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  1. Article ; Online: Single-cell analysis of cell fate bifurcation in the chordate Ciona.

    Winkley, Konner M / Reeves, Wendy M / Veeman, Michael T

    BMC biology

    2021  Volume 19, Issue 1, Page(s) 180

    Abstract: Background: Inductive signaling interactions between different cell types are a major mechanism for the further diversification of embryonic cell fates. Most blastomeres in the model chordate Ciona robusta become restricted to a single predominant fate ... ...

    Abstract Background: Inductive signaling interactions between different cell types are a major mechanism for the further diversification of embryonic cell fates. Most blastomeres in the model chordate Ciona robusta become restricted to a single predominant fate between the 64-cell and mid-gastrula stages. The deeply stereotyped and well-characterized Ciona embryonic cell lineages allow the transcriptomic analysis of newly established cell types very early in their divergence from sibling cell states without the pseudotime inference needed in the analysis of less synchronized cell populations. This is the first ascidian study to use droplet scRNAseq with large numbers of analyzed cells as early as the 64-cell stage when major lineages such as primary notochord first become fate restricted.
    Results and conclusions: We identify 59 distinct cell states, including new subregions of the b-line neural lineage and the early induction of the tail tip epidermis. We find that 34 of these cell states are directly or indirectly dependent on MAPK-mediated signaling critical to early Ciona patterning. Most of the MAPK-dependent bifurcations are canalized with the signal-induced cell fate lost upon MAPK inhibition, but the posterior endoderm is unique in being transformed into a novel state expressing some but not all markers of both endoderm and muscle. Divergent gene expression between newly bifurcated sibling cell types is dominated by upregulation in the induced cell type. The Ets family transcription factor Elk1/3/4 is uniquely upregulated in nearly all the putatively direct inductions. Elk1/3/4 upregulation together with Ets transcription factor binding site enrichment analysis enables inferences about which bifurcations are directly versus indirectly controlled by MAPK signaling. We examine notochord induction in detail and find that the transition between a Zic/Ets-mediated regulatory state and a Brachyury/FoxA-mediated regulatory state is unexpectedly late. This supports a "broad-hourglass" model of cell fate specification in which many early tissue-specific genes are induced in parallel to key tissue-specific transcriptional regulators via the same set of transcriptional inputs.
    MeSH term(s) Animals ; Cell Differentiation ; Ciona ; Gene Expression Regulation, Developmental ; Notochord ; Single-Cell Analysis
    Language English
    Publishing date 2021-08-31
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2133020-7
    ISSN 1741-7007 ; 1741-7007
    ISSN (online) 1741-7007
    ISSN 1741-7007
    DOI 10.1186/s12915-021-01122-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Brachyury controls

    Reeves, Wendy M / Shimai, Kotaro / Winkley, Konner M / Veeman, Michael T

    Development (Cambridge, England)

    2021  Volume 148, Issue 3

    Abstract: The notochord is a defining feature of the chordates. The transcription factor Brachyury (Bra) is a key regulator of notochord fate but here we show that it is not a unitary master regulator in the model ... ...

    Abstract The notochord is a defining feature of the chordates. The transcription factor Brachyury (Bra) is a key regulator of notochord fate but here we show that it is not a unitary master regulator in the model chordate
    MeSH term(s) Animals ; Ciona/genetics ; Ciona/metabolism ; Ciona intestinalis/genetics ; Ciona intestinalis/metabolism ; Fetal Proteins/genetics ; Fetal Proteins/metabolism ; Gene Expression Regulation, Developmental ; Gene Regulatory Networks ; Notochord/growth & development ; Notochord/metabolism ; T-Box Domain Proteins/genetics ; T-Box Domain Proteins/metabolism ; Trans-Activators ; Transcription Factors/metabolism
    Chemical Substances Fetal Proteins ; T-Box Domain Proteins ; Trans-Activators ; Transcription Factors ; Brachyury protein (EQ43SC3GDB)
    Language English
    Publishing date 2021-02-05
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 90607-4
    ISSN 1477-9129 ; 0950-1991
    ISSN (online) 1477-9129
    ISSN 0950-1991
    DOI 10.1242/dev.195230
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: A temperature-adjusted developmental timer for precise embryonic staging.

