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Montgomery BE, Knittel TL, Reed KJ, Chong MC, Isolehto IJ, Cafferty ER, Smith MJ, Sprister RA, Magelky CN, Scherman H, Ketting RF, Montgomery TA. Regulation of Microprocessor assembly and localization via Pasha's WW domain in C. elegans. bioRxiv 2024:2024.04.23.590772. [PMID: 38712061 PMCID: PMC11071396 DOI: 10.1101/2024.04.23.590772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Primary microRNA (pri-miRNA) transcripts are processed by the Microprocessor, a protein complex that includes the ribonuclease Drosha and its RNA binding partner DGCR8/Pasha. We developed a live, whole animal, fluorescence-based sensor that reliably monitors pri-miRNA processing with high sensitivity in C. elegans. Through a forward genetic selection for alleles that desilence the sensor, we identified a mutation in the conserved G residue adjacent to the namesake W residue of Pasha's WW domain. Using genome editing we also mutated the W residue and reveal that both the G and W residue are required for dimerization of Pasha and proper assembly of the Microprocessor. Surprisingly, we find that the WW domain also facilitates nuclear localization of Pasha, which in turn promotes nuclear import or retention of Drosha. Furthermore, depletion of Pasha or Drosha causes both components of the Microprocessor to mislocalize to the cytoplasm. Thus, Pasha and Drosha mutually regulate each other's spatial expression in C. elegans.
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Affiliation(s)
| | - Thiago L. Knittel
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Kailee J. Reed
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
- Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Madeleine C. Chong
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Ida J. Isolehto
- Biology of Non-coding RNA group, Institute of Molecular Biology, Mainz, Germany
- International PhD Program on Gene Regulation, Epigenetics and Genome Stability, Mainz, Germany
| | - Erin R. Cafferty
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Margaret J. Smith
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Reese A. Sprister
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Colin N. Magelky
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Hataichanok Scherman
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Rene F. Ketting
- Biology of Non-coding RNA group, Institute of Molecular Biology, Mainz, Germany
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University, Mainz, Germany
| | - Taiowa A. Montgomery
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
- Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
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Montgomery BE, Vijayasarathy T, Marks TN, Cialek CA, Reed KJ, Montgomery TA. Dual roles for piRNAs in promoting and preventing gene silencing in C. elegans. Cell Rep 2021; 37:110101. [PMID: 34879267 PMCID: PMC8730336 DOI: 10.1016/j.celrep.2021.110101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/25/2021] [Accepted: 11/15/2021] [Indexed: 12/30/2022] Open
Abstract
Piwi-interacting RNAs (piRNAs) regulate many biological processes through mechanisms that are not fully understood. In Caenorhabditis elegans, piRNAs intersect the endogenous RNA interference (RNAi) pathway, involving a distinct class of small RNAs called 22G-RNAs, to regulate gene expression in the germline. In the absence of piRNAs, 22G-RNA production from many genes is reduced, pointing to a role for piRNAs in facilitating endogenous RNAi. Here, however, we show that many genes gain, rather than lose, 22G-RNAs in the absence of piRNAs, which is in some instances coincident with RNA silencing. Aberrant 22G-RNA production is somewhat stochastic but once established can occur within a population for at least 50 generations. Thus, piRNAs both promote and suppress 22G-RNA production and gene silencing. rRNAs and histones are hypersusceptible to aberrant silencing, but we do not find evidence that their misexpression is the primary cause of the transgenerational sterility observed in piRNA-defective mutants. Montgomery et al. show that piRNAs both promote and suppress siRNA production and RNA silencing in C. elegans. Gain or loss of siRNAs occurs somewhat stochastically in piRNA-defective mutants but once established, it occurs across numerous generations.
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Affiliation(s)
- Brooke E Montgomery
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Tarah Vijayasarathy
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Taylor N Marks
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Charlotte A Cialek
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Kailee J Reed
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Taiowa A Montgomery
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA.
