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Background: The organochlorine dichlorodiphenyltrichloroethane (DDT) is banned worldwide owing to its negative health effects. It is exceptionally used as an insecticide for malaria control. Exposure occurs in regions where DDT is applied, as well as in the Arctic, where its endocrine disrupting metabolite, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) accumulates in marine mammals and fish. DDT and p,p'- DDE exposures are linked to birth defects, infertility, cancer, and neurodevelopmental delays. Of particular concern is the potential of DDT use to impact the health of generations to come via the heritable sperm epigenome. Objectives: The objective of this study was to assess the sperm epigenome in relation to p,p'-DDE serum levels between geographically diverse populations. Methods: In the Limpopo Province of South Africa, we recruited 247 VhaVenda South African men and selected 50 paired blood serum and semen samples, and 47 Greenlandic Inuit blood and semen paired samples were selected from a total of 193 samples from the biobank of the INUENDO cohort, an EU Fifth Framework Programme Research and Development project. Sample selection was based on obtaining a range of p,p'- DDE serum levels (mean = 870.734 [+ or -] 134.030 ng/mL). We assessed the sperm epigenome in relation to serump,p'-DDE levels using MethylC-Capture-sequencing (MCCseq) and chromatin immunoprecipitation followed by sequencing (ChIP-seq). We identified genomic regions with altered DNA methylation (DNAme) and differential enrichment of histone H3 lysine 4 trimethylation (H3K4me3) in sperm. Results: Differences in DNAme and H3K4me3 enrichment were identified at transposable elements and regulatory regions involved in fertility, disease, development, and neurofunction. A subset of regions with sperm DNAme and H3K4me3 that differed between exposure groups was predicted to persist in the preimplantation embryo and to be associated with embryonic gene expression. Discussion: These findings suggest that DDT and p,p'-DDE exposure impacts the sperm epigenome in a dose-response- like manner and may negatively impact the health of future generations through epigenetic mechanisms. Confounding factors, such as other environmental exposures, genetic diversity, and selection bias, cannot be ruled out. https://doi.org/10.1289/EHP12013, Introduction Dichlorodiphenyltrichloroethane (DDT) is a lipophilic organochlorine pollutant that is listed under the Stockholm Convention, with the objective to eliminate its use so as to protect human health and the [...]

Several species of harmful algal blooms (HAB) exert inimical effects on bivalve molluscs, with mass mortalities and pathologies reported worldwide. Information on the effects of HAB on the reproduction of bivalve molluscs, however, remains very limited. The Japanese pearl oyster Pinctada fucata martensii is an important economic species cultured in Japan. In previous studies, harmful dinoflagellates and raphidophytes were shown to affect embryos and larvae of Japanese pearl oyster. In the present study, quantitative deleterious effects of Alexandrium calenella, Alexandrium affine, Heterosigma akashiwo, and Chattonella marina on egg viability and spermatozoa swimming velocity are reported. All four HAB species significantly reduced the swimming velocity of spermatozoa. Egg viability was affected only after exposure to A. catenella and A. affine. An additional cytotoxicity test using Vero cells showed that bioactive exudates are associated with the deleterious effects and these effects are more prominent during the death phase of the algal culture. The results of the present study warrant further research on the effects of HAB species on gamete quality of bivalves, further characterization of bioactive compounds secreted by Alexadnrium spp., and highlight the role of physical activation of the toxic mechanism of harmful raphidophytes suggested in a previous study and confirmed in the present study. KEY WORDS: harmful algal blooms, Alexandrium calenella, Alexandrium affine, Heterosigma akashiwo, Chattonella marina, Pinctada fucata martensii, spermatozoa, eggs, cytotoxicity, INTRODUCTION Diverse species of harmful algal blooms (HAB) are known to induce human poisonings with significant public-health impacts after the ingestion of fish, but mainly filter-feeding shellfish. Contaminated shellfish accumulate [...]

ABSTRACT The Deepwater Horizon (DWH) oil spill in 2010 resulted in the release of millions of liters of oil into the Gulf of Mexico. Dispersants such as Corexit 9500A were [...]

Animals in many freshwater habitats are experiencing decreased recruitment due to declines in reproductive health. Both subspecies of a long-lived aquatic salamander, (Cryptobranchus alleganiensis alleganiensis and C. a. bishopi) have experienced severe population declines characterized by low recruitment. For many states throughout their geographic range, captive propagation and translocation are the only remaining form of management given the severity of declines. These captive rearing programs should rely on techniques to assess male reproductive health, which are currently lacking. In this study, we compared the sperm health (motility, viability, and concentration) of male hellbenders from declining and stable populations. Sperm motility and viability were similar among populations, but sperm concentrations (sp/ml) were significantly lower in declining Missouri populations than in hellbenders from populations with higher recruitment in the southeast. Sperm from Ozark hellbenders was successfully cryopreserved but with low post thaw motilities. This method for assessing male reproductive health provides the first baseline comparative study among populations of this cryptic species in decline and has broad implications for use in monitoring male health across the distribution of the eastern hellbender., INTRODUCTION Anthropogenic encroachment and habitat degradation have placed many populations at risk, with increasingly isolated and fragmented populations threatened (Reed, 2004). Some causal factors, such as overfishing or habitat loss [...]

