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Quantifying Mosaic Development: Towards an Evo-Devo Postmodern Synthesis of the Evolution of Development via Differentiation Trees of Embryos

View Article: PubMed Central - PubMed

ABSTRACT

Embryonic development proceeds through a series of differentiation events. The mosaic version of this process (binary cell divisions) can be analyzed by comparing early development of Cionaintestinalis and Caenorhabditis elegans. To do this, we reorganize lineage trees into differentiation trees using the graph theory ordering of relative cell volume. Lineage and differentiation trees provide us with means to classify each cell using binary codes. Extracting data characterizing lineage tree position, cell volume, and nucleus position for each cell during early embryogenesis, we conduct several statistical analyses, both within and between taxa. We compare both cell volume distributions and cell volume across developmental time within and between single species and assess differences between lineage tree and differentiation tree orderings. This enhances our understanding of the differentiation events in a model of pure mosaic embryogenesis and its relationship to evolutionary conservation. We also contribute several new techniques for assessing both differences between lineage trees and differentiation trees, and differences between differentiation trees of different species. The results suggest that at the level of differentiation trees, there are broad similarities between distantly related mosaic embryos that might be essential to understanding evolutionary change and phylogeny reconstruction. Differentiation trees may therefore provide a basis for an Evo-Devo Postmodern Synthesis.

No MeSH data available.


An isometric graph showing the Hamming distance of the differentiation tree from the lineage tree in C. elegans (N = 230). The H abbreviation stands for Hamming distance. The position of a point representing a cell is based on the depth of its node in the differentiation tree. The positions of all points are rotated 45 degrees clockwise from a bottom-to-top differentiation tree ordering (where the one-cell stage is at the bottom of the graph). Each cell is colored with its Hamming distance. See the legend of Figure 11 for other details.
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biology-05-00033-f012: An isometric graph showing the Hamming distance of the differentiation tree from the lineage tree in C. elegans (N = 230). The H abbreviation stands for Hamming distance. The position of a point representing a cell is based on the depth of its node in the differentiation tree. The positions of all points are rotated 45 degrees clockwise from a bottom-to-top differentiation tree ordering (where the one-cell stage is at the bottom of the graph). Each cell is colored with its Hamming distance. See the legend of Figure 11 for other details.

Mentions: Each depth of the tree is represented by a discrete isometric line. These isometric lines are drawn diagonally across the graph, and represent the number of cells at each depth of the tree. The numbers on the axes of both Figure 11 and Figure 12 represent the length (number of cells) in a given depth of the lineage tree. For example, in Figure 11, the fourth depth (lineage depth of 4) in the Ciona tree has a total of 32 cells, and crosses both the x- and y-axes at 31 (with cells at that level numbered from 0 to 31). This type of contour map allows us to overlay the differentiation and lineage tree orders, as well as to visualize both the isomorphic and non-isomorphic components of this overlap.


Quantifying Mosaic Development: Towards an Evo-Devo Postmodern Synthesis of the Evolution of Development via Differentiation Trees of Embryos
An isometric graph showing the Hamming distance of the differentiation tree from the lineage tree in C. elegans (N = 230). The H abbreviation stands for Hamming distance. The position of a point representing a cell is based on the depth of its node in the differentiation tree. The positions of all points are rotated 45 degrees clockwise from a bottom-to-top differentiation tree ordering (where the one-cell stage is at the bottom of the graph). Each cell is colored with its Hamming distance. See the legend of Figure 11 for other details.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037352&req=5

biology-05-00033-f012: An isometric graph showing the Hamming distance of the differentiation tree from the lineage tree in C. elegans (N = 230). The H abbreviation stands for Hamming distance. The position of a point representing a cell is based on the depth of its node in the differentiation tree. The positions of all points are rotated 45 degrees clockwise from a bottom-to-top differentiation tree ordering (where the one-cell stage is at the bottom of the graph). Each cell is colored with its Hamming distance. See the legend of Figure 11 for other details.
Mentions: Each depth of the tree is represented by a discrete isometric line. These isometric lines are drawn diagonally across the graph, and represent the number of cells at each depth of the tree. The numbers on the axes of both Figure 11 and Figure 12 represent the length (number of cells) in a given depth of the lineage tree. For example, in Figure 11, the fourth depth (lineage depth of 4) in the Ciona tree has a total of 32 cells, and crosses both the x- and y-axes at 31 (with cells at that level numbered from 0 to 31). This type of contour map allows us to overlay the differentiation and lineage tree orders, as well as to visualize both the isomorphic and non-isomorphic components of this overlap.

View Article: PubMed Central - PubMed

ABSTRACT

Embryonic development proceeds through a series of differentiation events. The mosaic version of this process (binary cell divisions) can be analyzed by comparing early development of Cionaintestinalis and Caenorhabditis elegans. To do this, we reorganize lineage trees into differentiation trees using the graph theory ordering of relative cell volume. Lineage and differentiation trees provide us with means to classify each cell using binary codes. Extracting data characterizing lineage tree position, cell volume, and nucleus position for each cell during early embryogenesis, we conduct several statistical analyses, both within and between taxa. We compare both cell volume distributions and cell volume across developmental time within and between single species and assess differences between lineage tree and differentiation tree orderings. This enhances our understanding of the differentiation events in a model of pure mosaic embryogenesis and its relationship to evolutionary conservation. We also contribute several new techniques for assessing both differences between lineage trees and differentiation trees, and differences between differentiation trees of different species. The results suggest that at the level of differentiation trees, there are broad similarities between distantly related mosaic embryos that might be essential to understanding evolutionary change and phylogeny reconstruction. Differentiation trees may therefore provide a basis for an Evo-Devo Postmodern Synthesis.

No MeSH data available.