25-50 % in the GnRHa-treated groups. Sperm production was significantly lower in the GnRHa-treated groups than in the CPE and Ovopel groups and decreased 72 h after hormonal treatment. Sperm motility and velocity were higher in the Ovopel and GnRHa (75 ?g) groups compared to the CPE and GnRHa (25 ?g) groups and decreased 72 h after hormonal treatment. Androgens were only affected in spermiating males and changed in the Ovopel and GnRHa (75 ?g) after hormonal treatment. Significant correlations were observed between sperm production, sperm motility and sperm velocity, but not androgens. The present study suggests involvement of dopamine in sturgeon spawning. Additionally, better sperm quality observed in the Ovopel group and particularly sperm motility in the GnRHa (75 ?g) suggests enhancement of sperm quality in sturgeon treated with GnRHa. Therefore, further study is needed to induce fully spermiation using GnRHa implants in combination with a dopamine inhibitor. PMID:22665160

Alavi, Sayyed Mohammad Hadi; Hatef, Azadeh; Mylonas, Constantinos C; Gela, David; Papadaki, Maria; Rodina, Marek; Kašpar, Vojtech; Pšeni?ka, Martin; Podhorec, Peter; Linhart, Otomar

2012-06-05

382

Dioxin-Induced Changes in Epididymal Sperm Count and Spermatogenesis  

PubMed Central

Background A single in utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on gestation day 15 decreased epididymal sperm count in adult rats and thus was used to establish a tolerable daily intake for TCDD. However, several laboratories have been unable to replicate these findings. Moreover, conflicting reports of TCDD effects on daily sperm production suggest that spermatogenesis may not be as sensitive to the adverse effects of TCDD as previously thought. Data sources We performed a PubMed search using relevant search terms linking dioxin exposure with adverse effects on reproduction and spermatogenesis. Data synthesis Developmental exposure to TCDD is consistently linked with decreased cauda epididymal sperm counts in animal studies, although at higher dose levels than those used in some earlier studies. However, the evidence linking in utero TCDD exposure and spermatogenesis is not convincing. Conclusions Animal studies provide clear evidence of an adverse effect of in utero TCDD exposure on epididymal sperm count but do not support the conclusion that spermatogenesis is adversely affected. The mechanisms underlying decreased epididymal sperm count are unknown; however, we postulate that epididymal function is the key target for the adverse effects of TCDD.

Foster, Warren G.; Maharaj-Briceno, Serena; Cyr, Daniel G.

2010-01-01

383

Functional nonequivalence of sperm in Drosophila pseudoobscura.  

PubMed

We report on a form of sperm polymorphism, termed polymegaly, that occurs in species of the Drosophila obscura group. Individual males of species in this group characteristically produce more than one discrete length of nucleated, motile sperm. Hypotheses suggested to explain the evolutionary significance of sperm polymorphism have been either nonadaptive or adaptive, with the latter focusing on sperm competition or nutrient provisioning. These hypotheses assume all sperm types fertilize eggs; however, no data have been gathered to test this assumption. We found that two size classes of sperm are produced and transferred to females in approximately equal numbers by the male; only long sperm persist in significant numbers in female sperm storage organs. Furthermore, we used a DNA-specific dye (bisbenzimide) and sperm-specific antibodies to ask if both sperm types fertilize eggs in Drosophila pseudoobscura. Confocal microscopy and immunofluorescent analyses of fertilized eggs using anti-sperm polyclonal antisera demonstrated that only long sperm participate in fertilization. These data falsify those hypotheses in which all sperm types are assumed to be functionally equivalent (fertilize eggs). Any remaining or new hypotheses for the evolutionary significance of polymegaly must incorporate these findings. Several new areas of research are suggested. PMID:7972038

Snook, R R; Markow, T A; Karr, T L

1994-11-01

384

Phospholipid methylation in starfish spermatozoa is linked to sperm chemoattraction.  

