Dorsal-ventral axis formation in sea urchin embryos
1Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
Current Topics in Developmental Biology
|February 14, 2022
Summary
Sea urchin larvae develop distinct dorsal-ventral polarity through differential gene expression and cell movements. Key signaling pathways, like TGF-β, pattern these axes, with variations seen across species.
Area of Science:
- Developmental Biology
- Marine Biology
- Evolutionary Biology
Background:
- Sea urchin larvae exhibit clear dorsal-ventral polarity, crucial for post-gastrulation development.
- Morphogenesis and cell differentiation occur asymmetrically along this axis, establishing key larval structures.
Purpose of the Study:
- To summarize current understanding of sea urchin dorsal-ventral patterning mechanisms.
- To discuss variations in patterning between feeding and nonfeeding larvae, and in cidaroid species.
- To provide evolutionary insights from comparative analyses.
Main Methods:
- Review of existing literature on sea urchin embryogenesis and gene regulatory networks.
- Analysis of signaling pathways, specifically TGF-β (Nodal and BMP).
- Comparative studies across different sea urchin taxa.
Main Results:
- Dorsal-ventral patterning involves differential gut bending, skeletogenesis, and pigment cell differentiation.
- Opposing TGF-β pathways (Nodal and BMP) are central to ventral and dorsal patterning, respectively.
- Distinct patterning mechanisms exist between feeding and nonfeeding larval types.
Conclusions:
- Sea urchin dorsal-ventral axis formation is a complex process regulated by conserved signaling pathways.
- Comparative studies reveal evolutionary adaptations in developmental mechanisms.
- Understanding these patterns offers insights into broader principles of animal development.
Related Concept Videos
01:56Gastrulation
59.4K
Gastrulation establishes the three primary tissues of an embryo: the ectoderm, mesoderm, and endoderm. This developmental process relies on a series of intricate cellular movements, which in humans transforms a flat, “bilaminar disc” composed of two cell sheets into a three-tiered structure. In the resulting embryo, the endoderm serves as the bottom layer, and stacked directly above it is the intermediate mesoderm, and then the uppermost ectoderm. Respectively, these tissue strata...
59.4K
01:30Neurulation
43.0K
Neurulation is the embryological process which forms the precursors of the central nervous system and occurs after gastrulation has established the three primary cell layers of the embryo: ectoderm, mesoderm, and endoderm. In humans, the majority of this system is formed via primary neurulation, in which the central portion of the ectoderm—originally appearing as a flat sheet of cells—folds upwards and inwards, sealing off to form a hollow neural tube. As development proceeds, the...
43.0K
02:13Determining the Plane of Cell Division
3.5K
Positioning the cell division plane is a critical step during development and cell differentiation, particularly during mitosis when the plane is essential for determining the size of the two daughter cells. The cell division plane is perpendicular to the plane of chromosome segregation, but different types of organisms have different cell division mechanisms to suit their morphology and function.
Animal cells
In animal cells, the cleavage furrow forms along the plane of cell division...
Animal cells
In animal cells, the cleavage furrow forms along the plane of cell division...
3.5K
01:51Determination
19.5K
During embryogenesis, cells become progressively committed to different fates through a two-step process: specification followed by determination. Specification is demonstrated by removing a segment of an early embryo, “neutrally” culturing the tissue in vitro—for example, in a petri dish with simple medium—and then observing the derivatives. If the cultured region gives rise to cell types that it would normally generate in the embryo, this means that it is specified. In...
19.5K