    Winkley, Konner / Veeman, Michael

    Biology open

    2018  Volume 7, Issue 6

    Abstract: Developmental biology research depends on careful staging of developing embryos, but the rate of development is extremely sensitive to the temperature at which embryos are raised. It is not always practical to grow embryos at a precisely controlled ... ...

    Abstract Developmental biology research depends on careful staging of developing embryos, but the rate of development is extremely sensitive to the temperature at which embryos are raised. It is not always practical to grow embryos at a precisely controlled temperature, so here we describe a simple, inexpensive device based on an Arduino-compatible microprocessor and temperature sensor that provides a metric of developmental time that compensates for changes in temperature. The underlying assumption is that the rate of development will be linear with respect to temperature over an organism's thermal tolerance range. The device measures the ambient temperature and integrates effective degree-minutes over time. For convenience, this is displayed to the user as a temperature-adjusted standard developmental time. In initial testing we have found the device to be extremely helpful for fixing
    Language English
    Publishing date 2018-06-11
    Publishing country England
    Document type Journal Article
    ZDB-ID 2632264-X
    ISSN 2046-6390
    ISSN 2046-6390
    DOI 10.1242/bio.032110
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: A temperature-adjusted developmental timer for precise embryonic staging

    Konner Winkley / Michael Veeman

    Biology Open, Vol 7, Iss

    2018  Volume 6

    Abstract: Developmental biology research depends on careful staging of developing embryos, but the rate of development is extremely sensitive to the temperature at which embryos are raised. It is not always practical to grow embryos at a precisely controlled ... ...

    Abstract Developmental biology research depends on careful staging of developing embryos, but the rate of development is extremely sensitive to the temperature at which embryos are raised. It is not always practical to grow embryos at a precisely controlled temperature, so here we describe a simple, inexpensive device based on an Arduino-compatible microprocessor and temperature sensor that provides a metric of developmental time that compensates for changes in temperature. The underlying assumption is that the rate of development will be linear with respect to temperature over an organism's thermal tolerance range. The device measures the ambient temperature and integrates effective degree-minutes over time. For convenience, this is displayed to the user as a temperature-adjusted standard developmental time. In initial testing we have found the device to be extremely helpful for fixing Ciona embryos during precise developmental windows.
    Keywords Arduino ; Embryo staging ; Thermal time ; Science ; Q ; Biology (General) ; QH301-705.5
    Subject code 541
    Language English
    Publishing date 2018-06-01T00:00:00Z
    Publisher The Company of Biologists
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Single-cell analysis of cell fate bifurcation in the chordate Ciona

    Konner M. Winkley / Wendy M. Reeves / Michael T. Veeman

    BMC Biology, Vol 19, Iss 1, Pp 1-

    2021  Volume 26

    Abstract: Abstract Background Inductive signaling interactions between different cell types are a major mechanism for the further diversification of embryonic cell fates. Most blastomeres in the model chordate Ciona robusta become restricted to a single ... ...

