RGM Regulates BMP-Mediated Secondary Axis Formation in the Sea Anemone Nematostella vectensis

Robust morphogenetic events are pivotal for animal embryogenesis. However, comparison of the modes of development of different members of a phylum suggests that the spectrum of developmental trajectories accessible for a species might be far broader than can be concluded from the observation of normal development. Here, by using a combination of microsurgery and transgenic reporter gene expression, we show that, facing a new developmental context, the aggregates of dissociated embryonic cells of the sea anemone Nematostella vectensis take an alternative developmental trajectory. The self-organizing aggregates rely on Wnt signals produced by the cells of the original blastopore lip organizer to form body axes but employ morphogenetic events typical for normal development of distantly related cnidarians to re-establish the germ layers. The reaggregated cells show enormous plasticity including the capacity of the ectodermal cells to convert into endoderm. Our results suggest that new developmental trajectories may evolve relatively easily when highly plastic embryonic cells face new constraints.

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Microinjection of mRNA or morpholinos for reverse genetic analysis in the starlet sea anemone, Nematostella vectensis

Nature Protocols ◽

10.1038/nprot.2013.009 ◽

2013 ◽

Vol 8 (5) ◽

pp. 924-934 ◽

Cited By ~ 45

Author(s):

Michael J Layden ◽

Eric Röttinger ◽

Francis S Wolenski ◽

Thomas D Gilmore ◽

Mark Q Martindale

Keyword(s):

Genetic Analysis ◽

Sea Anemone ◽

Nematostella Vectensis ◽

Reverse Genetic

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Starlet Sea Anemone (Nematostella vectensis) 2021 Environmental Summary, Reptile & Aquatics, Stowers Institute for Medical Research v1

10.17504/protocols.io.bzvap62e ◽

2021 ◽

Author(s):

Shane C. Miller ◽

Diana P Baumann ◽

M. Shane Merryman

Keyword(s):

North America ◽

Medical Research ◽

Environmental Conditions ◽

Atlantic Coast ◽

Model Organism ◽

Environmental Parameters ◽

Sea Anemone ◽

Nematostella Vectensis ◽

Research Results ◽

Impact Research

The starlet sea anemone (Nematostella vectensis) is an emerging model organism, and we have maintained a colony at the Stowers Institute since 2007. Nematostella are known as a simple sea anemone, related to other cnidarians such as jellyfish and corals. Native to estuarine environments across the Atlantic coast of North America, from Novia Scotia to Florida, they encounter a variety of environmental conditions (e.g., temperature, salinity). Acknowledging that husbandry conditions and environmental parameters can impact research results we provide information about the housing, nutrition, maintenance, and health for our colony of Nematostella. This information will be applicable to any Nematostella housed in the facility in 2021.

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Meganuclease-assisted generation of stable transgenics in the sea anemone Nematostella vectensis

Nature Protocols ◽

10.1038/nprot.2017.075 ◽

2017 ◽

Vol 12 (9) ◽

pp. 1844-1854 ◽

Cited By ~ 20

Author(s):

Eduard Renfer ◽

Ulrich Technau

Keyword(s):

Sea Anemone ◽

Nematostella Vectensis ◽

Stable Transgenics

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Development and epithelial organisation of muscle cells in the sea anemone Nematostella vectensis

Frontiers in Zoology ◽

10.1186/1742-9994-11-44 ◽

2014 ◽

Vol 11 (1) ◽

pp. 44 ◽

Cited By ~ 22

Author(s):

Stefan M Jahnel ◽

Manfred Walzl ◽

Ulrich Technau

Keyword(s):

Muscle Cells ◽

Sea Anemone ◽

Nematostella Vectensis

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A cytoplasmic determinant for dorsal axis formation in an early embryo of Xenopus laevis

Development ◽

10.1242/dev.110.4.1051 ◽

1990 ◽

Vol 110 (4) ◽

pp. 1051-1056 ◽

Cited By ~ 6

Author(s):

M. Yuge ◽

Y. Kobayakawa ◽

M. Fujisue ◽

K. Yamana

Keyword(s):

Xenopus Laevis ◽

Direct Evidence ◽

Early Embryo ◽

Dorsal Side ◽

Axis Formation ◽

Secondary Axis ◽

Dorsal Axis ◽

Cell Embryo ◽

Dorsal Cells ◽

Cytoplasmic Determinant

In Xenopus laevis, dorsal cells that arise at the future dorsal side of an early cleaving embryo have already acquired the ability to cause axis formation. Since the distribution of cytoplasmic components is markedly heterogeneous in an egg and embryo, it has been supposed that the dorsal cells are endowed with the activity to form axial structures by inheriting a unique cytoplasmic component or components localized in the dorsal region of an egg or embryo. However, there has been no direct evidence for this. To examine the activity of the cytoplasm of dorsal cells, we injected cytoplasm (dorsal cytoplasm) from dorsal vegetal cells of a Xenopus 16-cell embryo into ventral vegetal cells of a simultaneous recipient. The cytoplasm caused secondary axis formation in 42% of recipients. Histological examination revealed that well-developed secondary axes included notochord, as well as a neural tube and somites. However, injection of cytoplasm of ventral vegetal cells never caused secondary axis and most recipients became normal tailbud embryos. Furthermore, about two-thirds of ventral isolated halves injected with dorsal cytoplasm formed axial structures. These results show that dorsal, but not ventral, cytoplasm contains the component or components responsible for axis formation. This can be the first step towards identifying the molecular basis of dorsal axis formation.

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