Gary N Cherr

University of California, Davis, Davis, California, United States

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Publications (131)419.16 Total impact

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    ABSTRACT: Low levels of graphene and graphene oxide (GO) are considered to be environmentally safe. In this study, we analyzed the potential effects of graphene and GO at relatively low concentrations on cellular xenobiotic defense system mediated by efflux transporters. The results showed that graphene (<0.5 μg/mL) and GO (<20 μg/mL) did not decrease cell viability, generate reactive oxygen species, or disrupt mitochondrial function. However, graphene and GO at the nontoxic concentrations could increase calcein-AM (CAM, an indicator of membrane ATP-binding cassette (ABC) transporter) activity) accumulation, indicating inhibition of ABC transporters' efflux capabilities. This inhibition was observed even at 0.005 μg/mL graphene and 0.05 μg/mL GO, which are 100 times and 400 times lower than their lowest toxic concentration from cytotoxicity experiments, respectively. The inhibition of ABC transporters significantly increased the toxicity of paraquat and arsenic, known substrates of ABC transporters. The inhibition of ABC transporters was found to be based on graphene and GO damaging the plasma membrane structure and fluidity, thus altering functions of transmembrane ABC transporters. This study demonstrates that low levels of graphene and GO are not environmentally safe since they can significantly make cell more susceptible to other xenobiotics, and this chemosensitizing activity should be considered in the risk assessment of graphene and GO.
    Nanotoxicology 11/2015; DOI:10.3109/17435390.2015.1104739 · 6.41 Impact Factor
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    ABSTRACT: During transit through the female reproductive tract mammalian spermatozoa are exposed to increasing concentrations of progesterone (P4) released by the cumulus oophorus. P4 triggers massive calcium influx into human sperm through activation of the sperm specific calcium channel CatSper. These properties of human spermatozoa are thought to be unique, since CatSper is not progesterone sensitive in rodent sperm. Here, by performing patch clamp recording from spermatozoa from rhesus macaque for the first time, we report that they express P4-sensitive CatSper channel identically to human sperm and react to P4 by inducing responsiveness to zona pellucida (ZP), unlike human sperm which respond directly to P4. We have also determined the physiologic levels of P4 capable of inducing capacitation-associated changes in macaque sperm. Progesterone (1 µM) induced up to a three-fold increase in the percentage of sperm undergoing the zona pellucida-induced acrosome reaction with the lowest threshold as low as 10 nM of P4. Sub-micromolar levels of P4 induced a dose-dependent increase in curvilinear velocity and lateral head displacement, while sperm protein tyrosine phosphorylation was not altered. Macaque spermatozoa exposed to 10 µM P4 developed fully hyperactivated motility. Similar to human sperm, upon approaching cumulus mass and binding to zona pellucida, macaque spermatozoa display hyperactivation, and undergo acrosome reaction that coincides with the rise in the sperm intracellular calcium. Taken together, these data indicate that P4 accelerates the completion of capacitation and provides evidence of spermatozoa "priming" as they move into a gradient of progesterone in search for the oocyte.
    Biology of Reproduction 10/2015; DOI:10.1095/biolreprod.115.129783 · 3.32 Impact Factor
  • Bing Wu · Cristina Torres Duarte · Bryan J Cole · Gary N. Cherr ·
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    ABSTRACT: The ability of engineered nanomaterials (NMs) to act as inhibitors of ATP-binding cassette (ABC) efflux transporters in embryos of white sea urchin (Lytechinus pictus) was studied. Nano-copper oxide (nano-CuO), nano-zinc oxide (nano-ZnO), and their corresponding metal ions (CuSO4 and ZnSO4) were used as target chemicals. The results showed that nano-CuO, nano-ZnO, CuSO4 and ZnSO4, even at relatively low concentrations (0.5ppm), significantly increased calcein-AM (CAM, an indicator of ABC transporter activity) accumulation in sea urchin embryos at different stages of development. Exposure to nano-CuO, a very low solubility NM, at increasing times after fertilization (>30min) decreased CAM accumulation, but nano-ZnO (much more soluble NM) did not, indicating that metal ions could cross the hardened fertilization envelope, but not undissolved metal oxide NMs. Moreover, non-toxic levels (0.5ppm) of nano-CuO and nano-ZnO significantly increased developmental toxicity of vinblastine (an established ABC transporter substrate) and functioned as chemosensitizers. The multidrug resistance associated protein (MRP, one of ABC transporters) inhibitor MK571 significantly increased copper concentrations in embryos, indicating ABC transporters are important in maintaining low intracellular copper levels. We show that low concentrations of nano-CuO and nano-ZnO can make embryos more susceptible to other contaminants, representing a potent amplification of nanomaterial-related developmental toxicity.
