LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 42

Search options

  1. Article ; Online: A histone demethylase links the loss of plasticity to nongenetic inheritance and morphological change.

    Levis, Nicholas A / Ragsdale, Erik J

    Nature communications

    2023  Volume 14, Issue 1, Page(s) 8439

    Abstract: Plasticity is a widespread feature of development, enabling phenotypic change based on the environment. Although the evolutionary loss of plasticity has been linked both theoretically and empirically to increased rates of phenotypic diversification, ... ...

    Abstract Plasticity is a widespread feature of development, enabling phenotypic change based on the environment. Although the evolutionary loss of plasticity has been linked both theoretically and empirically to increased rates of phenotypic diversification, molecular insights into how this process might unfold are generally lacking. Here, we show that a regulator of nongenetic inheritance links evolutionary loss of plasticity in nature to changes in plasticity and morphology as selected in the laboratory. Across nematodes of Diplogastridae, which ancestrally had a polyphenism, or discrete plasticity, in their feeding morphology, we use molecular evolutionary analyses to screen for change associated with independent losses of plasticity. Having inferred a set of ancestrally polyphenism-biased genes from phylogenetically informed gene-knockouts and gene-expression comparisons, selection signatures associated with plasticity's loss identify the histone H3K4 di/monodemethylase gene spr-5/LSD1/KDM1A. Manipulations of this gene affect both sensitivity and variation in plastic morphologies, and artificial selection of manipulated lines drive multigenerational shifts in these phenotypes. Our findings thus give mechanistic insight into how traits are modified as they traverse the continuum of greater to lesser environmental sensitivity.
    MeSH term(s) Animals ; Biological Evolution ; Phenotype ; Gene Expression ; Nematoda ; Histone Demethylases/genetics
    Chemical Substances Histone Demethylases (EC 1.14.11.-)
    Language English
    Publishing date 2023-12-19
    Publishing country England
    Document type Journal Article
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-023-44306-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article: Linking Molecular Mechanisms and Evolutionary Consequences of Resource Polyphenism.

    Levis, Nicholas A / Ragsdale, Erik J

    Frontiers in integrative neuroscience

    2022  Volume 16, Page(s) 805061

    Abstract: Resource polyphenism-the occurrence of environmentally induced, discrete, and intraspecific morphs showing differential niche use-is taxonomically widespread and fundamental to the evolution of ecological function where it has arisen. Despite ... ...

    Abstract Resource polyphenism-the occurrence of environmentally induced, discrete, and intraspecific morphs showing differential niche use-is taxonomically widespread and fundamental to the evolution of ecological function where it has arisen. Despite longstanding appreciation for the ecological and evolutionary significance of resource polyphenism, only recently have its proximate mechanisms begun to be uncovered. Polyphenism switches, especially those influencing and influenced by trophic interactions, offer a route to integrating proximate and ultimate causation in studies of plasticity, and its potential influence on evolution more generally. Here, we use the major events in generalized polyphenic development as a scaffold for linking the molecular mechanisms of polyphenic switching with potential evolutionary outcomes of polyphenism and for discussing challenges and opportunities at each step in this process. Not only does the study of resource polyphenism uncover interesting details of discrete plasticity, it also illuminates and informs general principles at the intersection of development, ecology, and evolution.
    Language English
    Publishing date 2022-02-08
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2452962-X
    ISSN 1662-5145
    ISSN 1662-5145
    DOI 10.3389/fnint.2022.805061
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: A Mediator subunit imparts robustness to a polyphenism decision.

    Casasa, Sofia / Katsougia, Eleni / Ragsdale, Erik J

    Proceedings of the National Academy of Sciences of the United States of America

    2023  Volume 120, Issue 32, Page(s) e2308816120

    Abstract: Polyphenism is a type of developmental plasticity that translates continuous environmental variability into discontinuous phenotypes. Such discontinuity likely requires a switch between alternative gene-regulatory networks, a principle that has been ... ...

