Publications by authors named "Kristopher M Fecteau"

Populations of the acidophilic purple nonsulfur bacterium were identified in two geographically distinct thermal areas in Yellowstone National Park (Wyoming, USA), as confirmed by 16S rRNA gene sequencing and detection of characteristic methoxylated ketocarotenoids. Microcosm-based carbon uptake assays where oxygenic photosynthesis was excluded via addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea yielded a light-driven dissolved inorganic carbon (DIC) assimilation rate (7 ± 2 mg C g C h) comparable to those of highly productive algal mats in acidic hot springs, suggesting that may be performing photoautotrophy at the time of the assay. Rates of acetate assimilation were more than two orders of magnitude lower than DIC assimilation and did not differ between light and dark treatments, indicating photoheterotrophic use of acetate was not occurring, though photoheterotrophic assimilation of other organic compounds cannot be excluded.

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It has previously been shown that rhesus macaques express two forms of gonadotropin-releasing hormone (GNRH1 and GNRH2) in the hypothalamus and that both forms can stimulate the release of luteinizing hormone (LH) in vivo. However, while much has been published about the role of GNRH1 in reproduction, very little is known about the hypophysiotropic function of GNRH2. To shed light on this issue, we studied the expression pattern of these two genes in different parts of the monkey hypothalamus and pituitary gland under controlled conditions of circulating estrogen levels, using qPCR, liquid chromatography with tandem mass spectrometry and RNAscope.

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Ovarian-derived estrogen can signal non-canonically at membrane-associated receptors in the brain to rapidly regulate neuronal function. Early alcohol drinking confers greater risk for alcohol use disorder in women than men, and binge alcohol drinking is correlated with high estrogen levels, but a causal role for estrogen in driving alcohol drinking has not been established. We found that female mice displayed greater binge alcohol drinking and reduced avoidance when estrogen was high during the estrous cycle than when it was low.

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Immunoassays have been the preferred method for steroid hormone analysis for more than 50 years. Automated immunoassays (AIAs) offer high throughput, rapid data turnaround, and low cost for measuring steroid hormone concentrations. The application of liquid chromatography-tandem mass spectrometry (LC-MS/MS) for steroid quantification provides greater specificity and selectivity for individual steroids, the ability to simultaneously analyze multiple steroids, and high throughput and automation.

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Ovarian-derived estrogen is a key modulator of numerous physiological processes via genomic and nongenomic mechanisms, including signaling non-canonically at membrane-associated estrogen receptors in the brain to rapidly regulate neuronal function. However, the mechanisms mediating estrogen regulation of behaviors such as alcohol consumption remain unclear. Early alcohol drinking confers greater risk for alcohol use disorder in women than men, and binge alcohol drinking is correlated with high circulating estrogen levels, but a causal role for estrogen signaling in driving alcohol drinking in gonadally-intact animals has not been established.

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Targeting the oxytocin (OXT) peptide system has emerged as a promising new approach for the treatment of alcohol use disorder (AUD). However, further advancements in this development depend on properly modeling various complex social aspects of AUD and its treatment. Here we examined behavioral and molecular underpinnings of OXT receptor (OXTR) agonism in prairie voles, a rodent species with demonstrated translational validity for neurobiological mechanisms regulating social affiliations.

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Hot springs integrate hydrologic and geologic processes that vary over short- and long-term time scales. However, the influence of temporal hydrologic and geologic change on hot spring biodiversity is unknown. Here, we coordinated near-weekly, cross-seasonal (~140 days) geochemical and microbial community analyses of three widely studied hot springs with local precipitation data in Yellowstone National Park.

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Objective: To develop a method to simultaneously quantify the synthetic contraceptive progestin segesterone acetate (Nestorone®, NES) and the endogenous steroid hormones estradiol (E2), progesterone (P4), and estrone (E1) in human serum samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Study Design: We analyzed 615 serum samples collected from 67 reproductive-age women actively using a contraceptive vaginal ring (CVR) designed to release NES (200 mcg/d) and E2 (75-200 mcg/d). Samples were taken prior to and up to 30 days after CVR insertion and analyzed for concentrations of NES, E2, P4, and E1 in human serum using a Shimadzu Nexera-LCMS-8050 LC-MS/MS platform.

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Hydrogen (H ) is enriched in hot springs and can support microbial primary production. Using a series of geochemical proxies, a model to describe variable H concentrations in Yellowstone National Park (YNP) hot springs is presented. Interaction between water and crustal iron minerals yields H that partition into the vapour phase during decompressional boiling of ascending hydrothermal fluids.

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Article Synopsis
  • The geochemistry of hot springs is affected by subsurface processes, leading to different fluid compositions and influences on microbial communities.
  • At Yellowstone, the acidic conditions at Roadside East (RSE) high in vapor-phase fluids promote distinct hydrogen-oxidizing chemoautotrophic communities, while circumneutral conditions at Roadside West (RSW) foster different microbes due to liquid-phase fluids.
  • The study finds that oxidant availability plays a crucial role in determining which specific microorganisms thrive in these environments, highlighting its importance in microbial ecology and evolution.
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Chemosynthetic sediment and planktonic community composition and sizes, aqueous geochemistry and sediment mineralogy were determined in 15 non-photosynthetic hot springs in Yellowstone National Park (YNP). These data were used to evaluate the hypothesis that differences in the availability of dissolved or mineral substrates in the bulk fluids or sediments within springs coincides with ecologically differentiated microbial communities and their populations. Planktonic and sediment-associated communities exhibited differing ecological characteristics including community sizes, evenness and richness.

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The extent to which geochemical variation shapes the distribution of phototrophic metabolisms was modeled based on 439 observations in geothermal springs in Yellowstone National Park (YNP), Wyoming. Generalized additive models (GAMs) were developed to predict the distribution of phototrophic metabolism as a function of spring temperature, pH, and total sulfide. GAMs comprised of temperature explained 38.

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