    Environmental Science & Technology 04/2015; 49(9). DOI:10.1021/acs.est.5b00345 · 5.33 Impact Factor
  • Gary N. Cherr · Ryuzo Yanagimachi ·

    Molecular Reproduction and Development 12/2014; 81(12). DOI:10.1002/mrd.22434 · 2.53 Impact Factor
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    ABSTRACT: Coastal development has generated multiple stressors in marine and estuarine ecosystems, including habitat degradation and pollutant exposure, but the effects of these stressors on the ecology of fishes remain poorly understood. We studied the separate and combined effects of an acute 4 h sublethal exposure of the pyrethroid pesticide esfenvalerate and structural habitat complexity on behavior and predation risk of larval topsmelt (Atherinops affinis). Larvae were exposed to four nominal esfenvalerate concentrations (control, 0.12, 0.59, 1.18 μg/L), before placement into 12 L mesocosms with a three-spine stickleback (Gasterosteus aculeatus) predator. Five treatments of artificial eelgrass included a (1) uniform and (2) patchy distribution of eelgrass at a low density (500 shoots per m(2)), a (3) uniform and (4) patchy distribution of eelgrass at a high density (1,000 shoots per m(2)), and (5) the absence of eelgrass. The capture success of predators and aggregative behavior of prey were observed in each mesocosm for 10 min of each trial, and mortality of prey was recorded after 60 min. Exposure to esfenvalerate increased the proportion of larvae with swimming abnormalities. Surprisingly, prey mortality did not increase linearly with pesticide exposure but increased with habitat structure (density of eelgrass), which may have been a consequence of compensating predator behavior. The degree of prey aggregation decreased with both habitat structure and pesticide exposure, suggesting that anti-predator behaviors by prey may have been hampered by the interactive effects of both of these factors.
    Ecotoxicology 11/2014; 24(2). DOI:10.1007/s10646-014-1388-2 · 2.71 Impact Factor
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    ABSTRACT: The widespread use of engineered nanomaterials (ENMs) in a variety of technologies and consumer products inevitably causes their release into aquatic environments and final deposition into the oceans. In addition, a growing number of ENM products are being developed specifically for marine applications, such as antifouling coatings and environmental remediation systems, thus increasing the need to address any potential risks for marine organisms and ecosystems. To safeguard the marine environment, major scientific gaps related to assessing and designing ecosafe ENMs need to be filled. In this Nano Focus, we examine key issues related to the state-of-the-art models and analytical tools being developed to understand ecological risks and to design safeguards for marine organisms.
    ACS Nano 09/2014; 8(10). DOI:10.1021/nn504684k · 12.88 Impact Factor
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    ABSTRACT: In many modern teleost fish, chorion (egg envelope) glycoproteins are synthesized in the liver of females, and the expression of those genes is controlled by endogenous estrogen released from the ovary during maturation. However, among the classical teleosts, such as salmonid, carp, and zebrafish, the chorion glycoproteins are synthesized in the oocyte as in higher vertebrates. Sturgeon, classified as Chondrostei, represent an ancient lineage of ray-finned fishes that differ from other teleosts in that their sperm possess acrosomes, their eggs have numerous micropyles, and early embryo development is similar to amphibians. In order to understand the molecular mechanisms of chorion formation and the phylogenetic relationship between sturgeon and other teleosts, we employed specific antibodies directed against the primary components of sturgeon chorion glycoproteins, using immunoblotting and immunocytochemistry approaches. The origin of each chorion glycoprotein was determined through analyses of both liver and ovary, and their localization during ovarian development was investigated. Our data indicate that the origin of the major chorion glycoproteins of sturgeon, ChG1, ChG2, and ChG4, derive not only from the oocyte itself but also from follicle cells in the ovary, as well as from hepatocytes. In the follicle cell layer, granulosa cells were found to be the primary source of ChGs during oogenesis in white sturgeon. The unique origins of chorion glycoproteins in sturgeon suggest that sturgeons are an intermediate form in the evolution of the teleost lineage.