    Abstract Polyphenism is a type of developmental plasticity that translates continuous environmental variability into discontinuous phenotypes. Such discontinuity likely requires a switch between alternative gene-regulatory networks, a principle that has been borne out by mechanisms found to promote morph-specific gene expression. However, whether robustness is required to execute a polyphenism decision has awaited testing at the molecular level. Here, we used a nematode model for polyphenism,
    MeSH term(s) Animals ; Receptors, Cytoplasmic and Nuclear/genetics ; Tooth ; Rhabditida/physiology ; Phenotype ; Gene Regulatory Networks
    Chemical Substances Receptors, Cytoplasmic and Nuclear
    Language English
    Publishing date 2023-08-01
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.2308816120
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Comparative reconstruction of the predatory feeding structures of the polyphenic nematode Pristionchus pacificus.

    Harry, Clayton J / Messar, Sonia M / Ragsdale, Erik J

    Evolution & development

    2022  Volume 24, Issue 1-2, Page(s) 16–36

    Abstract: Pristionchus pacificus is a nematode model for the developmental genetics of morphological polyphenism, especially at the level of individual cells. Morphological polyphenism in this species includes an evolutionary novelty, moveable teeth, which have ... ...

    Abstract Pristionchus pacificus is a nematode model for the developmental genetics of morphological polyphenism, especially at the level of individual cells. Morphological polyphenism in this species includes an evolutionary novelty, moveable teeth, which have enabled predatory feeding in this species and others in its family (Diplogastridae). From transmission electron micrographs of serial thin sections through an adult hermaphrodite of P. pacificus, we three-dimensionally reconstructed all epithelial and myoepithelial cells and syncytia, corresponding to 74 nuclei, of its face, mouth, and pharynx. We found that the epithelia that produce the predatory morphology of P. pacificus are identical to Caenorhabditis elegans in the number of cell classes and nuclei. However, differences in cell form, spatial relationships, and nucleus position correlate with gross morphological differences from C. elegans and outgroups. Moreover, we identified fine-structural features, especially in the anteriormost pharyngeal muscles, that underlie the conspicuous, left-right asymmetry that characterizes the P. pacificus feeding apparatus. Our reconstruction provides an anatomical map for studying the genetics of polyphenism, feeding behavior, and the development of novel form in a satellite model to C. elegans.
    MeSH term(s) Animals ; Biological Evolution ; Caenorhabditis elegans/physiology ; Nematoda/anatomy & histology ; Nematoda/physiology ; Predatory Behavior
    Language English
    Publishing date 2022-03-03
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2020288-X
    ISSN 1525-142X ; 1520-541X
    ISSN (online) 1525-142X
    ISSN 1520-541X
    DOI 10.1111/ede.12397
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Regulators of an ancient polyphenism evolved through episodic protein divergence and parallel gene radiations.

    Biddle, Joseph F / Ragsdale, Erik J

    Proceedings. Biological sciences

    2020  Volume 287, Issue 1921, Page(s) 20192595

    Abstract: Polyphenism is a form of developmental plasticity that transduces environmental cues into discontinuous, often disparate phenotypes. In some cases, polyphenism has been attributed to facilitating morphological diversification and even the evolution of ... ...

    Abstract Polyphenism is a form of developmental plasticity that transduces environmental cues into discontinuous, often disparate phenotypes. In some cases, polyphenism has been attributed to facilitating morphological diversification and even the evolution of novel traits. However, this process is predicated on the origins and evolutionary maintenance of genetic mechanisms that specify alternate developmental networks. When and how regulatory loci arise and change, specifically before and throughout the history of a polyphenism, is little understood. Here, we establish a phylogenetic and comparative molecular context for two dynamically evolving genes,
    MeSH term(s) Animals ; Biological Evolution ; Genetic Speciation ; Phenotype ; Phylogeny ; Rhabditida
    Language English
    Publishing date 2020-02-26
    Publishing country England
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 209242-6
    ISSN 1471-2954 ; 0080-4649 ; 0962-8452 ; 0950-1193
    ISSN (online) 1471-2954
    ISSN 0080-4649 ; 0962-8452 ; 0950-1193
    DOI 10.1098/rspb.2019.2595
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Tokorhabditis tauri n. sp. and T. atripennis n. sp. (Rhabditida

    Ragsdale Erik J. / Kanzaki Natsumi / Yamashita Tatsuya / Shinya Ryoji

    Journal of Nematology, Vol 54, Iss 1, Pp 309-

    Rhabditidae), isolated from Onthophagus dung beetles (Coleoptera: Scarabaeidae) from the Eastern USA and Japan

    2022  Volume 321

    Abstract: Two new species of Tokorhabditis, T. tauri n. sp. and T. atripennis n. sp., which were isolated from multiple Onthophagus species in North America and from O. atripennis in Japan, respectively, are described. The new species are each diagnosed by ... ...

