1
|
Blanton LV, San Roman AK, Wood G, Buscetta A, Banks N, Skaletsky H, Godfrey AK, Pham TT, Hughes JF, Brown LG, Kruszka P, Lin AE, Kastner DL, Muenke M, Page DC. Stable and robust Xi and Y transcriptomes drive cell-type-specific autosomal and Xa responses in vivo and in vitro in four human cell types. bioRxiv 2024:2024.03.18.585578. [PMID: 38562807 PMCID: PMC10983990 DOI: 10.1101/2024.03.18.585578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Recent in vitro studies of human sex chromosome aneuploidy showed that the Xi ("inactive" X) and Y chromosomes broadly modulate autosomal and Xa ("active" X) gene expression in two cell types. We tested these findings in vivo in two additional cell types. Using linear modeling in CD4+ T cells and monocytes from individuals with one to three X chromosomes and zero to two Y chromosomes, we identified 82 sex-chromosomal and 344 autosomal genes whose expression changed significantly with Xi and/or Y dosage in vivo . Changes in sex-chromosomal expression were remarkably constant in vivo and in vitro across all four cell types examined. In contrast, autosomal responses to Xi and/or Y dosage were largely cell-type-specific, with up to 2.6-fold more variation than sex-chromosomal responses. Targets of the X- and Y-encoded transcription factors ZFX and ZFY accounted for a significant fraction of these autosomal responses both in vivo and in vitro . We conclude that the human Xi and Y transcriptomes are surprisingly robust and stable across the four cell types examined, yet they modulate autosomal and Xa genes - and cell function - in a cell-type-specific fashion. These emerging principles offer a foundation for exploring the wide-ranging regulatory roles of the sex chromosomes across the human body.
Collapse
|
2
|
San Roman AK, Skaletsky H, Godfrey AK, Bokil NV, Teitz L, Singh I, Blanton LV, Bellott DW, Pyntikova T, Lange J, Koutseva N, Hughes JF, Brown L, Phou S, Buscetta A, Kruszka P, Banks N, Dutra A, Pak E, Lasutschinkow PC, Keen C, Davis SM, Lin AE, Tartaglia NR, Samango-Sprouse C, Muenke M, Page DC. The human Y and inactive X chromosomes similarly modulate autosomal gene expression. Cell Genom 2024; 4:100462. [PMID: 38190107 PMCID: PMC10794785 DOI: 10.1016/j.xgen.2023.100462] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/15/2023] [Accepted: 11/14/2023] [Indexed: 01/09/2024]
Abstract
Somatic cells of human males and females have 45 chromosomes in common, including the "active" X chromosome. In males the 46th chromosome is a Y; in females it is an "inactive" X (Xi). Through linear modeling of autosomal gene expression in cells from individuals with zero to three Xi and zero to four Y chromosomes, we found that Xi and Y impact autosomal expression broadly and with remarkably similar effects. Studying sex chromosome structural anomalies, promoters of Xi- and Y-responsive genes, and CRISPR inhibition, we traced part of this shared effect to homologous transcription factors-ZFX and ZFY-encoded by Chr X and Y. This demonstrates sex-shared mechanisms by which Xi and Y modulate autosomal expression. Combined with earlier analyses of sex-linked gene expression, our studies show that 21% of all genes expressed in lymphoblastoid cells or fibroblasts change expression significantly in response to Xi or Y chromosomes.
Collapse
Affiliation(s)
| | - Helen Skaletsky
- Whitehead Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA
| | - Alexander K Godfrey
- Whitehead Institute, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Neha V Bokil
- Whitehead Institute, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Levi Teitz
- Whitehead Institute, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Isani Singh
- Whitehead Institute, Cambridge, MA 02142, USA; Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | - Julian Lange
- Whitehead Institute, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | | | - Laura Brown
- Whitehead Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA
| | - Sidaly Phou
- Whitehead Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA
| | - Ashley Buscetta
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Paul Kruszka
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicole Banks
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA; Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Amalia Dutra
- Cytogenetics and Microscopy Core, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Evgenia Pak
- Cytogenetics and Microscopy Core, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | - Shanlee M Davis
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Angela E Lin
- Medical Genetics, Massachusetts General for Children, Boston, MA 02114, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | - Nicole R Tartaglia
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA; Developmental Pediatrics, eXtraOrdinarY Kids Program, Children's Hospital Colorado, Aurora, CO 80011, USA
| | - Carole Samango-Sprouse
- Focus Foundation, Davidsonville, MD 21035, USA; Department of Pediatrics, George Washington University, Washington, DC 20052, USA; Department of Human and Molecular Genetics, Florida International University, Miami, FL 33199, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David C Page
- Whitehead Institute, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA.
| |
Collapse
|
3
|
Han CZ, Li RZ, Hansen E, Trescott S, Fixsen BR, Nguyen CT, Mora CM, Spann NJ, Bennett HR, Poirion O, Buchanan J, Warden AS, Xia B, Schlachetzki JCM, Pasillas MP, Preissl S, Wang A, O'Connor C, Shriram S, Kim R, Schafer D, Ramirez G, Challacombe J, Anavim SA, Johnson A, Gupta M, Glass IA, Levy ML, Haim SB, Gonda DD, Laurent L, Hughes JF, Page DC, Blurton-Jones M, Glass CK, Coufal NG. Human microglia maturation is underpinned by specific gene regulatory networks. Immunity 2023; 56:2152-2171.e13. [PMID: 37582369 PMCID: PMC10529991 DOI: 10.1016/j.immuni.2023.07.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 04/11/2023] [Accepted: 07/21/2023] [Indexed: 08/17/2023]
Abstract
Microglia phenotypes are highly regulated by the brain environment, but the transcriptional networks that specify the maturation of human microglia are poorly understood. Here, we characterized stage-specific transcriptomes and epigenetic landscapes of fetal and postnatal human microglia and acquired corresponding data in induced pluripotent stem cell (iPSC)-derived microglia, in cerebral organoids, and following engraftment into humanized mice. Parallel development of computational approaches that considered transcription factor (TF) co-occurrence and enhancer activity allowed prediction of shared and state-specific gene regulatory networks associated with fetal and postnatal microglia. Additionally, many features of the human fetal-to-postnatal transition were recapitulated in a time-dependent manner following the engraftment of iPSC cells into humanized mice. These data and accompanying computational approaches will facilitate further efforts to elucidate mechanisms by which human microglia acquire stage- and disease-specific phenotypes.
