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Variability of an Early Developmental Cell Population Underlies Stochastic Laterality Defects
Roberto Moreno-Ayala1, Pedro Olivares-Chauvet1, Ronny Schäfer1
1Max Delbrück Center for Molecular Medicine, Berlin Institute for Medical Systems Biology, Hannoversche Strasse 28, 10115 Berlin, Germany.
Cell Reports
|January 13, 2021
Summary
Microscopic variations in early zebrafish development, specifically in dorsal forerunner cells (DFCs), can lead to significant left-right body plan defects. These developmental fluctuations are often stochastic and influenced by maternal factors.
Area of Science:
- Developmental biology
- Genetics
- Embryology
Background:
- Embryonic development appears precise, but the tolerance for microscopic variability is poorly understood.
- Understanding cellular variability is crucial for identifying causes of developmental defects.
Purpose of the Study:
- To quantify embryo-to-embryo cell number variation in zebrafish endoderm.
- To investigate the link between cellular variability and macroscopic developmental phenotypes, specifically left-right laterality defects.
Main Methods:
- Studied cell number variation in the zebrafish endoderm.
- Focused on dorsal forerunner cells (DFCs), a sub-population crucial for left-right axis formation.
- Incubated embryos at elevated temperatures to assess the impact on DFCs and laterality.
Main Results:
- DFCs showed significantly higher embryo-to-embryo variation compared to other endodermal cells.
- Elevated temperatures increased left-right laterality defects in embryos with fewer DFCs.
- Variations in DFC numbers exhibited a substantial stochastic component, even within the same genetic background.
Conclusions:
- Stochastic variations in early embryonic cell numbers can result in strong macroscopic phenotypes.
- Maternal effects play a role in the specification of DFCs and subsequent developmental variability.
- This study highlights the impact of seemingly minor cellular fluctuations on overall embryonic development.
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