Sixteen (mean age = 1.1 [+ or -] 0.1 yr; mean BW = 478 [+ or -] 34 kg) Brahman-influenced bulls were used to determine the influence of rescue type on sperm characteristics and serum concentrations of prolactin, cortisol, and testosterone. Bulls were blocked by BW, scrotal circumference (SC), and pregrazing sperm characteristics and randomly assigned to graze toxic endophyte-infected (EI; 4 bulls/pasture; 2 pastures) or novel endophyte-infected (NE; 4 bulls/pasture; 2 pastures) tall fescue for 121 d. Semen was collected by electroejaculation, and SC was measured and blood samples collected monthly. Sperm were evaluated for motility and morphology with an integrated visual optical system. Overall mean concentration of prolactin was decreased more (P < 0.01) in EI bulls than NE bulls from May to August. Scrotal circumference was not affected by fescue type (P = 0.58); overall SC averaged 36.7 [+ or -] 2.3 cm. Percentage of live sperm was not different (P = 0.24) between NE bulls (80%) than EI bulls (67%) in July and August. Bulls grazing NE fescue had more (P < 0.06) motile sperm than EI bulls in July and August. Percentages of progressive (57 vs. 38%, NE and EI, respectively; P < 0.06) and rapid (67 vs. 46%, NE and EI, respectively; P = 0.04) sperm were greater from bulls grazing NE than EI bulls in July and August. Average velocity of the smoothed sperm path and progressive velocity in a straight line from the beginning to the end of the sperm track were slower (P < 0.09) in EI bulls than NE bulls and were slower (P = 0.04) in August compared with July. Mean width of head oscillation as the sperm swims was less (P < 0.06) in August than July. Concentrations of cortisol and testosterone were not (P > 0.10) influenced by fescue type. Semen from bulls grazing EI had reduced motility and morphology than bulls grazing NE. Detrimental effects of toxic rescue may not be mediated by cortisol, testosterone, or both. Semen quality of bulls grazing toxic EI tall fescue was decreased with increased maximum ambient temperatures. Key words: bull, rescue, integrated visual optical system, sperm

BACKGROUND: Chlorination of drinking water generates disinfection by-products (DBPs), which have been shown to disrupt spermatogenesis in rodents at high doses, suggesting that DBPs could pose a reproductive risk to men. In this study we assessed DBP exposure and testicular toxicity, as evidenced by altered semen quality. METHODS: We conducted a cohort study to evaluate semen quality in men with well-characterized exposures to DBPs. Participants were 228 presumed fertile men with different DBP profiles. They completed a telephone interview about demographics, health history, water consumption, and other exposures and provided a semen sample. Semen outcomes included sperm concentration and morphology, as well as DNA integrity and chromatin maturity. Exposures to DBPs were evaluated by incorporating data on water consumption and bathing and showering with concentrations measured in tap water. We used multivariable linear regression to assess the relationship between exposure to DBPs and adverse sperm outcomes. RESULTS: The mean (median) sperm concentration and sperm count were 114.2 (90.5) million/mL and 362 (265) million, respectively. The mean (median) of the four trihalomethane species (THM4) exposure was 45.7 (65.3) [micro]g/L, and the mean (median) of the nine haloacetic acid species (HAA9) exposure was 30.7 (44.2) [micro]g/L. These sperm parameters were not associated with exposure to these classes of DBPs. For other sperm outcomes, we found no consistent pattern of increased abnormal semen quality with elevated exposure to trihalomethanes (THMs) or haloacetic acids (HAAs). The use of alternate methods for assessing exposure to DBPs and site-specific analyses did not change these results. CONCLUSIONS: The results of this study do not support an association between exposure to levels of DBPs near or below regulatory limits and adverse sperm outcomes in humans. KEY WORDS: disinfection by-products, environmental exposure, epidemiology, haloacetic acids, human, male, reproduction, semen, sperm count, trihalomethanes. Environ Health Perspect 115:1169-1176 (2007). doi:10.1289/ehp.10120 available via http://dx.doi.org/ [Online 22 May 2007], Disinfection by-products (DBPs) form when chlorine or other disinfectants react with organic matter during preparation of drinking water. There are many classes of DBPs, including trihalomethanes (THMs) and haloacetic acids [...]

The blueprint for producing mature, functional spermatozoa in a laboratory dish--all the way from stem cells to flagellated sperm--has eluded reproductive biologists for decades. With a view to the eventual [...]