Collapse
Affiliation(s)
- Claudia Z Han
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Rick Z Li
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Emily Hansen
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Samantha Trescott
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Bethany R Fixsen
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Celina T Nguyen
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Cristina M Mora
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Nathanael J Spann
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Hunter R Bennett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Olivier Poirion
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Center for Epigenomics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Justin Buchanan
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Center for Epigenomics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Anna S Warden
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Bing Xia
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Johannes C M Schlachetzki
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Martina P Pasillas
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sebastian Preissl
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Center for Epigenomics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Allen Wang
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Center for Epigenomics, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - Shreya Shriram
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Roy Kim
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Danielle Schafer
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Gabriela Ramirez
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Jean Challacombe
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Samuel A Anavim
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Avalon Johnson
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Mihir Gupta
- Department of Neurosurgery, University of California, San Diego, La Jolla, CA 92037, USA
| | - Ian A Glass
- Department of Pediatrics, University of Washington and Seattle Children's Research Institute, Seattle, WA, USA
| | - Michael L Levy
- Department of Neurosurgery, University of California, San Diego-Rady Children's Hospital, San Diego, CA 92123, USA
| | - Sharona Ben Haim
- Department of Neurosurgery, University of California, San Diego, La Jolla, CA 92037, USA
| | - David D Gonda
- Department of Neurosurgery, University of California, San Diego-Rady Children's Hospital, San Diego, CA 92123, USA
| | - Louise Laurent
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - David C Page
- Whitehead Institute, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA
| | - Mathew Blurton-Jones
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92696, USA
| | - Christopher K Glass
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Nicole G Coufal
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
| |
Collapse
|
4
|
San Roman AK, Skaletsky H, Godfrey AK, Bokil NV, Teitz L, Singh I, Blanton LV, Bellott DW, Pyntikova T, Lange J, Koutseva N, Hughes JF, Brown L, Phou S, Buscetta A, Kruszka P, Banks N, Dutra A, Pak E, Lasutschinkow PC, Keen C, Davis SM, Lin AE, Tartaglia NR, Samango-Sprouse C, Muenke M, Page DC. The human Y and inactive X chromosomes similarly modulate autosomal gene expression. bioRxiv 2023:2023.06.05.543763. [PMID: 37333288 PMCID: PMC10274745 DOI: 10.1101/2023.06.05.543763] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Somatic cells of human males and females have 45 chromosomes in common, including the "active" X chromosome. In males the 46th chromosome is a Y; in females it is an "inactive" X (Xi). Through linear modeling of autosomal gene expression in cells from individuals with zero to three Xi and zero to four Y chromosomes, we found that Xi and Y impact autosomal expression broadly and with remarkably similar effects. Studying sex-chromosome structural anomalies, promoters of Xi- and Y-responsive genes, and CRISPR inhibition, we traced part of this shared effect to homologous transcription factors - ZFX and ZFY - encoded by Chr X and Y. This demonstrates sex-shared mechanisms by which Xi and Y modulate autosomal expression. Combined with earlier analyses of sex-linked gene expression, our studies show that 21% of all genes expressed in lymphoblastoid cells or fibroblasts change expression significantly in response to Xi or Y chromosomes.
Collapse
Affiliation(s)
| | - Helen Skaletsky
- Whitehead Institute; Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Whitehead Institute; Cambridge, MA 02142, USA
| | - Alexander K. Godfrey
- Whitehead Institute; Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Neha V. Bokil
- Whitehead Institute; Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Levi Teitz
- Whitehead Institute; Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | - Isani Singh
- Whitehead Institute; Cambridge, MA 02142, USA
- Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | - Julian Lange
- Whitehead Institute; Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
| | | | | | - Laura Brown
- Whitehead Institute; Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Whitehead Institute; Cambridge, MA 02142, USA
| | - Sidaly Phou
- Whitehead Institute; Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Whitehead Institute; Cambridge, MA 02142, USA
| | - Ashley Buscetta
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda; MD 20892, USA
| | - Paul Kruszka
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda; MD 20892, USA
| | - Nicole Banks
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda; MD 20892, USA
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health; Bethesda, MD 20892 USA
| | - Amalia Dutra
- Cytogenetics and Microscopy Core, National Human Genome Research Institute, National Institutes of Health; Bethesda, MD 20892 USA
| | - Evgenia Pak
- Cytogenetics and Microscopy Core, National Human Genome Research Institute, National Institutes of Health; Bethesda, MD 20892 USA
| | | | | | - Shanlee M. Davis
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Angela E. Lin
- Medical Genetics, Massachusetts General for Children, Boston, MA 02114, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | - Nicole R. Tartaglia
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Developmental Pediatrics, eXtraOrdinarY Kids Program, Children’s Hospital Colorado, Aurora, CO 80011, USA
| | - Carole Samango-Sprouse
- Focus Foundation, Davidsonville, MD 21035, USA
- Department of Pediatrics, George Washington University, Washington, DC 20052, USA; Department of Human and Molecular Genetics, Florida International University, Miami, FL 33199, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda; MD 20892, USA
| | - David C. Page
- Whitehead Institute; Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Howard Hughes Medical Institute, Whitehead Institute; Cambridge, MA 02142, USA
| |
Collapse
|
5
|
Bellott DW, Cho TJ, Jackson EK, Skaletsky H, Hughes JF, Page DC. SHIMS 3.0: Highly efficient single-haplotype iterative mapping and sequencing using ultra-long nanopore reads. PLoS One 2022; 17:e0269692. [PMID: 35700171 PMCID: PMC9197060 DOI: 10.1371/journal.pone.0269692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 05/25/2022] [Indexed: 11/18/2022] Open
Abstract
The reference sequence of structurally complex regions can only be obtained through a highly accurate clone-based approach that we call Single-Haplotype Iterative Mapping and Sequencing (SHIMS). In recent years, improvements to SHIMS have reduced the cost and time required by two orders of magnitude, but internally repetitive clones still require extensive manual effort to transform draft assemblies into reference-quality finished sequences. Here we describe SHIMS 3.0, using ultra-long nanopore reads to augment the Illumina data from SHIMS 2.0 assemblies and resolve internally repetitive structures. This greatly minimizes the need for manual finishing of Illumina-based draft assemblies, allowing a small team with no prior finishing experience to sequence challenging targets with high accuracy. This protocol proceeds from clone-picking to finished assemblies in 2 weeks for about $80 (USD) per clone. We recently used this protocol to produce reference sequence of structurally complex palindromes on chimpanzee and rhesus macaque X chromosomes. Our protocol provides access to structurally complex regions that would otherwise be inaccessible from whole-genome shotgun data or require an impractical amount of manual effort to generate an accurate assembly.