PubMed Central

The mechanism whereby ovarian peptides cause sperm attraction was studied in the starfish. Phospholipid methylation and protein-O-carboxyl methylation, reactions linked to chemotactic responses in a variety of systems, were studied in starfish sperm. When sperm were preincubated with [methyl-3H]methionine and then exposed to the attractant, a rapid drop in radioactivity occurred in the phospholipid fraction. Methylated phospholipids decreased by 90% in the first 2 sec; however, no change was observed in endogenous methylation of protein carboxyl groups. The effect on phospholipid methylation was dose dependent, with a 40% reduction in radioactive phospholipids in sperm occurring with the minimal amount of attractant necessary to obtain a positive response in a sperm attraction bioassay. Attractants from species of starfish with little or no cross-reactivity in the bioassay had a limited effect on phospholipid methylation. The transmethylase inhibitor, homocysteine, caused a marked decrease in the accumulation of methylated phospholipids under basal conditions, which was correlated with as much as a 50-fold increase in sperm sensitivity to the attractant. The addition of chemoattractant resulted in a reduction in the amount of all individual methylated phospholipids, but the amount of phosphatidylmono[3H]methylethanolamine relative to the other methylated phospholipid decreased by a factor of 4 after stimulation. Homocysteine had the same effect. The reduction in methylated phospholipids by attractants suggests that phospholipid methylation is linked to the mechanism of action of these peptides. Methylation of phospholipids may play a role in the rapid desensitization of sperm cells to the attractant, which would be required for the orientation of the spermatozoa in the gradient of ovarian peptide.

Tezon, J; Miller, R L; Bardin, C W

1986-01-01

385

Phospholipid methylation in starfish spermatozoa is linked to sperm chemoattraction.  

PubMed

The mechanism whereby ovarian peptides cause sperm attraction was studied in the starfish. Phospholipid methylation and protein-O-carboxyl methylation, reactions linked to chemotactic responses in a variety of systems, were studied in starfish sperm. When sperm were preincubated with [methyl-3H]methionine and then exposed to the attractant, a rapid drop in radioactivity occurred in the phospholipid fraction. Methylated phospholipids decreased by 90% in the first 2 sec; however, no change was observed in endogenous methylation of protein carboxyl groups. The effect on phospholipid methylation was dose dependent, with a 40% reduction in radioactive phospholipids in sperm occurring with the minimal amount of attractant necessary to obtain a positive response in a sperm attraction bioassay. Attractants from species of starfish with little or no cross-reactivity in the bioassay had a limited effect on phospholipid methylation. The transmethylase inhibitor, homocysteine, caused a marked decrease in the accumulation of methylated phospholipids under basal conditions, which was correlated with as much as a 50-fold increase in sperm sensitivity to the attractant. The addition of chemoattractant resulted in a reduction in the amount of all individual methylated phospholipids, but the amount of phosphatidylmono[3H]methylethanolamine relative to the other methylated phospholipid decreased by a factor of 4 after stimulation. Homocysteine had the same effect. The reduction in methylated phospholipids by attractants suggests that phospholipid methylation is linked to the mechanism of action of these peptides. Methylation of phospholipids may play a role in the rapid desensitization of sperm cells to the attractant, which would be required for the orientation of the spermatozoa in the gradient of ovarian peptide. PMID:3459145

Tezon, J; Miller, R L; Bardin, C W

1986-06-01

386

Identifying X- and Y-chromosome-bearing sperm by DNA content: retrospective perspectives and prospective opinions  

SciTech Connect

Theoretically, since DNA should be the most constant component, quantitatively, of normal sperm, then genotoxic agents arising from energy production and consumption, and chemical and physical mutagens, could be identified by measuring variability in the DNA content of individual sperm from exposed men or test animals. The difference between the DNA content of X and Y sperm seemed a biologically significant benchmark for the measurement technology. Several methods are available for determining the genetic activity of agents in male germ cells, but these tests are generally laborious. Sperm-based methods provide an attractive alternate since they are not invasive, and are directly applicable to the study of human exposure. Slide-based assay of DNA content suggests that human sperm with X, Y, or YY chromosome constitutions can be distinguished by their fluorescence with quinacrine. Subsequent measurement of the dry mass of human sperm heads is performed. Dry mass is proportional to DNA content. While the study showed that human sperm with none and one quinacrine-fluorescent spot are X- and Y-bearing, respectively, the dry mass measurements indicated that many of the sperm with two quinacrine-fluorescent spots are not YY-bearing. While several reports on the initial application of flow cytometry of sperm to the investigation of mammalian infertility have appeared recently, emphasis here has been on the development of an in vivo sperm-based flow cytometric bioassay for mutations, and has not centered on andrological applications. In this review, the ability to differentiate between two equally sized populations of sperm, one bearing X and the other Y chromosomes with mean DNA content differing by about 3 to 4% is described. It has direct application to the preselection of sex of offspring, and could likely have a profound impact on animal improvement. (ERB)

Gledhill, B.L.; Pinkel, D.; Garner, D.L.

