TY  - GEN
KW  - Cnidarian
KW  -  Nesseltier
KW  -  ECM
KW  -  Mesoglea
ID  - heidok34469
Y1  - 2024///
TI  - Molecular Atlas and Developmental Dynamics of the Nematostella vectensis Mesoglea
CY  - Heidelberg
AV  - public
N2  - Cnidarians (corals, jellyfish and sea anemones) constitute ideal model systems
to investigate the dynamics and interactions of extracellular matrix (ECM) components.
Many cnidarians undergo a complex life cycle characterized by transitions
through different life stages with distinct morphologies. These morphological
changes recapitulate developmental processes observed in vertebrates and
involve the synthesis, degradation and remodeling of the ECM.
The simple body plan of cnidarians provides exceptional accessibility for ECM
imaging and manipulation, and previous studies have shown that the cnidarian
ECM shares striking compositional and structural similarities with the vertebrate
ECM. However, a major hurdle in the investigation of the cnidarian ECM is the
lack of fully annotated ECM datasets allowing for a deeper understanding of its
interactions and functions.
In this thesis, I used the starlet sea anemone Nematostella vectensis as a model
system to fully characterize the components of the cnidarian ECM by a combination
of electron microscopy, single cell transcriptomics, in silico matrisome prediction
and mass spectroscopic analysis of isolated ECM from three life stages (larvae,
primary polyp and adult).
I present the fully annotated in silico matrisome comprising 843 proteins, categorized
into 246 core matrisome, 309 matrisome-associated and 289 other ECM-like
proteins. 182 of these components are specific to the cnidocysts. My research
revealed that the primary source of ECM is the gastroderm while the contribution
of the ectoderm to ECM production is minimal.
The integration of single cell transcriptome analysis and stage-specific mass spectrometry unraveled dramatic changes of the ECM during development, showing
that the basal lamina gets established well in advance of the fibrillar interstitial
matrix.
Among the various ECM components upregulated during the larva-to-polyp transition,
I detected an expanded polydom/SVEP1 family in Nematostella. This family
encompasses several novel proteins, one of which emerges as a promising candidate
for genetic perturbation using shRNAs. The resulting knockdown phenotype
displayed defects in epithelial organization, body elongation, and development of
internal mesenteries. This underscores that individual ECM components can heavily
affect crucial developmental processes.
In summary, my work establishes a foundational framework for future studies of the
ECM by providing the first annotated molecular atlas for a cnidarian life cycle. In
addition, it provides evidence for an ancient specification of ECM-producing cells
within the endomesodermal lineage, along with a hierarchical function of basement
membrane and interstitial matrix components in the life history of Nematostella.
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/34469/
A1  - Bergheim, Bruno Gideon
ER  -