Collapse
Affiliation(s)
- Daniel W. Bellott
- Whitehead Institute, Cambridge, Massachusetts, United States of America
- * E-mail:
| | - Ting-Jan Cho
- Whitehead Institute, Cambridge, Massachusetts, United States of America
| | - Emily K. Jackson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Helen Skaletsky
- Whitehead Institute, Cambridge, Massachusetts, United States of America
- Howard Hughes Medical Institute, Whitehead Institute, Cambridge, Massachusetts, United States of America
| | | | - David C. Page
- Whitehead Institute, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Howard Hughes Medical Institute, Whitehead Institute, Cambridge, Massachusetts, United States of America
| |
Collapse
|
6
|
Hughes JF, Skaletsky H, Nicholls PK, Drake A, Pyntikova T, Cho TJ, Bellott DW, Page DC. A gene deriving from the ancestral sex chromosomes was lost from the X and retained on the Y chromosome in eutherian mammals. BMC Biol 2022; 20:133. [PMID: 35676717 PMCID: PMC9178871 DOI: 10.1186/s12915-022-01338-8] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 05/25/2022] [Indexed: 11/14/2022] Open
Abstract
Background The mammalian X and Y chromosomes originated from a pair of ordinary autosomes. Over the past ~180 million years, the X and Y have become highly differentiated and now only recombine with each other within a short pseudoautosomal region. While the X chromosome broadly preserved its gene content, the Y chromosome lost ~92% of the genes it once shared with the X chromosome. PRSSLY is a Y-linked gene identified in only a few mammalian species that was thought to be acquired, not ancestral. However, PRSSLY’s presence in widely divergent species—bull and mouse—led us to further investigate its evolutionary history. Results We discovered that PRSSLY is broadly conserved across eutherians and has ancient origins. PRSSLY homologs are found in syntenic regions on the X chromosome in marsupials and on autosomes in more distant animals, including lizards, indicating that PRSSLY was present on the ancestral autosomes but was lost from the X and retained on the Y in eutherian mammals. We found that across eutheria, PRSSLY’s expression is testis-specific, and, in mouse, it is most robustly expressed in post-meiotic germ cells. The closest paralog to PRSSLY is the autosomal gene PRSS55, which is expressed exclusively in testes, involved in sperm differentiation and migration, and essential for male fertility in mice. Outside of eutheria, in species where PRSSLY orthologs are not Y-linked, we find expression in a broader range of somatic tissues, suggesting that PRSSLY has adopted a germ-cell-specific function in eutherians. Finally, we generated Prssly mutant mice and found that they are fully fertile but produce offspring with a modest female-biased sex ratio compared to controls. Conclusions PRSSLY appears to be the first example of a gene that derives from the mammalian ancestral sex chromosomes that was lost from the X and retained on the Y. Although the function of PRSSLY remains to be determined, it may influence the sex ratio by promoting the survival or propagation of Y-bearing sperm. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01338-8.
Collapse
Affiliation(s)
| | - Helen Skaletsky
- Whitehead Institute, Cambridge, MA, 02142, USA.,Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA, 02142, USA
| | - Peter K Nicholls
- Whitehead Institute, Cambridge, MA, 02142, USA.,Present Address: Faculty of Life Sciences, University of Bradford, BD71DP, Bradford, UK
| | | | | | | | | | - David C Page
- Whitehead Institute, Cambridge, MA, 02142, USA.,Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA, 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02142, USA
| |
Collapse
|
7
|
Jackson EK, Bellott DW, Cho TJ, Skaletsky H, Hughes JF, Pyntikova T, Page DC. Large palindromes on the primate X Chromosome are preserved by natural selection. Genome Res 2021; 31:1337-1352. [PMID: 34290043 PMCID: PMC8327919 DOI: 10.1101/gr.275188.120] [Citation(s) in RCA: 6] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 05/17/2021] [Indexed: 12/27/2022]
Abstract
Mammalian sex chromosomes carry large palindromes that harbor protein-coding gene families with testis-biased expression. However, there are few known examples of sex-chromosome palindromes conserved between species. We identified 26 palindromes on the human X Chromosome, constituting more than 2% of its sequence, and characterized orthologous palindromes in the chimpanzee and the rhesus macaque using a clone-based sequencing approach that incorporates full-length nanopore reads. Many of these palindromes are missing or misassembled in the current reference assemblies of these species' genomes. We find that 12 human X palindromes have been conserved for at least 25 million years, with orthologs in both chimpanzee and rhesus macaque. Insertions and deletions between species are significantly depleted within the X palindromes' protein-coding genes compared to their noncoding sequence, demonstrating that natural selection has preserved these gene families. The spacers that separate the left and right arms of palindromes are a site of localized structural instability, with seven of 12 conserved palindromes showing no spacer orthology between human and rhesus macaque. Analysis of the 1000 Genomes Project data set revealed that human X-palindrome spacers are enriched for deletions relative to arms and flanking sequence, including a common spacer deletion that affects 13% of human X Chromosomes. This work reveals an abundance of conserved palindromes on primate X Chromosomes and suggests that protein-coding gene families in palindromes (most of which remain poorly characterized) promote X-palindrome survival in the face of ongoing structural instability.
Collapse
Affiliation(s)
- Emily K Jackson
- Whitehead Institute, Cambridge, Massachusetts 02142, USA
- Howard Hughes Medical Institute, Whitehead Institute, Cambridge, Massachusetts 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | - Ting-Jan Cho
- Whitehead Institute, Cambridge, Massachusetts 02142, USA
| | - Helen Skaletsky
- Whitehead Institute, Cambridge, Massachusetts 02142, USA
- Howard Hughes Medical Institute, Whitehead Institute, Cambridge, Massachusetts 02142, USA
| | | | | | - David C Page
- Whitehead Institute, Cambridge, Massachusetts 02142, USA
- Howard Hughes Medical Institute, Whitehead Institute, Cambridge, Massachusetts 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| |
Collapse
|
8
|
Hughes JF, Skaletsky H, Pyntikova T, Koutseva N, Raudsepp T, Brown LG, Bellott DW, Cho TJ, Dugan-Rocha S, Khan Z, Kremitzki C, Fronick C, Graves-Lindsay TA, Fulton L, Warren WC, Wilson RK, Owens E, Womack JE, Murphy WJ, Muzny DM, Worley KC, Chowdhary BP, Gibbs RA, Page DC. Sequence analysis in Bos taurus reveals pervasiveness of X-Y arms races in mammalian lineages. Genome Res 2020; 30:1716-1726. [PMID: 33208454 PMCID: PMC7706723 DOI: 10.1101/gr.269902.120] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [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: 08/06/2020] [Accepted: 10/28/2020] [Indexed: 12/28/2022]
Abstract
Studies of Y Chromosome evolution have focused primarily on gene decay, a consequence of suppression of crossing-over with the X Chromosome. Here, we provide evidence that suppression of X-Y crossing-over unleashed a second dynamic: selfish X-Y arms races that reshaped the sex chromosomes in mammals as different as cattle, mice, and men. Using super-resolution sequencing, we explore the Y Chromosome of Bos taurus (bull) and find it to be dominated by massive, lineage-specific amplification of testis-expressed gene families, making it the most gene-dense Y Chromosome sequenced to date. As in mice, an X-linked homolog of a bull Y-amplified gene has become testis-specific and amplified. This evolutionary convergence implies that lineage-specific X-Y coevolution through gene amplification, and the selfish forces underlying this phenomenon, were dominatingly powerful among diverse mammalian lineages. Together with Y gene decay, X-Y arms races molded mammalian sex chromosomes and influenced the course of mammalian evolution.