    Biology of Reproduction 05/2014; 90(6). DOI:10.1095/biolreprod.113.116194 · 3.32 Impact Factor
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    ABSTRACT: This chapter serves as an initial orientation to the 2010 Gulf of Mexico deepwater horizon (DWH) oil blowout. It presents background information on past oil spills, and gives a brief summary on the Gulf of Mexico marine ecosystems. The chapter gives an overview of offshore petroleum extraction, before discussing the 2010 Deepwater Horizon Spill. It lays out the spill paradigm that prevailed prior to the DWH blowout, and proposes a new conceptual model for the fate, transport, and exposure pathways for ecological effects of a marine oil spill that unifies the understanding of historic spills. The chapter also discusses a new oil spill scenario when turbulence of the wellhead release combines with high pressure to result in the production of droplets of oil which remain at depth in the sea. The need for an interdisciplinary marine oil spill oceanography approach is also given in the chapter.
    Oil Spill Remediation, 04/2014: pages 19-57; , ISBN: 9781118206706
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    ABSTRACT: Endocrine disrupting chemicals (EDCs) cause physiological abnormalities and population decline in fishes. However, few studies have linked environmental EDC exposures with responses at multiple tiers of the biological hierarchy, including population-level effects. To this end, we undertook a four-tiered investigation in the impacted San Francisco Bay estuary with the Mississippi silverside (Menidia audens), a small pelagic fish. This approach demonstrated links between different EDC sources and fish responses at different levels of biological organization. First we determined that water from a study site primarily impacted by ranch run-off had only estrogenic activity in vitro, while water sampled from a site receiving a combination of urban, limited ranch run-off, and treated wastewater effluent had both estrogenic and androgenic activity. Secondly, at the molecular level we found that fish had higher mRNA levels for estrogen-responsive genes at the site where only estrogenic activity was detected but relatively lower expression levels where both estrogenic and androgenic EDCs were detected. Thirdly, at the organism level, males at the site exposed to both estrogens and androgens had significantly lower mean gonadal somatic indices, significantly higher incidence of severe testicular necrosis and altered somatic growth relative to the site where only estrogens were detected. Finally, at the population level, the sex ratio was significantly skewed towards males at the site with measured androgenic and estrogenic activity. Our results suggest that mixtures of androgenic and estrogenic EDCs have antagonistic and potentially additive effects depending on the biological scale being assessed, and that mixtures containing androgens and estrogens may produce unexpected effects. In summary, evaluating EDC response at multiple tiers is necessary to determine the source of disruption (lowest scale, i.e. cell line) and what the ecological impact will be (largest scale, i.e. sex ratio).
    PLoS ONE 09/2013; 8(9):e74251. DOI:10.1371/journal.pone.0074251 · 3.23 Impact Factor
  • Gary N Cherr ·
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    ABSTRACT: In this issue of Biology of Reproduction, Chauvigne and colleagues show that multiple aquaporins are associated with water and fluid homeostasis during spermatogenesis and in the male reproductive tract, as well as in mature motile spermatozoa.
    Biology of Reproduction 07/2013; 89(2). DOI:10.1095/biolreprod.113.112342 · 3.32 Impact Factor
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    ABSTRACT: The objective of this study was to evaluate the efficacy of integrating a traditional sediment quality triad approach with selected sublethal chronic indicators in resident species in assessing sediment quality in four salt marshes in northern California, USA. These included the highly contaminated (Stege Marsh) and relatively clean (China Camp) marshes in San Francisco Bay and two reference marshes in Tomales Bay. Toxicity potential of contaminants and benthic macroinvertebrate survey showed significant differences between contaminated and reference marshes. Sublethal responses (e.g., apoptotic DNA fragmentation, lipid accumulation, and glycogen depletion) in livers of longjaw mudsucker (Gillichthys mirabilis) and embryo abnormality in lined shore crab (Pachygrapsus crassipes) also clearly distinguished contaminated and reference marshes, while other responses (e.g., cytochrome P450, metallothionein) did not. This study demonstrates that additional chronic sublethal responses in resident species under field exposure conditions can be readily combined with sediment quality triads for an expanded multiple lines of evidence approach. This confirmatory step may be warranted in environments like salt marshes in which natural variables may affect interpretation of toxicity test data. Qualitative and quantitative integration of the portfolio of responses in resident species and traditional approach can support a more comprehensive and informative sediment quality assessment in salt marshes and possibly other habitat types as well.
