Nuclear genomic signals of the 'microturbellarian' roots of platyhelminth evolutionary innovation

  1. Christopher E Laumer  Is a corresponding author
  2. Andreas Hejnol
  3. Gonzalo Giribet
  1. Harvard University, United States
  2. University of Bergen, Norway

Abstract

Flatworms number among the most diverse invertebrate phyla, and represent the most biomedically significant branch of the major bilaterian clade Spiralia, but to date, deep evolutionary relationships within this group have been studied using only a single locus (the rRNA operon), leaving the origins of many key clades unclear. Here, using a survey of genomes and transcriptomes representing all free-living flatworm orders, we provide resolution of platyhelminth interrelationships based on hundreds of nuclear protein-coding genes, exploring phylogenetic signal through concatenation as well as recently developed consensus approaches. These analyses robustly support a modern hypothesis of flatworm phylogeny, one which emphasizes the primacy of the often-overlooked 'microturbellarian' groups in understanding the major evolutionary transitions within Platyhelminthes: perhaps most notably, we propose a novel scenario for the interrelationships between free-living and vertebrate-parasitic flatworms, providing new opportunities to shed light on the origins and biological consequences of parasitism in these iconic invertebrates.

Article and author information

Author details

  1. Christopher E Laumer

    Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, United States
    For correspondence
    claumer@oeb.harvard.edu
    Competing interests
    The authors declare that no competing interests exist.
  2. Andreas Hejnol

    Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
    Competing interests
    The authors declare that no competing interests exist.
  3. Gonzalo Giribet

    Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, United States
    Competing interests
    The authors declare that no competing interests exist.

Copyright

© 2015, Laumer et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 4,414
    views
  • 1,053
    downloads
  • 138
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Christopher E Laumer
  2. Andreas Hejnol
  3. Gonzalo Giribet
(2015)
Nuclear genomic signals of the 'microturbellarian' roots of platyhelminth evolutionary innovation
eLife 4:e05503.
https://doi.org/10.7554/eLife.05503

Share this article

https://doi.org/10.7554/eLife.05503

Further reading

    1. Epidemiology and Global Health
    2. Genetics and Genomics
    Rashmi Sukumaran, Achuthsankar S Nair, Moinak Banerjee
    Research Article

    Burden of stroke differs by region, which could be attributed to differences in comorbid conditions and ethnicity. Genomewide variation acts as a proxy marker for ethnicity, and comorbid conditions. We present an integrated approach to understand this variation by considering prevalence and mortality rates of stroke and its comorbid risk for 204 countries from 2009 to 2019, and Genome-wide association studies (GWAS) risk variant for all these conditions. Global and regional trend analysis of rates using linear regression, correlation, and proportion analysis, signifies ethnogeographic differences. Interestingly, the comorbid conditions that act as risk drivers for stroke differed by regions, with more of metabolic risk in America and Europe, in contrast to high systolic blood pressure in Asian and African regions. GWAS risk loci of stroke and its comorbid conditions indicate distinct population stratification for each of these conditions, signifying for population-specific risk. Unique and shared genetic risk variants for stroke, and its comorbid and followed up with ethnic-specific variation can help in determining regional risk drivers for stroke. Unique ethnic-specific risk variants and their distinct patterns of linkage disequilibrium further uncover the drivers for phenotypic variation. Therefore, identifying population- and comorbidity-specific risk variants might help in defining the threshold for risk, and aid in developing population-specific prevention strategies for stroke.

    1. Genetics and Genomics
    Wenjing Liu, Shujin Li ... Xianjun Zhu
    Research Article

    Familial exudative vitreoretinopathy (FEVR) is a severe genetic disorder characterized by incomplete vascularization of the peripheral retina and associated symptoms that can lead to vision loss. However, the underlying genetic causes of approximately 50% of FEVR cases remain unknown. Here, we report two heterozygous variants in calcyphosine-like gene (CAPSL) that is associated with FEVR. Both variants exhibited compromised CAPSL protein expression. Vascular endothelial cell (EC)-specific inactivation of Capsl resulted in delayed radial/vertical vascular progression, compromised endothelial proliferation/migration, recapitulating the human FEVR phenotypes. CAPSL-depleted human retinal microvascular endothelial cells (HRECs) exhibited impaired tube formation, decreased cell proliferation, disrupted cell polarity establishment, and filopodia/lamellipodia formation, as well as disrupted collective cell migration. Transcriptomic and proteomic profiling revealed that CAPSL abolition inhibited the MYC signaling axis, in which the expression of core MYC targeted genes were profoundly decreased. Furthermore, a combined analysis of CAPSL-depleted HRECs and c-MYC-depleted human umbilical vein endothelial cells uncovered similar transcription patterns. Collectively, this study reports a novel FEVR-associated candidate gene, CAPSL, which provides valuable information for genetic counseling of FEVR. This study also reveals that compromised CAPSL function may cause FEVR through MYC axis, shedding light on the potential involvement of MYC signaling in the pathogenesis of FEVR.