Collapse
Affiliation(s)
| | - Helen Skaletsky
- Whitehead Institute, Cambridge, Massachusetts 02142, USA.,Howard Hughes Medical Institute, Whitehead Institute, Cambridge, Massachusetts 02142, USA
| | | | | | - Terje Raudsepp
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843, USA
| | - Laura G Brown
- Whitehead Institute, Cambridge, Massachusetts 02142, USA.,Howard Hughes Medical Institute, Whitehead Institute, Cambridge, Massachusetts 02142, USA
| | | | - Ting-Jan Cho
- Whitehead Institute, Cambridge, Massachusetts 02142, USA
| | - Shannon Dugan-Rocha
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Ziad Khan
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Colin Kremitzki
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Catrina Fronick
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Tina A Graves-Lindsay
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Lucinda Fulton
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Wesley C Warren
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Richard K Wilson
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Elaine Owens
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843, USA
| | - James E Womack
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843, USA
| | - William J Murphy
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843, USA
| | - Donna M Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Kim C Worley
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Bhanu P Chowdhary
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843, USA
| | - Richard A Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - David C Page
- Whitehead Institute, Cambridge, Massachusetts 02142, USA.,Howard Hughes Medical Institute, Whitehead Institute, Cambridge, Massachusetts 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| |
Collapse
|
9
|
Naqvi S, Godfrey AK, Hughes JF, Goodheart ML, Mitchell RN, Page DC. Conservation, acquisition, and functional impact of sex-biased gene expression in mammals. Science 2020; 365:365/6450/eaaw7317. [PMID: 31320509 DOI: 10.1126/science.aaw7317] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 06/12/2019] [Indexed: 12/15/2022]
Abstract
Sex differences abound in human health and disease, as they do in other mammals used as models. The extent to which sex differences are conserved at the molecular level across species and tissues is unknown. We surveyed sex differences in gene expression in human, macaque, mouse, rat, and dog, across 12 tissues. In each tissue, we identified hundreds of genes with conserved sex-biased expression-findings that, combined with genomic analyses of human height, explain ~12% of the difference in height between females and males. We surmise that conserved sex biases in expression of genes otherwise operating equivalently in females and males contribute to sex differences in traits. However, most sex-biased expression arose during the mammalian radiation, which suggests that careful attention to interspecies divergence is needed when modeling human sex differences.
Collapse
Affiliation(s)
- Sahin Naqvi
- Whitehead Institute, Cambridge, MA 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexander K Godfrey
- Whitehead Institute, Cambridge, MA 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Mary L Goodheart
- Whitehead Institute, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA
| | - Richard N Mitchell
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - David C Page
- Whitehead Institute, Cambridge, MA 02142, USA. .,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA
| |
Collapse
|
10
|
|
11
|
Abstract
Mammals have the oldest sex chromosome system known: the mammalian X and Y chromosomes evolved from ordinary autosomes beginning at least 180 million years ago. Despite their shared ancestry, mammalian Y chromosomes display enormous variation among species in size, gene content, and structural complexity. Several unique features of the Y chromosome--its lack of a homologous partner for crossing over, its functional specialization for spermatogenesis, and its high degree of sequence amplification--contribute to this extreme variation. However, amid this evolutionary turmoil many commonalities have been revealed that have contributed to our understanding of the selective pressures driving the evolution and biology of the Y chromosome. Two biological themes have defined Y-chromosome research over the past six decades: testis determination and spermatogenesis. A third biological theme begins to emerge from recent insights into the Y chromosome's roles beyond the reproductive tract--a theme that promises to broaden the reach of Y-chromosome research by shedding light on fundamental sex differences in human health and disease.
Collapse
Affiliation(s)
- Jennifer F Hughes
- Whitehead Institute, Howard Hughes Medical Institute, and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142;
| | - David C Page
- Whitehead Institute, Howard Hughes Medical Institute, and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142;
| |
Collapse
|
12
|
Hughes JF, Skaletsky H, Koutseva N, Pyntikova T, Page DC. Sex chromosome-to-autosome transposition events counter Y-chromosome gene loss in mammals. Genome Biol 2015; 16:104. [PMID: 26017895 PMCID: PMC4446799 DOI: 10.1186/s13059-015-0667-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/06/2015] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Although the mammalian X and Y chromosomes evolved from a single pair of autosomes, they are highly differentiated: the Y chromosome is dramatically smaller than the X and has lost most of its genes. The surviving genes are a specialized set with extraordinary evolutionary longevity. Most mammalian lineages have experienced delayed, or relatively recent, loss of at least one conserved Y-linked gene. An extreme example of this phenomenon is in the Japanese spiny rat, where the Y chromosome has disappeared altogether. In this species, many Y-linked genes were rescued by transposition to new genomic locations, but until our work presented here, this has been considered an isolated case. RESULTS We describe eight cases of genes that have relocated to autosomes in mammalian lineages where the corresponding Y-linked gene has been lost. These gene transpositions originated from either the X or Y chromosomes, and are observed in diverse mammalian lineages: occurring at least once in marsupials, apes, and cattle, and at least twice in rodents and marmoset. For two genes--EIF1AX/Y and RPS4X/Y--transposition to autosomes occurred independently in three distinct lineages. CONCLUSIONS Rescue of Y-linked gene loss through transposition to autosomes has previously been reported for a single isolated rodent species. However, our findings indicate that this compensatory mechanism is widespread among mammalian species. Thus, Y-linked gene loss emerges as an additional driver of gene transposition from the sex chromosomes, a phenomenon thought to be driven primarily by meiotic sex chromosome inactivation.
Collapse
Affiliation(s)
| | - Helen Skaletsky
- Whitehead Institute, Cambridge, MA, 02142, USA. .,Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA, 02142, USA.
| | | | | | - David C Page
- Whitehead Institute, Cambridge, MA, 02142, USA. .,Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA, 02142, USA. .,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02142, USA.
| |
Collapse
|
13
|
Soh YQS, Alföldi J, Pyntikova T, Brown LG, Graves T, Minx PJ, Fulton RS, Kremitzki C, Koutseva N, Mueller JL, Rozen S, Hughes JF, Owens E, Womack JE, Murphy WJ, Cao Q, de Jong P, Warren WC, Wilson RK, Skaletsky H, Page DC. Sequencing the mouse Y chromosome reveals convergent gene acquisition and amplification on both sex chromosomes. Cell 2014; 159:800-13. [PMID: 25417157 DOI: 10.1016/j.cell.2014.09.052] [Citation(s) in RCA: 213] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 09/04/2014] [Accepted: 09/22/2014] [Indexed: 01/27/2023]
Abstract
We sequenced the MSY (male-specific region of the Y chromosome) of the C57BL/6J strain of the laboratory mouse Mus musculus. In contrast to theories that Y chromosomes are heterochromatic and gene poor, the mouse MSY is 99.9% euchromatic and contains about 700 protein-coding genes. Only 2% of the MSY derives from the ancestral autosomes that gave rise to the mammalian sex chromosomes. Instead, all but 45 of the MSY's genes belong to three acquired, massively amplified gene families that have no homologs on primate MSYs but do have acquired, amplified homologs on the mouse X chromosome. The complete mouse MSY sequence brings to light dramatic forces in sex chromosome evolution: lineage-specific convergent acquisition and amplification of X-Y gene families, possibly fueled by antagonism between acquired X-Y homologs. The mouse MSY sequence presents opportunities for experimental studies of a sex-specific chromosome in its entirety, in a genetically tractable model organism.