    Abstract Abstract Background Inductive signaling interactions between different cell types are a major mechanism for the further diversification of embryonic cell fates. Most blastomeres in the model chordate Ciona robusta become restricted to a single predominant fate between the 64-cell and mid-gastrula stages. The deeply stereotyped and well-characterized Ciona embryonic cell lineages allow the transcriptomic analysis of newly established cell types very early in their divergence from sibling cell states without the pseudotime inference needed in the analysis of less synchronized cell populations. This is the first ascidian study to use droplet scRNAseq with large numbers of analyzed cells as early as the 64-cell stage when major lineages such as primary notochord first become fate restricted. Results and conclusions We identify 59 distinct cell states, including new subregions of the b-line neural lineage and the early induction of the tail tip epidermis. We find that 34 of these cell states are directly or indirectly dependent on MAPK-mediated signaling critical to early Ciona patterning. Most of the MAPK-dependent bifurcations are canalized with the signal-induced cell fate lost upon MAPK inhibition, but the posterior endoderm is unique in being transformed into a novel state expressing some but not all markers of both endoderm and muscle. Divergent gene expression between newly bifurcated sibling cell types is dominated by upregulation in the induced cell type. The Ets family transcription factor Elk1/3/4 is uniquely upregulated in nearly all the putatively direct inductions. Elk1/3/4 upregulation together with Ets transcription factor binding site enrichment analysis enables inferences about which bifurcations are directly versus indirectly controlled by MAPK signaling. We examine notochord induction in detail and find that the transition between a Zic/Ets-mediated regulatory state and a Brachyury/FoxA-mediated regulatory state is unexpectedly late. This supports a “broad-hourglass” model of cell fate specification in which many early tissue-specific genes are induced in parallel to key tissue-specific transcriptional regulators via the same set of transcriptional inputs.
    Keywords Ciona ; Ascidian ; Single-cell RNAseq ; FGF ; MAPK ; Cell state transition ; Biology (General) ; QH301-705.5
    Subject code 571
    Language English
    Publishing date 2021-08-01T00:00:00Z
    Publisher BMC
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Iterative and Complex Asymmetric Divisions Control Cell Volume Differences in Ciona Notochord Tapering.

    Winkley, Konner / Ward, Spencer / Reeves, Wendy / Veeman, Michael

    Current biology : CB

    2019  Volume 29, Issue 20, Page(s) 3466–3477.e4

    Abstract: The notochord of the invertebrate chordate Ciona forms a tapered rod at tailbud stages consisting of only 40 cylindrical cells in a single-file column. This tapered shape involves differences in notochord cell volume along the anterior-posterior axis. ... ...

    Abstract The notochord of the invertebrate chordate Ciona forms a tapered rod at tailbud stages consisting of only 40 cylindrical cells in a single-file column. This tapered shape involves differences in notochord cell volume along the anterior-posterior axis. Here, we quantify sibling cell volume asymmetry throughout the developing notochord and find that there are distinctive patterns of unequal cleavage in all 4 bilateral pairs of A-line primary notochord founder cells and also in the B-line-derived secondary notochord founder cells. A quantitative model confirms that the observed patterns of unequal cleavage are sufficient to explain all the anterior-posterior variation in notochord cell volume. Many examples are known of cells that divide asymmetrically to give daughter cells of different size and fate. Here, by contrast, a series of subtle but iterative and finely patterned asymmetric divisions controls the shape of an entire organ. Quantitative 3D analysis of cell shape and spindle positioning allows us to infer multiple cellular mechanisms driving these unequal cleavages, including polarized displacements of the mitotic spindle, contributions from the shape of the mother cell, and late changes occurring between anaphase and abscission that potentially involve differential cortical contractility. We infer differential use of these mechanisms between different notochord blastomeres and also between different rounds of cell division. These results demonstrate a new role for asymmetric division in directly shaping a developing organ and point toward complex underlying mechanisms.
    MeSH term(s) Animals ; Asymmetric Cell Division ; Blastomeres/metabolism ; Cell Shape ; Cell Size ; Ciona intestinalis/embryology ; Embryo, Nonmammalian/cytology ; Embryo, Nonmammalian/embryology ; Notochord/cytology ; Notochord/embryology
    Language English
    Publishing date 2019-10-10
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 1071731-6
    ISSN 1879-0445 ; 0960-9822
    ISSN (online) 1879-0445
    ISSN 0960-9822
    DOI 10.1016/j.cub.2019.08.056
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: High-resolution epigenome analysis in nasal samples derived from children with respiratory viral infections reveals striking changes upon SARS-CoV-2 infection.

    Winkley, Konner / Koseva, Boryana / Banerjee, Dithi / Cheung, Warren / Selvarangan, Rangaraj / Pastinen, Tomi / Grundberg, Elin

    medRxiv : the preprint server for health sciences

    2021  

    Abstract: Background: DNA methylation patterns of the human genome can be modified by environmental stimuli and provide dense information on gene regulatory circuitries. We studied genome-wide DNA methylation in nasal samples from infants (<6 months) applying ... ...