1982-03-05

387

Establishment of a transport system for mouse epididymal sperm at refrigerated temperatures.  

PubMed

The exchange of genetically engineered mouse strains between research facilities requires transporting fresh mouse sperm under refrigerated temperatures. Although sperm generally maintains fertility for 48 h at cold temperatures, in vitro fertilization rates of C57BL/6 mouse sperm are low after 48-h cold storage. Furthermore, 48 h is often not sufficient for the specimens to reach their destinations. To increase the availability of this technology, we aimed to extend the cold storage period while maintaining sperm fertility. In this study, we determined the optimal medium for sperm preservation and evaluated the effect of reduced glutathione in the fertilization medium on sperm fertility after cold storage. We found that higher fertility levels were maintained after 72-h cold storage in the preservation medium Lifor compared with storage in paraffin oil, M2 medium, or CPS-1 medium. In addition, 1.0 mM glutathione enhanced sperm fertility. After transporting sperm from Asahikawa Medical University to our laboratory, embryos were efficiently produced from the cold-stored sperm. After transfer, these embryos developed normally into live pups. Finally, we tested the transport system using genetically engineered mouse strains and obtained similar high fertilization rates with all specimens. In summary, we demonstrated that cold storage of sperm in Lifor maintains fertility, and glutathione supplementation increased the in vitro fertilization rates of sperm after up to 96 h of cold storage. This improved protocol provides a simple alternative to transporting live animals or cryopreserved samples for the exchange of genetically engineered mouse strains among research facilities. PMID:22722060

Takeo, Toru; Tsutsumi, Aki; Omaru, Taichi; Fukumoto, Kiyoko; Haruguchi, Yukie; Kondo, Tomoko; Nakamuta, Yuko; Takeshita, Yumi; Matsunaga, Hiroko; Tsuchiyama, Shuuji; Sakoh, Kazuhito; Nakao, Satohiro; Yoshimoto, Hidetaka; Shimizu, Norihiko; Nakagata, Naomi

2012-06-18

388

Novel association between sperm deformity index and oxidative stress-induced DNA damage in infertile male patients  

Microsoft Academic Search

Aim:To investigate the impact of abnormal sperm morphology using the sperm deformity index (SDI) on reactive oxygen species (ROS) production and its correlation with sperm DNA damage.Methods:Semen samples were collected from men undergoing infertility screening (n = 7) and healthy donors (n = 6). Mature spermatozoa were isolated and incubated with 5 mmol\\/L ?-nicotinamide adenine dinucleotide phosphate (NADPH) for up

Tamer M. Said; Nabil Aziz; Rakesh K. Sharma; Iwan Lewis-Jones; Anthony J. Thomas Jr; Ashok Agarwal; Ashok Agarwal

2005-01-01

389

Smoking cigarettes is associated with increased sperm disomy in teenage men 1 1 This manuscript has been reviewed in accordance with the policy of the National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for their use. 8 8 This study was performed in part under the auspices of the U.S. DOE by the Lawrence Livermore National Laboratory under contract W-7405ENG48 with support from U.S. Environmental Protection Agency IA DW8 9936308 and Tobacco-Related Disease Research Program 3RT0223. Recruitment, field work, and conventional semen analyses were supported by the Czech Ministry of the Environment (Teplice Program), the U.S. Environmental Protection Agency\\/U.S. AID and CEC (PHARE II, EC\\/HEA\\/18\\/CZ), and U.S. Environm  