Collapse
Affiliation(s)
- Y Q Shirleen Soh
- Whitehead Institute, 9 Cambridge Center, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Jessica Alföldi
- Whitehead Institute, 9 Cambridge Center, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | | | - Laura G Brown
- Whitehead Institute, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA
| | - Tina Graves
- The Genome Institute, Washington University School of Medicine, 4444 Forest Park Boulevard, St. Louis, MO 63108, USA
| | - Patrick J Minx
- The Genome Institute, Washington University School of Medicine, 4444 Forest Park Boulevard, St. Louis, MO 63108, USA
| | - Robert S Fulton
- The Genome Institute, Washington University School of Medicine, 4444 Forest Park Boulevard, St. Louis, MO 63108, USA
| | - Colin Kremitzki
- The Genome Institute, Washington University School of Medicine, 4444 Forest Park Boulevard, St. Louis, MO 63108, USA
| | - Natalia Koutseva
- Whitehead Institute, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Jacob L Mueller
- Whitehead Institute, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Steve Rozen
- Whitehead Institute, 9 Cambridge Center, Cambridge, MA 02142, USA
| | | | - Elaine Owens
- College of Veterinary Medicine and Biomedical Sciences, 4458 Texas A&M University, College Station, TX 77843, USA
| | - James E Womack
- College of Veterinary Medicine and Biomedical Sciences, 4458 Texas A&M University, College Station, TX 77843, USA
| | - William J Murphy
- College of Veterinary Medicine and Biomedical Sciences, 4458 Texas A&M University, College Station, TX 77843, USA
| | - Qing Cao
- BACPAC Resources, Children's Hospital Oakland, 747 52nd Street, Oakland, CA 94609, USA
| | - Pieter de Jong
- BACPAC Resources, Children's Hospital Oakland, 747 52nd Street, Oakland, CA 94609, USA
| | - Wesley C Warren
- The Genome Institute, Washington University School of Medicine, 4444 Forest Park Boulevard, St. Louis, MO 63108, USA
| | - Richard K Wilson
- The Genome Institute, Washington University School of Medicine, 4444 Forest Park Boulevard, St. Louis, MO 63108, USA
| | - Helen Skaletsky
- Whitehead Institute, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA
| | - David C Page
- Whitehead Institute, 9 Cambridge Center, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA 02142, USA.
| |
Collapse
|
14
|
Bellott DW, Hughes JF, Skaletsky H, Brown LG, Pyntikova T, Cho TJ, Koutseva N, Zaghlul S, Graves T, Rock S, Kremitzki C, Fulton RS, Dugan S, Ding Y, Morton D, Khan Z, Lewis L, Buhay C, Wang Q, Watt J, Holder M, Lee S, Nazareth L, Alföldi J, Rozen S, Muzny DM, Warren WC, Gibbs RA, Wilson RK, Page DC. Erratum: Corrigendum: Mammalian Y chromosomes retain widely expressed dosage-sensitive regulators. Nature 2014. [DOI: 10.1038/nature13719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
15
|
Bellott DW, Hughes JF, Skaletsky H, Brown LG, Pyntikova T, Cho TJ, Koutseva N, Zaghlul S, Graves T, Rock S, Kremitzki C, Fulton RS, Dugan S, Ding Y, Morton D, Khan Z, Lewis L, Buhay C, Wang Q, Watt J, Holder M, Lee S, Nazareth L, Alföldi J, Rozen S, Muzny DM, Warren WC, Gibbs RA, Wilson RK, Page DC. Mammalian Y chromosomes retain widely expressed dosage-sensitive regulators. Nature 2014; 508:494-9. [PMID: 24759411 PMCID: PMC4139287 DOI: 10.1038/nature13206] [Citation(s) in RCA: 432] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 03/06/2014] [Indexed: 12/31/2022]
Abstract
The human X and Y chromosomes evolved from an ordinary pair of autosomes, but
millions of years ago genetic decay ravaged the Y chromosome, and only three percent of
its ancestral genes survived. We reconstructed the evolution of the Y chromosome across
eight mammals to identify biases in gene content and the selective pressures that
preserved the surviving ancestral genes. Our findings indicate that survival was
non-random, and in two cases, convergent across placental and marsupial mammals. We
conclude that the Y chromosome's gene content became specialized through selection
to maintain the ancestral dosage of homologous X-Y gene pairs that function as broadly
expressed regulators of transcription, translation and protein stability. We propose that
beyond its roles in testis determination and spermatogenesis, the Y chromosome is
essential for male viability, and plays unappreciated roles in Turner syndrome and in
phenotypic differences between the sexes in health and disease.
Collapse
Affiliation(s)
- Daniel W Bellott
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Jennifer F Hughes
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Helen Skaletsky
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Laura G Brown
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Tatyana Pyntikova
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Ting-Jan Cho
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Natalia Koutseva
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Sara Zaghlul
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Tina Graves
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Susie Rock
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Colin Kremitzki
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Robert S Fulton
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Shannon Dugan
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Yan Ding
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Donna Morton
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Ziad Khan
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Lora Lewis
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Christian Buhay
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Qiaoyan Wang
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jennifer Watt
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Michael Holder
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Sandy Lee
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Lynne Nazareth
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jessica Alföldi
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Steve Rozen
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Donna M Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Wesley C Warren
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - Richard A Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Richard K Wilson
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108, USA
| | - David C Page
- Whitehead Institute, Howard Hughes Medical Institute, & Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| |
Collapse
|
16
|
Abstract
In mammals, the Y chromosome plays the pivotal role in male sex determination and is essential for normal sperm production. Yet only three Y chromosomes have been completely sequenced to date--those of human, chimpanzee, and rhesus macaque. While Y chromosomes are notoriously difficult to sequence owing to their highly repetitive genomic landscapes, these dedicated sequencing efforts have generated tremendous yields in medical, biological, and evolutionary insight. Knowledge of the complex structural organization of the human Y chromosome and a complete catalog of its gene content have provided a deeper understanding of the mechanisms that generate disease-causing mutations and large-scale rearrangements. Variation among human Y-chromosome sequences has been an invaluable tool for understanding relationships among human populations. Comprehensive comparisons of the human Y-chromosome sequence with those of other primates have illuminated aspects of Y-chromosome evolutionary dynamics over much longer timescales (>25 million years compared with 100,000 years). The future sequencing of additional Y chromosomes will provide a basis for a more comprehensive understanding of the evolution of Y chromosomes and their roles in reproductive biology.
Collapse
Affiliation(s)
- Jennifer F Hughes
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
| | | |
Collapse
|
17
|
Hughes JF, Skaletsky H, Page DC. Sequencing of rhesus macaque Y chromosome clarifies origins and evolution of the DAZ (Deleted in AZoospermia) genes. Bioessays 2012; 34:1035-44. [PMID: 23055411 DOI: 10.1002/bies.201200066] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Studies of Y chromosome evolution often emphasize gene loss, but this loss has been counterbalanced by addition of new genes. The DAZ genes, which are critical to human spermatogenesis, were acquired by the Y chromosome in the ancestor of Old World monkeys and apes. We and our colleagues recently sequenced the rhesus macaque Y chromosome, and comparison of this sequence to human and chimpanzee enables us to reconstruct much of the evolutionary history of DAZ. We report that DAZ arrived on the Y chromosome about 38 million years ago via the transposition of at least 1.1 megabases of autosomal DNA. This transposition also brought five additional genes to the Y chromosome, but all five genes were subsequently lost through mutation or deletion. As the only surviving gene, DAZ experienced extensive restructuring, including intragenic amplification and gene duplication, and has been the target of positive selection in the chimpanzee lineage. Editor's suggested further reading in BioEssays Should Y stay or should Y go: The evolution of non-recombining sex chromosomes Abstract.