    Abstract Two new species of Tokorhabditis, T. tauri n. sp. and T. atripennis n. sp., which were isolated from multiple Onthophagus species in North America and from O. atripennis in Japan, respectively, are described. The new species are each diagnosed by characters of the male tail and genitalia, in addition to molecular barcode differences that were previously reported. The description of T. tauri n. sp. expands the suite of known nematode associates of O. taurus, promoting ecological studies using a beetle that is an experimental model for insect–nematode–microbiota interactions in a semi-natural setting. Furthermore, our description of a third Tokorhabditis species, T. atripennis n. sp., sets up a comparative model for such ecological interactions, as well as other phenomena as previously described for T. tufae, including maternal care through obligate vivipary, the evolution of reproductive mode, and extremophilic living.
    Keywords insect–nematode interactions ; morphometrics ; new species ; taxonomy ; trioecy ; vivipary ; Biology (General) ; QH301-705.5
    Subject code 590
    Language English
    Publishing date 2022-08-01T00:00:00Z
    Publisher Sciendo
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  7. Article: Tokorhabditis Tauri

    Ragsdale, Erik J / Kanzaki, Natsumi / Yamashita, Tatsuya / Shinya, Ryoji

    Journal of nematology

    2022  Volume 54, Issue 1, Page(s) 20220028

    Abstract: Two new species ... ...

    Abstract Two new species of
    Language English
    Publishing date 2022-08-21
    Publishing country Poland
    Document type Journal Article
    ZDB-ID 410426-2
    ISSN 0022-300X
    ISSN 0022-300X
    DOI 10.2478/jofnem-2022-0028
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Multiple Plasticity Regulators Reveal Targets Specifying an Induced Predatory Form in Nematodes.

    Bui, Linh T / Ragsdale, Erik J

    Molecular biology and evolution

    2019  Volume 36, Issue 11, Page(s) 2387–2399

    Abstract: The ability to translate a single genome into multiple phenotypes, or developmental plasticity, defines how phenotype derives from more than just genes. However, to study the evolutionary targets of plasticity and their evolutionary fates, we need to ... ...

    Abstract The ability to translate a single genome into multiple phenotypes, or developmental plasticity, defines how phenotype derives from more than just genes. However, to study the evolutionary targets of plasticity and their evolutionary fates, we need to understand how genetic regulators of plasticity control downstream gene expression. Here, we have identified a transcriptional response specific to polyphenism (i.e., discrete plasticity) in the nematode Pristionchus pacificus. This species produces alternative resource-use morphs-microbivorous and predatory forms, differing in the form of their teeth, a morphological novelty-as influenced by resource availability. Transcriptional profiles common to multiple polyphenism-controlling genes in P. pacificus reveal a suite of environmentally sensitive loci, or ultimate target genes, that make up an induced developmental response. Additionally, in vitro assays show that one polyphenism regulator, the nuclear receptor NHR-40, physically binds to promoters with putative HNF4α (the nuclear receptor class including NHR-40) binding sites, suggesting this receptor may directly regulate genes that describe alternative morphs. Among differentially expressed genes were morph-limited genes, highlighting factors with putative "on-off" function in plasticity regulation. Further, predatory morph-biased genes included candidates-namely, all four P. pacificus homologs of Hsp70, which have HNF4α motifs-whose natural variation in expression matches phenotypic differences among P. pacificus wild isolates. In summary, our study links polyphenism regulatory loci to the transcription producing alternative forms of a morphological novelty. Consequently, our findings establish a platform for determining how specific regulators of morph-biased genes may influence selection on plastic phenotypes.
    Language English
    Publishing date 2019-07-25
    Publishing country United States
    Document type Journal Article
    ZDB-ID 998579-7
    ISSN 1537-1719 ; 0737-4038
    ISSN (online) 1537-1719
    ISSN 0737-4038
    DOI 10.1093/molbev/msz171
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: A draft genome for a species of Halicephalobus (Panagrolaimidae)

    Ragsdale Erik J. / Koutsovoulos Georgios / Biddle Joseph F.