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3
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Mayo CE, Weyer CT, Carpenter MJ, Reed KJ, Rodgers CP, Lovett KM, Guthrie AJ, Mullens BA, Barker CM, Reisen WK, MacLachlan NJ. Diagnostic applications of molecular and serological assays for bluetongue and African horse sickness. REV SCI TECH OIE 2021; 40:91-104. [PMID: 34140738 DOI: 10.20506/rst.40.1.3210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The availability of rapid, highly sensitive and specific molecular and serologic diagnostic assays, such as competitive enzyme-linked immunosorbent assay (cELISA), has expedited the diagnosis of emerging transboundary animal diseases, including bluetongue (BT) and African horse sickness (AHS), and facilitated more thorough characterisation of their epidemiology. The development of assays based on real-time, reverse-transcription polymerase chain reaction (RT-PCR) to detect and identify the numerous serotypes of BT virus (BTV) and AHS virus (AHSV) has aided in-depth studies of the epidemiology of BTV infection in California and AHSV infection in South Africa. The subsequent evaluation of pan-serotype, real-time, RT-PCR-positive samples through the use of serotype-specific RT-PCR assays allows the rapid identification of virus serotypes, reducing the need for expensive and time-consuming conventional methods, such as virus isolation and serotype-specific virus neutralisation assays. These molecular assays and cELISA platforms provide tools that have enhanced epidemiologic surveillance strategies and improved our understanding of potentially altered Culicoides midge behaviour when infected with BTV. They have also supported the detection of subclinical AHSV infection of vaccinated horses in South Africa. Moreover, in conjunction with whole genome sequence analysis, these tests have clarified that the mechanism behind recent outbreaks of AHS in the AHS-controlled area of South Africa was the result of the reversion to virulence and/or genome reassortment of live attenuated vaccine viruses. This review focuses on the use of contemporary molecular diagnostic assays in the context of recent epidemiologic studies and explores their advantages over historic virus isolation and serologic techniques.
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Reed KJ, Kunz IGZ, Scare JA, Nielsen MK, Turk PJ, Coleman RJ, Coleman SJ. The pelvic flexure separates distinct microbial communities in the equine hindgut. Sci Rep 2021; 11:4332. [PMID: 33619300 PMCID: PMC7900177 DOI: 10.1038/s41598-021-83783-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 02/08/2021] [Indexed: 01/31/2023] Open
Abstract
As hindgut fermenters, horses are especially dependent on the microbiota residing in their cecum and large intestines. Interactions between these microbial populations and the horse are critical for maintaining gut homeostasis, which supports proper digestion. The current project was motivated to determine if any features of the fecal microbiota are informative of the microbial communities from the cecum, ventral colon, or dorsal colon. Digesta from the cecum, ventral colon, dorsal colon and feces were collected from 6 yearling miniature horses. Microbial DNA was isolated and the microbiota from each sample was characterized by profiling the V4 region of the 16S rRNA. Principal coordinate analysis of the beta diversity results revealed significant (p = 0.0001; F = 5.2393) similarities between the microbial populations from cecal and ventral colon and the dorsal colon and fecal samples, however, there was little overlap between the proximal and distal ends of the hindgut. These distinct population structures observed in our results coincide with the pelvic flexure, which itself separates intestinal compartments with distinct roles in digestive physiology. An indicator species analysis confirmed the population differences, supported by the identification of several microbial families characteristic of the compartments upstream of the pelvic flexure that were not represented following it. Our data suggest that the fecal microbiota is not informative of the proximal hindgut but can provide insight into communities of the distal compartments. Further, our results suggest that the pelvic flexure might be an important anatomical landmark relative to the microbial communities in the equine large intestine.