    Abstract Background: DNA methylation patterns of the human genome can be modified by environmental stimuli and provide dense information on gene regulatory circuitries. We studied genome-wide DNA methylation in nasal samples from infants (<6 months) applying whole-genome bisulfite sequencing (WGBS) to characterize epigenome response to 10 different respiratory viral infections including SARS-CoV-2.
    Results: We identified virus-specific differentially methylated regions (vDMR) with human metapneumovirus (hMPV) and SARS-CoV-2 followed by Influenza B (Flu B) causing the weakest vs. strongest epigenome response with 496 vs. 78541 and 14361 vDMR, respectively. We found a strong replication rate of FluB (52%) and SARS-CoV-2 (42%) vDMR in independent samples indicating robust epigenome perturbation upon infection. Among the FluB and SARS-CoV-2 vDMRs, around 70% were hypomethylated and significantly enriched among epithelial cell-specific regulatory elements whereas the hypermethylated vDMRs for these viruses mapped more frequently to immune cell regulatory elements, especially those of the myeloid lineage. The hypermethylated vDMRs were also enriched among genes and genetic loci in monocyte activation pathways and monocyte count. Finally, we perform single-cell RNA-sequencing characterization of nasal mucosa in response to these two viruses to functionally analyze the epigenome perturbations. Which supports the trends we identified in methylation data and highlights and important role for monocytes.
    Conclusions: All together, we find evidence indicating genetic predisposition to innate immune response upon a respiratory viral infection. Our genome-wide monitoring of infant viral response provides first catalogue of associated host regulatory elements. Assessing epigenetic variation in individual patients may reveal evidence for viral triggers of childhood disease.
    Language English
    Publishing date 2021-03-11
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2021.03.09.21253155
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Immune cell residency in the nasal mucosa may partially explain respiratory disease severity across the age range.

    Winkley, Konner / Banerjee, Dithi / Bradley, Todd / Koseva, Boryana / Cheung, Warren A / Selvarangan, Rangaraj / Pastinen, Tomi / Grundberg, Elin

    Scientific reports

    2021  Volume 11, Issue 1, Page(s) 15927

    Abstract: Previous studies focusing on the age disparity in COVID-19 severity have suggested that younger individuals mount a more robust innate immune response in the nasal mucosa after infection with SARS-CoV-2. However, it is unclear if this reflects increased ... ...

    Abstract Previous studies focusing on the age disparity in COVID-19 severity have suggested that younger individuals mount a more robust innate immune response in the nasal mucosa after infection with SARS-CoV-2. However, it is unclear if this reflects increased immune activation or increased immune residence in the nasal mucosa. We hypothesized that immune residency in the nasal mucosa of healthy individuals may differ across the age range. We applied single-cell RNA-sequencing and measured the cellular composition and transcriptional profile of the nasal mucosa in 35 SARS-CoV-2 negative children and adults, ranging in age from 4 months to 65 years. We analyzed in total of ~ 30,000 immune and epithelial cells and found that age and immune cell proportion in the nasal mucosa are inversely correlated, with little evidence for structural changes in the transcriptional state of a given cell type across the age range. Orthogonal validation by epigenome sequencing indicate that it is especially cells of the innate immune system that underlie the age-association. Additionally, we characterize the predominate immune cell type in the nasal mucosa: a resident T cell like population with potent antiviral properties. These results demonstrate fundamental changes in the immune cell makeup of the uninfected nasal mucosa over the lifespan. The resource we generate here is an asset for future studies focusing on respiratory infection and immunization strategies.
    MeSH term(s) Adolescent ; Adult ; COVID-19/genetics ; COVID-19/immunology ; Child ; Child, Preschool ; Female ; Humans ; Immunity, Cellular ; Immunity, Innate ; Infant ; Male ; Middle Aged ; Nasal Mucosa/cytology ; Nasal Mucosa/immunology ; Nasal Mucosa/metabolism ; SARS-CoV-2/immunology ; Severity of Illness Index ; T-Lymphocytes/immunology ; T-Lymphocytes/metabolism ; Transcriptome ; Young Adult
    Language English
    Publishing date 2021-08-05
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-021-95532-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Tunicate gastrulation.