    Journal of Nematology, Vol 51, Iss 1, Pp 1-

    2019  Volume 4

    Abstract: Halicephalobus is a clade of small, exclusively parthenogenic nematodes that have sometimes colonized remarkable habitats. Given their phylogenetic closeness to other parthenogenic panagrolaimid species with which they likely share a sexually reproducing ...

    Abstract Halicephalobus is a clade of small, exclusively parthenogenic nematodes that have sometimes colonized remarkable habitats. Given their phylogenetic closeness to other parthenogenic panagrolaimid species with which they likely share a sexually reproducing ancestor, Halicephalobus species provide a point of comparison for parallelisms in the evolution of asexuality. Here, we present a draft genome of a putatively new species of Halicephalobus isolated from termites in Japan.
    Keywords comparative genomics ; free-living ; panagrolaimorpha ; parthenogenesis ; Biology (General) ; QH301-705.5
    Language English
    Publishing date 2019-01-01T00:00:00Z
    Publisher Sciendo
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  10. Article ; Online: The oscillating Mucin-type protein DPY-6 has a conserved role in nematode mouth and cuticle formation.

    Sun, Shuai / Theska, Tobias / Witte, Hanh / Ragsdale, Erik J / Sommer, Ralf J

    Genetics

    2022  Volume 220, Issue 3

    Abstract: Nematodes show an extraordinary diversity of mouth structures and strikingly different feeding strategies, which has enabled an invasion of all ecosystems. However, nearly nothing is known about the structural and molecular architecture of the nematode ... ...

    Abstract Nematodes show an extraordinary diversity of mouth structures and strikingly different feeding strategies, which has enabled an invasion of all ecosystems. However, nearly nothing is known about the structural and molecular architecture of the nematode mouth (stoma). Pristionchus pacificus is an intensively studied nematode that exhibits unique life history traits, including predation, teeth-like denticle formation, and mouth-form plasticity. Here, we used a large-scale genetic screen to identify genes involved in mouth formation. We identified Ppa-dpy-6 to encode a Mucin-type hydrogel-forming protein that is macroscopically involved in the specification of the cheilostom, the anterior part of the mouth. We used a recently developed protocol for geometric morphometrics of miniature animals to characterize these defects further and found additional defects that affect mouth form, shape, and size resulting in an overall malformation of the mouth. Additionally, Ppa-dpy-6 is shorter than wild-type with a typical Dumpy phenotype, indicating a role in the formation of the external cuticle. This concomitant phenotype of the cheilostom and cuticle provides the first molecular support for the continuity of these structures and for the separation of the cheilostom from the rest of the stoma. In Caenorhabditis elegans, dpy-6 was an early mapping mutant but its molecular identity was only determined during genome-wide RNAi screens and not further investigated. Strikingly, geometric morphometric analysis revealed previously unrecognized cheilostom and gymnostom defects in Cel-dpy-6 mutants. Thus, the Mucin-type protein DPY-6 represents to the best of our knowledge, the first protein involved in nematode mouth formation with a conserved role in cuticle deposition. This study opens new research avenues to characterize the molecular composition of the nematode mouth, which is associated with extreme ecological diversification.
    MeSH term(s) Animals ; Caenorhabditis elegans/genetics ; Caenorhabditis elegans/metabolism ; Ecosystem ; Mouth ; Mucins/genetics ; Mucins/metabolism ; Nematoda/genetics
    Chemical Substances Mucins
    Language English
    Publishing date 2022-01-31
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2167-2
    ISSN 1943-2631 ; 0016-6731
    ISSN (online) 1943-2631
    ISSN 0016-6731
    DOI 10.1093/genetics/iyab233
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top