    Science of The Total Environment 03/2013; 454-455C:189-198. DOI:10.1016/j.scitotenv.2013.02.039 · 4.10 Impact Factor
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    ABSTRACT: In some animals, such as fish, insects and cephalopods, the thick egg coat has a narrow canal--a micropyle--through which spermatozoa enter the eggs. In fish, there is no indication that spermatozoa are attracted by eggs from a distance, but once spermatozoa come near the outer opening of the micropyle, they exhibit directed movement toward it, suggesting that a substance exists in this defined region to attract spermatozoa. Since Coomassie Blue (CB) binds preferentially to the micropyle region in flounder, herring, steelhead and other fish, it probably stains this sperm guidance substance. This substance--a glycoprotein based on lectin staining--is bound tightly to the surface of the chorion, but can be removed readily by protease treatment. Although fertilization in fish (flounder) is possible after removal of this substance, its absence makes fertilization inefficient as reflected by a drastic reduction in fertilization rate. The sperm "attraction" to the micropyle opening is species-specific and is dependent on extracellular Ca(2+). Eggs of some insects, including Drosophila, have distinct micropyle caps with CB-affinity, which also may prove to assist sperm entry. Our attempts to fertilize fly eggs in vitro were not successful.
    Biology of Reproduction 01/2013; 88(2). DOI:10.1095/biolreprod.112.105072 · 3.32 Impact Factor
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    ABSTRACT: Pyrethroids are highly toxic to fish at parts per billion or parts per trillion concentrations. Their intended mechanism is prolonged sodium channel opening, but recent studies reveal that pyrethroids such as permethrin and bifenthrin also have endocrine activity. Additionally, metabolites may have greater endocrine activity than parent compounds. The authors evaluated the in vivo concentration-dependent ability of bifenthrin and permethrin to induce choriogenin (an estrogen-responsive protein) in Menidia beryllina, a fish species known to reside in pyrethroid-contaminated aquatic habitats. The authors then compared the in vivo response with an in vitro assay-chemical activated luciferase gene expression (CALUX). Juvenile M. beryllina exposed to bifenthrin (1, 10, 100 ng/L), permethrin (0.1, 1, 10 µg/L), and ethinylestradiol (1, 10, 50 ng/L) had significantly higher ng/mL choriogenin (Chg) measured in whole body homogenate than controls. Though Chg expression in fish exposed to ethinylestradiol (EE2) exhibited a traditional sigmoidal concentration response, curves fit to Chg expressed in fish exposed to pyrethroids suggest a unimodal response, decreasing slightly as concentration increases. Whereas the in vivo response indicated that bifenthrin and permethrin or their metabolites act as estrogen agonists, the CALUX assay demonstrated estrogen antagonism by the pyrethroids. The results, supported by evidence from previous studies, suggest that bifenthrin and permethrin, or their metabolites, appear to act as estrogen receptor (ER) agonists in vivo, and that the unmetabolized pyrethroids, particularly bifenthrin, act as an ER antagonists in cultured mammalian cells. Environ. Toxicol. Chem. © 2012 SETAC.
    Environmental Toxicology and Chemistry 12/2012; 31(12). DOI:10.1002/etc.2019 · 3.23 Impact Factor
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    BioScience 12/2012; 62(12):1010-1011. DOI:10.1525/bio.2012.62.12.17 · 5.38 Impact Factor
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    ABSTRACT: Research into the health and environmental safety of nanotechnology has seriouslylagged behind its emergence in industry. While humans have often adopted synthetic chemicals without considering ancillary consequences, the lessons learned from worldwide pollution should motivate making nanotechnology compatible with environmental concerns. Researchers and policymakers need to understand exposure and harm of engineered nanomaterials (ENMs), currently nanotechnology’s main products, to influence the ENM industry toward sustainable growth. Yet, how should research proceed? Standard toxicity testing anchored in single-organism, dose-response characterizations does not adequately represent real-world exposure and receptor scenarios and their complexities. Our approach is different: it derives from ecology, the study of organisms’ interactions with each other and their environments. Our approach involves the characterization of ENMs and the mechanistic assessment of their property-based effects. Using high throughput/content screening (HTS/HCS) with cells or environmentally-relevant organisms, we measure the effects of ENMs on a subcellular or population level. We then relate those effects to mechanisms within dynamic energy budget (DEB) models of growth and reproduction. We reconcile DEB model predictions with experimental data on organism and population responses. Finally, we use microcosm studies to measure the potential for community- or ecosystem-level effects by ENMs that are likely to be produced in large quantities and for which either HTS/HCS or DEB modeling suggest their potential to harm populations and ecosystems.