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Affiliation(s)
- Kailee J. Reed
- grid.47894.360000 0004 1936 8083Animal Sciences, Colorado State University, Fort Collins, CO 80521 USA ,grid.47894.360000 0004 1936 8083Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80521 USA
| | - Isabelle G. Z. Kunz
- grid.47894.360000 0004 1936 8083Animal Sciences, Colorado State University, Fort Collins, CO 80521 USA
| | - Jessica A. Scare
- grid.266539.d0000 0004 1936 8438M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546 USA
| | - Martin K. Nielsen
- grid.266539.d0000 0004 1936 8438M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546 USA
| | - Philip J. Turk
- grid.47894.360000 0004 1936 8083Animal Sciences, Colorado State University, Fort Collins, CO 80521 USA ,grid.427669.80000 0004 0387 0597Atrium Health, Charlotte, NC 28203 USA
| | - Robert J. Coleman
- grid.266539.d0000 0004 1936 8438Animal and Food Sciences, University of Kentucky, Lexington, KY 40546 USA
| | - Stephen J. Coleman
- grid.47894.360000 0004 1936 8083Animal Sciences, Colorado State University, Fort Collins, CO 80521 USA ,grid.47894.360000 0004 1936 8083Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80521 USA
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Svendsen JM, Reed KJ, Vijayasarathy T, Montgomery BE, Tucci RM, Brown KC, Marks TN, Nguyen DAH, Phillips CM, Montgomery TA. henn-1/HEN1 Promotes Germline Immortality in Caenorhabditis elegans. Cell Rep 2020; 29:3187-3199.e4. [PMID: 31801082 PMCID: PMC6922003 DOI: 10.1016/j.celrep.2019.10.114] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 09/28/2019] [Accepted: 10/28/2019] [Indexed: 12/21/2022] Open
Abstract
The germline contains an immortal cell lineage that ensures the faithful transmission of genetic and, in some instances, epigenetic information from one generation to the next. Here, we show that in Caenorhabditis elegans, the small RNA 3′-2′-O-methyltransferase henn-1/HEN1 is required for sustained fertility across generations. In the absence of henn-1, animals become progressively less fertile, becoming sterile after ~30 generations at 25°C. Sterility in henn-1 mutants is accompanied by severe defects in germline proliferation and maintenance. The requirement for henn-1 in transgenerational fertility is likely due to its role in methylating and, thereby, stabilizing Piwi-interacting RNAs (piRNAs). However, despite being essential for piRNA stability in embryos, henn-1 is not required for piRNA stability in adults. Thus, we propose that methylation is important for the role of piRNAs in establishing proper gene silencing during early stages of development but is dispensable for their role in the proliferated germline. Svendsen et al. identify a requirement for the small RNA methyltransferase HENN-1 in germline immortality. HENN-1 is required for piRNA stability during embryogenesis but is dispensable in the adult germline, pointing to a role for piRNAs in establishing a gene regulatory network in embryos that protects the germline throughout development.
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Affiliation(s)
- Joshua M Svendsen
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Kailee J Reed
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Tarah Vijayasarathy
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Brooke E Montgomery
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Rachel M Tucci
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Kristen C Brown
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Taylor N Marks
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Dieu An H Nguyen
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Carolyn M Phillips
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Taiowa A Montgomery
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.
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6
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Reed KJ, Svendsen JM, Brown KC, Montgomery BE, Marks TN, Vijayasarathy T, Parker DM, Nishimura EO, Updike DL, Montgomery TA. Widespread roles for piRNAs and WAGO-class siRNAs in shaping the germline transcriptome of Caenorhabditis elegans. Nucleic Acids Res 2020; 48:1811-1827. [PMID: 31872227 PMCID: PMC7038979 DOI: 10.1093/nar/gkz1178] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 12/05/2019] [Accepted: 12/06/2019] [Indexed: 12/31/2022] Open
Abstract
Piwi-interacting RNAs (piRNAs) and small interfering RNAs (siRNAs) are distinct classes of small RNAs required for proper germline development. To identify the roles of piRNAs and siRNAs in regulating gene expression in Caenorhabditis elegans, we subjected small RNAs and mRNAs from the gonads of piRNA and siRNA defective mutants to high-throughput sequencing. We show that piRNAs and an abundant class of siRNAs known as WAGO-class 22G-RNAs are required for proper expression of spermatogenic and oogenic genes. WAGO-class 22G-RNAs are also broadly required for transposon silencing, whereas piRNAs are largely dispensable. piRNAs, however, have a critical role in controlling histone gene expression. In the absence of piRNAs, histone mRNAs are misrouted into the nuclear RNAi pathway involving the Argonaute HRDE-1, concurrent with a reduction in the expression of many histone mRNAs. We also show that high-level gene expression in the germline is correlated with high level 22G-RNA production. However, most highly expressed genes produce 22G-RNAs through a distinct pathway that presumably involves the Argonaute CSR-1. In contrast, genes targeted by the WAGO branch of the 22G-RNA pathway are typically poorly expressed and respond unpredictably to loss of 22G-RNAs. Our results point to broad roles for piRNAs and siRNAs in controlling gene expression in the C. elegans germline.