Microsoft Academic Search

Objective: To determine whether moderate cigarette smoking and alcohol consumption in teenage men is associated with increases in disomic sperm and detectable changes in semen quality.Design: Cohort study.Setting: Military recruiting station, Teplice, Czech Republic.Patient(s): Ten current smokers (20 cigarettes per day for at least 2 years, exposure confirmed by urine cotinine) who also consumed alcohol and 15 nonsmokers. All patients

Ji??? Rubes; Xiu Lowe; Dan Moore; Sally Perreault; Valerie Slott; Donald Evenson; Sherry G Selevan; Andrew J Wyrobek

1998-01-01

390

Pattern of sperm transfer in redback spiders: implications for sperm competition and male sacrifice  

Microsoft Academic Search

Many sperm competition studies have identified copulation duration as an important predictor of paternity. This result is often interpreted as a sperm transfer effect--it is assumed that sperm transfer is limited by copulation duration. Here we test the assumption of duration-dependent sperm transfer in the Australian redback spider, Latrodectus hasselti, in which a correlation between copulation duration and paternity has

Lindsay S. E. Snow; Maydianne C. B. Andrade

2004-01-01

391

No evidence of sperm conjugate formation in an Australian mouse bearing sperm with three hooks  

PubMed Central

Sperm conjugation occurs when two or more sperm physically unite for motility or transport through the female reproductive tract. In many muroid rodent species, sperm conjugates have been shown to form by a single, conspicuous apical hook located on the sperm head. These sperm “trains” have been reported to be highly variable in size and, despite all the heads pointing in roughly the same direction, exhibit a relatively disordered arrangement. In some species, sperm “trains” have been shown to enhance sperm swimming speed, and thus have been suggested to be advantageous in sperm competition. Here, we assessed the behavior of sperm in the sandy inland mouse (Pseudomys hermannsburgensis), a muroid rodent that bears sperm with three apical hooks. First, we accrued genetic evidence of multiple paternity within “wild” litters to unequivocally show that sperm competition does occur in this species. Following this we utilized both in vitro and in vivo methodologies to determine whether sandy inland mouse sperm conjugate to form motile trains. Our observations of in vitro preparations of active sperm revealed that sandy inland mouse sperm exhibit rapid, progressive motility as individual cells only. Similarly, histological sections of the reproductive tracts of mated females revealed no in vivo evidence of sperm conjugate formation. We conclude that the unique, three-hooked morphology of the sandy inland mouse sperm does not facilitate the formation of motile conjugates, and discuss our findings in relation to the different hypotheses for the evolution of the muroid rodent hook/s.

Firman, Renee C; Bentley, Blair; Bowman, Faye; Marchant, Fernando Garcia-Solis; Parthenay, Jahmila; Sawyer, Jessica; Stewart, Tom; O'Shea, James E

2013-01-01

392

No evidence of sperm conjugate formation in an Australian mouse bearing sperm with three hooks.  

PubMed

Sperm conjugation occurs when two or more sperm physically unite for motility or transport through the female reproductive tract. In many muroid rodent species, sperm conjugates have been shown to form by a single, conspicuous apical hook located on the sperm head. These sperm "trains" have been reported to be highly variable in size and, despite all the heads pointing in roughly the same direction, exhibit a relatively disordered arrangement. In some species, sperm "trains" have been shown to enhance sperm swimming speed, and thus have been suggested to be advantageous in sperm competition. Here, we assessed the behavior of sperm in the sandy inland mouse (Pseudomys hermannsburgensis), a muroid rodent that bears sperm with three apical hooks. First, we accrued genetic evidence of multiple paternity within "wild" litters to unequivocally show that sperm competition does occur in this species. Following this we utilized both in vitro and in vivo methodologies to determine whether sandy inland mouse sperm conjugate to form motile trains. Our observations of in vitro preparations of active sperm revealed that sandy inland mouse sperm exhibit rapid, progressive motility as individual cells only. Similarly, histological sections of the reproductive tracts of mated females revealed no in vivo evidence of sperm conjugate formation. We conclude that the unique, three-hooked morphology of the sandy inland mouse sperm does not facilitate the formation of motile conjugates, and discuss our findings in relation to the different hypotheses for the evolution of the muroid rodent hook/s. PMID:23919134