    Accounts of Chemical Research 10/2012; 46(3). DOI:10.1021/ar300069t · 22.32 Impact Factor
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    ABSTRACT: Pacific herring early life stages provide good model systems for studying effects of suspended sediments on estuarine organisms. To investigate effects on the herring larval stage, we used environmentally relevant particle concentrations for San Francisco Bay (200–400 mg/L of particles <50 μm in size) and exposure times of 16 h in a novel two-pump sediment suspension mesocosm. There were no mortalities during the 16-h suspended sediment incubation. Following sediment exposure, larvae were cultured in sediment-free water for up to 10 days during which survival and condition were measured. None were affected by previous sediment treatment. Four criteria for larval condition included growth, heart rate, prey capture, and critical swimming velocity. These results provide a framework for implementing regulatory decisions on anthropogenic activities such as dredging.
    Estuaries and Coasts 09/2012; 35(5). DOI:10.1007/s12237-012-9518-7 · 2.54 Impact Factor
  • Elise A Fairbairn · Jessica Bonthius · Gary N Cherr ·
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    ABSTRACT: The canonical Wnt/β-catenin signaling pathway is critical during early teleost development for establishing the dorsal-ventral axis. Within this pathway, GSK-3β, a key regulatory kinase in the Wnt pathway, regulates β-catenin degradation and thus the ability of β-catenin to enter nuclei, where it can activate expression of genes that have been linked to the specification of the dorsal-ventral axis. In this study, we describe the morphological abnormalities that resulted in zebrafish embryos when axis determination was disrupted by environmental contaminants. These abnormalities were linked to abnormal nuclear accumulation of β-catenin. Furthermore, we demonstrated that the developmental abnormalities and altered nuclear β-catenin accumulation occurred when embryos were exposed to commercial GSK-3β inhibitors. Zebrafish embryos were exposed to commercially available GSK-3 inhibitors (GSK-3 Inhibitor IX and 1-azakenpaullone), or common environmental contaminants (dibutyl phthalate or the polycyclic aromatic hydrocarbons phenanthrene and fluorene) from the 2 to 8-cell stage through the mid-blastula transition (MBT). These embryos displayed morphological abnormalities at 12.5h post-fertilization (hpf) that were comparable to embryos exposed to lithium chloride (LiCl) (300mM LiCl for 10min, prior to the MBT), a classic disruptor of embryonic axis determination. Whole-mount immunolabeling and laser scanning confocal microscopy were used to localize β-catenin. The commercial GSK-3 Inhibitors as well as LiCl, dibutyl phthalate, fluorene and phenanthrene all induced an increase in the levels of nuclear β-catenin throughout the embryo, indicating that the morphological abnormalities were a result of disruption of Wnt/β-catenin signaling during dorsal-ventral axis specification. The ability of environmental chemicals to directly or indirectly target GSK-3β was assessed. Using Western blot analysis, the ability of these chemicals to affect enzymatic inhibitory phosphorylation at serine 9 on GSK-3β was examined, but no change in the serine phosphorylation state of GSK-3β was detected in exposed embryos. Furthermore, polycyclic aromatic hydrocarbons and dibutyl phthalate had no direct effect on the in vitro kinase activity of GSK-3β. While developmental abnormalities resulting from these axis-disrupting contaminants were linked to β-catenin accumulation in nuclei, the details of the disruption of this signaling pathway remain unknown. Since phenanthrene and fluorene as well as other hydrocarbons have been shown to disrupt axial development in sea urchin embryos, and since axis determination and the Wnt/β-catenin signaling pathway are highly conserved, we propose that these environmental contaminants may impact embryo development through a similar mechanism across phyla.