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Affiliation(s)
- Kailee J Reed
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.,Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Joshua M Svendsen
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.,Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Kristen C Brown
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.,Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
| | - Brooke E Montgomery
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Taylor N Marks
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Tarah Vijayasarathy
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Dylan M Parker
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Erin Osborne Nishimura
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Dustin L Updike
- Mount Desert Island Biological Laboratory, Bar Harbor, ME 04672, USA
| | - Taiowa A Montgomery
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
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7
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Winkenbach LP, Doser R, Reed KJ, Pasquinelli AE, Phillips CM, Claycomb JM. Todos Santos small RNA symposium. RNA Biol 2019; 16:1526-1530. [PMID: 31397621 DOI: 10.1080/15476286.2019.1649586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Worm biologists from the United States, Canada, and the United Kingdom gathered at the Colorado State University Todos Santos Center in Baja California Sur, Mexico, April 3-5, 2019 for the Todos Santos Small RNA Symposium. Meeting participants, many of whom were still recovering from the bomb cyclone that struck a large swath of North America just days earlier, were greeted by the warmth and sunshine that is nearly ubiquitous in the sleepy seaside town of Todos Santos. With only 24 speakers, the meeting had the sort of laid-back vibe you might expect amongst the palm trees and ocean breeze of the Pacific coast of Mexico. The meeting started with tracing the laboratory lineages of participants. Not surprisingly, the most common parental lineages represented at the meeting were Dr. Craig Mello, Dr. Gary Ruvkun, and Dr. Victor Ambros, whom, together with Dr. Andy Fire and Dr. David Baulcombe, pioneered the small RNA field. In sad irony, on the closing day of the meeting, participants were met with the news of Dr. Sydney Brenner's passing. By establishing the worm, Caenorhabditis elegans, as a model system Dr. Brenner paved the way for much of the research discussed here.
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Affiliation(s)
- Lindsay P Winkenbach
- Department of Biochemistry and Molecular Biology, Colorado State University , Fort Collins , CO , USA
| | - Rachel Doser
- Department of Biomedical Sciences, Colorado State University , Fort Collins , CO , USA
| | - Kailee J Reed
- Department of Biology, Colorado State University , Fort Collins , CO , USA.,Cell and Molecular Biology Program, Colorado State University , Fort Collins , CO , USA
| | - Amy E Pasquinelli
- Division of Biology, University of California , San Diego , CA , USA
| | - Carolyn M Phillips
- Department of Biological Sciences, University of Southern California , Los Angeles , CA , USA
| | - Julie M Claycomb
- Department of Molecular Genetics, University of Toronto , Toronto , ON , Canada
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Kunz IGZ, Reed KJ, Metcalf JL, Hassel DM, Coleman RJ, Hess TM, Coleman SJ. Equine Fecal Microbiota Changes Associated With Anthelmintic Administration. J Equine Vet Sci 2019; 77:98-106. [PMID: 31133326 DOI: 10.1016/j.jevs.2019.01.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 12/03/2018] [Accepted: 01/30/2019] [Indexed: 12/22/2022]
Abstract
The gastrointestinal microbiota (GIM) plays an essential role in maintaining intestinal homeostasis with disruptions having profound effects on the wellbeing of the host animal. Parasitic infection is a long-standing issue for the equine industry, and the use of anthelmintic drugs for parasite control has long been standard practice. The impact of anthelmintic treatment on the GIM in healthy horses is not well known. This study evaluated the hypothesis that anthelmintic administration will alter the equine fecal microbiota in horses without an observed helminth infection. Ten horses were treated with a single dose of QUEST PLUS (active ingredients: Moxidectin and Praziquantel) (Zoetis), and fecal samples were collected before and after treatment. Amplicon sequencing data were quality filtered, processed, and analyzed using QIIME2. Anthelmintic treatment corresponded with a small but significant decrease in alpha diversity (P-value < .05). Analysis of taxonomic abundances before and after treatment with DESeq2 identified 21 features that were significantly different after treatment (Padj-value < .05). Differences in beta diversity associated with treatment were not significant and potentially suggest factors unique to the individual may play an essential role in the specific responses observed. Overall, the present study does not indicate a broad, large-scale impact on the GIM after anthelmintic treatment. The results do, however, suggest the potential of individualized responses that are based instead on host factors. Identification of these factors and investigation of their impact on the host/microbiota relationship will contribute significantly to our understanding of the role of the microbiome in horse health.