Collapse
Affiliation(s)
- Jennifer F Hughes
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | | | | |
Collapse
|
18
|
Hughes JF. Fulminating Septicaemia associated with Purpura and Adrenal Haemorrhage (Waterhouse-Friderichsen Syndrome). Br Med J 2011; 2:353-4. [PMID: 20783292 DOI: 10.1136/bmj.2.4158.353] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
19
|
Page DC, Hughes JF, Bellott DW, Mueller JL, Gill ME, Larracuente A, Graves T, Muzny D, Warren WC, Gibbs RA, Wilson RK, Skaletsky H. Reconstructing sex chromosome evolution. Genome Biol 2010. [PMCID: PMC3026214 DOI: 10.1186/gb-2010-11-s1-i21] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
20
|
Hoffmann GR, Gessner GS, Hughes JF, Ronan MV, Sylvia KE, Willett CJ. Modulation of the genotoxicity of bleomycin by amines through noncovalent DNA interactions and alteration of physiological conditions in yeast. Mutat Res 2007; 623:41-52. [PMID: 17428504 DOI: 10.1016/j.mrfmmm.2007.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Revised: 02/24/2007] [Accepted: 02/27/2007] [Indexed: 11/26/2022]
Abstract
The effects of amines on the induction of mitotic gene conversion by bleomycin (BLM) were studied at the trp5 locus in Saccharomyces cerevisiae strain D7. BLM induces double-strand breaks in DNA and is a potent recombinagen in this assay. The polyamine spermidine causes concentration-dependent protection against the genotoxicity of BLM, reducing the convertant frequency by over 90% under the most protective conditions. Spermine, diethylenetriamine, ethylenediamine, putrescine, and ethylamine were also antigenotoxic in combined treatments with BLM. There was a general correspondence between the protective effect and the number of amino groups, suggesting that more strongly cationic amines tend to be stronger antirecombinagens. Electrostatic association of the amines with DNA probably hinders BLM access to the 4' position of deoxyribose where it generates a free radical. Other amines interact with BLM differently from these unbranched aliphatic amines. The aminothiol cysteamine inhibits the genotoxicity of BLM under hypoxic conditions but increases it under euoxic conditions. In contrast, pargyline potentiates the genotoxicity of BLM under hypoxic conditions but not under euoxic conditions. The antirecombinagenic effect of cysteamine apparently involves DNA binding and depletion of oxygen needed for BLM activity, whereas its potentiation of BLM entails its serving as an electron source for the activation of BLM. Pargyline may enhance BLM indirectly by preventing the depletion of oxygen by monoamine and polyamine oxidase. The planar 9-aminoacridine weakly induces gene conversion in strain D7, but it is strongly synergistic with BLM. Enhancement of BLM activity by this compound and by the related nitroacridine Entozon is apparently mediated by intercalation of the acridine ring system into DNA. Thus, the influence of amines on the genotoxicity of BLM in yeast encompasses antigenotoxic, potentiating, and synergistic interactions. The underlying mechanisms involve noncovalent association with DNA, altered BLM access to DNA, and modulation of physiological conditions.
Collapse
Affiliation(s)
- George R Hoffmann
- Department of Biology, College of the Holy Cross, One College Street, Worcester, MA 01610-2395, USA.
| | | | | | | | | | | |
Collapse
|
21
|
|
22
|
Hughes JF, Skaletsky H, Pyntikova T, Minx PJ, Graves T, Rozen S, Wilson RK, Page DC. Erratum: Corrigendum: Conservation of Y-linked genes during human evolution revealed by comparative sequencing in chimpanzee. Nature 2006. [DOI: 10.1038/nature04776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
23
|
Abstract
AIMS The aim of this study was to investigate the antibacterial activity of candles containing specific-antibacterial compounds, such as essential oils and their constituent compounds. The importance of the ionization products from the flame and the aerial concentration of the volatile compounds were investigated. METHODS AND RESULTS Agar plates inoculated with Escherichia coli (DH5alpha) or Staphylococcus aureus (NCTC strain number 8532) were exposed in a large air-tight chamber to candle flames combined with the volatile bactericidal compounds beta-pinene and orange oil. A steady decline in E. coli numbers was observed over time because of the effect of a candle flame. This was significantly increased by the addition of volatile oils. The number of S. aureus colonies was not reduced by a plain candle, but significant reductions were caused following exposure to beta-pinene and orange oil candles. As aerial concentration of the volatiles was increased the viability of E. coli and S. aureus declined. Ionization products from the flame made a significant contribution to the observed effects, as intercepting the ions on a grounded grid over the agar plates allowed at least 20% more cells to survive. CONCLUSIONS This study demonstrates the antibacterial properties of ionization products from a candle flame, and that this effect can be significantly increased by the addition of specific-antibacterial compounds, such as orange oil and beta-pinene. The role of both the ionization products from the candle flame and the concentration of volatile compounds released are important to the effect. SIGNIFICANCE AND IMPACT OF THE STUDY The technique described here offers a new and novel technique for reducing the concentration of bacteria on surfaces.
Collapse
Affiliation(s)
- L F Gaunt
- School of Electronics and Computer Science, University of Southampton, Southampton, UK.
| | | | | |
Collapse
|
24
|
Hughes JF, Skaletsky H, Pyntikova T, Minx PJ, Graves T, Rozen S, Wilson RK, Page DC. Conservation of Y-linked genes during human evolution revealed by comparative sequencing in chimpanzee. Nature 2005; 437:100-3. [PMID: 16136134 DOI: 10.1038/nature04101] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Accepted: 08/03/2005] [Indexed: 11/10/2022]
Abstract
The human Y chromosome, transmitted clonally through males, contains far fewer genes than the sexually recombining autosome from which it evolved. The enormity of this evolutionary decline has led to predictions that the Y chromosome will be completely bereft of functional genes within ten million years. Although recent evidence of gene conversion within massive Y-linked palindromes runs counter to this hypothesis, most unique Y-linked genes are not situated in palindromes and have no gene conversion partners. The 'impending demise' hypothesis thus rests on understanding the degree of conservation of these genes. Here we find, by systematically comparing the DNA sequences of unique, Y-linked genes in chimpanzee and human, which diverged about six million years ago, evidence that in the human lineage, all such genes were conserved through purifying selection. In the chimpanzee lineage, by contrast, several genes have sustained inactivating mutations. Gene decay in the chimpanzee lineage might be a consequence of positive selection focused elsewhere on the Y chromosome and driven by sperm competition.
Collapse
Affiliation(s)
- Jennifer F Hughes
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
HERV elements make up a significant fraction of the human genome and, as interspersed repetitive elements, have the capacity to provide substrates for ectopic recombination and gene conversion events. To understand the extent to which these events occur and gain further insight into the complex evolutionary history of these elements in our genome, we undertook a phylogenetic study of the long terminal repeat sequences of 15 HERV-K(HML-2) elements in various primate species. This family of human endogenous retroviruses first entered the primate genome between 35 and 45 million years ago. Throughout primate evolution, these elements have undergone bursts of amplification. From this analysis, which is the largest-scale study of HERV sequence dynamics during primate evolution to date, we were able to detect intraelement gene conversion and recombination at five HERV-K loci. We also found evidence for replacement of an ancient element by another HERV-K provirus, apparently reflecting an occurrence of retroviral integration by homologous recombination. The high frequency of these events casts doubt on the accuracy of integration time estimates based only on divergence between retroelement LTRs.
