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Mesenchyme cells can function to induce epithelial cell proliferation in starfish embryos
Gen Hamanaka1, Midori Matsumoto, Masaya Imoto
1School of Fundamental Science and Technology, Department of Biology, Keio University, Kohoku-ku, Yokohama, Japan.
Summary
Mesenchyme cells regulate starfish epithelial cell proliferation. An optimal number of mesenchyme cells promotes epithelial growth, while excess cells disrupt development and extracellular matrix organization.
Area of Science:
- Developmental biology
- Cell biology
- Marine biology
Background:
- Epithelial cell proliferation is crucial for embryonic development.
- The role of mesenchyme cells in regulating epithelial growth is not fully understood.
Purpose of the Study:
- To investigate the morphogenetic function of mesenchyme cells in starfish embryonic epithelial cell proliferation.
- To determine the effect of mesenchyme cell number on epithelial cell growth and overall development.
Main Methods:
- Starfish blastula embryos were microinjected with defined numbers of mesenchyme cells.
- Total cell numbers were quantified at different developmental stages (mid-gastrula, bipinnaria larvae).
- Morphological and extracellular matrix changes were observed in response to mesenchyme cell injection.
Main Results:
- Injection of 40-50 mesenchyme cells significantly increased total cell numbers (1.3-fold) in embryos and larvae, without mesenchyme cell division.
- Over-injection (>150 cells) inhibited epithelial proliferation and caused developmental abnormalities.
- Excess mesenchyme cells led to severe condensation of the extracellular matrix's fibrous component.
Conclusions:
- Mesenchyme cells possess a novel morphogenetic function in controlling epithelial cell proliferation in starfish embryos.
- An appropriate number of mesenchyme cells, in conjunction with the extracellular matrix, is essential for inducing epithelial cell proliferation and normal development.
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