    Winkley, Konner M / Kourakis, Matthew J / DeTomaso, Anthony W / Veeman, Michael T / Smith, William C

    Current topics in developmental biology

    2019  Volume 136, Page(s) 219–242

    Abstract: Tunicates are a diverse group of invertebrate marine chordates that includes the larvaceans, thaliaceans, and ascidians. Because of their unique evolutionary position as the sister group of the vertebrates, tunicates are invaluable as a comparative model ...

    Abstract Tunicates are a diverse group of invertebrate marine chordates that includes the larvaceans, thaliaceans, and ascidians. Because of their unique evolutionary position as the sister group of the vertebrates, tunicates are invaluable as a comparative model and hold the promise of revealing both conserved and derived features of chordate gastrulation. Descriptive studies in a broad range of tunicates have revealed several important unifying traits that make them unique among the chordates, including invariant cell lineages through gastrula stages and an overall morphological simplicity. Gastrulation has only been studied in detail in ascidians such as Ciona and Phallusia, where it involves a simple cup-shaped gastrula driven primarily by endoderm invagination. This appears to differ significantly from vertebrate models, such as Xenopus, in which mesoderm convergent extension and epidermal epiboly are major contributors to involution. These differences may reflect the cellular simplicity of the ascidian embryo.
    MeSH term(s) Animals ; Body Patterning ; Cell Lineage ; Embryo, Nonmammalian/cytology ; Embryo, Nonmammalian/physiology ; Endoderm/physiology ; Evolution, Molecular ; Gastrula/cytology ; Gastrula/physiology ; Gastrulation ; Gene Expression Regulation, Developmental ; Morphogenesis ; Urochordata/embryology ; Urochordata/physiology
    Language English
    Publishing date 2019-11-22
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S. ; Review
    ISSN 1557-8933 ; 0070-2153
    ISSN (online) 1557-8933
    ISSN 0070-2153
    DOI 10.1016/bs.ctdb.2019.09.001
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Immune cell residency in the nasal mucosa may partially explain respiratory disease severity across the age range

    Konner Winkley / Dithi Banerjee / Todd Bradley / Boryana Koseva / Warren A. Cheung / Rangaraj Selvarangan / Tomi Pastinen / Elin Grundberg

    Scientific Reports, Vol 11, Iss 1, Pp 1-

    2021  Volume 9

    Abstract: Abstract Previous studies focusing on the age disparity in COVID-19 severity have suggested that younger individuals mount a more robust innate immune response in the nasal mucosa after infection with SARS-CoV-2. However, it is unclear if this reflects ... ...

    Abstract Abstract Previous studies focusing on the age disparity in COVID-19 severity have suggested that younger individuals mount a more robust innate immune response in the nasal mucosa after infection with SARS-CoV-2. However, it is unclear if this reflects increased immune activation or increased immune residence in the nasal mucosa. We hypothesized that immune residency in the nasal mucosa of healthy individuals may differ across the age range. We applied single-cell RNA-sequencing and measured the cellular composition and transcriptional profile of the nasal mucosa in 35 SARS-CoV-2 negative children and adults, ranging in age from 4 months to 65 years. We analyzed in total of ~ 30,000 immune and epithelial cells and found that age and immune cell proportion in the nasal mucosa are inversely correlated, with little evidence for structural changes in the transcriptional state of a given cell type across the age range. Orthogonal validation by epigenome sequencing indicate that it is especially cells of the innate immune system that underlie the age-association. Additionally, we characterize the predominate immune cell type in the nasal mucosa: a resident T cell like population with potent antiviral properties. These results demonstrate fundamental changes in the immune cell makeup of the uninfected nasal mucosa over the lifespan. The resource we generate here is an asset for future studies focusing on respiratory infection and immunization strategies.
    Keywords Medicine ; R ; Science ; Q
    Subject code 570
    Language English
    Publishing date 2021-08-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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