Collapse
Affiliation(s)
- Jennifer F Hughes
- Department of Molecular Microbiology and Program in Genetics, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | | |
Collapse
|
26
|
Hughes JF, Coffin JM. Human endogenous retrovirus K solo-LTR formation and insertional polymorphisms: implications for human and viral evolution. Proc Natl Acad Sci U S A 2004; 101:1668-72. [PMID: 14757818 PMCID: PMC341815 DOI: 10.1073/pnas.0307885100] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Human endogenous retroviruses (HERVs) are a potential source of genetic diversity in the human genome. Although many of these elements have been inactivated over time by the accumulation of deleterious mutations or internal recombination leading to solo-LTR formation, several members of the HERV-K family have been identified that remain nearly intact and probably represent recent integration events. To determine whether HERV-K elements have caused recent changes in the human genome, we have undertaken a study of the level of HERV-K polymorphism that exists in the human population. By using a high-resolution unblotting technique, we analyzed 13 human-specific HERV-K elements in 18 individuals. We found that solo LTRs have formed at five of these loci. These results enable the estimation of HERV solo-LTR formation in the human genome and indicate that these events occur much more frequently than described in inbred mice. Detailed sequence analysis of one provirus shows that solo-LTR formation occurred at least three separate times in recent history. An unoccupied preintegration site also was present at this locus in two individuals, indicating that although the age of this provirus is estimated to be approximately 1.2 million years, it has not yet become fixed in the human population.
Collapse
Affiliation(s)
- Jennifer F Hughes
- Department of Molecular Biology and Microbiology and Program in Genetics, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | | |
Collapse
|
27
|
|
28
|
Hughes JF, Coffin JM. A novel endogenous retrovirus-related element in the human genome resembles a DNA transposon: evidence for an evolutionary link? Genomics 2002; 80:453-5. [PMID: 12408960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
A significant fraction of the human genome is composed of various types of transposable elements, which are divided into two broad classes based on their mehcanism of transposition: via an RNA intermediate (retroelements) or via a DNA intermediate (DNA transposons). The retroelements, which include endogenous retroviruses, are the more prominent group in humans and seem to be restricted to eukaryotes. DNA transposons are known in almost all well-studied organisms, including bacteria. In the human genome, they exist as mere fossils and seem to have been inactive for millions of years. We report here an element in the human genome that is the product of a recent retrotransposition event, yet apparently, by a novel mechanism of reverse transcription, has acquired inverted repeats more characteristic of DNA transposons.
Collapse
Affiliation(s)
- Jennifer F Hughes
- Department of Molecular Biology and Microbiology and Program in Genetics, Tufts University School of Medicine, 136 Harrison Avenue, Boston, Massachusetts, 02111, USA
| | | |
Collapse
|
29
|
Abstract
BACKGROUND To reduce the risk of sensitization and the elicitation of allergy symptoms, it is important to reduce the level of allergens in the home. It has previously been demonstrated that corona discharge, the process by which ionizers produce ions, can destroy the major house dust mite allergen Der p 1. OBJECTIVE In this paper the denaturing efficacy of an experimental ionizer and two commercially available products are evaluated. METHODS The first test was conducted in an electrically grounded chamber with samples of Der p 1 placed in various positions for 1, 2 and 3 weeks. The second test was conducted in situ in an unoccupied, furnished office room for 1 week. Der p 1 concentration was quantified by two-site monoclonal antibody enzyme-linked immunosorbent assay (ELISA). RESULTS All ionizers in both tests caused significant reductions in allergen concentration (P < 0.05), reaching a maximum of 92% with the experimental ionizer in the chamber after 3 weeks. The percentage reductions observed in situ with the experimental and the larger commercial ionizer were similar, reaching a maximum of 32% at a distance of 4 m away from the experimental ionizer after 1 week of exposure. CONCLUSION With a revised protocol for use, air ionizers may offer a simple, efficient and inexpensive way to reduce allergen levels in the domestic environment.
Collapse
Affiliation(s)
- N Goodman
- Bioelectrostatics Research Centre, Department of Electronics and Computer Science, University of Southampton, Southampton, UK.
| | | |
Collapse
|
30
|
Abstract
BACKGROUND Reduction of house dust mite allergens in the domestic environment can play an important part in reducing sensitization and in the amelioration of symptoms in atopic individuals. Chemical and physical methods have been tried with varied levels of success. The present paper presents a novel electrostatic way of destroying Der p 1, the major mite allergen. OBJECTIVE To assess the efficacy of negative Trichel, negative continuous glow, positive pulse and positive continuous glow corona in destroying Der p 1. To determine whether ozone has any effect on the integrity of Der p 1 in the experimental conditions present. METHODS A simple point-to-plane apparatus was used to irradiate samples of Der p 1 for periods of 1, 15, 30, 45, 60, 120, 180, 240 and 300 min. Controls were exposed to the atmosphere with no corona products present for the equivalent time. The effect of the corona by-product ozone was investigated alone by exposing samples of Der p 1 to molecular ozone for 60 min. Der p 1 concentration was quantified by two-site monoclonal antibody ELISA. RESULTS High current negative glow resulted in a 67.37% reduction in Der p 1 concentration after 300 min compared with a 50.5% reduction from a low current Trichel regime. High current positive glow corona gave a reduction of 25.22% while a low current positive pulse corona caused a 13.72% reduction after 300 min. All these reductions were statistically significant (P < 0.05) compared with unexposed controls. Negative corona always gave greater percentage reductions in Der p 1 concentration for each time exposure investigated. The pattern of percentage reduction follows an exponential rise to maximum relationship in respect to time. Samples of Der p 1 were not affected by exposure to molecular ozone. CONCLUSION These data indicate corona products to be a powerful new method of destroying Der p 1 allergen that is not dependent on the presence of the oxidizing corona product ozone.
Collapse
Affiliation(s)
- N Goodman
- Bioelectrostatics Research Centre, Department of Electronics and Computer Science, Faculty of Engineering and Applied Science, University of Southampton, Highfield, Southampton, UK.
| | | |
Collapse
|
31
|
Abstract
Human endogenous retroviruses (HERVs), which are remnants of past retroviral infections of the germline cells of our ancestors, make up as much as 8% of the human genome and may even outnumber genes. Most HERVs seem to have entered the genome between 10 and 50 million years ago, and they comprise over 200 distinct groups and subgroups. Although repeated sequence elements such as HERVs have the potential to lead to chromosomal rearrangement through homologous recombination between distant loci, evidence for the generality of this process is lacking. To gain insight into the expansion of these elements in the genome during the course of primate evolution, we have identified 23 new members of the HERV-K (HML-2) group, which is thought to contain the most recently active members. Here we show, by phylogenetic and sequence analysis, that at least 16% of these elements have undergone apparent rearrangements that may have resulted in large-scale deletions, duplications and chromosome reshuffling during the evolution of the human genome.