    Aquatic toxicology (Amsterdam, Netherlands) 08/2012; 124-125:188-96. DOI:10.1016/j.aquatox.2012.08.017 · 3.45 Impact Factor
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    ABSTRACT: Background/Question/Methods Endocrine disrupting chemicals (EDCs) interfere with endogenous hormones and cause physiological abnormalities in fishes. Both theory and empirical data confirm that EDCs can also cause declines in fish populations. However, few studies have attempted to link complex environmental EDC mixtures with responses at multiple tiers of the biological hierarchy, including population-level effects. Additionally, the use of environmentally relevant fishes as model species from regions with demonstrated fish population decline is lacking. To this end, we undertook a four-tiered investigation into estrogenic and androgenic EDC effects in Menidia audens (Mississippi silverside), an atherinid distributed throughout the impacted San Francisco Bay (SFB) estuary. Our main objective was to integrate observations at each biological scale with the goal of determining whether the reproductive health of Menidia populations is being negatively impacted by sites receiving either urban run-off and treated wastewater effluent or ranch run-off, and if so what the mechanisms of endocrine disruption may be. Results/Conclusions Clear links were observed between the four biological scales. At the ranch site, where primarily estrogenic compounds were present, males had significantly higher and females trended towards higher expression of estrogen-responsive genes. At the urban/wastewater outfall site, which is more polluted and contaminated by both estrogens and comparatively higher concentrations of androgens, both males and females had relatively low expression of estrogen-responsive genes, and males had lower gonadal somatic index and higher incidence of severe testicular necrosis. Notably, the proportion of females caught from the urban/wastewater outfall site throughout the spawning season over a two year period was significantly lower than the ranch site and in comparison to historical observations of Menidia sex ratios in other populations. Menidia appear to be highly sensitive to EDCs and our results suggest that the population at the urban/wastewater site is being negatively impacted by these contaminants at several biological scales. Results from this study were also used to parameterize a population model that predicts the conditions under which EDC exposure could contribute to population decline.
    97th ESA Annual Convention 2012; 08/2012
  • Theodore L Tollner · Charles L Bevins · Gary N Cherr ·
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    ABSTRACT: During maturation, the surface of mammalian spermatozoa undergoes dramatic changes leading to the acquisition of properties vital for survival and performance in the female reproductive tract. A prominent change is the addition to the sperm surface of an atypical β-defensin polypeptide. In primates, the β-defensin DEFB126 becomes adsorbed to the entire sperm surface as spermatozoa move through the epididymal duct. DEFB126 has a conserved β-defensin core and a unique long glycosylated peptide tail. The carbohydrates of this domain contribute substantially to the sperm glycocalyx. DEFB126 is critical for efficient transport of sperm in the female reproductive tract, preventing their recognition by the female immune system, and might facilitate the delivery of capacitated sperm to the site of fertilization. A newly discovered dinucleotide deletion in the human DEFB126 gene is unusually common in diverse populations and results in a null allele. Predictably, men who are homozygous for the deletion produce sperm with an altered glycocalyx and impaired function, and have reduced fertility. Insights into the biology of DEFB126 are contributing to a better understanding of reproductive fitness in humans, as well as the development of diagnostics and therapeutics for male infertility.
    Nature Reviews Urology 06/2012; 9(7):365-75. DOI:10.1038/nrurol.2012.109 · 4.84 Impact Factor
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    ABSTRACT: The 2010 Deepwater Horizon oil release posed the challenges of two types of spill: a familiar spill characterized by buoyant oil, fouling and killing organisms at the sea surface and eventually grounding on and damaging sensitive shoreline habitats, and a novel deepwater spill involving many unknowns. The subsurface retention of oil as finely dispersed droplets and emulsions, wellhead injection of dispersants, and deepwater retention of plumes of natural gas undergoing rapid microbial degradation were unprecedented and demanded the development of a new model for deepwater well blowouts that includes subsurface consequences. Existing governmental programs and policies had not anticipated this new theater of impacts, which thereby challenged decisionmaking on the spill response, on the assessment of natural resource damages, on the preparation for litigation to achieve compensation for public trust losses, and on restoration. Modification of laws and policies designed to protect and restore ocean resources is needed in order to accommodate oil drilling in the deep sea and other frontiers.
    BioScience 05/2012; 62(5). DOI:10.1525/bio.2012.62.5.7 · 5.38 Impact Factor

Publication Stats

4k Citations
419.16 Total Impact Points


  • 1984-2015
    • University of California, Davis
      • • Department of Environmental Toxicology
      • • Bodega Marine Laboratory
      • • Department of Animal Science
      Davis, California, United States
  • 2012
    • University of California, Santa Barbara
      Santa Barbara, California, United States
  • 1996-2001
    • CSU Mentor
      Long Beach, California, United States
  • 1998
    • University of Turku
      Turku, Varsinais-Suomi, Finland