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Affiliation(s)
- Isabelle G Z Kunz
- Department of Animal Sciences, College of Agricultural Sciences, Colorado State University, Fort Collins, CO
| | - Kailee J Reed
- Department of Animal Sciences, College of Agricultural Sciences, Colorado State University, Fort Collins, CO
| | - Jessica L Metcalf
- Department of Animal Sciences, College of Agricultural Sciences, Colorado State University, Fort Collins, CO
| | - Diana M Hassel
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO
| | - Robert J Coleman
- Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY
| | - Tanja M Hess
- Department of Animal Sciences, College of Agricultural Sciences, Colorado State University, Fort Collins, CO
| | - Stephen J Coleman
- Department of Animal Sciences, College of Agricultural Sciences, Colorado State University, Fort Collins, CO.
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Freeman NC, Jimenez M, Reed KJ, Gurunathan S, Edwards RD, Roy A, Adgate JL, Pellizzari ED, Quackenboss J, Sexton K, Lioy PJ. Quantitative analysis of children's microactivity patterns: The Minnesota Children's Pesticide Exposure Study. J Expo Anal Environ Epidemiol 2001; 11:501-9. [PMID: 11791166 DOI: 10.1038/sj.jea.7500193] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2001] [Indexed: 04/17/2023]
Abstract
The National Human Exposure Assessment Survey (NHEXAS)/Minnesota Children's Pesticide Exposure Study (MNCPES) was a population-based study designed to characterize children's exposure to residential pesticides and to evaluate the contribution of residential and children's activities to children's exposure. Families of 168 children were surveyed for residential use of pesticides and children's activities. From these homes, families of 102 children between the ages of 3 and 13 years participated in a week-long intensive exposure study. Of the 102 children, 19 children were videotaped for four consecutive hours in their normal daily activities. The survey responses indicated that the youngest children were more likely to exhibit behaviors that would foster exposure to environmental contaminants. Comparison of questionnaire responses indicated that the videotaped subsample was representative of the exposure study population. The microactivities of the videotaped children that might contribute to their exposure via ingestion or dermal routes were quantified. Hand-to-mouth and object-to-mouth activities were observed most frequently among the youngest children. The youngest children were also most likely to be barefoot both indoors and outside. Gender differences were found in mouthing behavior and the proportion of observed time spent outdoors.
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Affiliation(s)
- N C Freeman
- Robert Wood Johnson Medical School, Piscataway, New Jersey, USA.
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10
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Affiliation(s)
- C A Smith
- Department of Paediatrics and Centre for Hormone Research, University of Melbourne, Royal Children's Hospital, Victoria, Australia
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11
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Reed KJ, Jimenez M, Freeman NC, Lioy PJ. Quantification of children's hand and mouthing activities through a videotaping methodology. J Expo Anal Environ Epidemiol 1999; 9:513-20. [PMID: 10554153 DOI: 10.1038/sj.jea.7500047] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
A videotaping methodology has been developed for use in quantifying the types and frequencies of children's hand and mouthing activities that could lead to exposure to environmental pollutants via dermal and ingestion pathways. Twenty children in day care, ages 3-6 years and 10 children in residences, ages 2-5 years, were videotaped during their waking hours for 1 day. Parents of each child completed questionnaires for the purpose of evaluating the accuracy of parental reports of hand-to-mouth rates. Videotapes were translated as quantifiable activities by two trained observers whose reporting reliability was checked throughout the investigation. Results determined that reliability of the videotaping method was very good, even over a year post-training. From videotape data, the average hand-to-mouth frequency rate was determined to be 9.5 contacts/h. These values are considerably higher than the current default value of 1.56 contacts/h under consideration by the EPA.