Collapse
Affiliation(s)
- J F Hughes
- Department of Molecular Biology and Microbiology and Program in Genetics, Tufts University School of Medicine, 136 Harrison Avenue, Boston, Massachusetts 02111, USA
| | | |
Collapse
|
32
|
Whitmore LF, Hughes JF, Harrison N, Abela M, O'Rourke P. Enhanced efficiency of electrostatically charged insecticide aerosols. Pest Manag Sci 2001; 57:432-436. [PMID: 11374160 DOI: 10.1002/ps.292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The bioefficacy of a standard domestic aerosol insecticide has been compared with that of a similar spray in which the droplets were electrostatically charged. The aerosol was charged without the need for an external power supply, by enhancing natural charge separation processes that occur during atomisation. The charge-to-mass ratio achieved was 1.1 x 10(-4) C kg-1, compared with 2.2 x 10(-5) C kg-1 for the standard aerosol. Efficiency was assessed for insects in free flight. A direct space-spray application method was used to study the bioefficacy of these aerosols on houseflies, Musca domestica, and an indirect space-spray method on houseflies and mosquitoes, Culex quinquefasciatus. Two levels of concentration of active ingredients were compared. At low concentrations of 1.57 g kg-1 of bioallethrin and 0.29 g kg-1 of bioresmethrin, the charged aerosol achieved a significant reduction in KDT50 (time at which 50% of the flies were knocked down), compared with the standard aerosol. In the direct spray application to houseflies, the KDT50 was reduced by 50%, while in the indirect spray the KDT50 was reduced by 40%. In the indirect spray of mosquitoes, the KDT50 was reduced by 22%. With higher active ingredient concentrations of 2.09 g kg-1 for bioallethrin and 0.39 g kg-1 for bioresmethrin, the charged aerosol also demonstrated faster knockdown than the standard, but the improvement was less marked. In the direct spray application to houseflies, the KDT50 was reduced by 21% compared with the standard aerosol, while in the indirect spray the KDT50 was reduced by 16%. In the indirect spray of mosquitoes, the KDT50 was reduced by 24%. The percentage mortality after 24 h was also increased with the charged aerosol. Charge carried by the droplets results in increased interception of the insecticide, as the droplets are attracted to the insects in flight and space charge effects within the aerosol could cause improved dispersion in the test chamber.
Collapse
Affiliation(s)
- L F Whitmore
- Bioelectrostatics Research Centre, Department of Electronics and Computer Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | | | | | | | | |
Collapse
|
33
|
Abstract
The avoidance of house dust mite allergens is a major area of interest and essentially requires a significant removal of these allergens from the immediately respirable air. Electrostatic attraction and anchoring of particulate matter using electret polymers is commonly used for air filtration purposes. This effect is investigated for its possible use in domestic allergen avoidance. Polypropylene electret, heat-treated electret and non-electret, and wool and nylon fibre samples were soiled with house dust known to contain Der p 1 allergen. These samples were vacuumed at three air face velocities. The proportions of released and anchored dust were calculated. Released dust was collected and analysed for Der p 1 concentration and compared to stock dust values. Results showed that compared to uncharged fibres at least 95% more dust remained anchored in the electret fibres. Also, overall Der p 1 release was reduced by more than 49%. Der p 1 allergen concentrations in the collected dust were relatively constant for all the fibres tested, indicating no selective attraction or repulsion of Der p 1 allergen carrying particles in the experimental dust. The consistently high dust anchoring ability of the electret fibres could be used in many domestic products that are known to harbour particulate allergens, to reduce their release and inhalation.
Collapse
Affiliation(s)
- P T Gaynor
- Bioelectrostatics Research Centre, University of Southampton, Highfield, UK
| | | |
Collapse
|
34
|
Gaynor PT, Hughes JF. Electrostatic charge characteristics of Der p1 allergen-carrying particles and the house dust mite dermatophagoides pteronyssinus. Med Biol Eng Comput 1998; 36:351-4. [PMID: 9747576 DOI: 10.1007/bf02522482] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Control of the house dust mite allergen has received considerable attention owing to its importance in some allergic diseases. One aspect of dust mites and their allergen-carrying faecal particles that has not been reported on, which may have allergen control applications, is the electrostatic charge they carry in the natural environment. To promote tribo-electric charging, household dust containing dust mite allergen and live house dust mites are separately agitated while in contact with either polypropylene, nylon or earthed metal. The charged dust and mites are subsequently subjected to electrostatic separation and collection. Results for concentrations of the house dust mite allergen, Der p1, indicate that, when subjected to nylon, Der p1 carrier particles appear to be predominantly positively charged. Similarly, when subjected to polypropylene, Der p1 carrier particles also appear to be positively charged. Reduction of excess free charge by agitation against earthed metal does not appear to affect the observed charging characteristics, indicating that the positive charge may be bound or inherent in the Der p1 carrier particles. In contrast, house dust mites exposed to nylon appear to be generally charging negative, whereas mites exposed to polypropylene appear to be charging positive. The observed electrostatic characteristics of the mites and Der p1 carrying particles will be useful in the future development of electrostatic allergen control methods.
Collapse
Affiliation(s)
- P T Gaynor
- Bioelectrostatics Research Centre, University of Southampton, UK
| | | |
Collapse
|
35
|
Abstract
The current routine diagnostic procedures for foot and mouth disease (FMD) virus antigen detection combine the use of an indirect sandwich enzyme-linked immunosorbent assay (ELISA) with virus isolation and amplification on cell culture. Several field samples recently received by the World Reference Laboratory for Foot and Mouth Disease which were initially diagnosed as containing a single virus type have subsequently been found to contain an additional virus type. Examples are given of the results of ELISAs performed on certain Saudia Arabian samples; these examples illustrate the problem which such multiple-infected samples present for laboratory diagnosis.
Collapse
Affiliation(s)
- N P Ferris
- Biotechnology and Biological Sciences Research Council, Institute for Animal Health, Pirbright Laboratory, Woking, Surrey, United Kingdom
| | | | | |
Collapse
|
36
|
Abstract
Five cases of lincomycin-clindamycin-associated acute pseudomembranous colitis, demonstrating a spectrum of clinical, histological and radiological severity, were encountered over a five-months period. All patients presented with watery diarrhoea without the passage of macroscopic blood or pus. Two patients were seriously ill with fulminant colitis, but responded rapidly to corticosteroids given parenterally and supportive therapy. The diagnosis of acute colitis should be considered in all patients developing diarrhoea during or up to three weeks after beginning therapy with lincomycin or clindamycin and can be confirmed by sigmoidoscopic examination. Withdrawal of the antibiotic and symptomatic treatment is appropriate for mild cases of colitis, but our experience suggests that corticosteroid therapy is safe and effective in severe cases. Indiscriminate use of these antibiotics should be avoided.
Collapse
|
37
|
Evans EO, Coigley M, Lewis JV, Woodward NA, Hodson J, McWhinney AR, Ferguson D, Nicol HG, Ganner AN, Lockie A, Murray A, Sykes GW, Hughes JF, Fitchford RJ. Letter: Coping with minor casualties. Br Med J 1974; 2:440. [PMID: 4835304 PMCID: PMC1610460 DOI: 10.1136/bmj.2.5916.440-a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
38
|
Hughes JF. Third party podiatry. J Am Podiatry Assoc 1973; 63:336-41. [PMID: 4715280 DOI: 10.7547/87507315-63-7-336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|