Firman, Renée C; Bentley, Blair; Bowman, Faye; Marchant, Fernando García-Solís; Parthenay, Jahmila; Sawyer, Jessica; Stewart, Tom; O'Shea, James E

2013-05-20

393

Computer-assisted sperm analysis (CASA) as a tool for monitoring sperm quality in fish  

Microsoft Academic Search

The use of motility as a measure of sperm quality in fish is reviewed. Computer assisted sperm analysis (CASA) provides a simple and rapid quantitative assessment of the quality of fish sperm and may predict its ability to fertilise eggs. It has been used to: monitor the effects of heavy metal pollutants, such as mercury and tributyltin, on sperm quality;

D. E Kime; K. J. W Van Look; B. G McAllister; G Huyskens; E Rurangwa; F Ollevier

2001-01-01

394

Motile sperm organelle morphology examination (MSOME): intervariation study of normal sperm and sperm with large nuclear vacuoles  

Microsoft Academic Search

BACKGROUND: Although the motile sperm organelle morphology examination (MSOME) was developed only as a selection criterion, its application as a method for classifying sperm morphology may represent an improvement in evaluation of semen quality, with potential clinical repercussions. The present study aimed to evaluate individual variations in the motile sperm organelle morphology examination (MSOME) analysis after a time interval. METHODS:

João Batista A Oliveira; Claudia G Petersen; Fabiana C Massaro; Ricardo LR Baruffi; Ana L Mauri; Liliane FI Silva; Juliana Ricci; José G Franco

2010-01-01

395

Microsurgical Vasovasostomy versus Microsurgical Epididymal Sperm Aspiration/Testicular Extraction of Sperm Combined with Intracytoplasmic Sperm Injection  

Microsoft Academic Search

Purpose: Vasovasostomy (VVS) represents the standard therapy of choice for the treatment of obstructive azoospermia following vasectomy. However, recently, intracytoplasmic sperm injection (ICSI) has been suggested by some to represent the solution for all cases of malefactor infertility regardless of its etiology based on its success rates. Therefore, we compared VVS to microsurgical epididymal sperm aspiration (MESA)/testicular extraction of sperm

Axel Heidenreich; Petra Altmann; Udo H. Engelmann

2000-01-01

396

Quercetin exacerbates the effects of subacute treatment of atrazine on reproductive tissue antioxidant defence system, lipid peroxidation and sperm quality in rats.  

PubMed

The study investigated the reproductive function and the antioxidant defence system of rats co-exposed to atrazine [ATZ, 120 mg kg(-1) body weight (b. wt)] and quercetin (QT, 20 mg kg(-1) b. wt.). ATZ had no significant effects on feed intake, body weights and reproductive organs weight except prostate weight. Sperm abnormalities were increased, whereas sperm production, sperm motility and epididymal and testicular sperm numbers were decreased with ATZ treatment. Antioxidant enzymes including superoxide dismutase, glutathione-S-transferase and glutathione peroxidase were significantly altered in the epididymis and testis resulting to lipid peroxidation. A potentiating response on glutathione-S-transferase and aspartate aminotransferase activities in the testis and on lactate dehydrogenase activity and glutathione level in the epididymis was observed in the QT + ATZ animals. Quercetin alone decreased seminal vesicle and prostate weights, increased superoxide dismutase activity in the testis and ascorbate level in the epididymis. Mild pathological changes were observed in the ATZ group, whereas considerable necrosis of seminiferous tubular cells with hypoplasia of the epithelia was observed in the QT + ATZ animals. The epididymis of these animals had multilayered and sometimes a single lining epididymal epithelium with few spermatozoa. We conclude that quercetin at the investigated dose increases the susceptibility of rat reproductive tissues to atrazine-induced oxidative damage. PMID:22897171

Farombi, E O; Abarikwu, S O; Adesiyan, A C; Oyejola, T O

2012-08-17

397

Nuclear microscopy of sperm cell elemental structure.  

National Technical Information Service (NTIS)

Theories suggest there is a link between protamine concentrations in individual sperm and male fertility. Previously, biochemical analyses have used pooled samples containing millions of sperm to determine protamine concentrations. These methods have not ...

G. S. Bench R. Balhorn A. M. Friz S. P. H. Freeman

1994-01-01