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Affiliation(s)
- K J Reed
- Joint Program in Exposure Assessment, Rutgers University and the University of Medicine and Dentistry of New Jersey, USA
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Reed KJ, Chen MH. Distorted-wave cross sections for electron-impact ionization of Ar7+. Phys Rev A 1996; 54:2967-2972. [PMID: 9913812 DOI: 10.1103/physreva.54.2967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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13
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Smith AJ, Beiersdorfer P, Decaux V, Widmann K, Reed KJ, Chen MH. Measurement of the contributions of high-n satellite lines to the K beta lines of He-like Ar16+. Phys Rev A 1996; 54:462-466. [PMID: 9913498 DOI: 10.1103/physreva.54.462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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14
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Beiersdorfer P, Vogel DA, Reed KJ, Decaux V, Scofield JH, Widmann K, Hölzer G, Förster E, Wehrhan O, Savin DW, Schweikhard L. Measurement and interpretation of the polarization of the x-ray line emission of heliumlike Fe. Phys Rev A 1996; 53:3974-3981. [PMID: 9913360 DOI: 10.1103/physreva.53.3974] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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15
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Chen MH, Reed KJ, McWilliams DM. Resonant effects on electron-impact ionization of sodiumlike selenium. Phys Rev A 1995; 52:2881-2884. [PMID: 9912572 DOI: 10.1103/physreva.52.2881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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16
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Wong KL, Beiersdorfer P, Reed KJ, Vogel DA. Electron-impact excitation cross-section measurements of highly charged heliumlike and lithiumlike ions. Phys Rev A 1995; 51:1214-1220. [PMID: 9911701 DOI: 10.1103/physreva.51.1214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Moores DL, Reed KJ. Effect of the Mo-slashller interaction on electron-impact ionization of high-Z hydrogenlike ions. Phys Rev A 1995; 51:R9-R11. [PMID: 9911657 DOI: 10.1103/physreva.51.r9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Chen MH, Reed KJ. Relativistic effects on angular distribution of Auger electrons emitted from Be-like ions following electron-impact excitation. Phys Rev A 1994; 50:2279-2283. [PMID: 9911141 DOI: 10.1103/physreva.50.2279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Chen MH, Reed KJ, Hazi AU. Effects of Coster-Kronig transitions on electron-impact excitation rates for fluorinelike ions in their ground states. Phys Rev A 1994; 49:1782-1785. [PMID: 9910429 DOI: 10.1103/physreva.49.1782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Reed KJ, Chen MH. Relativistic effects on the polarization of line radiation emitted from He-like and H-like ions following electron-impact excitation. Phys Rev A 1993; 48:3644-3651. [PMID: 9910031 DOI: 10.1103/physreva.48.3644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Wong KL, Beiersdorfer P, Chen MH, Marrs RE, Reed KJ, Scofield JH, Vogel DA, Zasadzinski R. Electron-impact ionization of lithiumlike ions: Ti19+, V20+, Cr21+, Mn22+, and Fe23+. Phys Rev A 1993; 48:2850-2859. [PMID: 9909934 DOI: 10.1103/physreva.48.2850] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Chen MH, Reed KJ. Effects of relativity and M2 transitions on the resonance contributions to electron-impact ionization of highly charged Li-like ions. Phys Rev A 1993; 48:1129-1133. [PMID: 9909714 DOI: 10.1103/physreva.48.1129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Chen MH, Reed KJ. Indirect contributions to electron-impact ionization of Kr24+, Kr25+, and Xe43+. Phys Rev A 1993; 47:1874-1877. [PMID: 9909141 DOI: 10.1103/physreva.47.1874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Reed KJ, Chen MH. Distorted-wave calculations of cross sections for electron-impact ionization of lithiumlike ions. Phys Rev A 1992; 45:4519-4524. [PMID: 9907529 DOI: 10.1103/physreva.45.4519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Chen MH, Reed KJ. Electron-impact ionization of highly charged lithiumlike ions. Phys Rev A 1992; 45:4525-4529. [PMID: 9907530 DOI: 10.1103/physreva.45.4525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Reed KJ, Chen MH, Moores DL. Excitation-autoionization in highly charged sodiumlike ions. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1991; 44:4336-4344. [PMID: 9906472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Reed KJ, Chen MH, Moores DL. Indirect processes in electron-impact ionization of Xe43+. Phys Rev A 1990; 42:5315-5318. [PMID: 9904661 DOI: 10.1103/physreva.42.5315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Beiersdorfer P, Osterheld AL, Chen MH, Henderson JR, Knapp DA, Levine MA, Marrs RE, Reed KJ, Schneider MB, Vogel DA. Indirect x-ray line formation processes in highly charged barium. Phys Rev Lett 1990; 65:1995-1998. [PMID: 10042420 DOI: 10.1103/physrevlett.65.1995] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Schneider D, DeWitt D, Clark MW, Schuch R, Cocke CL, Schmieder R, Reed KJ, Chen MH, Marrs RE, Levine M, Fortner R. Ion-collision experiments with slow, very highly charged ions extracted from an electron-beam ion trap. Phys Rev A 1990; 42:3889-3895. [PMID: 9904487 DOI: 10.1103/physreva.42.3889] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Chen MH, Reed KJ. Effects of autoionizing resonances on electron-impact excitation rates for transitions among n=3 levels in neonlike selenium. Phys Rev A 1990; 41:4759-4765. [PMID: 9903696 DOI: 10.1103/physreva.41.4759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Chen MH, Reed KJ, Moores DL. Contributions of resonant excitation double autoionization to the electron-impact ionization of Fe15+. Phys Rev Lett 1990; 64:1350-1353. [PMID: 10041373 DOI: 10.1103/physrevlett.64.1350] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Reed KJ, Chen MH, Moores DL. Excitation-autoionization processes in electron-impact ionization of Au68+. Phys Rev A 1990; 41:550-553. [PMID: 9902908 DOI: 10.1103/physreva.41.550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Chen MH, Reed KJ. Direct and resonance contributions to electron-impact excitation of n=2 to n=3 transitions in neonlike ions. Phys Rev A Gen Phys 1989; 40:2292-2300. [PMID: 9902403 DOI: 10.1103/physreva.40.2292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Moores DL, Reed KJ. Electron-impact ionization of Se24+. Phys Rev A Gen Phys 1989; 39:1747-1755. [PMID: 9901428 DOI: 10.1103/physreva.39.1747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Reed KJ, Chen MH, Hazi AU. Autoionizing resonances in electron-impact excitation of oxygenlike selenium. Phys Rev A Gen Phys 1988; 38:3319-3326. [PMID: 9900762 DOI: 10.1103/physreva.38.3319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Reed KJ, Chen MH, Hazi AU. Resonance enhancement of electron collision rates for fluorinelike ions. Phys Rev A Gen Phys 1987; 36:3117-3124. [PMID: 9899227 DOI: 10.1103/physreva.36.3117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Msezane AZ, Reed KJ, Henry RJ. Coupling effects in electron-impact excitation of oxygenlike krypton. Phys Rev A Gen Phys 1986; 34:2540-2542. [PMID: 9897560 DOI: 10.1103/physreva.34.2540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Clapis P, Roser R, Reed KJ, Kessel QC. Continuum electron emission from collisions of 0.1-3.2-MeV Kr ions with Xe targets. Phys Rev Lett 1985; 55:1563-1566. [PMID: 10031857 DOI: 10.1103/physrevlett.55.1563] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Abstract
Sera from patients with IgA myeloma inhibit normal human eosinophil chemotaxis. No correlation was noted between inhibition and the absolute concentration of IgA or lambda-K light-chain type. Eosinophil chemotactic inhibitory activity was associated with isolated IgA paraproteins and was found to be cell directed and stable at 56 degrees C. Pepsin digestion of IgA paraproteins resulted in loss of both IgA Fc fragment and eosinophil chemotactic inhibitory activity. Polymeric IgA accounted for most of the inhibitory activity as evidenced by sucrose density gradient centrifugation studies and a loss of inhibitory activity following dithiothrietol reduction and iodoacetamide alkylation which converted polymeric IgA to monomeric IgA. Comparative studies with neutrophils showed that both neutrophil and eosinophil chemotaxis and chemokinesis were effectively inhibited by IgA paraproteins. The mechanisms of suppression of eosinophil and neutrophil chemotaxis by IgA paraproteins appear to be similar and possibly may involve a membrane receptor for IgA.
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